Monday, February 7, 2011

Garrett GT20 - GT2056 – 55 TRIM - 260 HP

The Garrett GT2056 turbocharger is the biggest turbo in the GT20 family. With a 55 Trim compressor this turbo will give you 260 HP. Recommended for engines in the range 1400cc - 2000cc this is the turbo you can find under the bonet of many different cars. Also this is a popular turbo to turbocharge motorcycles with. Will work well for anyone looking for 140 - 260 HP and have good spoolup also.

Model: 751578-2
CHRA: 433289-234

Bearing: Journal
Cooling: Oil
Inducer: 41.5 mm
Exducer: 56.0 mm
Trim: 55
A/R 0.53

Wheel: 47.0 mm
Trim: 72
A/R: 0.46


If we have a look at the compressor map we can see that this turbo is capable to reach almost 300 HP. And if you need to you can push the GT2056 to over 2 Bar of boost pressure. But it wont give you any more air flow. So no more power.

The oil outlet thread is the same M6x1.0 that the other GT20 turbochargers use. But you get two options with oil inlet the ordinary M10x1.0 (F) or M14x1.5 (M)

But still the Garrett GT2056 turbo is not watercooled. It's not a big deal, but if you don't like to do cool down everytime you shut of you're engine. You might want to consider some other turbo.

Garrett GT2056 Turbo Compressor Wheel

Suitable for Garrett GT2056 Turbochargers 
Aluminum Alloy
41.55 mm / 56 mm
31 mm 
8.3-3.6 mm
5.083 mm

Garrett GT17 GT20 Turbo Turbine Wheel

434715-0013 / 434715-0027
Suitable for Garrett GT17 GT2056S Turbochargers 
40 mm / 47 mm
6.1 mm
7.88 mm
5.09 mm

Service Kit
Journal bearing

Retaining ring, jnl/brg
Pin, anti-rotation, jnl/brg
Piston ring, t/end
Thrust bearing
Bolt, seal plate/th brg
Thrust spacer
Piston ring, c/end
O ring, seal plate/brg hsg
Thrust collar
O ring, c/hsg112
Bolt, c/end613
Bolt, t/end 4 16

I also have more technical pages for you that will come in handy. They will be of great help when looking at compressor maps Use the conversion tools And you will be able to calculate airflow, pressure and HP figures for the turbocharger you are interested in.


Trevor Amayo said...


Digital Agency said...

HI ,
I have Renault Megane Coupe III 1.9dci 130HP f9q engine.
The engine have the GT17/49V Turbo.
Tunner said me with this turbo can handle 180Hp with some mods filter,exhaust.

I was wondering for upgrade the turbo and how much can handle the stock engine .After that i readed in on post you suggested this turbo for 1.9Dci F9Q can Handle 250-300hp.

How many Max Hp Could get with GT2056 in safe mode with stock engine?
If is yes what others mods i need to make to archive this HP?

Thanks in advance.

JD said...

Hello, I'm not too familiar with the 1.9dci engines and also there are not many people that choose to tune these engines, other than the normal chip tunes and filter exhaust mods.. So I can't really give you any good advice on what you should upgrade for the stock engine to be reliable.

That said I would not worry about things like upgraded connecting rods and pistons because the stock 1.9dci parts look strong to me and I see no reason why they should not handle more power.

With the GT2056 turbo fitted you should be able to get at least 200 hp on your stock engine. I'm not sure what the stock boost pressure is on the 1.9 dci engines and what the stock map sensor is capable of running but the turbo is capable of +250 hp, but I would expect you need to run at least 2 bar boost pressure to get close to that power figure if not more. The turbo is capable of running around 2.5 bar if needed, but I doubt the stock sensors etc can handle that high boost pressures.

RRVV said...

Hello from Spain, I have a bmw 330D N57D, 258 Cv stock, my car has 310 hp power map, but I can not upload it anymore because the turbo is in the limit. I want to get to 370-380Cv, what is the turbo that you consider perfect for it? Of course within my plan is to update the intercooler and the exhaust system, for the moment I want to keep the stock injection system

All the best anf thanks in advance

RRVV said...

Of course my stock turbo is GTB2056

Thanks again

JD said...

Hello RRVV, for drivability I would try to get hold of the compound BorgWarner triple-turbo system that is found on the new N57S engines. That should be good for 380-440hp with a good powerband from 1500rpm+

If you want to stick to a single turbo then something like the Holset HX35 would make the power and be less complicated if you can make it fit, but you would also not have the wide powerband and power delivery as going with a smaller twin turbo or triple turbo compound setup that the other N57 engines use.

RRVV said...

Thank you for your quick answer!
I have been looking at the different options of the big brothers of my engine, with double or triple turbo and it seems complicated and expensive ...
With a single turbo for a power of 370-380 hp I feel that it could be a bit uncomfortable for the day to day, do you think there could be an option with a single turbo that Works more efficiently if the final power is around 350 cv?


JD said...

Hello, well there is not that many stock options around for that power range. But if you go with a custom made hybrid turbo something like the GTB2565VK turbo made by AVD Turbo at

You can get around 360hp with their smaller GTB2565VK single turbo and they also have a 400hp option with bigger compressor wheel. But either way, going with a big single turbo you will lose low end power and probably only start to make boost around 2000-2500rpm with that setup.

RRVV said...

hello, thanks again, it seems that the GTB2565VK could work well, thank you very much.
Do you think the G25-550 could work? I have seen that it is a high quality turbo that has a lot of operating range available with different A / R 49, 72 and 92. What would be the right one?

Reading your blog is a great help and I am learning a lot about this world, thanks

JD said...

Hello, the G25-550 turbo could also give you similar power but they also use a bit smaller compressor wheels, but I would say you could get around 350-360hp.

The 0.72 A/R would probably be the best option for a bigger engine I think the 0.49 A/R might be too small for the engine and might choke the power and you could run into surge issues. With the 0.92 A/R you would lose a bit too much low end spool before the turbo starts to build boost.

However only the 0.49 A/R housing use T25 flanges, and the other turbine housings comes with V-Band flanges so you need to check if this is the right style flange for your engine otherwise you would need to make an adapter if you plan on using this turbo.

Navara d40 said...

Hello I have a Nissan Navara with 171ps and I use gt2056v turbo.1)What can I do in order to listen to it more;2)Can i use more bar pressure(1.8 for example)

JD said...

Hello, if you only want to hear the turbo more then all you need is a simple open air filter fitted, similar to what is done in this video

However the best solution and also more expensive is always to get a cold air induction kit like what K&N have, where the filter is blocked off from the warm air inside the engine bay and only cold air is going into the turbo. But then again that might also block a bit more of the sound coming from the turbo vs having only the open air filter fitted.

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Folks don't forget about racing safety gear when buying auto racing parts

I have been tuning engines for a long time and with that experience I tend to look a bit more at how other people tune their cars and bikes than anyone else. Now this is not true for everyone, but most of you will recognize yourself at some level.

About 25 years ago the level of tuning an ordinary street car would ever see was at most 30% increase in power. (Not true for every car out there, but I'm talking ordinary street cars here)

So if you had an Ford, Volvo or BMW the amount of power you could get would have been in the 150hp range and in some extreme cases 250hp. At this point this was the "limit" of ordinary naturally aspirated engines at that time. Yes there was a lot of racing going on at that time, and some of these race engines did get put into street cars and power levels would have been 300+ hp. But the amount of maintenance these race engines required and the cost to keep them running were too much for most people.

Back then you could not just go into a racing store and buy yourself a set of forged pistons and connecting rods. Let alone camshafts and valves to build your race engine.

With the introduction of turbochargers however the power suddenly increased to levels that are still uncommon in today’s cars. At the beginning people where not really sure how to tune turbo engines and intercoolers where something that most people had never heard of. Silicone hoses where did you get that?

You would have to know someone in the maintenence department that did service on trucks or busses that had turbocharged Diesel engines at the time to buy the simple things like, clamps, hoses, gaskets, oil lines etc. Even something like an external Wastegate that are availiable almost everywhere now today you could not get your hands on. And something like real drag tires where not that common either.

But as time passed by, engine tuners got their hands on more parts, most that had the machines and tools started to make their own intercoolers, wastegates and all the parts that were hard to get and the knowledge and the tuning business took of.

Now it still took some time before engine management systems and electric fuel injection where you could really start to extract power out of engines became common and figure out how to tune the software to make that work. To start if you found someone who could tune these you would have to fork out serious doe to get everything working. Well you still might have to do that today, and serious race teams do spend alot of money to get the electrical side working right. Today there are so many more things you can do with a powerful ECU, like traction control, different boost pressures for low and high gears, launch control, shiftcut etc.. This list is very long.

But before all that came chip tuning and fuel injected turbo engines. What was unheard of just 20 years ago would now become a reality for anyone with a few minutes of tuning. Some of you might know the story of the Ford RS Cosworth, Nissan Skyline, Audi S1 Quattro, Lancia S4 to name a few and other icons of the late 1980 and early 1990. The turbo engines back then would give you 200hp and that is still today 25 years on about the same power level you would get from a new car. However today this is a common power figure for a station wagon. And back in the 80s only a few racing breed turbo engines would give you that.

But with a few changes to the ECU with chip tuning and some larger fuel injectors all that was needed then was to turn up the boost pressure and 350hp where unleashed. The only real limit here was only how much air the standard turbocharger could supply.

Sure there where different levels of basic tuning you could do but the effect was the same, more power.

With more and more tuner friendly cars coming out over the years the power figures are still holding almost the same. Just until recently where the powerfigures have really started to go up and beyond what was thought possible only a few years ago..

But what have really changed today is the huge amount of DIY tuners out there. What engine tuners did 25 years ago have now entered the garage and racing parts have now become widely available to anyone. From the cheap Chinese made turbo exhaust manifolds to wastegates and almost every tuning part you can think of to the pure racing parts like forged pistons and engine management systems on sale that anyone can buy.

So what has happened is anyone with a little background in mechanics can now build their own race engine. Power levels have just gone up and up and up.. It’s not uncommon to see street cars today with 500hp and then there are the ones who have gone even higher, breaking the 1000hp barrier.

The one thing that all these engines have in common to achieve such power levels are of course the turbocharger. Without the turbo it would not have been possible. Well a supercharger or N02 injection could do the job too but that’s another story.

However time and time again people forget the most important parts when tuning cars. I’m talking about safety and racing safety gear. I do see that people buy racing seats and that’s good. But most of the time they don’t buy racing seats because of the added safety. It’s because they think racing seats look good. And what about things like auto racing helmets that keeps your head intact. Most of the time people come to the track without real racing helmets and if it’s street racing that’s taking place, no one seems to bother wearing any kind of racing helmets at all.

I do understand that people feel protected inside their cars and they don’t think they need roll cages and in some cases opt for roll bars instead but you really need to think about this.

Some of the racing safety gear you should look at are the following:
racing suit
racing shoes
racing helmets
racing gloves

This would be the minimum for my liking if your going on a trackday or similar race day event with your tuned car.

In case you don’t have a fuel cell in your car and there is a chance of fire or fuel leak then you should consider racing fire suits also because these will save your life.

Fire is not to be taken lightly. If you have a good fuel system in place to feed your engine and anyone who are looking for power is going to have that. Then you need to understand that at any given time those racing fuel pumps are pumping 2 gallons of fuel every minute. And if you get a leak and have an accident you are in real trouble if the power to the pumps are not cut right away.

So having the right racing safety gear to protect you is always a good choice. Today’s car are much safer than the ones years ago, but you need to understand that when we double and triple the amount of power and turn our 100mph car into a 200mph fire spitting monster of a car you really, really should spend some time and pick out some racing safety gear also.