BOV's Surging Under Light Acceleration

[Thunter3497]

Hello all, I'm new here and was wondering if anyone more experienced could throw some suggestions my way. I have a 2014 Sho that I just finished installing CRP billet wheels, Turbosmart wastegates and downpipes on and have developed an annoying BOV surge at very light acceleration. I know the problem has been experienced in the past by other members and seems that multiple things could cause the issue so I was wondering where I should start looking this weekend. Vacuum hoses all seem attached, I don't see any visible boost leaks, I have the hot pipes. The car is on the v20 93 octane LMS tune, Did not have any issues prior to the turbo upgrades. Is it possible that the wastegate rod length needs to be adjusted? Could a small amount of oil in the intercooler cause this? If I were to collect a data log of my car, which parameters should I record? There is no BOV surge that I can tell at any other engine load other than very light accel (like going up a hill). If I press the pedal just enough to build more boost the BOV surging stops. Are the CRP wheels producing more boost than the ecu is commanding at a lower rpm and hence the bovs surging? Other than that annoyance, the car pulls like a freight train with the new turbo wheels/downpipe combo!

 

[stripSHO]

Did you get a tune revision???

 

[Thunter3497]

Yes, the tune is updated for the new components. I sent LMS an email just now as well asking if they can look at the tune or if anything needs to be modified on it.

 

[Ecoboost_xsport]

First step is to get rid of the **** LMS stuff. Go with a real tune from GH, AJP, Unleashed, 5Star, BCB....basically ANYBODY but LMS.

 

[802SHO]

I sometimes would get a little on/off/on/off wastegate activity under very light load like you said. It wasn’t too big of a concern but it stopped doing it after a bunch of revisions. Not sure why it did that. I know that doesn’t help you but I can vouch for changing tuners….LMS isn’t a great tuning company for rectifying problematic issues with their cookie cutter tunes. I’d be suspicious if your revised tune is even a good one for your mods. LMS isn’t known for their data logging tuning support. Whatever they say don’t agree to drive there and do a custom dyno tune. Big waste of money.

 

[stripSHO]

What spring are you running?
I personally never liked the idea of a wastegate mod. These turbos are already being way over-exerted by most- in testing I've seen inferred speeds >240,000 RPM and you best believe guys with GH intercoolers throwing 100% WGDC at their turbos are spinning that fast, probably even more. I try keep it at or below 200,000 Adding more wastegate spring just seems like beating a dead horse and asking for catastrophic failure.

There could be several reasons for what you are experiencing but in my opinion if you're running a 7 psi spring then you're pretty well guaranteed to run into the compressor surge line at light loads unless you do some significant tuning work to veer around it.

 

[Ecoboost_xsport]

I sometimes would get a little on/off/on/off wastegate activity under very light load like you said. It wasn’t too big of a concern but it stopped doing it after a bunch of revisions. Not sure why it did that. I know that doesn’t help you but I can vouch for changing tuners….LMS isn’t a great tuning company for rectifying problematic issues with their cookie cutter tunes. I’d be suspicious if your revised tune is even a good one for your mods. LMS isn’t known for their data logging tuning support. Whatever they say don’t agree to drive there and do a custom dyno tune. Big waste of money.

This was such a better way of putting it. Andrew...you're way more tactful than I, LOL.

It's true, LMS does NOT support tunes for mods that do not carry their logo (which are simply re-branded parts from other companies), so if you have any aftermarket performance parts that are not from them, they won't work with you on dialing in a tune to reflect whatever that mod may be. They basically want you locked into their product line and tuning device.

 

[ShatteredMJ]

It happens with the Turbosmart wastegate. This is the only reason I didn’t go ahead and install it when upgrading turbos; car keeps sneezing like it has a cold.