034 Motorsports Tune - 18 psi @ 2500 rpm down to 10 psi at 5200 rpm?!?!

[ActiveMonkey]

Let me start by saying that 034 Motorsport is a great shop and I absolutely love some of the products so when I heard they had their own tune for my new-to-me B5 I was all in. I head over to their shop and they flash my ECU. Awesome... kinda... The car didn't feel any faster, boost leaks, etc. My other thread goes into that one. http://www.audizine.com/forum/showth...-Missing-Boost but since I bought the tune on 8/19/16 I have leak tested probably 10 times, new DV, new

With everything fixed and running as great as can be, the car spikes to 18psi @ 2500 rpm then promptly drops down to 10psi by 5200 rpm?! I have had the GIAC & APR on my last b5 and I've never seen drop off like this without some MAJOR leaks and I have none. Seriously I have pressure tested everything, every which way and no more leaks. I even took the front off to put it in the Audi Service Position and leak tested it again, nothing. It was also suggested by a few people that my waste gate flap was bad on the turbo. (see photo) Its all still there and virtually no shaft play on the k03s.



Next step was to call 034 and ask them what the tune was supposed to boost. My assumption was, just like GIAC & APR, that it should spike to ~18 psi then hold ~16 psi to redline. Nope. 034 said that it should spike to ~18-20 psi then by ~5200rpm drop off to ~11 psi and the reason for this is that they don't need to run as much boost to make the same or more power as the other tunes because their tune is better and is tuned on CA 91 octane where as other tuners rune to 93 octane and just back it off a bit to run on CA 91 octane.


Something in 034's explanation seems really funky but as I am no tuning guru, please give me your guys thoughts.

Personally, had I known the boost drop off was this bad I would have had very strong second thoughts and may have paid slightly more for a GIAC or APR tune.

[Seerlah]

Log actual vs requested boost. Will answer a lot.

[Davdraco1]

I have kompresd's tune and mine drops off pretty good at the end. It also depends on how much load your engine is under. My tune is good for 22psi but if I'm going downhill and floor it I'll probably see 16-18 psi then it tapers. Doing the same thing uphill it will hold boost much longer.

[ActiveMonkey]

I will log later today.

While going WOT on my last 2 tunes on a flat road I was able to hold ~16 psi to redline no problem.

Is there anything mechanically which can cause a boost bleed off like this?

Wastegate arm not adjusted for the proper tension?

[MetalMan]

Wastegate arm not adjusted for the proper tension?

A fairly quick/easy check on this is to unplug the N75 valve's electrical connector. This will basically cause the N75 to stay open and allow the wastegate to open at whatever level the wastegate actuator is set to (this pressure level is also known as the "wastegate cracking pressure"). Under this scenario you should expect to see 4-5psi max and it should hold that to redline.
If you see less than 4-5psi then either your wastegate needs to be tightened or there's something else going on.

[ActiveMonkey]

A fairly quick/easy check on this is to unplug the N75 valve's electrical connector. This will basically cause the N75 to stay open and allow the wastegate to open at whatever level the wastegate actuator is set to (this pressure level is also known as the "wastegate cracking pressure"). Under this scenario you should expect to see 4-5psi max and it should hold that to redline.
If you see less than 4-5psi then either your wastegate needs to be tightened or there's something else going on.

Going for a drive now to test.

Thanks.

[ActiveMonkey]

My boost gauge reads 2-2.5 psi and my ECU reader which links to my smart phone shows 3.7 psi

[MetalMan]

Sounds like it could be worthwhile to try tightening the wastegate to increase that boost level to 4-5psi.

[Davdraco1]

How do you tighten the WG?

[ActiveMonkey]

This is a great video showing how to adjust.

[ActiveMonkey]

I pulled the turbo and adjusted the preload. I went 4 turns of preload because why the hell not. The result is that I now spike to ~20 psi at 2500 rpm, then I still drop off to ~10 psi by 5200 rpm. I can find no other cause for this other than the tune which is beyond frustrating. I really wish 034 motorsport had done a better job informing their customers of what the tune was supposed to run since it boosts considerably lower than all other stage 1 tunes. Had I known it was only going to hold ~11-12 psi until redline I would have saved myself dozens of hours investigating and looking for phantom boost leaks.


I sort of understand the idea that 034 can boost 11psi and make the same power as everyone else who boosts 16+ psi. But doesn't that mean that 034 could tune it to 16+ psi and make more power than the other tunes?!

At this point I really cannot recommend the 034 Motorsport Stage 1 tune. I regret not going GIAC or APR.