The GT2860RS "Disco Potato" model 739548-1 and 739548-5 turbocharger is basically a GT28R turbo with a 62 trim compressor 0.60 A/R and a 76 trim turbine 0.86 A/R. The Disco Potato was voted top 20 New Products at SEMA 2003.
This turbocharger is an upgrade turbocharger for the GT2554R model number 471171-3 and GT2560R model 466541-1 turbine housing flanges are outline interchangeable.
This turbo has a flow capacity of about 250 - 360HP and works well for engines between 1.8L - 3.0L. Gives good spool and would be comparable to the HKS GT2530. But have the fastest spool of the turbochargers in it's category.
The Dual Ball Bearing GT2860RS turbo assembly have a T25 style turbine inlet (NOTE: without studs). It also has an internally wastegated style T25 turbine housing with actuator bracket and actuator fitted from the factory.
Now before I go any further you need to know that there are actually 3 different versions of the GT2860R turbocharger (ONLY R at the ending). This turbo is the RS version named GT2860RS, and somewhat a hybrid with a bigger compressor and of these there are 2 different RS versions 739548-1 and 739548-5. Both these are called “The Disco Potato” and the only difference between these RS versions are basically the turbine housing. So I will cover both "Disco Potato" turbos here.
It's a bit confusing yes, however don't forget to read the story behind the Disco Potato turbo and how it came to be further down after I give you the specifications.
Model: 739548-1 and 739548-5
CHRA: 446179-66
Bearing: Dual Ball bearing
Cooling: Oil & Water cooled bearings
Compressor
Inducer: 47.20 mm
Exducer: 60.1 mm
Trim: 62
A/R 0.60
Turbine Model 739548-1
Wheel: 53.90 mm
Trim: 76
A/R: 0.64
Turbine Housing PN 430609-230
Turbine Model 739548-5
Wheel: 53.90 mm
Trim: 76
A/R: 0.86
Turbine Housing PN 430609-231
Wastegated
Turbine Flange: T25 without studs
Turbine outlet: T25 flange 5-bolt pattern
Looking at the compressor map for the GT2860RS turbochargers will show you that it have a very broad range. Even if you have a low boost of 1bar it will flow 350+ hp if your engine is capable.
Here we see the two different turbine housings at work. And the bigger 0.86 A/R will give you more flow and in effect even more top end power. However it should be recomended to use the bigger one also if you have a big 3 liter engine. The ball bearings will give you exellent spool even if you don't use the smller 0.64 A/R turbine housing.
The GT2860RS use the Standard T25 oil drain flange.
Oil inlet 0.4375IN - 24 Thread for 6.35 Tube Inverted flare connection PER SEA J512 Oil inlet
Oil outlet 2 x M8x1.25 13.5 oil outlet
Water connections thread M14x1.50
The Turbine wheel is cast from "Inconel" material suited for extreme applications. The Turbine housing have the traditional T25 5-bolt flange.
This is the story behind the Disco Potato Turbocharger
The story starts with Dan Passe who, at the time, was a Nissan PR genius with a penchant for bending rules. He conveniently "lost" the paperwork for a 1.8-liter Sentra which Nissan Design International had modified for the L.A. Auto Show. The car quietly landed in the hands of Nissan engineers Steve Mitchell and Mike Kojima.
Meanwhile, a few miles away at Garrett, turbo engineer Jay Kavanagh wanted to boost his Miata. Having full access to the newest Garrett technology, he concocted a physically small turbo with a ball-bearing center section and internal aerodynamics 20 years more modern than the T3/T4 standard the aftermarket is used to.
A few cubicles from Kavanagh, Rob Cadle, a good friend of Mitchell and Kojima, realized Kavanagh's Miata turbo would be perfect for the SR20DET the Nissan boys were planning for the Sentra. He brewed up a turbo, stuffed it under his shirt, and went out the back door.
The Sentra was painted a unique combination of psychedelic, color-shifting brownish paint and was thus dubbed the Disco Potato.
Jim Wolf Technology built a very mild SR20 for the Sentra, making it functionally equivalent to a stock Japanese-spec SR20DET. The turbo was installed, and amazing things started happening. The car's power was impressive, 280 hp at the wheels, but not earth-shattering. The driving experience however, was. Throttle response was excellent, turbo lag virtually non-existent, and the tire-shredding power was easily modulated. The turbo spooled up early, making so much torque, that the best quarter-mile time (13.7 at 104.5 mph) was achieved launching in second gear.
Mitchell brought the Disco Potato to the Ultimate Street Car Challenge in 2001, and placed an impressive fourth overall. The rest of the time, the car was stashed away in Nissan USA's service garage and used strategically as an attitude adjustment tool. Whenever Nissan or Garret executives needed an injection of gasoline in their veins, they were offered the keys. They would inevitably come back grinning from ear to ear and breathing heavily, eager to bring horsepower to the masses.
During one such outing, which included a 1,000-mile road trip as well as a track day at Thunderhill Raceway, the fwd Disco Potato outran every car at the track and then blasted down the freeway at 140 mph. Several Garrett executives also experienced the Potato. They were so impressed, they decided to produce the turbo, double the engineering staff in the aftermarket department, and start applying this modern Garrett technology to a whole range of aftermarket turbos. End of story.
Did you like the story? I sure did. A lot of people find the Disco Potato turbocharger as a very fun turbo to drive. And here is a little video of a Honda Civic B16 fitted with a GT2860RS turbocharger. I might add that this 1.6 liter engine drives and spools the GT28RS Disco Potato quite well.
Video text:
This car now has a third setup. First setup was a b16a2 N/A, second - b16a2 turbo, but burst slevees and now I will gave him a new life with the next engine, he has forged pistons and connecting rods. I'm using a turbocharger Garrett GT28RS (Disco Potato), what generating power 328,3HP and 323,3Nm with the 1bar of boost (14,5PSI).
You might want to fit this turbocharger to you're own car perhaps. Well sometimes there are a few problems, especially when using the existing turbo manifold.
Because most standard cars don't come with a turbo this big from the factory, you start to run into clearance problems.
However these problems can be solved quite easily with an simple turbocharger flang fitted as a spacer between you're standard turbo manifold and the turbo itself. Like on this Saab turbo. There was no need for grinding or further modification to make the GT28RS turbocharger fit. We can see the extra turbo flange with seals in the picture.
This turbocharger is an upgrade turbocharger for the GT2554R model number 471171-3 and GT2560R model 466541-1 turbine housing flanges are outline interchangeable.This turbo has a flow capacity of about 250 - 360HP and works well for engines between 1.8L - 3.0L. Gives good spool and would be comparable to the HKS GT2530. But have the fastest spool of the turbochargers in it's category.
The Dual Ball Bearing GT2860RS turbo assembly have a T25 style turbine inlet (NOTE: without studs). It also has an internally wastegated style T25 turbine housing with actuator bracket and actuator fitted from the factory.Now before I go any further you need to know that there are actually 3 different versions of the GT2860R turbocharger (ONLY R at the ending). This turbo is the RS version named GT2860RS, and somewhat a hybrid with a bigger compressor and of these there are 2 different RS versions 739548-1 and 739548-5. Both these are called “The Disco Potato” and the only difference between these RS versions are basically the turbine housing. So I will cover both "Disco Potato" turbos here.
It's a bit confusing yes, however don't forget to read the story behind the Disco Potato turbo and how it came to be further down after I give you the specifications.
CHRA: 446179-66
Bearing: Dual Ball bearing
Cooling: Oil & Water cooled bearings
Compressor
Inducer: 47.20 mm
Exducer: 60.1 mm
Trim: 62
A/R 0.60
Turbine Model 739548-1
Wheel: 53.90 mm
Trim: 76
A/R: 0.64 Turbine Housing PN 430609-230
Turbine Model 739548-5
Wheel: 53.90 mm
Trim: 76
A/R: 0.86
Turbine Housing PN 430609-231
Wastegated
Turbine Flange: T25 without studs
Turbine outlet: T25 flange 5-bolt pattern
Looking at the compressor map for the GT2860RS turbochargers will show you that it have a very broad range. Even if you have a low boost of 1bar it will flow 350+ hp if your engine is capable.
Here we see the two different turbine housings at work. And the bigger 0.86 A/R will give you more flow and in effect even more top end power. However it should be recomended to use the bigger one also if you have a big 3 liter engine. The ball bearings will give you exellent spool even if you don't use the smller 0.64 A/R turbine housing.
The measurements and turbo flange drawings can be viewed in fullscreen.
The GT2860RS use the Standard T25 oil drain flange.Oil inlet 0.4375IN - 24 Thread for 6.35 Tube Inverted flare connection PER SEA J512 Oil inlet
Oil outlet 2 x M8x1.25 13.5 oil outlet
Water connections thread M14x1.50
The Turbine wheel is cast from "Inconel" material suited for extreme applications. The Turbine housing have the traditional T25 5-bolt flange.
This is the story behind the Disco Potato Turbocharger The story starts with Dan Passe who, at the time, was a Nissan PR genius with a penchant for bending rules. He conveniently "lost" the paperwork for a 1.8-liter Sentra which Nissan Design International had modified for the L.A. Auto Show. The car quietly landed in the hands of Nissan engineers Steve Mitchell and Mike Kojima.
Meanwhile, a few miles away at Garrett, turbo engineer Jay Kavanagh wanted to boost his Miata. Having full access to the newest Garrett technology, he concocted a physically small turbo with a ball-bearing center section and internal aerodynamics 20 years more modern than the T3/T4 standard the aftermarket is used to. 
A few cubicles from Kavanagh, Rob Cadle, a good friend of Mitchell and Kojima, realized Kavanagh's Miata turbo would be perfect for the SR20DET the Nissan boys were planning for the Sentra. He brewed up a turbo, stuffed it under his shirt, and went out the back door. The Sentra was painted a unique combination of psychedelic, color-shifting brownish paint and was thus dubbed the Disco Potato.
Jim Wolf Technology built a very mild SR20 for the Sentra, making it functionally equivalent to a stock Japanese-spec SR20DET. The turbo was installed, and amazing things started happening. The car's power was impressive, 280 hp at the wheels, but not earth-shattering. The driving experience however, was. Throttle response was excellent, turbo lag virtually non-existent, and the tire-shredding power was easily modulated. The turbo spooled up early, making so much torque, that the best quarter-mile time (13.7 at 104.5 mph) was achieved launching in second gear.
Mitchell brought the Disco Potato to the Ultimate Street Car Challenge in 2001, and placed an impressive fourth overall. The rest of the time, the car was stashed away in Nissan USA's service garage and used strategically as an attitude adjustment tool. Whenever Nissan or Garret executives needed an injection of gasoline in their veins, they were offered the keys. They would inevitably come back grinning from ear to ear and breathing heavily, eager to bring horsepower to the masses.
During one such outing, which included a 1,000-mile road trip as well as a track day at Thunderhill Raceway, the fwd Disco Potato outran every car at the track and then blasted down the freeway at 140 mph. Several Garrett executives also experienced the Potato. They were so impressed, they decided to produce the turbo, double the engineering staff in the aftermarket department, and start applying this modern Garrett technology to a whole range of aftermarket turbos. End of story.
Did you like the story? I sure did. A lot of people find the Disco Potato turbocharger as a very fun turbo to drive. And here is a little video of a Honda Civic B16 fitted with a GT2860RS turbocharger. I might add that this 1.6 liter engine drives and spools the GT28RS Disco Potato quite well.
Video text:
This car now has a third setup. First setup was a b16a2 N/A, second - b16a2 turbo, but burst slevees and now I will gave him a new life with the next engine, he has forged pistons and connecting rods. I'm using a turbocharger Garrett GT28RS (Disco Potato), what generating power 328,3HP and 323,3Nm with the 1bar of boost (14,5PSI).
You might want to fit this turbocharger to you're own car perhaps. Well sometimes there are a few problems, especially when using the existing turbo manifold.
Because most standard cars don't come with a turbo this big from the factory, you start to run into clearance problems.
However these problems can be solved quite easily with an simple turbocharger flang fitted as a spacer between you're standard turbo manifold and the turbo itself. Like on this Saab turbo. There was no need for grinding or further modification to make the GT28RS turbocharger fit. We can see the extra turbo flange with seals in the picture.
Hello Sir, Thank you for your kind reply regarding GT2052 previously.
ReplyDeleteI am thinking to change to GT28RS since my GT2052'output did not change after pushing to higher boost.
My car is CRZ 1.5L, manual. 2inch piping, stock internal.
Currently running 0.6 bar with 170whp, 230Nm torque with GT2052.
I am thinking to change to GT28RS to get around 200whp with stock internal.
From what I read, can achieve 200whp with this turbo even with low boost.
My only concern for current project :
1.Is GT28RS will work fine with small engine like crz 1.5L ?
2.Internal engine's strength is rely on the boost pressure(bar) or HP?
Some says CRZ internal can only hold until 0.8bar. So if I get 200whp with 0.6 bar with
GT28RS, should I be fine? >.<
Note: Planning to change the internal later for next stage to get 250whp.
Hello Erlissa, the Garrett GT28RS turbocharger should work fine with your 1.5liter engine but make sure you get the smaller 0.64 a/r turbine housing. The GT28RS comes with both bigger and smaller turbine housings.
ReplyDeleteFor your CRZ engine, it would be best to use the smaller turbine to help spool the turbo faster. It should have the part number PN 430609-230 for the correct size. You would need to be careful and start out at a low boost pressure like 0.5 bar and see how much power that gives you. I say this because the GT28RS is a much bigger turbocharger and can flow as much as 300hp with as little as 0.5 bar boost. Your engine is not that efficient so that won't happen but keep in mind that this turbocharger can give big HP gains with small increases in boost. So start low and work your way up.
Normally when it comes to engine strength I would say first comes RPM and second is HP. To keep it short and simple, a regular piston weight is around 500 grams. Because of the rotating forces when the engine is running at 7000 rpm that piston now have a weight of 3.5 Tons (500x7000) inside the engine. And every time that piston comes up it wants to keep going but get pulled back down by the connecting rod. Now if we start tuning our engine and push the revs even higher to 9000 rpm that same piston now have a weight of 4.5 Tons. Both the pistons and connecting rods live a hard life and at some point in time something starts to give.
Now if we instead look at HP alone then this is more of an compressive force pushing down the piston and connecting rod. And you really need to make some serious power to be able to compress a connecting rod and piston in such a way that with HP alone it would make something break.
Most often when something does break in an engine it's either fatigue by "lots of abuse over many years at high rpms" or a longer period of misfires / lean conditions due to poor setups or faults in the ECU that cause one or more engine parts to fail.
The problems with modern engines is that manufacturers want better fuel economy and efficient engines. And one way to make an efficient engine is to take weight of the internal parts to make them lighter.. That's good if you keep everything stock and keep the rpms and hp down but you start to run into problems with fatigue when you start pushing the engine for more power. This is most likely what's happening with the CRZ engines.
I would stay with the stock internals for the time being and try and make a safe 200whp tune with the GT28RS turbocharger. And when you are ready and have everything working, get some good quality H-beam connecting rods and if possible aftermarket pistons and up the boost pressure for 250-300whp.
Thank you Sir for your very details explanation!
ReplyDeleteI will share the result and probably the video once my project is done!
Thank you again Sir!You are rock!
Hello again Sir, today I bought this ball bearing turbo.
ReplyDeleteM24 A/R80 1-2
got a tag at the housing:
DA 01 21 J
14411-WA200
471171-6
The guy said taken out from Silvia but not sure which silvia.
URL : https://www.facebook.com/photo.php?fbid=10154443153008447&set=a.10150167045193447.305914.777488446&type=3&theater
I hope u can give a rough idea about this turbo.
-target to get 200whp with stock internals n low boost(around 0.5)with this turbo.
-Later if I get bored, then I will change the internal and up the boost to get 250WHP.
Do you think it is possible to do achieve by using this turbo?
My car is CR-Z manual 1.5L(stock without turbo +-120WHP)
Hi Erlissa, looks like you have what is called a T25G turbo. Because the turbcharger have a round inlet we can confirm two possible engines this turbo came fitted to from Nissan.
ReplyDeleteIf you check inside the oil inlet / outlet and see it really is a ball bearing T25G turbo then it's possible it came from the Nissan SR20VET engine. But if it's a journal bearing T25G turbocharger then it's probably from the Nissan Avenirs SR20DET engine.
You can find these turbos in many different configurations and it's seen on many different engines.
But considering the compressor size and a good flowing engine you could see 200whp from 0.5 bar boost with this turbocharger. This also means you really won't need to bleed any air to adjust boost (makes it spool a bit faster) and run the stock wastegate connected like it's from the factory. The turbo wastegate stock spring is usually 6-7 psi and that's right around 0.5bar.
A Honda D15B 1500cc engine running stock internals made 200whp at 0.5bar boost with this T25G turbo. You would need to run higher boost around 1 bar boost to get 250whp, but like you said it's best to change the pistons and rods before doing that. 250whp is twice the power this engine was designed for.
Hello whats going on , i have a 2009 acura rdx ( i think it have a td03 turbo ) and i want to know if i change the turbo for some garret , wich one are the good to put on in a rdx between gt25r or gt28rs
ReplyDeleteThank you !
Hi Aaron, if peak power is what you want then I would say if you can find a good deal for a Garrett GT2860RS then that's the turbocharger I would go for. However The Garrett GT2560R would also be a great turbocharger if you can get one. Both of these turbochargers are ball bearing and support 300whp.
ReplyDeleteIf it's spool and low end power you are looking for instead then you have the option of the Garrett GT2854R and GT2554R turbochargers. These turbochargers can support around 250whp. All of the above turbochargers share the same T25 flange and outlet so it's pretty easy to swap between them if you like to try different ones.
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ReplyDeleteHello Sir, after postponed the upgrade a few months, today i managed to get it done. I used the turbo that i bought previously(u said GT25) and upgraded to 2.5 inch piping. tuned with emanage ultimate and the result is 202whp and 26.7Nm torque with 0.55bar. Will keep this setup until the next project to change the internal parts and push more. Here is the result for now :
ReplyDeletehttps://www.facebook.com/plugins/post.php?href=https%3A%2F%2Fwww.facebook.com%2Fifan9701%2Fposts%2F10155034855533447
Thank you so much for your kind advices! :)
Hi Erlissa, thanks for letting me know, that's nice to hear. Your Honda D15B 1500cc engine made very good power with that GT25 turbo, and the power keeps going all the way to 7000rpm also. I'm sure later if you change the rods and pistons and turn the boost up to 1bar you might even make over 250whp with this setup.
ReplyDeleteits the CR-Z sir.hehe!tuner also said the same. the GT25 still can be push more just need the internal parts upgraded.thanks alot!
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteThis comment has been removed by the author.
Deletehttp://pl.tinypic.com/view.php?pic=1zvr680&s=9#.WTkKd2ndjqA
ReplyDeletehttp://pl.tinypic.com/view.php?pic=r79es8&s=9#.WTkLlmndjqA
ReplyDeletehttp://pl.tinypic.com/view.php?pic=2i8x8cz&s=9#.WTkPGGndjqA
ReplyDeleteI have civic d16z6 345km 375nm
ReplyDeleteI just curious if this turbo can give me obout 400hp ?
Hello Adrian, looks like it's a Garrett GT2540 Turbocharger. Would be good for around 250hp. You would need something like the Garrett GT3071r to get 400hp. The GT2860R gives you close to 360hp but to see 400hp you need something in the GT30 range.
ReplyDeleteYes on plate is gt25 40 but it looks like someone upgraded putting hks trim
ReplyDeleteThat turbo from picture run 1.3bar boost an give me 345km so max range is 360km ? I will put 1.5bar an we will see what happens
Hi Adrian, hard to say if 360 is possible. The turbo should be able to do 1.5bar no problems so you would be safe to try and see if it makes more power.
ReplyDeleteHi. I bought a Lotus Exige, which has a GT2860, forged 2ZZ motor, but struggling to make 280whp. Tuning the 2nd cam "lift " was impossible with the stage 2 cams in it, so the workshop I was dealing with put standard cams back in, which lifted power from 250 hp at the wheels to 280 hp at the wheels at 17 psi and lift worked again. It still felt like the top end was struggling, low end spool insane though. Anyway, a recent blown turbo inlet gasket had me checking things out closer. For some reason ( stupidity ? ) the guy who screwed this engine together chose the .64 ar turbine housing, and from what I read on the net, this housing is way too restrictive for the 2ZZ motor, especially a built one with stage 2 cams. Before I change this housing out and retune, can you confirm that this is what would be holding my motor back. In reality, I'd be happy with around 320 hp at the wheels, but staying within the efficiency of the turbo.
ReplyDeleteHello Exige Pilot, if there is nothing after the turbo like a restrictive exhaust system.. Check for collapsed / clogged muffler or failed catalytic converter etc.. Then it could very well be the exhaust housing that is causing you problems.
ReplyDeleteIf you really want to max out the GT2860r turbo then your only option is to get the 0.86 A/R housing anyway with the loss of some low end spool.
However before you change anything I would advice you to check the turbo back pressure (pressure before the turbo in the exhaust manifold). This would tell if it really is a problem with the housing being to small.
If you have an aftermarket ECU or logger that can handle extra input then there are back pressure kits to install www.ipgparts.com/store/Race-Spec-Exhaust-Manifold-Back-Pressure-Kit.html
If not then you can use a simple oil pressure, or boost gauge (really any gauge that reads pressure works) and connect it to the exhaust manifold with a coiled copper pipe, this cools the gases to not damage the gauge.
Here's a good discussion with pictures on Miataturbo.net - MSM Exhaust Manifold Pressure Test
https://www.miataturbo.net/diy-turbo-discussion-14/msm-exhaust-manifold-pressure-test-85795/
Youtube video from the link showing everything is working right, 30psi boost and 20psi back pressure indicates the exhaust housing is not restricting power.
www.youtube.com/watch?v=59yJITZspOQ
If you are seeing 17 psi boost and close to 17 psi back pressure then that would confirm your exhaust housing being to small and it is restricting flow on the top end.
Hello, I have a 97 Audi S6. I have upgraded to a stage 1 which give me around 300hp. I'm thinking about upgrading to Stage 1+ which would bring it to 350+ hp. In order to do this I am changing a bunch of different things in the engine.
ReplyDeleteOne question for you is I'm thinking about putting in GT2860RS Turbo, there is 250,000kms on engine. Do I need to worry about rods and pistions, etc...
Pleae can you give me some advise.
Thx.
Kevin
Hi Kevin, the Audi engines are pretty well built so I would not really worry about it at 350hp. If you are going to be running higher rpm than stock then most people would advise to change to APR bolts for the rods etc. But not really needed if you are staying at the stock rev limit.
ReplyDeleteStock pistons can take alot and won't fail with a good tune. If you are staying with stock pistons then make sure to check and change the oil more often. Running high boost on old engines can cause blowby and then you get fuel dilution of the oil. So check oil and have a good crankcase ventilation fitted.
That said it's better to have aftermarket forged pistons put in if you already have the engine out, that way you also get new piston rings and you would have less piston blow by.
I would not change the connecting rods at 350hp but if the engine is out I would change to aftermarket rods. That way you have a good solid engine and if you wanted more power in the future you would only have to go with a bigger turbo.
Hi, I have a 2.1L flatfour VW engine. I'm running twin dellortos with timing management and turbo cam. My specs are 1.8 pr and 22 lbs/min airflow @ 55k rpm. I would like to know how the Gt2860 would perform at 3k to 55k rpm. N/aspirated it makes 146hp and 109kw, my target hp is 250.
ReplyDeleteHi, I have a 2.1L flatfour VW engine. I'm running twin dellortos with timing management and turbo cam. My specs are 1.8 pr and 22 lbs/min airflow @ 55k rpm. I would like to know how the Gt2860 would perform at 3k to 55k rpm. N/aspirated it makes 146hp and 109kw, my target hp is 250.
ReplyDeleteHi Bruce, the Garrett GT2860 turbo would be a good match for your engine, the Volkswagen flat-four boxer engines are also known for how well they build boost early on in the rev range. So you should probably see full boost around 3000rpm if not sooner if everything is set up right and you can get the right ignition timing and air fuel mixtures. You should see 250 hp no problems and there is still potential to get to 300+ hp with this setup if you wanted to push it higher.
ReplyDeleteHello. You seem to know your turbos well.
ReplyDeleteBetter than me... maybe you can give your thoughts
I'm planing a crazy build... and want to do something a little crazy with the motor... I'll explain.
First I'm fitting up a k24 and 6speed box in a mid engine layout. I'm hoping that eventually I'll get 400whp (after the motor rebuild)...
But thats an arbitrary number.
I plan on track daying it..
so i want quick spool response.
So on top of the mid engine.... I want to do something a lttle differant.
I dont want to do the typical big turbo.
I want to use 2 parallel gt25's or gt28's. (I have 2x t25 and 2x t28 I can use for inital mockup)
But running a 4 cylinder with 2 turbos make me wonder about the possible problem.
Can I have your thoughts
Hi Tony, that's an interesting build. A good single turbo setup like a single GT28rs on a 2 liter engine makes around 300whp at 4000rpm and goes up to about 350whp at 6-6500rpm where it then starts to drop off in power (due to the "small" turbine housing).
ReplyDeleteSo I would use that as a baseline. Simply having two turbochargers won't necessarily mean you are going to get any faster spool, even if you block off one GT28 turbo with a wastegate before the turbines and direct all exhaust to a single GT28 turbo you still won't get a faster spool. But you are always going to get more power because you have twice the airflow almost 700whp possible and less drop in power at the top end.
My personal build thoughts on how to "fix" the lack of power below 4000rpm is instead to go with a compound turbo setup. Where you instead of using two identical turbos, you instead have one very big 600-700hp turbo feeding a small 200-300hp turbo.
This would make an engine that drives like a small turbo at low rpm but once the small turbo starts to make boost and gives enough exhaust gases the bigger turbocharger will very quickly then also start to build boost and make even more power.
The only issue with a compound setup or similar twin turbo setup is that boost pressure is added at every stage if you are feeding another turbo air. So the small turbo making 20-30psi to make the initial power let's say 200hp then gets a "boost" from the bigger turbo. If the big turbo need 20-30psi to make the final power say 500hp, then the combined boost pressure is now 40-60psi at the engine.
This is what makes the compound setups more difficult, because you need wastegates to control the exhaust gases and be able to bypass any excess gases. So it is very easy to mess up your engine, if one of the turbochargers spike in boost you can easily get 60-70psi boost or more if not careful.
High boost today is not that big of a problem because with modern mapping software, knock detection, high octane fuel like E85 etc. It's pretty safe, but having a built engine and a good engine builder / tuner is key. And if you are doing the build yourself make sure you take time and not rush things and keep an close eye on all the gauges. And if possible try and do an engine log every trackday.
Some interesting things to think about. I need to research compond systems more...
ReplyDeleteI've thought of supercharger/turbo in the past ... but the complexity put me off it.
I do like the thought of the 2 smallish turbos. Apart from the cost saving... its a much more simple set up....
And with the t2 series. Its easy/cheap to move up and down in sizes....
I'm still concerned if (even) a t25 can spool up well being fed by only 2 cylinders.
I'm not up to doing the maths to work out pros and cons. Your thoughts on this would be appreciated?
Like I said i've got a few t series sitting around and fab-ing it up is simple enough.... ok getting myself confused LOL
Hi Tony, I think if going with a twin t2 or t25 turbo setup you would still need to direct or "wastegate" the exhaust to a single turbo for it to be worth it and get the low rpm boost. The problem is there are really no off the shelf easy to buy parts that does that for you, except what is called a Quick Spool Valve.
ReplyDeleteHowever I watched a video of it failing and destroying a GTX35 turbo recently https://www.youtube.com/watch?v=xtVPSG8EQyE
So it's not really something I would recommend, it will work and improve spool, but when/if it fails it will take out the turbo. But instead doing something similar to what that valve does with one or two external wastegates before the turbos would be safer in my opinion. You could maybe split the manifold and run exhaust through a single 60mm wastegate to one t2 turbo, maybe block off one turbo with a wastegate and do a bypass and direct the exhaust like that. Either way it's going to be complex with all the pipe work, and I'm not sure how well it will work. I guess it's one of those things you need to try and see what happens.
The thing with a supercharger turbo setup is the supercharger still needs RPMs to start to build boost, so it's important to pick the right size supercharger for it to work well.
If I may confuse you even more you can check out Peter Schmidt that runs a supercharger GT42r turbo setup in his 2.7l 16v Volvo 360 timeattack car. His setup is pretty nice.
His build with pictures found at
https://rejsa.nu/forum/viewtopic.php?t=78155&postdays=0&postorder=asc&start=1176&sid=4abbd8808eae6f6962d7fdf51cc69109
And there was a technical video done recently by Peter Bjorck
Volvo 360 with Turbo+Supercharger + F1 Parts!
https://www.youtube.com/watch?v=aSIpjNU1p4c
Hi, I am looking at upgrading the standard Turbo in my right hand drive Citroen Ct Turbo Activa and the Gt 2860 RS has been suggested as a good choice to achieve 300 fwhp together with programmable injection with standard internals. The main problem with largrer turbos on the right hand drive Activas seems to be room to fit them as what will fit on a left hand drive will not fit on the right hand drive models. You`re obviously expert opinion would be much appreciated. Cheers Keith
ReplyDeleteHello Keith, if you think the GT2860R would have clearance issues you might want to look at the GT2560R turbocharger instead. The internal wategates fitted on both turbos do take up some space but the wastegate on the GT2860R do stick out a bit more.
ReplyDeleteThe GT2560R if you have a look at the measurements is a little bit more compact so it might be easier to fit. The compressor inlet on the GT2860R take a 3 inch pipe. The smaller GT2560R use a 2.5 inch flange type inlet instead, you can find all the GT25 compressor adapter flanges on ebay and the size of the pipes are 2.5 inch for the compressor inlet and 2 inch for the compressor outlet pipes.
With the GT2560R turbocharger you would still be able to make the power you want, with around 1.3 bar or 19 psi boost you should see 300whp with the GT2560R. But that is maxing out the turbo, so don't expect a lot more. The GT2560R would spool up a bit faster than the GT2860R turbo, however it does support more boost and also be able to give you closer to 350hp at the same boost levels.
Hi there,
ReplyDeleteIam trying to boost my 2.5L TDI (land rover 300tdi) engine to 30psi for competition use. Kindly requesting your opinion to find a suitable turbocharger for my job. I really need the turbo to kick at low RPM.
thanks
Indula
Hello Indula, if you are looking for a turbo that is efficient at 30psi in the Garrett GT28 range of turbos, then I would use either the GT2860R turbocharger or the GT2859R. You could probably push the GT2860RS turbo to 30psi however that would be outside it's compressor map efficiency range.
ReplyDeleteFor max horsepower go with the GT2860R. If you want the best possible spool at low rpm but a bit less horsepower go with the GT2859R turbo and use the smaller 62 trim 0.64 a/r turbine housing.
At what point would you go for the bigger a/r86 housing, I have a 2.3l factory turbo, single ohc that runs about 180hp at the moment, my goal is around 250-270 ish
ReplyDeleteHello, well the best way to know if you need a bigger exhaust housing would be to fit an exhaust back pressure gauge to your existing turbo manifold. That way you can see if you really need a bigger turbine housing. A rule of thumb is that you do not want to have more exhaust back pressure than boost pressure. So if you run 1 bar / 15 psi boost pressure then on the exhaust side you should be reading less pressure. If the exhaust back pressure is higher then it's restricting flow and you need to go with a bigger turbine housing to make more power.
ReplyDeleteThere's a few ways you can install an exhaust back pressure gauge. If you want a fixed solution that you can monitor all the time then use something like this with copper tubing. The copper tubing is there to cool down the exhaust gases before they get to the sensor / gauge.
Exhaust Back Pressure Sensor Gauge Wiring
https://1.bp.blogspot.com/-tNxz7BTJ_yY/W_RalA7DrjI/AAAAAAAAEVM/rUzMGZtaabEoUdmYGCAQafPbwWwj35HxgCEwYBhgL/s1600/Exhaust%2BBack%2BPressure%2BSensor%2BGauge%2BWiring.jpg
Just drill and tap the turbo manifold and have the copper tubing connected all the time.
Exhaust Back Pressure Gauge Install Manifold
https://2.bp.blogspot.com/-eSSwF5w5trw/W_RalJdtvOI/AAAAAAAAEVQ/apAY8fouMo0QGEacZ_d1pmW6lab49o3wgCLcBGAs/s1600/Exhaust%2BBack%2BPressure%2BGauge%2BInstall%2BManifold.jpg
Or you can go with the less expensive setup that use a mechanical gauge and braided line that you connect to the turbo manifold in a similar manner. However it is not recommended to run this connected for an extended period of time, because the hot exhaust gas will eventually melt away the braided line and destroy the gauge if left connected.
Exhaust Back Pressure Gauge
https://2.bp.blogspot.com/-RDJBdTv8-b4/W_RalIPQpGI/AAAAAAAAEVU/i37F36fjXjEftuvp0Ag_UzZJ-z6j1DdGQCEwYBhgL/s1600/Exhaust%2BBack%2BPressure%2BGauge.jpg
With a turbo like the Garrett GT2860RS if you want the best performance from it you would not want to see over 22 psi / 1.5 bar of exhaust back pressure.
the current turbo is a TD04h-13c which has a turbine housing a/r of about .38 to.40 from what i can work out, it's very responsive but chokes the engine like breathing through a straw at the top end of between 4k-6.8k rpm. It runs about 26-28 lb/min at 6500rpm. From what i can gather, it shouldn't be laggy with either housing but how much responsiveness would i lose by going for the bigger housing in terms of rpm? I will do the backpreasure test but with the current turbo im guessing it's unnecessary because i can feel it chocking the engine at the top. to get the power i want, it shouldn't be necessary to run more than 1 bar of positive pressure
ReplyDeleteHello, going bigger turbine you might lose around 500rpm or even 1000rpm on some smaller engines. The bigger 2.3 is going to help a lot with responsiveness going to a bigger turbine. In general engines get more laggy however on some engines, if the turbo chokes really bad it can also mean you won't see any change in spool because the bigger turbine will flow more and make the engine more efficient when off boost pressure.
ReplyDeleteThe TD04h-13c is a turbo that normally runs around 170hp in the 6k rpm range, and 220-230hp is about what you can expect if you push this turbo to the max.
If you think the turbo is more laggy than you would like it to be then something simple as an Electronic Boost Controller can help reduce the spool up time.
Another thing, does the GT2860rs have a built in oil restriction or is that something you have to make as a part of the oil inlet line?
ReplyDeleteHello, Garret have restrictors built in. But most ball bearing turbochargers should come with an oil restrictor fitted. You should clearly see the restrictor in place if you look in the oil inlet on the turbo.
ReplyDeleteIf no restrictor is in place and you can see all the way down to the bearing, like you can on the oil return side. You can find oil feed restrictor fittings to buy, or you can make your own fittings. Oil restrictors should have around 0.9 - 1.00mm / 0.040 inch feed hole for ball bearing turbochargers. The restrictor size depends on the oil pressure present.
Please note:
DO NOT FIT AN INLINE OIL RESTRICTOR TO A TURBO THAT ALREADY HAVE A BUILT IN RESTRICTOR IN PLACE, YOU RISK RUNNING TO LITTLE OIL PRESSURE AND IT WILL DESTROY THE BALL BEARINGS.
From Garrett Tech Support
Ball-bearing turbochargers can benefit from the addition of an oil restrictor, as most engines deliver more pressure than a ball bearing turbo requires. The benefit is seen in improved boost response due to less windage of oil in the bearing. In addition, lower oil flow further reduces the risk of oil leakage compared to journal-bearing turbochargers. Oil pressure entering a ball-bearing turbocharger needs to be between 40 psi and 45 psi at the maximum engine operating speed. For many common passenger vehicle engines, this generally translates into a restrictor with a minimum of 0.040" diameter orifice upstream of the oil inlet on the turbocharger center section. Again, it is imperative that the restrictor be sized according to the oil pressure characteristics of the engine to which the turbo is attached. Always verify that the appropriate oil pressure is reaching the turbo.
Hi JD, really enjoyed this article and tech info on the famous Garret 2860RS. I'm wondering what advice you might have for a fella who wants to build a custom single turbo kit for a 4.0 Ford Mustang engine. The car is a daily driver 5 speed manual with 4.10 gears and a few mods. Wanna take it to the next level now and go FI turbo.
ReplyDeleteI think I've researched how to build the proper Turbo manifolds tubular style and connected with a cross pipe into the inlet flange.
So the driving dyna mic of the car currently is pretty fun, but after 4k rpm the engine seems to start to lose power quickly. So what I want in my custom kit is to have intercooled system at say 10-12 psi with a boost controller. However I don't think I want the turbo to spool too quickly because I need that max boost to happen above say 4k rpm so I can compensate and keep a strong surge of linear power delivery all the way up to 5500RPM.
I guess I think for my desired power level and to keep it reliable I'm looking to get about 350+ hp from the system and over 400 lb ft of torque. Based on that the GT2860RS with the 0.84 trim might be the right way to go for what I want, but maybe something on the GT 30 series would actually pair better with my v6 at 245 cubic inches.
Here's a few numbers I worked up on the engine airflow characteristics...
388 CFM Max
311 CFM @ 80% VE
32.2 lbs/min air flow
3 inch exhust outlet from turbo manifolds (proposed)
Would love to know your thoughts on this set up. I would also like to do road course track days too. This things gonna flY on those back straights I hope!
Hello Tom, the GT2860RS would work on the Mustang 4.0 engine and you should see close to 350 hp with 10 psi boost pressure. However it being a very small turbo for your engine and power, it is going to spool and give full boost much lower down the rpm range around 2000 rpm.
ReplyDeleteSo because of that I would recommend you go with the Garrett GT3076R turbocharger instead, because then you would get the turbo to start to build boost around 3000-4000 rpm like you want.
This depends on the exhaust housing you choose, and Garrett have the options to go with either a 1.06 A/R turbine that is more suitable for big engines and a 0.82 A/R turbine that might be a good option for you. The 0.63 A/R turbine option I think would be too small for you and it would defeat the purpose of going to a bigger turbocharger in the first place.
With the same 10 psi boost pressure you could expect +350 hp closer to 400 hp with the bigger GT3076R and 0.82 A/R turbine, but in the end it comes down to how good you can get the Mustang engine to flow with the stock parts. And if you still think the boost comes in too hard and you can't control it with a good boost controller, you would have the option to swap out the housing and go with the 1.06 A/R turbine for a even smoother power delivery.
Wow thanks for the fast and thorough response JD! Sounds like the GT3076R would be a great fit for the max boost to hit in 3-4k on a 245CID engine.
ReplyDeleteSo with the 0.82 vs the 1.06 A/R basically the smaller housing one will spoll sooner in the Rev range but the 1.06 has a better chance to fill in the top end power? Maybe the 0.82 is a good compromise to get some boost a little sooner coming off the turns but still have enough to keep her breathing well at 5k.
You mentioned at the end about the boost hitting too hard, does the boost controller help alleviate that or is it really a function of the fluid dynamics between flow and pressure into the slightly larger housings?
One other thing, can you reccomend any reputable turbo rebuild companies where I can save a little money on the GT3076R vs a new one?
- Tks
Hello, yes a 1.06 A/R will help your engine breath even higher up in the rev range so the power won't drop off as much and at the same time the power comes on a bit slower and controlled due to the bigger housing size. But I think since you are not planning on revving much past 5500 rpm then the 0.82 A/R would be a good compromise.
ReplyDeleteYou could also try the 0.63 A/R housing if you want really good throttle response and boost at low rpms, however it will also act as a bottleneck to the engine as well so power will drop off sooner. Not to talk about how it might also make the car hard to handle having the power come on at a low rpm when exiting a corner etc..
But another issue you might run into with a small turbine housing is the turbo building boost too soon on your 4.0 engine, and risk running into compressor surge.
There's a few different ways to do boost controlling nowadays, the popular option if running an aftermarket ECU is to have it control a 3 or 4 port solenoid. This gives much more control over the boost pressure and you can have boost by gear, high or low boost at a flip of a button etc.
So in short if you run a 7 psi spring in the wastegate you can have the boost controller adjust the boost pressure in 1-2 gear from 7 - 12 psi in 3-5 gear. Check the video below for a brief explanation.
Boost Control for Cars That Need More Traction. - Jay's Tech Tips - Real Street Performance
https://www.youtube.com/watch?v=-mMK-yG7FlU
The GT3076R is a pretty popular turbocharger and you should be able to find a used one for around 6-800 dollars. The different size turbine housings can be bought separate also for around 200 dollars and are easy to swap.
Here's one for US $625.00
https://www.ebay.com/itm/Garrett-GT3076R-Ball-Bearing-Turbo-USED-GOOD-/233043189203
You could just send in the used turbo to a local turbo rebuild firm to have them check it over and even if they find something that needs replacing you would probably save a good deal of money vs buying a new Garrett turbo.
Very cool, definitely want to avoid any turbo surge so 0.82 A/R it is. Thanks for the solid advice JD!
ReplyDeleteTom :)
Hi is this a good turbo for a standard sr20 DET? and howmuch and KW can I get out of it?, I recently changed from gt25 to gt28
ReplyDeleteHello, it's probably the best Garret turbo in this hp range for the sr20 engine. You should see around 220kw with the GT2860RS at around 22 psi / 1.5bar boost. Now if you want a bit more power but don't want spend time to port the head or go with bigger cams, you could look at the new GTX2860R GEN II turbocharger.
ReplyDeleteThe GTX2860R flows a bit more air and supports higher boost pressures so at 26 psi / 1.8 bar boost you should have a soild 250kw.
I have a Kia 2.5L diesel red line is 4300 (but like to keep it at about 3500 to 3800. Was considering the gt2860r with 62 trim but would like a professional opinion.
ReplyDeleteHello, it depends on what power you are expecting to get, but if you are looking for a Diesel turbo in the 300hp range then you should consider something a bit smaller and more suitable for a Diesel. Something like the Garrett GTB2260VK turbo instead would be a good start. The GTB2260VK turbo should give you around 300hp and you also should have full boost around 2500rpm on the 2.5 liter Diesel engine. So that would give you a good 1000-1500rpm power band.
ReplyDeleteThe bigger option similar to the Garrett GT2860R is a hybrid GT2566BK turbo however don't expect to have full boost until 3000rpm if you go with something this big. Expect around 340-350hp but you would basically cut the power band in half with only a 40-50hp gain in power. The GT2860R however have a bigger turbine still, so this would spool a bit slower also so if you would go with that you would really need to push the engine to red line to have a useful 1000rpm power band.
Hello JD Twin charging my Toyota 4agze would appreciate your help finding a correct size turbo stand alone autronic management 264 colt triflow camshafts msd ignition H bean connecting rods 800cc injectors.
ReplyDeleteI'm hoping to make 300 hp completely lag free it will have a one way bypass valve around the supercharger, turbo only used in the mid to upper range.Supercharger for bottom end pulling.
ReplyDeleteI'm hoping JD to make 300hp with no lag my 4agze will have a one way bypass valve around supercharger turbo for midrange top end.
ReplyDeleteHello, you could go with either the Garrett GT2860RS or the GT2860R turbo if you like. Since the supercharger is adding boost pressure and you are turbocharging an already boosted engine I would guess in this case the turbo would only need to supply around 10 psi / 0.7 bar for you to get to 300hp.
ReplyDeleteHowever if the bypass valve or boost pipes end up a bit restrictive in some places you might have to run a bit higher boost on the turbo, but that would not be a problem for the GT2860 turbos. I would leave the wastegate at stock wastegate pressure to begin with since that is set to 10 psi.
I would say around 21 psi / 1.5 bar boost in total pressure would get you to a solid 300hp.
Thank you JD most appreciated with the help for the GZE
DeleteHi,
ReplyDeleteI've a honda h22/h23 hybrid sliveed engine (2300cc) with forged pistons and rods and I would like to boost it. How ever, I am not that much interested about max hp reather about good power through the whole rpm range with first goal to have as fast as possible spooling turbo. When I said that I mean something spooling around 2500rpm already but also not chocking the engine after. Pls advice.
Hello Igor, if you want a turbo that will be on full boost on your Honda engine at 2500rpm then something like the GT2554 turbo would do the job. And it might even come on earlier than that due to the bigger 2300cc engine helping spool. It's a turbo good for around 270hp.
ReplyDeleteThe next step would be to go with the GT2560R turbo that also use the same 0.64 A/R turbine housing. You would be spooling around 2500rpm and hit full boost around 3000-3500rpm with that turbo. The bigger compressor used makes it good for around 330hp.
The bigger GT2860RS turbo supports even more power around 360hp and would not be that far off in spool, if you go with the 0.64 A/R turbine housing. But expect to lose another 500-1000rpm in spool from that turbo on your engine.
My 3sge beams blacktop engine is using the TD04H 16t 11cm2 (.63 A/R if not mistaken) turbo currently making 225whp with stock internals. Which spec of GT2860RS would you recommend to go for?
ReplyDeleteHello, I would go with the 0.64 A/R GT2860RS turbo on the 3sge engine if you are still planning on running the stock internals and have the rev limit set to stock 7000rpm. And only go with the bigger 0.86 A/R turbine housing if you want to go over 7000rpm and rev to 8-9000rpm.
ReplyDeleteHowever if you like a turbo that's a bit more responsive, that starts spooling a little bit earlier and still make around 300whp then you could go with the GT2560R turbo with an 0.64 A/R turbine housing.
Hi JD, thank you for the info. Some info in one of the forums say that 11cm2 turbine inlet is equal to .86 A/R, do you have any idea if thats correct?
ReplyDeleteHello, they might be similar in size but the TD04H 16t turbo should have a 45.6 mm x 52 mm turbine wheel fitted. And the GT2860RS have a bigger 47.00 mm x 53.90 mm turbine wheel. So even though the cm2 and A/R would seem similar, the bigger turbine wheel would still be able to flow a bit more.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteHello, JD. I have a 1.8-liter Audi S3 engine, a GTX 2860 GEN 1 .86 A / R turbo, I want to increase the pressure to 22 psi. Does the turbo handle this pressure without problems?
ReplyDeleteHello Gabriel, your GTX 2860 should handle 1.5 bar / 22 psi boost without problems. The GTX line of turbos handle high boost very well and you can push these to 2.8 bar / 40 psi boost and still be on the safe side.
ReplyDeleteThanks for the tip JD, my engine is forged and supports up to 1000 hp, but I am afraid about the turbo, because on Garrett's website they indicate to use up to 17 psi only, in reality I wanted to go with 24 psi, do you think it would support this pressure without problems?
ReplyDeleteI don't know if there is a difference, but my turbo is a GTX2860 of the first generation(GEN 1)!
ReplyDeleteHello Gabriel, I can't find anything like that, perhaps they have mixed up info on the GT2860RS turbo with the first gen GTX2860 turbo. In that case the GT turbo is most efficient around 17 psi. But that does not mean it won't support higher boost. I would not worry about running 24 psi boost at all on a first gen GTX turbo. Just make sure you have stable oil pressure, and perhaps add a good quality turbo oil filter.
ReplyDeleteMy car has a good oil pressure, I won't have any problems with that, my concern was about the turbo pressure, as I've never seen anyone use higher pressure on turbo bearings, and it's hard to find information about these high psi turbo gtx!
ReplyDeleteHi JD.
ReplyDeleteSubject still interesting after many years!
I'm running a small 2,4L V6 charged by an old T3 .48 A/R at 0.9bar, on my old Renault. Stock engine power is 210whp at 6000rpm, but i find it too laggy to really enjoy it on road (almost nothing under 3000rpm). APT advice me to choose the gt2860rs .48 A/R or the gt2560r.48 A/R.
In your opinion, does it make a great diference? Which one would have the quicker spool? The best powerband up to 250whp?
Thank you a lot!
Hello Mat, you should make 250whp with the GT2560R turbo around 1.2 bar / 17 psi boost if I am correct that the engine now with the old T3 turbo at 0,9 bar / 13 psi makes around 210whp.
ReplyDeleteBut at 250whp with the GT2560R turbo you are really at its limit so you won't be able to make much more power even if you go higher boost. You would make around the same power with the 55 trim GT2860R turbo but it's got slightly bigger turbine housing so spool would be a little bit worse. For best spool the GT2560R would be the better option.
However I think the slow spool is not only due to the old journal bearing T3 turbo, but also the V6 configuration with long exhaust runner lengths that are hurting the spool.
Yes the T3 turbo is slow to spool with the journal bearings and 1980s design of turbine and compressor wheels but even on a small 2 liter inline-4 engine with a good manifold you would have full boost around 3000 rpm with the T3 turbo. So in your case you could get 500rpm faster spool, but a lot can be done to improve spool if there is a way to improve the exhaust manifold also.
Thank you for your answer JD.
ReplyDeleteI think you're right.
The exhaust manifolds are so long and unsynchronized (each are 1/2/3, compact but unefficient). And no place to set 3 in 1 manifolds... unless I find a welding genius!
I also think those long manifolds induce an excess of pumping (leak of pressure from one to the other manifold between each fire, instead of load the spool).
APT adviced me at first to try the GT2860rs .82 A/R T3 DIVIDED! If I was able to set the external waste gate with all the piping complications.
I think a twinscroll DiscoP should be very nice to reduce the pumping effects but only available in .82, which seem's to be quitte big. So, not ready yet to go for a long story of piping and welding work unless be sure that it Will be quicker than a single GT2560r or even my old T3 upgraded with modern spool and Ball bearing CHRA...
Before boring you with those considerations, what do you think about those two opposite alternatives (.82 divided DP or upgraded plug n play T3)?
Thank you for your informed opinion!
Hello Mat, I would say with a perfect setup, manifold with the right angles and good collector etc.. You chould see the divided .82 GT2860r spool better than the T3. But mostly due to it being a ball bearing turbo. But with a bad design it's really hard to say how big the difference would be.
ReplyDeleteThe stock T3 and GT2860r both can make around the same power with the GT2860r able to make maybe 30hp more. And an upgraded T3 to a hybrid T34 turbo would match the GT2860r in power. But the advantage of the T3 or T34 is you can (with the upgraded 360 thrust bearings) push 1.6 bar / 23 psi boost without issues if needed.
I'm thinking if there is space between the turbo and manifold to get one fitted you could try and fit a turbo quick spool valve. Similar to this https://www.dieselpumpuk.com/shop/turbo-accessories/quick-spool-valve/
The few I have seen for sale in the US are pretty expensive ($500) for what it is but the UK one is only £225.00 now. If there is nothing really wrong in the stock manifold design right now you should see an improvement in spool with this valve alone.
It would be an easy upgrade to do if you have the space required that is.. With 1.2 bar / 17 psi boost you should see around 250whp with the T3 turbo and you could push 280whp with 1.4 bar / 20 psi if you feel like it.
Yes! Quickspool valves are very smarts systems. But, except if I'm wrong, they
ReplyDeleteonly fit with twinscroll turbo combined with single exhaust manifold. So unfortunately, i think this is not adapted for my single T3.
What a pity that twinscroll turbos are not aviable on smaller A/R... especially since my T3 stock flange is almost divided (it could be a real divided flange with very few welding).
Anyway, for road, i prefer to privilege quickspool on power. So, if the best of the two world seems to be tard to get , i will follow your first indications. I think i should go for the single Gt2560r (or evantually my T3 upgraded with inconel wheel and ballbearing chra, which have the advantage to be pnp). To me, 500 easy earlier spool rpm are better than 750 hypotecal and complicated rpm
A big thank you for your attitude of sharing without judgment JD.
Hello,
ReplyDeleteI was wondering if you could give me advice on the correct turbo for my engine.
I was figuring that the GT2860rs would be the right turbo but I wanted to make sure.
My engine is a Honda D16Z6 and my power goal is to make 250-300whp with a very quick spool and minimal turbo lag. I would like my car to have good power in the lower RPMS and decent top end all the way up to around 7500-8000 rpm.
Thank you!
Hello ES04, for the stock B16Z6 setup the smaller 55 Trim GT2860R turbo would be the better option if you want to make 250whp and have good spool. You would need around 1.4 bar / 20 psi boost to make 250whp.
ReplyDeleteHowever for 300whp you should consider the 62 trim GT2860R instead, as you would need to run around 1.9 bar / 27 psi boost to make around 300whp. At higher boost pressures the Disco Potato turbo will start to struggle or at least run outside the compressor map.
However if you can switch to a better camshaft and make 150hp N/A then you would be able to use the Disco Potato GT2860rs turbo, with lower 1.4 bar / 20 psi boost you could make around 280-290whp.
This comment has been removed by the author.
Delete