Low power - weird dyno numbers - Suggestions?

[Detailer_rs4]

Good day everyone,

New owner of an Audi RS4 since last december. Car had EPC and Check engine light when purchased, codes were regarding the flap sensors. Car ran great still, nice kick around 5000 rpm during test runs. We knew about the flap issue and that it needed a decarb. We managed to lower the price by a few thousands and signed.

Couple of tweaks made this winter before I could really enjoy the car. So it has been out of the mechanic since about two months now. Here what was done :

-Removed intake manifold flap
-Decarb done
-Remapping (was APR chipped but since flap were removed we had to remap with a local tuner that has done many deflapped rs4 without issues)
-New exhaust (downpipe till the end)

Finally had the time to do a 1/4 and 1/2 run. Numbers were horrible. Went to dyno and this is what it's like.




Looking for suggestions and where to start.
Since dyno sheets shows air/fuel ratio is good, i'm guessing the air admission and the injectors must be in good shape. Correct me if i'm wrong!
I'm clueless, anyone ever seen that kind of numbers on a dyno sheet ? Could the map be that wrong ? Where is the power past 5400?

[Brooner]

if the numbers a correct the car must feel like its in limp mode it almost as if they have de tuned the car with those numbers
if i were you i would speak to the tuner about it give him a chance to rectify any issues
but personally i would get it booked in to MRC you wont be disappointed

[RS4LAD]

Should have gone to MRC.

[AA_954]

I assume you don’t have a dyno sheet from before the work?

A few questions/comments:

- Whats the mileage on the car? I would not trust keeping OEM injectors on a higher mileage car ie 90K+ miles plus without at least a clean, not all go bad but there have been a small number of owners that have had injectors perform poorly
- Have you checked your LPFP readings and fuel rail readings? What are the values at WOT?
- There is a flap in the airbox that sometimes gets stuck although it should never drop power the way your dyno sheet is showing
- Did you ever do a compression/leak down test?
- Are you getting any codes? Misfires, etc?

Not sure about that AFR level being ok, seems to me its running at around 13 or slightly lower? Could be the scale and although it’s below stoic I would expect it to be more in the low 12’s at WOT on a dyno

Hope this helps and good luck getting this solved




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[Detailer_rs4]

I assume you don’t have a dyno sheet from before the work?

A few questions/comments:

- Whats the mileage on the car? I would not trust keeping OEM injectors on a higher mileage car ie 90K+ miles plus without at least a clean, not all go bad but there have been a small number of owners that have had injectors perform poorly
- Have you checked your LPFP readings and fuel rail readings? What are the values at WOT?
- There is a flap in the airbox that sometimes gets stuck although it should never drop power the way your dyno sheet is showing
- Did you ever do a compression/leak down test?
- Are you getting any codes? Misfires, etc?

Not sure about that AFR level being ok, seems to me its running at around 13 or slightly lower? Could be the scale and although it’s below stoic I would expect it to be more in the low 12’s at WOT on a dyno

Hope this helps and good luck getting this solved

No dyno sheet before the work. That would have been of great help for sure!

Car has 166k kms (just over 100k miles). I'll do a run video whenever i get the car back. It rides flawlesly trough all rpm
No codes, no missfire.

Compression test been done last week : everything is between 145-160
Havn't done the leak test (mech didn't suggested)

Cold air installed, verified to be in good shape. So i'm guessing there is no more flap in the air duct, unless it is very close to the top elbow ?

I have a genuine Vag Com coming in this week, i'll be able to test a couple of things then.

Should have gone to MRC.

I live in Canada. MRC is not an option. I contacted them a few days ago still, asking if they do oversea diagnosis/tuning with the car on our local dyno but sadly, they don't.

[AA_954]

I assume you don’t have a dyno sheet from before the work?

A few questions/comments:

- Whats the mileage on the car? I would not trust keeping OEM injectors on a higher mileage car ie 90K+ miles plus without at least a clean, not all go bad but there have been a small number of owners that have had injectors perform poorly
- Have you checked your LPFP readings and fuel rail readings? What are the values at WOT?
- There is a flap in the airbox that sometimes gets stuck although it should never drop power the way your dyno sheet is showing
- Did you ever do a compression/leak down test?
- Are you getting any codes? Misfires, etc?

Not sure about that AFR level being ok, seems to me its running at around 13 or slightly lower? Could be the scale and although it’s below stoic I would expect it to be more in the low 12’s at WOT on a dyno

Hope this helps and good luck getting this solved

No dyno sheet before the work. That would have been of great help for sure!

Car has 166k kms (just over 100k miles). I'll do a run video whenever i get the car back. It rides flawlesly trough all rpm
No codes, no missfire.

Compression test been done last week : everything is between 145-160
Havn't done the leak test (mech didn't suggested)

Cold air installed, verified to be in good shape. So i'm guessing there is no more flap in the air duct, unless it is very close to the top elbow ?

I have a genuine Vag Com coming in this week, i'll be able to test a couple of things then.

Should have gone to MRC.

I live in Canada. MRC is not an option. I contacted them a few days ago still, asking if they do oversea diagnosis/tuning with the car on our local dyno but sadly, they don't.

In what part of Canada are you in? Theres a few members in our North America chat that are spread around Ontario and BC and it might be worth talking with someone if they are close to you, this forum although great and with a lot of information has perhaps less visibilty with North American owners, you might want to create an account on Audizine too if you already haven’t...

By the way who tuned your car? Other than JHM there is no other reputable tuner in NA that will provide an off the shelf flap delete tune that I’m ware off, other known tuners like APR and UM don’t offer this of the shelf although they do have custom tunes for vehicles that are either APR or AMD supercharged and I do know of at least 1 TTS supercharged car that is custom tuned by UM

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[Detailer_rs4]

Thanks for the heads up AA-954,

Yes I know about audizine, been scrolling through their forum for a while now. Might be good to post over there as well.

The car is neurotuning chipped. It's a local tuner here in Québec. We have a Shop that installs JHM tune two hours away. It's tempting but I could also be throwing a thousand $$$ away if the problem is mechanical or non related to mapping.

I just received my Vagcom cable. Altough I have a bit of knowledge in mechanic, I have honestly no idea which channel / measurement to look for and get some logs.
Any Q would be awesome to check actual vs requested timing, injectors health, air temp around throttle body to see if cold air is working properly, etc..

[Ads50]

Is that wheel horsepower? Or fly wheel power ?


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[Nige_RS4]

Dyno plot says WHP but there is definitely and issue and looking at the plot it's at the revs where the flaps activate, so my first thought was that it was mapping. This post may help ... viewtopic.php?t=85306