Ok heres the situation, currently the shop I have been taking my car to has had problems tuning it to where it should be based on what it has. They told me if I switch from UTEC to Osiris they can tune it but it seems like theres no reason they cant with UTEC. They just told me there were issues with UTEC that were preventing good tuning. So far the max theyve gotten out of the car is 334rwhp Heres a list of my performance modifications:

STS Turbo Kit
Kinetix intake manifold
Berk Tech test pipes
440CC injectors( switching to 850CC because they told me 440CC were maxing out)
UTEC
Snow Performance Water/Meth injection kit
Walbro fuel pump

Also they mentioned that I might need to upgrade my fuel system to a return type fuel system because mine might not push enough fuel for more power.

So should I bother buying Osiris or just find another tuner? It just annoys me when I see on STS website a dyno sheet showing 387whp 400tq and they havent gotten close to that and its always some reason. Thanks in advance!

 

850's are going to be tough to tune smoothly on a UTEC. Even on Osiris unless they really know what they're doing and have done lots of them it's still gonna be tough. 600's are the max I'd run on your setup.

Either way there's no reason they shouldn't be able to make the same power with either unless the UTEC is faulty.

 

What PSI are you running? The Utec has maps on their website for the TN kit, and the APS kit for 550cc injectors and greddy TT with 750cc injectors.
I'm pretty sure one of those would be a good base

http://turboxs.com/shop/246-350z-utec-discontinued.html

 

My boost gauge (aem tru boost) showed peak boost was 9psi.

 

And they used the STS maps for a base map and tuned from there.

 

I never tuned with utec on a g35/z but on my sti I had no issues running large injectors and making power.

If it works keep it. It sounds like your tuner isn't that great.

Don't worry about dyno numbers. Worry about how the car runs and feels. Some dynos just read high and read low.

Uprev gives you a lot more to work with over the utec but power gains from one to the other shouldn't be far off.

 

Exactly, I made the same power with both.