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Audi S3 GT3582R stroker Build (previously GT3071r)

tufftybloke

Badger 5 Edition
Feb 28, 2009
657
0
Gloucestershire, UK
Been a very long day so gonna keep it fairly short as I am going to collapse into the sofa...

First of all the N75 pipe blew (sure it was tight) which threw us for a bit then VAGCOM was reporting requested and actual boost of around 1.5bar but my boost gauge was only showing 1bar so changed the MAP sensor to see if that was the prob and it wasn't... check for obvious boost leaks but couldn't find any so will look properly when I can. Might be the actuator being problematic or maybe the N75... will look into this and see if I can find the missing half a bar of boost...

After a few logging runs, it became evident that the injectors were getting near to being on all the time... we hit 20ms on time when 22/23ms is just on.... looking at a 4bar FPR I think to give me some overhead.

Anyhoo... settled on 1 bar of boost for now until I can find out what the prob is and did some runs...

383bhp and 326ftlbs torques....

Both curves are as smooth as you like with power climbing on boost from around 3600rpm to peak at 6600rpm, torque climbing from a similar figure to a peak at 5500rpm.

Car feels very nice to drive now...

EGT's are a bit of a problem getting a little high... changing the exhaust should help keep them in check and I won't be looking for more boost just yet as they will get worse and cause probs.

Considering how much power she is producing on just 1 bar of boost, there isn't much I need to do to get 400bhp so I will look at making a few tweaks to sort any potential reliability issues out and then tweak the boost up a bit.

The extra boost will of course give me more torque so at least while its a little on the low side my clutch will last a bit longer ;P

<tuffty/>
 
Last edited:

caney

Full Member
Apr 24, 2005
600
0
380bhp from only 1 bar boost?i thought it was a smallish gt30 you had on?most gt30's make 420-450 at 2 bar!did it make this on the dyno?
 

tufftybloke

Badger 5 Edition
Feb 28, 2009
657
0
Gloucestershire, UK
Boost gauge was showing 1 bar... dyno showed 383bhp...

Seem to have a prob with it though as requested is supposed to be 1.5(ish) bar but wouldn't go anywhere near this, didn't even get the normal peak then settle...

VAGCOM was showing requested and actual (MAP sensor) as around 2540/2550 but boost gauge still only showing 1bar...

Actuator has gone a tad soft... supposed to be a 1bar actuator but now opens about 0.8bar... wondering if the preload has gone soft and getting a hotside leak through the wastegate.

<tuffty/>
 

Wilko

Badge snob
I'd believe your map sensor over your boost guage any day of the week.
If your map sensor is overreading ( which it isn't) your ecu would be looking for flow through the maf. If map is over Reading it would be pulling timing out, hurting your power.

If you're running in excess of 1.55 bar (which you are) then it's beleivable to get 380+hp on stealths dyno.

2871 should make about 380 flat out so it looks beleivable.
 

tufftybloke

Badger 5 Edition
Feb 28, 2009
657
0
Gloucestershire, UK
After yesterdays fun and games I spent a bit of time trying to find out whats going on...

Bill suggested checking the boost pressure post MAP sensor to see if the the actual boost being made is correct... connected a boost gauge to the N75 outlet on the top charge pipe and took it for a run up the road... my gauge showed 1 bar and the other one showed nearly 2 bar... something was definitely not right...

Was gearing up to take the bumper off and check all the boost pipes when I noticed the FPR pipe looked a little shabby so thought I would just look that quickly as that is where the gauge is tee'd from and bugger me...

20091031_IMG_3859.jpg


...pipe had split under the manifold... I checked these before refitting the mani and deemed them ok... looking at it, the vacuum pipes coming off the end of the manifold (hard pipes) have been rubbing up against it and bingo!!

So replaced this and bang.... 1.7/1.8bar of boost, quick map change and the car feels even better than before.... much better pull in third now :)

While I was messing about under the bonnet, I also tidied up the N249 bypass by removing the pipes and vacuum reservoir but still leaving the N249 valve electrically connected to stop the ECU from complaining...

20091031_IMG_3860.jpg


20091031_IMG_3861.jpg


Going to do some logging tomorrow to see how the adaption is coping with fuelling and maybe tweak the map some more....

Just goes to show how much trouble one little pipe can cause... it was giving erroneous boost readings and affecting the fuelling as the FPR wasn't working properly which incorrect pressure... Hoping that logging the injectors tomorrow will show that they are not maxing out anymore...

<tuffty/>
 

tufftybloke

Badger 5 Edition
Feb 28, 2009
657
0
Gloucestershire, UK
Will do once I have sorted the exhaust at least. EGT's are too high as a consequence of the excessive back pressure.

Few other tweaks to do I feel then ready to see if I can breach 400bhp :)

<tuffty/>
 

Rick1.8t

Full Member
Feb 18, 2006
150
0
I dont live far from MIJ - My friend had a cat-back exhaust made by them and it looks to be very good quality - sounded nice and not too ott which is what he asked for.

They seem good and listen to what you want so i wouldnt think theres much to worry about :)

Great project too - always liked the s3.

Rick
 
Lecatona HPFP (High-pressure Fuel Pump Upgrades)