The GT12 have been the smallest of the small frame Garrett GT turbochargers until late 2012 when Garrett came out with it's currently smallest GT06 turbocharger the Garrett GT0632SZ.
Unlike the GT06 that can give a maximum of 80 hp, the GT12 will give you at max 130 HP. It will work well down to 50 HP and that makes it perfect for small engines like ATV's, motorbikes or other engines.
Unlike the GT06 that can give a maximum of 80 hp, the GT12 will give you at max 130 HP. It will work well down to 50 HP and that makes it perfect for small engines like ATV's, motorbikes or other engines.
Recommended displacement from Garrett for this turbo is at a minimum 400cc and at most 1200cc.
But I see videos of people turbocharging their lawn mowers, mopeds and so on with this turbo also.
Model: 756068-1
CHRA: 757864-1
Bearing: Journal
Cooling: Oil & Water
Compressor
Inducer: 29 mm
Exducer: 41 mm
Trim: 50
A/R 0.33
Turbine
Wheel: 35.5 mm
Trim: 72
A/R: 0.43
Wastegated
Wastegated
You can see on the compressor map above how this turbo works. The pressure ratio is an absolute pressure so that means you have the pressure we live in 1 bar + the pressure the turbo supplies to the engine.
So to read the pressure ratio above you get 1 bar boost pressure from the turbo where it says 2 in the middle of the compressor map. And you can see that the turbo is most effective at around 0.7 - 1 bar boost pressure. However you can force the turbo up to 1.5 bar if you want but it wont give you any extra air flow / horsepower
Above you have all the measurements in MM for the Garrett GT12 turbo. Click to get a bigger picture.
The GT12 thread size for the water is M12 x 1.50
And the oil inlet and outlet thread size are M6x1.0
TITLE
Garrett GT12 Turbo Compressor Wheel
APPLICATION
Suitable for Garrett GT12 Turbochargers
MATERIAL
Aluminum Alloy
DIAMETER (A/C)
22.56 mm / 38.1 mm
HUB LENGTH (D)
29 mm
TIP WIDTH (B)
11.6-8.73 mm
SHAFT SIZE (E)
4.11 mm
BOTTOM
Superback
BLADES
6/6
TITLE
Garrett GT12 Turbo Turbine Wheel
OE NO
434927-0002
APPLICATION
Suitable for Garrett GT1238S Turbochargers
MATERIAL
Inconel
DIAMETER (A/B)
28.4 mm / 35.5 mm
TIP HEIGHT (C)
4.11 mm
JOURNAL BEARING (D)
6 mm
COMP. WHEEL BORE (E)
4.08 mm
BLADES
12
Vehicles that use the Garrett GT12 family turbocharger
Garrett GT123
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Garrett | Smart | Smart 0.6L | 1999 | M160 (0.6) | 55 | - | GT123 | 708116-0001 | 1600960399 | 3K |
| Garrett | Smart | Smart 0.6L | 1999 | M160 (0.6) | 55 | - | GT123 | 454197-0001 | - | 3K |
| Garrett | Smart | Smart 0.6L | 1999 | M160 (0.6) | 55 | - | GT123 | 708837-0001 | 1600960499 | 3K |
| Garrett | Smart | Smart 0.6L | 2001 | M160 (0.6) | 55 | - | GT123 | 712290-0001 | 1600960599 | 3K |
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code |
Garrett GT1238S
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Garrett | Honda | BAMOS | 2006 | - (0.7) | 64 | D | GT1238S | TBD | TBD | 3K |
| Garrett | Mercedes-Benz | For Two 45kW | 2002 | M160 45kW (0.6) | 0 | D | GT1238S | 727211-0001 | A 160 096 09 99 | 3K |
| Garrett | Mercedes-Benz | Smart | 1999 | M160 (0.6) | 54 | B | GT1238S | 454197-0002 | A1600960199 | 3K |
| Garrett | Mercedes-Benz | Smart | 36179 | M160 (0.6) | 54 | B | GT1238S | 708116-0001 | A1600960399 | 3K |
| Garrett | Mercedes-Benz | Smart | - | M160 (0.6) | 0 | B | GT1238S | 724961-0001 | A1600960699 | 3K |
| Garrett | Mercedes-Benz | Smart | 37408 | M160 (0.6) | 0 | B | GT1238S | 724961-0002 | A1600960699 | 3K |
| Garrett | Mercedes-Benz | Smart | 2003 | M160-1 (0.7) | 82 | B | GT1238S | 727238-0001 | A1600961099 | 3K |
| Garrett | Mercedes-Benz | Smart MCC | 1998- | M160R3 (0.6) | 54 | B | GT1238S | 454197-0001 | A1600960199 | 3K |
| Garrett | Mercedes-Benz | Smart MCC | 1998- | M160R3 (0.6) | 54 | B | GT1238S | 454197-0003 | A1600960299 | 3K |
| Garrett | Mercedes-Benz | Smart MCC | 1998- | M160R3 (0.6) | 54 | B | GT1238S | 704487-0001 | A1600960399 | 3K |
| Garrett | Mercedes-Benz | Smart MCC | 1999- | M160R3 (0.6) | 54 | B | GT1238S | 708837-0001 | A1600960499 | 3K |
| Garrett | Mercedes-Benz | Smart MCC | 1999- | M160R3 (0.6) | 54 | B | GT1238S | 712290-0001 | A1600960599 | 3K |
| Garrett | Mercedes-Benz | Smart MCC | 1999- | M160R3 (0.6) | 54 | B | GT1238S | 724808-0001 | A1600960699 | 3K |
| Garrett | Smart | SMART 0.6 | 1999 | M160 (0.6) | 54 | - | GT1238S | 454197-0002 | A1600960199 | 3K |
| Garrett | Smart | SMART 0.6 | 1999 | M160 (0.6) | 54 | - | GT1238S | 454197-0003 | A1600960299 | 3K |
| Garrett | Smart | SMART 0.6/3 | 1999 | M160 (0.6) | 54 | - | GT1238S | 454197-0002 | A1600960199 | 3K |
| Garrett | Smart | SMART 0.6/3 | 1999 | M160 (0.6) | 54 | - | GT1238S | 454197-0001 | A1600960199 | 3K |
| Garrett | Smart | SMART 0.6/3 | 1999 | M160 (0.6) | 54 | - | GT1238S | 708116-0001 | A1600960399 | 3K |
| Garrett | Smart | SMART 0.6/3 | 1999 | M160 (0.6) | 54 | - | GT1238S | 454197-0003 | A1600960299 | 3K |
| Garrett | Smart | SMART 0.6/3 | 1999 | M160 (0.6) | 54 | - | GT1238S | 708837-0001 | A1600960499 | 3K |
| Garrett | Smart | SMART 0.6/3 | 1999 | M160 (0.6) | 54 | - | GT1238S | 704487-0001 | A1600960399 | 3K |
| Garrett | Smart | SMART 0.6 | 2000 | M160 (0.6) | 54 | - | GT1238S | 712290-0001 | A1600960599 | 3K |
| Garrett | Smart | SMART 0.6/3 | 2000 | M160 (0.6) | 54 | - | GT1238S | 712290-0001 | A1600960599 | 3K |
| Garrett | Smart | SMART 0.6/3 | 2001 | M160 (0.6) | 54 | - | GT1238S | 724961-0001 | A1600960699 | 3K |
| Garrett | Smart | SMART 0.6 | 2002 | M160 (0.6) | 54 | - | GT1238S | 724808-0001 | A1600960699 | 3K |
| Garrett | Smart | SMART 0.6 | 2002 | M160 (0.6) | 54 | - | GT1238S | 724961-0002 | A1600960699 | 3K |
| Garrett | Smart | SMART 0.6 | 2002 | M160 (0.6) | 54 | - | GT1238S | 733717-0001 | - | 3K |
| Garrett | Smart | SMART 0.6/3 | 2002 | M160 (0.6) | 54 | - | GT1238S | 733717-0001 | - | 3K |
| Garrett | Smart | SMART 0.6/3 | 2002 | M160 (0.6) | 54 | - | GT1238S | 724808-0001 | A1600960699 | 3K |
| Garrett | Smart | SMART 0.6/3 | 2002 | M160 (0.6) | 54 | - | GT1238S | 724961-0002 | A1600960699 | 3K |
| Garrett | Smart | SMART 0.6 | 2003 | M160 (0.6) | 54 | - | GT1238S | 724961-0003 | A1600960699 | 3K |
| Garrett | Smart | SMART 0.6/3 | 2003 | M160 (0.6) | 54 | - | GT1238S | 724961-0003 | A1600960699 | 3K |
| Garrett | Smart | SMART ROADSTER 0.7 | 2003 | M160-1 (0.7) | 82 | - | GT1238S | 727238-0001 | A1600961099 | 3K |
| Garrett | Smart | SMART ROADSTER 0.7/3 | 2003 | M160-1 (0.7) | 82 | - | GT1238S | 727238-0001 | A1600961099 | 3K |
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code |
Garrett GT124
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Garrett | Volkswagen | GOLF T 1.0T | 2001 | EA111 (1.0) | 100 | - | GT124 | 708001-0001 | 36145701 | 3K |
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code |
Garrett GT1241Z
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Garrett | VW | Gol | 2001 | EA111 (1.0) | 101 | B | GT1241Z | 708001-0001 | 36145701 | 3K |
| Garrett | VW | Gol | 2001 | EA111 (1.0) | 101 | D | GT1241Z | 756068-0001 | - | 3K |
| Garrett | VW | Parati | 2001 | EA111 (1.0) | 101 | B | GT1241Z | 708001-0001 | 36145701 | 3K |
| Garrett | VW | Parati | 2001 | EA111 (1.0) | 101 | D | GT1241Z | 756068-0001 | - | 3K |
| Garrett | Volkswagen | GOL 1.0/4 | 2001 | - (1.0) | 100 | - | GT1241Z | 708001-0001 | 036145701 | 3K |
| Garrett | Volkswagen | PARATI 1.0 | 2001 | EA111 (1.0) | 100 | - | GT1241Z | 708001-0001 | 036145701 | 3K |
| Garrett | Volkswagen | PARATI 1.0/4 | 2001 | EA111 (1.0) | 100 | - | GT1241Z | 708001-0001 | 036145701 | 3K |
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code |
Garrett GT128
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Garrett | Smart | Smart 0.6L | 1999 | M160 (0.6) | 55 | - | GT128 | 704487-0001 | 1600960399 | 3K |
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code |
Garrett GT12SM
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Garrett | Mercedes-Benz | Brabus Roadster 74kW | 2004 | M160 74 kW (0.6) | 101 | D | GT12SM | 743317-0001 | A 160 096 11 99 | 3K |
| Turbocharger | Mark | Model | Year | Engine | H.p. | Family Turbo | Turbo Code | O.E.M Turbo Code |
Hi there, I've bought my first Smart Fortwo 0.7 - Looking to build a better motor up to 150-200hp... Will a GT15 compressor body bolt onto a GT12 turbine body? I'm looking for more air volume without increased lag. Thanks really enjoy your blog!
ReplyDeleteHello Smart Madness, well unfortunately I don't think you would be able to fit a GT15 to the Smart Fourtwo turbine housing. Maybe you could machine the housing to get the GT15 body to fit the Fortwo housing but it would involve some tricky setup to even get it machined to begin with if even possible. The GT15 turbine wheel is around 42.2 mm and the GT1238 turbine is around 28.4 mm.
ReplyDeleteAlso if you would manage to fit a GT15 compressor housing and wheel to the GT12 turbo you could probably run into some surge issues because the GT15 is a much bigger turbo and it would be a bit of a mismatch.
The best way to get more power would be to have a custom turbo manifold made similar to this one from rt-dynamics.com. That way you have to option to get a bigger turbo fitted, because a GT12 will not make the numbers you are after.
https://1.bp.blogspot.com/-_kcYgsbBDSc/W7vf1E92QEI/AAAAAAAAEUw/5ibHOYtnqSgAfqYiyHWcj8LOxjQd704UACLcBGAs/s1600/Smart%2BFortwo%2B451%2BCustom%2BAftermarket%2BStainless%2BTurbo%2BExhaust%2BManifold.jpg
If you get a GT1241 turbocharger fitted and push around 26 psi or around 1.8 bar boost you might get around 100hp from the stock Smart engine.
But if you really want 150hp then you need to port the cylinder head and get some better camshafts, you need the engine without turbo to be able to produce around 55hp alone. If you get the GT2052 turbocharger you would be able to get to 150hp with the same boost pressures.
But at that this point you will not have the fast spooling engine you are after.
Thanks JD... That's great information!! Machining would not be any problem... My objective is to reduce lag by maintaining the GT12 compressor but increase volume allowing for higher engine rpm (10,000-12,000) but maintain usable revs (2000 up)... So with machining out of the way do you think this strategy would accomplish my end goal?
ReplyDeleteSorry, keeping the GT12 turbine to drive the GT15 compressor...
DeleteWell sure it can be done, the GT12 turbine should fit the GT15 compressor the way you want (it might need some machining done to get some parts fitted). However my main issue with the GT12 turbine is it is a very small turbine and the ports are also very small on the turbine manifold. So it will become a restriction on how much power the setup can make in the end (if you don't run into surge issues before that).
ReplyDeleteIf you can tune the engine to produce around 60hp without a turbo and you get the GT15 compressor fitted you would be looking at around 150hp with 22 psi or 1.5 bar boost pressure. But if the exhaust back pressure is too high due to the small GT12 turbine the engine might struggle to get to 130hp.
If you look at the GT1544 and GT1548 you can see the difference in compressor wheel size and turbine wheel size and how it affects how much air the turbos are able to flow vs the GT12 turbo.
Thanks again JD. I guess its time to have a play!!. My numbers tell me I need 180hp and 180ft/lbs torque to achieve my performance goal. Will let you know what happens... Much appreciated
DeleteHi JD
ReplyDeleteLove your work - so much great info.
I have been scouring the net looking for the specs on a turbo i have - its from a Peugeot (part number 9810681380C) and translates to a GT1341. any chance that you might have some info on this? looking at fitting it to a motorbike.
Hello, I think the correct one is called NGT1341Z made by Honeywell Garrett. It's found on the 110hp Peugeot 1.2L 308 MK2 and FIAT Viaggio, Bravo, Ottimo 1.4 T-Jet engines making 150hp. I don't know the inducer size on this turbo, but looking at the compressor wheel and turbine wheels the NGT1341Z have a 5 blade compressor vs the GT1241 that have the 6 blade design. And on the turbine wheel it's a 10 blade on the GT1341Z vs 12 blades on the GT1241.
ReplyDeleteIn short this means the NGT1341Z does flow more air and support more power over the GT1241 turbo, and we can confirm this by looking at the 1.4 liter Fiat engines producing 150hp with this turbocharger. Considering this it might be closer in size to the GT15 turbochargers.
JD, what about a variable vane turbo, are there small form units available that might be suitable?
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteHello Smart, one turbocharger you could consider would be the Garrett VNT15 turbos found on a number of Audi, Golf, Jetta VW tdi engines. I can't say how much difference in spool the variable vane turbine would be on your engine. But if you manage to tune your engine to around 60hp without turbo and use the Garrett VNT-15 turbo with 1.5bar / 22psi boost pressure, you could get around 150hp with that turbocharger.
ReplyDeleteTo get a solid 180hp you would need to tune your engine closer to 70hp and run 1.6bar / 23psi boost for 180hp.
Ok, that sounds like a more promising plan JD... I've stripped down an engine and turbo to study and measure. I've got enough room to take it to just under 900cc and throw a set of forged rods and pistons in and give the head bigger valves and some porting... I used to be able to get 110hp reliably from 875cc without any boosting, so 70hp from a smart engine shouldn't be a problem... Let's see where it all goes; thanks for the feedback so far, big help
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteHi everyone! I have a Ford Figo Aspire running a 1.5 DV5 Diesel engine, running 100 bhp and 215 nm of torque.
ReplyDeleteMy stock turbo is a GT1241Z.
Would there be something I could bolt on without making any modifications, that could give me a bump of, say 20 odd bhp?
Hello, if I'm not mistaken your Ford should have the same 1.5 tdci engine that's sold in the UK / EU. If that's the case then I think the easiest way to get 20-40hp more would be to fit a good Diesel tuning chip box to the car.
ReplyDeleteThere are many different chip tuners out there so I can't really give any recommendations but I advise you to look around and read some reviews first before you buy any Diesel box as some are more focused on improving MPG instead of HP.
The GT1241 turbo however should be able to handle the extra boost needed to give you a good increase in power over the stock setup so no need to go bigger turbo.
Thank you so much. Yes It's the 1.5.
DeleteThat's some great advice..
Ciao ho una domanda. Posseggo una smart fortwo 700 pulse 61 cv e volevo sapere fino a che pressione è affidabile la piccola gt1238s di serie. Pensavo di ottenere circa 90 cv. Grazie
ReplyDeleteHello, with the GT1238r Turbocharger the Fortwo 700 should have around 90hp if you run a bit higher boost, around 0.8 - 0.9 bar boost pressure. Also make sure there are no boost leaks around the boost hoses.
ReplyDeleteHello JD, i have a 91' daihatsu charade 1 liter turbo diesel, which outputs around 48hp. I was hoping to make a bit more power, would actually like a bit more low end torque.
ReplyDeleteWould i gain anything with the gt06 and an intercooler, or is the gt12 a better option?
Thank you, Tom
Hello Tom, because it's a 1 liter Diesel engine I would go with the GT12 turbo instead because it's much cheaper and easier to find.
ReplyDeleteThe GT06 turbo would give you better low end but I think that it might be a bit too small for you and it would limit the power instead.
Hello I have a gt1241 that I'm looking to install onto a 650cc single cylinder motorcycle. My main question is how do I align the oil port. I'm aware most turbos are gravity drain, so do I have to push the oil in from the bottom? It appears the oil enters and leaves from the same fitting. Is coolant really necessary if I give it time to cool before I shut it off? Any advise would be great!
ReplyDeleteHello, it does look like some GT12 turbos do have a joined oil inlet and outlet fitting. But you should still have two oil connections with fittings. One for pressure and one for drain. The bigger hole is the drain (looking inside you should see the turbo bearing / shaft etc..). And if you are looking into the water feed and drain holes they should be empty looking inside. So you want to connect oil pressure to the smaller fitting.
ReplyDeleteIf you need to mount the turbo really low on your bike then you can run into trouble with the oil not draining away properly with gravity to the crankcase. If that happens you can use a cheap small 6v or 12v oil suction scavenge pump to get the oil back to the crankcase.
Running without coolant is fine as long as you give the turbo a few minutes of slow no boost driving or idle before you shut down the engine.
I have a Polaris Ranger with a Kohler KDW1003 and want to add a turbo to get a bit more power and reading the posts here it sounds as if the GT12 would be the better option for this? What is the gate set at on these and what is your recommended boost for this application?
ReplyDeleteHello, the GT12 is a pretty good match for the KDW1003 Diesel engines. The wastegate would usually be set stock to around 10 psi. So without any change the GT12 at 0.7 bar / 10 psi boost would give you a solid 40 hp (if the pump can supply the extra fuel needed).
ReplyDeleteHowever the GT12 can still give you some more power. If the diesel pump or injector pump can supply enough fuel and you want even more power you can increase the boost pressure to 1.3 bar / 19 psi and you would be closer to 60 hp.
it this work for my drag bike yamaha R3 engine with 50hp mods and CR arround 11.3:1 13.750rpm rev .. im looking for extra 20-35hp.
ReplyDeleteHello speedlab, you would need to either switch to E85 fuel or drop the compression ratio to really take full advantage of the turbo. With lower compression or if you can fit a small intercooler and run E85 fuel with 1 bar / 15 psi boost you should get around 90hp.
ReplyDeleteI am looking at a 1.3L 3000rpm diesel engine right now. What turbo do you recommend? I have been looking at multiple of these pages.
ReplyDeleteHello killerGoKartsYeeeeticusMaximus, if you are going to stay at around 3000rpm then the GT1241 turbo would be a good option. Not knowing anything about the engine I can only guess, but I would expect around 50hp with 1 bar / 15 psi boost.
ReplyDeleteHi,
ReplyDeleteI have a 1933 Ford Model Y with a 933 cc (56.9 cu in) straight-four side-valve engine compression ratio 6.0:1.
thinking of putting a GT06 or GT12 and running only a 4 to 5 PSI boost, which one would be a better choice to give better bottom end power
Hello, I think for the Ford 8 hp sidevalve engine you should go with the smaller GT06 turbocharger instead. The low compression and low rpm makes the GT06 a better choice, especially if you want better low end power. You can expect to get around 30hp with 0.4 bar / 6 psi boost and that should be pretty safe.
ReplyDeleteHi, in my Alfa Romeo Mito I currently have a Garrett GT1238. Is the intake diameter of this turbo the same as the Garrett GT14? Looking to get a silicone intake pipe which is made for a Mito with the GT14, but has the same engine as my Gt12 Mito.
ReplyDeleteHello Alon, the GT14 is something of a hybrid turbo so I'm not sure what the exact size is. But the GT1241 turbo have the 45.9mm inlet size. And if we look at the bigger GT15 turbos they have 50mm inlets. But don't worry even if the silicone intake you get is a bit bigger you can simply use some quality gaffer tape and wrap that around the intake to make it the correct size if needed.
ReplyDeleteHi!
ReplyDeleteReally cool blog. Found few bits of info what help me a lot. So I hope you can give me some advice.
Somehow I can`t still find proper compressor map (similar what you post here) for the following turbo: Honeywell Garrett - GTB1444VZ / 775274-5002S / M282012A701
It is fitted in any Hyundai / KIA 1.4-1.6 CRDI engine.
I remapping my car and wish to find one so I can "guess" what boundaries can be safe to reach.
Will be great if you give me some tip or link.
Hello LongGo, because the GTB1444VZ turbos are hybrid types made for Hyundai Kia etc. there won't be any compressor maps around. However we can still make a good guess because the size difference is not that much.
ReplyDeleteThe GT1241 turbo compressor wheel is a 29mm inducer, while the GTB1444VZ use a bigger 32.6mm compressor wheel. You can take the GT1241 compressor map and extend it to around 15 lb/min. So you should be able to get around 20hp more from the GT1444VZ turbo. If you stay around 1.5 bar / 22 psi boost you should be safe.
Thanks for the answer JD!
ReplyDeleteI check on that link: https://turbocentras.com/parts-catalog/775274-0002.html and see some parameter of the turbo but yet it help me only to "guess" what differences with GT12 might be.
Actually, so far my tune is using boost about 1.53bar (theoretically about 140-143hp) at max and I was quite convinced it is in the turbo`s possible range. The original boost limit map was set to 1.5 bar,and i extend it to about 1.6 as limiter and use 1.52-1.53.
Hopefully I`m on the right track. Thanks again
Could you recommend a turbo for a 350cc 4 cylinder Motorcycle looking peak power around 12k rpm land speed racing
ReplyDeleteHello Slimzim, I guess the 350cc stock engine makes around 40hp so it would be possible to get around 100hp with 1.5 bar / 22 psi boost. The GT1241 turbo would be a good choise, however if you think you are going to have cooling issues with the GT12, because the inlet temps are going to be higher on a small turbo especially on a long run. Then you could also look at the GT1544 turbo.
ReplyDeleteHey JD!
ReplyDeleteI have a 1997 RHD Suzuki Jimny K6A JA22W and the turbo went bad. I just ordered a Garret GT12 and it seems like it will bolt on. Do you have any tips or know of anything I need to buy like mounting or special parts? Also -- Im looking to upgrade the flywheel and downpipe and get a boost controller to make sure its setup correctly, if you have any recommendations. Thanks so much for your time and knowledge I really appreciate it!
Hello .syndicate, I don't know about special parts but I would also buy some exhaust wrap. With the turbo off it's easier getting the manifold and downpipe wrapped. It should help spool time a bit and also cut down heat under the bonnet.
ReplyDeleteI mean to say blowoff valve and down pipe -- hehe. Im wondering now if my stock downpipe will work thats on the 1996 K6A Jimny engine or if I will need to make something custom because Im upgrading to the GT12. The exhaust wrap is a great idea thank you - Im going to search for some now!
ReplyDeleteHello .syndicate, you probably need to make or buy a flange to fit the stock downpipe for the GT12.
ReplyDeletehttps://www.ebay.com/itm/283895918790?hash=item421983f0c6:g:hmcAAOSwo6hdNHP7
Or you can get a GT12 V-band Adapter Flange like this
https://www.ebay.com/itm/2-5-5-bolts-Turbo-Downpipe-V-band-Adapter-Flange-Clamp-kit-For-Mazdaspeed-6-/383637767166?_ul=IN
And continue with something like a 2.5" V-Band Flanged Downpipe
https://www.ebay.com/itm/332849544324?hash=item4d7f60fc84:g:fYMAAOSwWSlbzZhQ
And then weld a 2.5" V-Band to the existing exhaust
https://www.ebay.com/itm/391490012586?hash=item5b269f85aa:g:7pEAAOSwM4xXaibw
However I don't really know how the exhaust is routed on the Suzuki Jimny so it might be easier to modify the stock downpipe instead.
Thank you so much for this info! I got the flanges and went ahead and ordered the downpipe to have options. I'm not an expert and the shop I have installing it works on Japanese cars and they said they shouldn't have a problem putting it on. I've read that the GT12 works fine on the 660cc K6A, but I was wondering if there will be any issues with lag or anything I should look out for / do special with tuning because its bigger? I bought a 2 stage boost controller as well. I really just want it to run rough and not overdo it. Thanks so much for your time!
ReplyDeleteto run tough** :)
ReplyDeleteSo sorry, another quick question. -- The company that I ordered the Garrett GT12 from just called and said the model I ordered is usually only sold for farm machinery... I think I don't know what I ordered and I need a specific GT12 model/part number to work on the K6A? Any idea here by chance? Thanks so much man
ReplyDeleteI found this on another forum hmmm:
ReplyDelete"I spent multiple months picking the correct turbo for the job. The most common two turbos to use are an unnamed GT12 (GT1241?) or the RHB31FW. Both are popular because they are bolt-in upgrades. The latter is a stock turbo with upgraded wheels and the former is an upgraded turbo that uses the stock flanges. Both couldn't get you past 130 crank horsepower even in the best of conditions, so they weren't in the running. Another commonly referenced upgrade is to an unnamed GT15 turbo. It loses the bolt-in status because it has different flanges and it also loses a water cooled CHRA, making it a lot less appealing for a daily driver. As the largest of the GT15 range, the GT1548 seemed like a good fit with respect to supporting up to 200hp, but it isn't very happy with high pressure ratios, and those will definitely be required to make power in an engine this small. And it has been discontinued without a replacement by Garrett and cannot be found, even used, unless you grab one from a diesel application. And that's not what you want. So I kept looking. It turns out that the "up to 20 lb/min" slot is vacant in pretty much everyone's aftermarket turbo portfolio, water cooled or not, so I turned to a turbo that I'm a little bit familiar with: the GT1446. It's the stock turbo on the Fiat 500 Abarth Essesse and Punto Abarth Evo where it makes 160hp and has been pushed up to 230hp in that application. The compressor absolutely loves high pressure ratios and should be right in the middle of its efficiency island when making 150-200hp on the Suzuki engine. The turbine section is unknown and it was hard enough to find a compressor map. I don't think that a turbine map exists for this turbo. And since a turbine is what determines the shape of your torque curve, I won't know what kind of response to expect until I get the turbo on the engine. After seeing a dyno chart of a Cappuccino (F6A) running a GT25, I don't think that I should be concerned about driveability with the GT1446."
https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/project-kujira-my-over-the-top-az-1-build/127816/page1/
Hello .syndicate, a 2 stage boost controller will help I would expect the turbo to start spooling around 4000rpm with a decent setup. One thing you can do when installing the boost controller is take all vacuum / boost lines from the intake manifold. The intercooled air is denser and acts faster on the boost controller and that makes the turbo spool a bit faster.
ReplyDeleteThis seems to say Garrett GT1241 http://www.teammightyboy.com/forum/viewtopic.php?t=5407
ReplyDeleteSorry for double post, I called them back and they said that the "GT1241" is the family of the turbos and I need to know the specific full digit part number or it probably wont work. Kinda stuck here
ReplyDeleteHello .syndicate yeah dealing with machinery dealers they usually want the part number. These numbers should be for the GT1241 turbo 756068-5001 or 7560685001S. If they can't find it with Model: 756068-1 CHRA: 757864-1
ReplyDeleteYou are a wealth of knowledge thank you. Id love to connect and pay you for your time if your open to it, but thank you either way.
ReplyDeleteI want to go the Garrett GT12 route, but Im concerned that I might need to also get a new ECU and other things before it will work again, Im fine doing that, but if I need to also do multiple other things aside from piping etc. then I might want to try and find the exact OEM replacement turbo now and repair it and then plan the GT12 project. Could I trouble you for one more piece of advice? Thanks so much!
Hello .syndicate, that's ok I'm glad I can help. You might be able to find someone local that can remap the ECU. It would probably need to be someone with experience with Japanese cars that have the right tools, because older ECUs are generally more difficult to work with.
ReplyDeleteBut if you really want full control you might as well get an aftermarket ECU like a Link G4 or Vipec ECU. Or if you are on a budget and like to tinker around you can get a Megasquirt ECU.
Ok Im def down to get an ECU. Is there any easiest to install model you recommend? Ill just order that now.
ReplyDeleteId like to get the stock replacement first so I can get it out of the shop - is this a bolt on with all the other original parts? https://www.fridayparts.com/turbo-rhb31-turbocharger-129044-18010-for-isuzu-f6a-k6a-500-660cc-engine?gclid=CjwKCAjwpMOIBhBAEiwAy5M6YBDrXAR2o1bHe74Ro953ELg1skQz-GA7YXVMDUm6Khfq6f0IivxMdRoCgOwQAvD_BwE
Thanks so so much!
Hello .syndicate, it looks like the correct turbo. There's no plug and play aftermarket ECU that I am aware of for the Jimny apart from this one Syvecs S7i ECU however I don't know anything about this ECU so I can't say how good the software / ECU really is, or if it actually fits your car model.
ReplyDeletehttps://efi-parts.co.uk/product/syvecs-s7i-ecu-suzuki-jimmy-manual-auto-pnp-kit/
But even though the Australian made Vipec or Link ECUs are not plug and play they do have most Japanese import cars in their software so the setup to get it running once you get it installed will be easier especially since there are more people around that run and the tune Vipec / Link ECUs.
Thanks for the reply! I was actually meaning the Vipec or Link ECUs! That sounds like the best route. Im looking here but not sure... https://www.vi-pec.com/ecus
ReplyDeleteMy stock ECU is still good -- do you think that will work with the RHB31 turbo for now and then I can get a Vipec and figure out the GT14 after? Thanks again and again you're really helping
or just Vipec now for both
ReplyDeleteHello .syndicate, the starting models like i44 would do all the things you need. But you can go a long way with the stock ECU also, if you can find someone that can do the tuning.
ReplyDeleteThe only real way to tell if you are unsure and you want to know how the current tune is doing is to get an AEM X-Series Wideband Gauge fitted, that will help a lot. It's best to stick with the stock ECU first and get everything up and running right and then switch over to an aftermarket ECU and get that working. Going to a bigger turbo after that is not that big of a deal.
Ok this seriously helped so much thank you. Im going to order the stock replacement right now and set it up with that -- and then also order the GT12 and a new ECU and the Wideband Gauge.
ReplyDeleteI was thinking about buying from these guys does this look like the correct model / part number?
https://turbochargersdirect.com/new-genuine-ihi-rhb31-turbocharger-tur-103445-ihn/?gclid=CjwKCAjwpMOIBhBAEiwAy5M6YPRtkKB1dMddqa-D9XnDZuEz7KJCh1vTQq48ImUt6pX9Cqi2_w-bcBoCi38QAvD_BwE
Thanks
There are a few diff end number models... https://turbochargersdirect.com/new-genuine-ihi-rhb31-turbocharger-tur-103445-ihn/?gclid=CjwKCAjwpMOIBhBAEiwAy5M6YPRtkKB1dMddqa-D9XnDZuEz7KJCh1vTQq48ImUt6pX9Cqi2_w-bcBoCi38QAvD_BwE
ReplyDeleteHello .syndicate, from what I can tell this one should be the correct one looking at the 13900-62D51 part number
ReplyDeletehttps://www.fridayparts.com/turbo-rhb31cw-30004cp7nrbrdl245az-turbocharger-13900-62d51-ve110069-for-suzuki-alto-works-with-ya1-f6at-engine
The one you linked to earlier do not have the 2 bolt flanges on the compressor housing but it could also be the right one for your engine https://www.fridayparts.com/turbo-rhb31-turbocharger-129044-18010-for-isuzu-f6a-k6a-500-660cc-engine
But apart from that the turbos should be the same. I can't really tell about the other ones, if they are for Yanmar Marine engines then there could be additional cooling for the turbine housing.
Thanks so much JD :) I ordered the fridayparts one and I guess we will see! I think Im going to grab this as well: https://www.vi-pec.com/ecus/i44 -- I saw people talking about needing to upgrade the injectors and the ones that the Toyota Starlet uses plug in, do you think I would need to do that with the GT12 upgrade? Thanks so much JD
ReplyDeleteHello .syndicate, I can't find what the fuel flow for the Jimny injectors are but going with the known Toyota Starlet injectors if they fit would be a good choice since it's more likely the i44 ECU have the correct data for the Starlet injectors in their software already.
ReplyDeleteThanks so much JD!!! You helped so much. I've ordered the GT12 so I will approach that upgrade later.
ReplyDeleteI also ordered the "fridayparts" replacement turbo, but they are now jerking me around on shipping times.
Do you know if this is the exact same model? https://turboturbos.com/products/fvz21
I tried to look it up by part number, but Im not sure if I did it correctly Thanks man!!
Hello .syndicate, it's the same model apart from the exhaust housing on that one is the 4 bolt style so it's not going to be a direct replacement https://turboturbos.com/products/fvz21
ReplyDeleteIf you can't get the correct one ordered you could still make it work if you fabricate an adapter for it though.
Ok thanks a ton JD. That helps me understand it a lot better. After I do this once I think ill be more prepared for the GT12 upgrade.
ReplyDeleteI might be getting ahead of myself but I got this blowoff valve: https://www.amazon.com/dp/B00IWFI3WW/?tag=td-blow-off-valves-pcr-20&asc_source=browser&asc_refurl=https://thedrive.com/reviews/30400/best-blow-off-valve
Would you recommend waiting until I do the GT12 to put that on or would it help with the stock small turbo Im doing as well?
My email is kieran kyle at gmail.com if you'd like to email me your venmo it would make me feel good to send you some cash for all your time and help :) Thanks JD!
Hello .syndicate it's ok, you can fit the blow off already. If you want the best performance I would put the blow off valve at the intake manifold side with an intercooler adapter pipe similar to this one
ReplyDeletehttps://www.amazon.com/Turbo-Valve-Flange-Adapter-Type-S/dp/B00U4A6B68/
I don't know the sizes on the Jimny engine and this one is 2.5" but you can get them in smaller sizes also and get some matching silicone hoses to connect everything.
Hi JD. I have a Ford Ecosport 1.5 TDCI 8V SOHC generating 100 ps and 205 Nm. Stock turbo is GT1241Z and ECU Bosch EDC17C10. I am looking to remap with a final power in 150 hp range. I thought of installing a hybrid GTD1244VZ capable upto 180 hp. But i have hit a dead end on how to replace a FGT with VNT and control it. Many said its pointless and instead go for bigger FGT. I like VNT due to faster spool up and less lag. Can you suggest a solution or a bigger FGT that can fit my requirements without getting too much lag?
ReplyDeleteHello chand, you have a few options. If you want you can fit a non electric wastegate actuator to the GTD1244VZ like you see on the GT1549V or GT1749V turbos, and control it that way with vacuum and boost.
ReplyDeleteYou need to be careful when doing this and keep an eye on boost however, it's not going to be perfect and will need some adjustments to get it to open and close right but I think that's the easiest and cheapest solution.
You could use a standard boost controller to help with adjustments, but you can also get a VNT Boost controller made for this like this one to better help control the turbo
https://www.gfbuk.com/product.details.cfm?productid=1120
Or you can also try the standalone electric route and get something like this DIGIBOOSTER DGB S + BCV (N75 valve)
https://www.tuning-diesels.com/store/DIGIBOOSTER-DGB-S-BCV-p103948664
Hi JD. Thank you for your suggestion. Someone from a ford forum tried similar install on a fiesta with Digibooster and ran into some control problems at https://www.fordownersclub.com/forums/topic/98057-fiesta-mk75-16-tdci-95dpf-vnt-turbo-retrofit/
ReplyDeleteHowever, I will relook into both Digibooster and non-electric wastegate actuator options. Do you have any FGT recommendations as well? Have a great day!
Hello chand, I had a look at the fordownersclub retrofit. I might be wrong but if his issue was fine control problems then one solution would have been to extend the nozzle ring crank arm to gain more control, or it could be the other way around. They sell different lengths for GT17 and GT20 turbos like this but can't find any for the GT12 https://pioneering-performance.com/products/vnt-short-vacuum-crank-arm-and-bush-kit
ReplyDeleteBut I could be wrong, so keep that in mind. It is tricky to get everything with VNT working perfect especially on very small turbos that comes on boost fast to begin with.
You would have to go up to a GT1548 turbo otherwise. There are several different versions made but any GT15 with around 37 mm inducer would be able to get you close to 180hp.
Hey JD! Everything seems to fit - I just realized I don't have a coolant pipe that fits the new turbo:
ReplyDeletehttps://www.fridayparts.com/turbo-rhb31cw-30004cp7nrbrdl245az-turbocharger-13900-62d51-ve110069-for-suzuki-alto-works-with-ya1-f6at-engine
Any idea where I can order one or what to look for exactly? Thank you SO MUCH
Hello .syndicate, if it is this two port coolant inlet/outlet you have then it looks like most people block the coolant and run the turbo without it. You could do that also but if you want you could have something made.
ReplyDeleteThe dimensions on the water port is 7mm for bolts and 35mm apart as seen in this picture https://ae01.alicdn.com/kf/H0df1c9ba59994f09842cc47c518c6a1bc/7-PCS-Turbocharge-Turbo-Flanges-Complete-Set-Fits-for-RHB31-VZ21-Turbocharger-Aluminum-Alloy-Flange-Automobiles.jpg_q50.jpg
But if the coolant inlet and outlet is in this same port/fitting you probably would need to drill some holes and get some small pipes welded in because using AN fittings for this job would be too tricky, there's not much room to work with.
to JD-- vehicle is 1973 Fiat 850 Spider car, with engine : a 1998 750cc Suzuki GSXR 4 cylinder m cycle engine--arnd 120 hp now with no turbo , no supercharger --has EFI--stock cyl head - stock compression--would like arnd 200 rear wh HP, using maybe 5 to 7 psi boost(?)-- can u recommend a model and size of turbocharger to use (this is a Bonneville salt car )-- thnks--signed -Ade
ReplyDeleteHello Ade, to get 200whp you would need around 230hp at the engine, this considering a drivetrain loss of 15%. So you need around 0.9 bar / 13 psi boost get to that target. You have a few options, you could go with a Journal Bearing GT2056 turbocharger or the more modern Ball Bearing GT2554R turbocharger. Both turbos should work well and you can expect full boost around 6-7000rpm. However with the stock 12.0:1 compression ratio on the 750cc GSXR engine, you should consider reducing it or run on E85 fuel because detonation will become a problem otherwise.
ReplyDeleteHello, I have been thinking about turbocharging a Suzuki G13 8 valve SOHC engine. I have had the GT154 turbo recommended(GT15 seems to be a good match for the G10, so the larger GT154 was recommended to me), but I recently came into possession of a GT1238Z and a GT1752S from a Mazda SKYACTIV-D twin turbo pair. I'm not sure which one would be a better match, I am concerned about the GT1238Z being too restrictive and also not having an internal wastegate adding complexity, but the GT1752S being too large. Research indicates that the stock G13 bottom end should be able to take around 100-110hp at ~.7bar of boost, 130+ with swift gti forged rods and 1+ bar of boost. I do not intend to beef up the bottom end as that would place me moneywise into the region of getting a G16 engine and running the GT1752S on that. The GT154 is also quite readily available here. What do you think?
ReplyDeleteHello John Doe, the GT1238Z turbo would be a good option if you want to stay around 100hp. It's true you might lose some top end power above 5-6000rpm due to the smaller turbine housing. But with a good tune / air fuel ratio past peak torque/power you can still mitigate the issue somewhat.
ReplyDeleteYou should see around 100hp with 0.7 bar / 10 psi boost pressure. And you could push the turbo to 1.2 bar / 17 psi to get around 130hp if you want to do that in the future with forged internals.
Universal internal wastegates set to 10 psi are pretty cheap, or if you want to go the external wastegate route there are external wastegate adapters you can buy. However these usually come with the more common T2, T25 or T3 flanges so you would probably need to make the flange to fit the turbo yourself, so it does add some complexity.
Thanks, this specific turbo housing seems to lack provisions for it though. I will asses the condition of the turbines and see if i should go for it.
ReplyDeleteBuonasera,ho un vitara 1.6 8v da 80cv, vorrei installare una gt1241 con pressione 0.7 lasciando il motore originale senza diminuire il rapporto di compressione che allo stato originario è 8.9, no. Ho bisogno di molti cv anche 15 o 20 per me andrebbero bene, ho bisogno di un turbo che si faccia sentire già ai bassi regimi (visto che nel fuoristrada vige per eccellenza la coppia ai bassi) è mi chiedo quindi se la gt1241 sia troppo piccola soprattutto allo scarico.
ReplyDeleteNon so mi potreste aiutare a capire se posso realizzare questo piccolo progetto.
Grazie
Saluti
Riccardo
Scusate ma il pc da i numeri..... Vorrei installare una gt1241 ecc ecc😁
DeleteScusate il pc stasera da i numeri ed è lentissimo anche nello scrivere.... Vorrei installare una gt1241 ecc ecc 😁
ReplyDeleteBuonasera Riccardo, the GT1241 would be perfect for the Suzuki Vitara 1.6 8v engine if you want quick spool and more low end power. You would only need around 0.5 bar / 7 psi boost to make around 100hp. However you would really need to install a small intercooler if you want to run higher boost in hot weather and off-road. You could expect to get around 120-130hp with 0.7 bar / 10 psi boost.
ReplyDeleteWhat are the best size options for a Honda shadow 600cc
ReplyDeleteHello, you could go with the GT1241 turbo but because the Honda Shadow isn't a high revving engine to begin with, I would instead go with the smaller GT0632SZ turbo if you can find one for a good price. You should get around 60hp with 0.7bar / 10 psi boost. If you want to go higher boost you should consider fitting an intercooler and lowering the compression ratio to around 8.0:1. With that done you could push the GT06 turbo to around max 75hp with 1.2bar / 17psi boost.
ReplyDeleteWith the GT1241 turbo however you can make more power and you could get around 90hp with 1.6bar / 23 psi boost. But with the bigger turbo you would also lose some low end power and have slower spool so that is something to consider especially if you are mostly using the bike to drive in traffic etc where you would want a faster responding engine.
Hello my friend I have opel astra j cdti 1.6 110ps diesel 110 ps original 1241z.
ReplyDeleteI remaped it and now has around 135bhp but with only low end performance. Is it possible to get same extra power if I fit 1249 bilet weel meke hybrid turbo with out much secrifice at low end? I am aiming around 155 to 165 range. Thank you
*to get some extra power not same
ReplyDeleteHello Gregls, you would need to get the bigger GT1249 34.66/49.00mm billet wheel. However it's not a direct replacement to the stock 29mm compressor wheel, so you would need to have the compressor housing machined bigger for it to fit. But if you do that you could get around 160hp and still have good low end performance.
ReplyDeleteIf we machine housing this wheel will is proper? Thank you very much for your time,
Deletehttps://www.turborebuild.co.uk/webshop/prod_7171406-GT1249-Turbocharger-Turbo-Billet-Performance-Compressor-Wheel-3466-49MM-EXT518632-66-BladeET1261PBC.html
Hello Gregls, yes that billet wheel should fit with a machined housing. Also depending on how good tolerance they have you might need to heat the compressor wheel a bit before you install it on the shaft.
ReplyDeleteHi JD, I hope you see this. Will this turbo suit a Yamaha WR450 single cylinder MX engine in a road racing frame? I want to run 20PSI at 6500-9000 engine RPM to make over 100HP. But it will be close to the max turbo RPM of 220000RPM, and also get a little close to the surge line when boost comes in. Will this turbo be ok operating in the top corners of it's compressor map?
ReplyDeleteHi Road Racer, you could run 20 psi but the efficiency at that operating pressure goes down and you would also be generating a lot of hot air that would need to be cooled down to get any benefit from the higher boost pressure.
ReplyDeleteTo keep things optimal I would instead aim for around 17 psi boost to keep the turbo around 200.000 rpm. You would still make around 110hp and have a turbo that will outlive the engine.. I would be more concerned about the life of the crankshaft bearings at that power level.