I have a 2012 r56 with manic stage 2 tune. When accerating hard, and in the boost (3000- 6000 rpm) the motor feels and sounds like its surging. The feeling and sound would be like lightly tapping the brake twice a second while you are WOT. I dont show any codes and the car seems to run fine in every other way.
Any ideas on what my issue may be? (hpfp?, wastegate? spark plugs? engine knock?)

Thanks

 

Does it make any unusual sounds or noise when it’s happening? Could be a number of things. Boost leak, misfire..... can you log data’ when it’s doing it?

 

No it does not make any unusual sounds. I do have dashcomand, i can try logging it and posting it soon.
I will also say, it doenst feel like a miss, which i have felt in other cars (non mini). I guessing it feels like maybe the DV is opening and closing rapdily as i am accelarating under boost. I dont know if this is a thing. but that the kind of feeling it has.

 

Manual? Sounds like a slipping clutch to me.. Watch the tach, are the rpm's increasing?

 

Do you have a sprint booster? That almost sounds like the bounce you can get if it’s set too high

 

First off thanks for the ideas to look too.
It is a Manual, I don't believe its the clutch, the rpms do not fluctuate with the "surgeing". you can hear the engine/ exhaust change volume as the power surges up and down.
I do not have a sprint booster.
I am going to try to log some info this weekend.

 

Factory turbo?

 

Yes factory turbo. car has 49,000 miles on it

 

How long has the tune been installed? I'd also check your boost levels. If its over-boosting the dme can command the DV to open to protect the engine. If so check the adjustment of the wategate arm. Even factory vehicles can vary from one to the next. Things that were fine at stock power levels may only become apparent at Stage 1 or when going from 1 to 2.

If boost is fine I'd look at the plugs. NGK 1422, gap should be 0.024" and replace every 20k.

 

The tune has been on it for about 3000 miles. I run it at B mostly. If i recall correctly (its been a while sence i have watched the boost levels on dashcommand) the peak boost was about 20 psi. But i watch and try to log info from dash command. I replaced the plugs when i got the tune with the recommonded ( i believe one range colder) plugs.
Also just for more info. I got the 91 octane tune, but run 92-92 almost always.

Can you give me more info on the wastegate adjustment?

Thanks everyone

 

^^ This is good info for you. Tigger2011 knows his stuff ^^

 

As far as the wastegate adjustments, I wouldn’t mess with it too much if you are hitting your boost target. But if it’s overboosting then you could have a situation like Tigger mentions above. For example, when I replaced my turbo, the wastegate was not set properly yet. It was making too much boost pressure and before hitting the boost/fuel cut-off, you could hear the diverter frantically opening and closing as it tried to dump boost pressure. If you are topping out at about 20psi it’s probably not the issue, but who knows? I am certainly not any kind of expert, for sure, lol.
If it was your HPFP I would think you would probably have cold start idle issues as well. That’s one of the first and most common symptoms of HPFP failure from what I’ve learned so far. That being said, absolutely monitor your fuel rail pressure to be sure.
Its always a crap shoot trying to help diagnose something from a distance, but hopefully something here will be helpful. Please keep posting and let us know what you find.

 

Here is a screenshot I took of my last trip. Hot day today. I have a log file that I will upload later. I do see that the boost topped out a 23.1. does any of this help at all?
The app isn't really responsive enough to see boost drops or fuel drops while I am driving live.
again thanks everyone for your help

 

Yeah you do get a little bit of lag with Dash Command. But being able to log or record and play back is pretty awesome. I ended up installing a boost gauge because I couldn’t stand the lag for that function. But in combination, the gauge and dash command together makes a pretty good setup.
23.1 seems a little high for boost pressure. I’m not sure what the boost target should be for Manic, but that’s getting up there towards the cut-off. Not there yet, but.....? I know that with my tune, I have a target boost of 22psi @ 5000 rpm under WOT. That’s where a little wastegate adjustment gets you where you need to be. If you are not sure, ask your tuner, or shoot a PM to Mariokart, he’s a Manic dealer.
If you still want more info on how to adjust it, let me know, and give me a few minutes to find some good pictures to go along with it.

 

Issue resolved!
I pulled out my sps switch to do some testing and found the the switch was set to map C. I must have mistaken the map to numbers on the switch. So after running on map A And map B the issue is no longer present. Also explains why I was peaking at 23 psi vs about 20 ( for map B)

Thanks again for everyone's input. Guess its time for meth injection. Lol

 

The vast majority of Manic Stage 2 tunes I've installed on an S model are set to 1.5 bar (21.75 psi) for Map C. When first installed they will boost slightly higher till the ecu adapts. So I think you've found your culprit.

When I do custom tunes for an S I usually set fuel cut to 1.6 bar as thats usually the max the S's MAP sensor can report.

 

For my own understanding.
What was likely happening, is the car was exceeding it programmed boost level, causing the ECU to cut fuel?
Is this correct?

Thanks

 

I can't say with certainty since I didn't install your tune, but more than likely yes. The target for mode B is 1.4 bar (20.3 psi). If your getting much over that I'd back off the wastegate actuator adjustment 2mm (two full turns) and see how it does.

 

Thanks so much. I will watch and track. And then adjust if needed.

Thanks

 

Any idea what’s the difference between MapB and MapC other than the target boost?

I’m experiencing the same boost surging issues though I’m not on the same tune.

 

There seems to be a bit of that going around. Are you on the factory turbo?

 

mines factory turbo and on Quantum Tuning Stg2