# IS38 Turbocharger Maximum Boost Pressure???



## IchLiebeMeinenAudi (Jun 24, 2016)

Hello everyone,

Does anyone have definitive proof of what the IS38 turbocharger in our cars was built to handle?  My APR Stage 2 High Torque and my UM Red File both run at around 29psi. 

https://www.goapr.com/products/ecu_upgrade_20tsi_gen3_mqb_r.html
http://unitedmotorsport.net/products/mk7-mqb-20-tsi-gen3/?vehicleId=1382&productId=1381

Does anyone have the specs on the IS38 to see if it can be pushed further or are we at its limits?

Thanks in advance. Any manuals or document links on the IS38 would be greatly appreciated!


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## 27turbocars (Jun 26, 2016)

I have been looking for similar information all over the forums. I only found the sizes of the compressor and turbine wheels(inducer, exducer, etc) and I also read of some (just a few) people that reported boost readings via Vag Com or from the P3 vent and stuff.

I have a bad a$$ Defi electronic boost gauge that comes with a independent module to record other gauges and can record and play back boost but I have been hesitant to spend $60 for a damn boost tap(ridiculous).

At 29PSI I would say we are pushing it very hard. My last few weeks have been busy reading and reading on methanol kits. I want to keep my current APR Stage II but improve the existing hardware so one of my next wish items is a methanol kit with a very low flow rate. I have had cars that actually lost power and torque on the dyno by pushing too much boost (beyond efficiency).

You should contact some of the dudes from the Golf R 1/4 mile registry, there are some people running 118-120 MPH on the stock IS38 and some people also running IS38 on GTI at 120mph, they would be your best bet for finding out how much boost they are running.


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## mroberte (Dec 18, 2014)

I'd be worried about overboosting the engine. While 29psi sounds "normal" to some, not sure I'd want to push the non built engine further than that, especially for DD. 

And as 27turbocars pointed out, going over efficiency of the turbo will hurt your gains. 

You could ask Dan from littco, he seems very familiar with the IS20/38 as he modifies them. 

What are you trying to do? Just trying to get more boost? 

Sent from my SM-N910V using Tapatalk


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## Six Speed Turbo (Mar 14, 2009)

My P3 usually levels out at 22.5psi on my APR Stage 2 high output file. Not sure what the maximum ability of the turbo is, APR usually writes their files to last with no complications. With that said, I would say they're semi conservative on their tunes, so there's probably more to be had if you get a more aggressive tune from somewhere else.


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## 27turbocars (Jun 26, 2016)

Looking for Air filters I read an article from 3 years ago about the technological advances on the EA888 gen 3 engine and in the specifications they were describing the turbo with a faster actuator(electronically controlled) but they say that the turbo runs at 1.2 Bars(17.4psi from factory). I am bringing this topic back again because I personally think that running high 20's PSI is very high already.


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## high_octaneGTI (Nov 10, 2007)

Buddy of mine destroyed his is38 @35psi

He just received his CTS big turbo kit as a replacement earlier this week lol


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## IchLiebeMeinenAudi (Jun 24, 2016)

Thank you everyone for your responses!

I have gone from Uni, to APR, and now to UM trying to get the most of out of ride. With UM now granting me access to modify my own boost levels I was wondering how far people are running the IS38's without complications. Just trying to squeeze out every last drop of power.

I'll check out the 1/4 mile registry and see what people are doing over there.

Thanks again!


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## 27turbocars (Jun 26, 2016)

IchLiebeMeinenAudi said:


> Thank you everyone for your responses!
> 
> I have gone from Uni, to APR, and now to UM trying to get the most of out of ride. With UM now granting me access to modify my own boost levels I was wondering how far people are running the IS38's without complications. Just trying to squeeze out every last drop of power.
> 
> ...



Are you monitoring your IAT? your EGR? your AFRs? Nothing wrong with trying to push every drop of HP but be aware of the extra stress. I was discussing the "stack" of JB4 on APR stageII and the people(VW/AUDI car enthusiast) at my local car meet were telling me that basically stacking add another 5 or 6 PSI so the existing APR tune which I think is ridiculous.
Me residing in AZ at 3100 ft and running only 91oct I have no choice but to play safe although I am doing my research with the big air intakes, methanol injection(small nozzle) and a couple of pipes here and there(Turbo inlet pipe, intercooler charge pipes etc). I am like you, trying to squeeze a little bit more power out of the stock turbo


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## IchLiebeMeinenAudi (Jun 24, 2016)

Stacking the APR stage 2 (High Torque) and the JB4 would likely result in boost up to 35lbs. Kiss that turbo goodbye after a little hard driving.

I had my car dyno tuned with the UM software so I know the car is running strong. I just wanted to know if turning up my boost to 30 or 31lb would result in engine failure. I have the cable and software to manage the tune from UM. Just wanted to see any specific documentation showing what the IS38 can handle before going nuclear.

Thanks again 

Sent from my SM-G955W using Tapatalk


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## 27turbocars (Jun 26, 2016)

^^ Honestly I think you are well informed already. I would skip the JB4 stacking all together. APR Stage II is perhaps the best software in the market, it runs very consistent times as is. The 2 extra PSI at this point wouldn't net you much (in my opinion). You would be better of at this point doing other type of hardware that might make a subtle difference (light weight rotors, decent air filter) or even switching to the 93oct map if you have access to that type of gas (I don't).

If I am not mistaken, UM is the one that offers a "red file" for a E30 map right? too bad their website is as good as a clogged toilet, I heard good thins on their tune but again their website under construction for months/years doesn't invite potential customers.


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