I have an 03 G35 Coupe and I installed the ST turbonetics kit with a UTEC. Problem is that I'm only getting about 305 whp max... tuner played with it a bit and said 320 is the most he could hit but he wasn't comfortable with the tune. Any ideas? I've had some UTEC issues with tuning and just bought a haltech and plan on switching it out soon. Could it be the install? Tips? Ideas? Suggestions?

Thanks

 

Do u still have your stock cats on? Also, is the peraon doing your tune a Nissan specialists? Look into an Osiris tune as well. Try My350Z.com... they have a huge wealth of knowledge over there when it comes to Forced Induction.

 

Nope, the kit removes the stock cats, and mine is the catless kit so there are none at all. Greddy exhaust now as well as the 5/16 spacer.

 

Did u buy it new or used? What boost level were running on the dyno? What kind of dyno was it? So many different factors...

 

Haltech would be massive overkill here though some might insist on it because of the safety factor? I don't know... Osiris seems more practical here.

You haven't said anything about your injectors or fuel pump. If you're hitting a wall that soon and the tuner is saying it can't go safely past there then I suspect you have injectors and or fuel pump pushed to the limit.

I have limited knowledge but that sounds like logical limitations of our stock systems if you have the exhaust upgraded already.

 

Some thing is seriously wrong. My car made 360whp on a dyno dynamics with the similar mods. If the kit is used the turbo could be junk there known to go bad on these kits. I would go with an osiris tune as well

 

I bought they kit used. The shaft has zero play in the turbo, and I can hit 8lbs of boost no problem, with quick spool up. I'm not sure on the type of dyno it was though.

I've already got the Haltech, so overkill or not, its going to be used. The safety factor is a big thing though, the last thing I need is me blowing my engine up, so better safe then sorry.

I've upgraded the turbo kits injectors to 550cc's and the walbro 255lph pump, so it can't be the fuel system either. My a/f ratio's are a bit rich under boost, but by no means are they being maxed as that would lean me out, right?

I'll look into it and find out what dyno it is I'm running on. I never did a compression or leak down test in advance, could that be it?

 

Looks very tuner experience level related assuming you're setup is mechanically sound. Any EMS is only as good as the person tuning it whether it's haltech or utec. UTEC is more than capable of 500+WHP and is very safe for stock blocks, if properly set up, with it's overboost cut and knock control. Stay out of boost until you get the tuning or other issue(s) resolved.