random_letters

I recently installed a GMS1 "kit" and had a friend tune my car with HPTuners with a tune from the repository that was supposedly a stock GMS1 tune with a K&N intake.

I put "kit" because I pieced it together because im cheep (cost $244CDN and a large coffee in total, including the tune).

Car runs and drives with out issue.

I went WOT in 4th on the highway today (1st time going WOT since install)... and my boost gauge shot up to over 200kPa (29PSI) at which point the BPV said nuts to this and started fluttering (im assuming because the stock spring isnt strong enough to hold the pressure the turbo was trying to put out).

So question is...

Is there an adjustable BPV that is a straight bolt on for our cars?
Will the forge BPV with the lightest spring stop from boosting over 20ish PSI?

Thanks in advance.

SSlobalt

I think you should be more worried about why your car spiked to 29 psi. Obviously, there is something wrong with the tune, if your car was functioning fine before the install.

random_letters

Im not really worried about why, its a pretty safe assumption that the tune was not a stock gms1 tune with a k&n.
It didnt spike randomly, it was a nice sweep when i went WOT.

Needless to say, i wont be going WOT again soon. But Its still functioning fine. It just doesnt have any 'safety' for the turbo anymore.

nathan112i

your turbo will hate you if you boost 29psi. a different bpv will not change your boost, what you need to do is work on is tuning your wastegate so it does not allow such crazy spikes

random_letters

I was hoping for an 'easy' route.

Thanks guys, ill see if he can 'fix' the tune.

ECaulk

iTrader: (6)

Negative ghost rider. Its more than just a simple wastegate adjustment. Also the turbo can handle 29psi if its only a spike.

tomj77

iTrader: (2)

the bpv wouldn't flutter cause it gives out, the bpv is held closed by boost as well. that may have been ur car opening solenoid open ur bov to stop the overboost

09CobaltSS1

I can take a quick look at the tune file for you if you'd like. If nothing else, just to at least confirm if it's a legit GMS1 or not. Plus I can give you and your buddy a few pointers on how to get those boost spikes and everything else under control.

Shoot me a PM and I'll give you my email addy.

63 Nova SS

iTrader: (3)

^he knows his stuff- you would be stupid not to take him up on it.

ECaulk

iTrader: (6)

I second this.

Terminator2

Beat me to it John lol. I bet it is not a stock tune with that big spike lol.

random_letters

Sweet, thanks man.

I have to grab the file off the car first (it was the only 09SS gms1 in the repository @ the time).

ECaulk

iTrader: (6)

And I'd almost bet its incorrect waste gate given the spike in 4th

Terminator2

Could be.

09CobaltSS1

I couldn't imagine it being. That's a tad ridiculous.. lol

Yeah, unfortunately the repository is a complete crap shoot. I have quite a few legit GMS1 files that I can vouch for. If you would like, you're more than welcome to one.

I'd like to see what you're working with first though. I'd like to see the tune file along with the log you guys created.

09CobaltSS1

There would have to be quite a bit more flogged with in the tune other than wgdc to be honest.

For example: A bone stock file is commanding 95% wgdc in wot areas, however, a stock car will be pretty unlikely to ever come close to hitting that high of a commanded duty cycle unless the correct conditions are met. Reason for it, is basically head room for varying elevations, air densities and barometric pressure to allow the ecm to compensate for and meet a commanded absolute pressure and torque model. A car at high elevations will require much more wgdc to created 200kpa absolute pressure vs a car at sea level.

ECaulk

iTrader: (6)

Oh I'm sure there is more than just the wgdc that is messed up, but seeing that high of pressure in only 4th leans towards wgdc. Without checking a log out its impossible to know, it was just some general speculation on my part.

random_letters

Im going to see if my buddy can pull the log and tune files today.
Ill lets you guys know if it happens.

09CobaltSS1

I just checked over the OP's tune file and corresponding log, and well....

I can with 100% certainty say that this is absolutely not a factory GMS1 calibration. It did however start life as one, but's it's definitely no longer one at this point. This just goes to show exactly why there is a warning box that appears anytime you down load a file saying to use these files at your own risk.

On the bright side, fortunately no where did I see him spike anywhere near hitting a 29psi in the log I was sent. While, due to the lack of data/sensor feedback in the log, I can't say with 100% certainty exactly what the boost pressure is spiking to. I can say that basing off of MAF flow and air mass calcs, it is likely spiking in the 23-24psi range, and holding right around the 20psi area. Nothing to really be too concerned with, and relatively close to normal for a GMS1 boost level quite honestly (surprisingly enough). There are some questionable settings in here that I'm not a very big fan of, but from the log I saw, I'm not terribly concerned.

What I'm guessing happened here, and caused the OP his concern in the first place is that, he is actually reading absolute pressure and not total pressure (or gauge pressure). Unlike absolute pressure, total pressure compensates for barometric pressure. So long and short of it, he just didn't account for the 98.9kpa of baro pressure. It's not his fault, he's just new to all this and likely hadn't realized.

random_letters

Sweet. Thanks again for taking a look.

Can you elaborate on the barometric and guage pressure please?

Im second guessing the 29psi... But when i supposedly hit 200kpa i was reading that from my stock a pillar boost gauge not hp tuners...

Or... Are you saying that when using the gauge i have to compensate for barometric in my area?

09CobaltSS1

You're reading that on the gauge? That doesn't at all correspond with what I'm seeing here in the log.

Here's what I'm going to do then. I'm going to send you a new configuration file for you guys to load into your scanner. Once you load the configuration file, record a new log for me if you don't mind. This way I can see everything I will need to see in order to tell you with absolute certainty what's going on here.

Also, just out of curiosity, when you say "I put "kit" because I pieced it together because im cheep". What exactly does that mean? What did you buy exactly and how did you put it together?

random_letters

Yea its from the gauge.

We didnt do a log when it was first 'tuned' because it was 2am and i just spent 2 hours in the cold putting the sensors in, backing up my ecu and installing the tune thats on it.

First 200kpa I saw, I was by myself with no Hptuners, just my pillar gauge.

Im hesitant to do a second log exactly like I did today...
1) If im actually running 29PSI, i really dont want to have to pay for a motor and/or turbo this close to Christmas...
2) I tried to redline it as fast as possible. When i hit the first WOT (easing into it) my wheels started spinning (completely dry asphalt, no debris)... Issue is I cant just shift and go WOT, I tried a few times and my wheels just broke free. Im running 225/45's @ 28psi they are also brand new winters.

Would you be ok with a recreation of the first time I hit 200kpa? I was WOT but not anywhere near red line, boost came on quick and it went right up to 200.
Or does it have to be a red line run?

LNFwagonSS

When you say "highway" I'm thinking 60mph and you went WOT in 4th gear when you should b in 3rd gear unless you have a badass engine build that can take all that boost at low rpm. If you do get 29psi spikes at low rpm in 4th, it could be as simple as compressor surge which you do want to avoid. Quick fix is only go WOT when your in the appropriate gear for the speed you are traveling with the intention of hauling ass.

random_letters

Psi was around the same today, wot high rpm 2nd and 3rd gear.

We had something set wrong in hptuners, so the boost on my log doesnt match my actual boost gauge.
John sent me a new config, hopefully going to have another log with the propper data for him on the weekend... Still debating going wot again though... We shall see.

Either way, thank you John for taking the time to help me out, much appreciated.

random_letters

Sorry, didnt catch the last part.

Im cheep, so i didnt want to pay $800 for the kit.
Bought the 2 sensors listed for the kit from gm $22each
Gave my buddy a large coffee and he grabbed me 2 connectors from a wiring harness they had kicking around at the dealership.
Paid for the hptuners credits to load the tune in my car.

I got the original install manual from the solder in gms1 kits and soldered the new harness', heat shrink'd, taped then put everything back in the loom.