For the past couple weeks I have been having an issue with my manual 2012 r56 s that no one seems to know the answer to. Under hard acceleration, the car will continuously lunge and will accelerate inconsistently. It feels like what would happen if you continually pumped the gas pedal making the car buck but at high speeds. It only does it when the turbo produces more than 12 psi or so, under that the car accelerates perfectly. I took it to my mechanic who did every scan possible and said the car has no boost leak or anything like that. He did say the clutch is starting to go bad and thinks it might be that, but he did not experience the issue because he doesn't drive customers cars at their limits for obvious reasons. I already tried replacing the recirculation valve and that did not help. You can clearly hear it from the engine, see it in the revs and feel it in the entire car. If anyone has any idea what it could be, I would really appreciate the help. Thanks!

 

Like this?

 

Not sure what the OP is experiencing, but mine surges like that...

 

Mine behaved like that on that particular day and never did it again.

 

Mine does that pretty consistently, but it really only started after loading the Manic tune. Doesn't surge like that on the "stock" map.

 

Yup that's it. And I did recently get an rpm stage 2 tune. My car was doing it before the tune as well though. the tune magnified it. Is there anything that can be done about it?

 

I too just got a stage 2 RPM tune within a few weeks of that happening. I am also 2012 manual.

But like I said, it only happened that one day, and never again. I attributed it to throttle adaptation.

If you have the means, reset your throttle adaptations and you should be good to go.

Also make sure you don’t have any boost leaks. Have you messed with the waste gate/ intercooler, intake piping?

 

I have not messed with the waste gate but I know I don't have any boost leaks. I'll start with the throttle adaptation reset cus that's easiest. If that doesn't work then I guess it's a waste gate issue. Thanks so much for the help!

 

It can also be the pressure converter under the intake manifold, it’s what tells the turbo “I need this much pressure”

 

I'll keep that in mind. Thanks!

 

When mine did that it was my coils going bad, it can take them a long time to fully die.

 

Just a point of interest... I performed the throttle adaptation reset, and no change on my car. I did notice it won't surge when punching it in forth gear from ~3000rpm. Boost pushes out to 18-19psi and holds pretty steady. If I do the same throttle application in 2nd or 3rd gear, the boost will surge predictably.

 

For turbo inlet pipe are you using silicone?

 

Yes, but the behavior was the same with the OEM turbo inlet pipe

 

Bumping an older thread here, just to close the loop on this issue...

I am convinced high psi boost surging is a result of poor tuning. My car would consistently surge during high boost runs after loading the Manic tune. Nothing I could do changed its behavior. I eventually chalked it up to "that's the way it is." Well, I had finally had enough, and decided to switch tunes. Since Manic support had dried up shortly after I purchased the tune, I connected with @Lou@Prototype-R to see what he could do for me. The surging I had with the Manic tune was gone after just two rounds of data logs with Lou. It seemed like it was pretty easy for him to figure out what needed adjustment, and now I have boost that holds rock steady.

So, if you have any boost surging issues, and you have an aftermarket tune loaded, either complain to your tuner, or seek a new calibration.

 

I know that is an very old thread. But did you solved the problem?

 

Just a follow up - I have a couple of high boost ( ~21 psi ) applications two different R57s. When doing the tunes - I experienced surging like this, which was do to PSI fluctuations - not good ( I surged to 22 psi ). Data logged with Lou for a bit and we "tuned them out". "Tuning out" is really to simplistic - as it deals with customizing how the ecu calls for boost so it does not over shoot or hit boost limiter etc. This is multivariate and involves several parameters My old days of tuning dealt with manually playing with a spring.

Other potential areas - not getting enough fuel or timing needs to be retarded a bit. Depending on your set up, this can be a bit of trial and error and involve multiple data logs. I would not advise a canned routine for stage 2, especially if you have changed/upgraded exhaust, turbo, cat ..... even a lightened flywheel can 'tuned' for ...

 

my rpm tune was essentially completely ruining my car
i ended up going with prototype r and its flawless