Boost leak on the turbo
 

Well I just purchased a twin turbo g37 and I put it on the dyno and noticed its taking forever to spool it up. Well I put my boost leak testers on it to check to see if mabe there is a leak and then I notice I cant get the psi meter to even move. Im guessing its one of the couplers on the turbos because i checked 99 percent of the couplers I can get my hands on and there are no leaks. I can hear one tho and it sounds like its coming from the driverside turbo. Its not a gtm kit but the piping is ran pretty much exactly like it. I was wondering if anyone had an idea of how I can access this turbo without pulling the motor to check the couplers? I know some of the guys on here did the turbo install without pulling the motor just wondering if you could give me some insight on how i may accomplish this.

Not sure but maybe putting the car in the air and checking behind the wheel wells? Maybe remove the wheel?

hmm is that possible?

i thought thats a frame rail right there?

I would suspect a leak at the turbo flange, or exhaust manifold itself, as opposed to a coupler if it feels like boost is coming on slower. A pre-turbo exhaust leak will really make the car feel lazy. Generally if it is that bad it would probably be audible, but if you don't know what your listening for it might be difficult to notice. Do you know what turbo kit the car currently has?

Thanks,
Alex Goodwin
AlexG@motionlabtuning.com

Its a custom kit built by a place in florida. Not really sure about everything iv only had it for about two weeks so im just trying to go thru things and get it checked out. Gtm was the last shop to see it two years ago so they really dont have much info on it. All I know is on the exaust side of the turbos it has 004 hks on it. The pipeing is ran pretty much the same way my gtm kit is ran on my 370 with some slight variation. the car seems to instantly jump a couple psi but is very slow to build to 10 psi after that. I was just telling someone the other day that the turbo seems to be a bit louder when in boost then my 370z. My dyno graph really looks more like a supercharger graph then a turbo graph.

Do you have an AFR gauge in the car? Car would be running very rich with a boost leak. Is 10PSI your target boost?

Thanks,
Alex Goodwin
AlexG@motionlabtuning.com

thats the problem. I have no info on this kit or psi levels or anything. It has a hks evc boost controller. How do I know on the boost controller what psi it is set to? On the dyno the afrs were higher then normal but not extremely high. the car cranks and idles ok right between 14 and 15 afr. drives around a little on the rich side but not crazy out of wack. just seems to me theres a leak. Im guessing smoke would be the way to go to really see where its coming from.

I have the HKS EVC-S controller. It is NOT very intuitive. Complicated settings which may affect yours.

Is yours the HKS EVC-S (Small display) or EVC-6 (larger display)? Big difference.

Coop

small one. they mounted it in the sunglass flip down in the ceiling

OK. Do you know how to check your settings? What are they?

Secondly: Up on a lift can likely get you access to the turbos. My tech did not remove my engine.

Coop

I dont really know anything on the controller. It didnt come with a book or anything. Yea were going to put it up on a lift and probably pull the sub frame down if need be.

HKS EVC-S

HKS no longer has a USA headquarters, only two master distributors for the territory. You can still request for technical information from HKS dealers but typical response time is 72hours. The EVC-S should show "Set" with either an "A" or a "B" directly below it. Then next to it should show your target boost setting in either KPA or PSI. Using the small switch should show what the target boost for each setting is currently configured to.

Its been a while since we have had to mess with the HKS EBCS but they work well when properly utilized.

Thanks,
Alex Goodwin
AlexG@motionlabtuning.com

thanks man thats the info that will help me out.

Thanks, Alex.

Press the button quickly left or right and it toggles the two presets (A&B).

Press and HOLD the button to the left, and it will scroll through the five settings.

The most confusing is 'Overboost' (OPT). It is actually 'Over Waste Gate Boost'. THis sets the initial range. 8lbs waste gate + 4lbs OPT = 12 lbs boost.

'Offset' tunes it further upward in percentages.

Let us know.

Coop