Boosted Performance

iTrader: (14)

Dug up my old dyno sheet, and it looks very much like the OP's dyno:





This was with a 6162 T3 .82a/r turbo, so very very close to the T4 .58a/r 6262 the OP has. This was with very conservative timing, just like the OP. Boost pressure was at about 8psi for that pull. So it is safe to say that timing has a lot to do with when the turbo spools, and what the torque curve looks like.

350XTCz

Hmm I guess I might be spooling a bit later too, but I think I have a boost leak that needs to be fixed.

BCs350z

iTrader: (11)

Yea that does look a lot like mine. i agree that it is a little laggy with tq coming in that late. In order for me to be fast i have to be at like 4500 rpms before i punch it, otherwise it kinda feels like a stock Z powerwise until then. Then it rips! I checked for boost leaks and when i looked at the boost log, it doesnt fall off any and hits full boost at 4000 rpms. The wastegate has the 8 lb spring in it but like i said im controlling the WG with an EBC.

binder

iTrader: (8)

I have a 6765 turbo and I see 10psi at 3900 rpms. Something has to be leaking or not working right. especially if you are using an EBC to hold solid boost til 8psi.

Boost won't drop off to show a boost leak because the turbo can provide more pressure than 8psi so it is just forcing it out the leak. It's not a massive leak, but a leak.

I would check from the headers to the turbo hot pipes. That 3 bolt pattern is hard to get nice and tight. if you take those apart i'm sure you will see some exhaust leak on those gaskets.

scoupe

iTrader: (3)

i can vouch that DSG has an very low reading DD... my car was actually the one matt tuned to 248 whp from 220 whp. they are indeed great guys to work with and matt knows his stuff. hope you get everything worked out.

str8dum1

iTrader: (11)

no one cares what the dyno read. we are all talking about how laggy his setup is. 800-1000 rpms slower onset of power than any of the other BP kits reviewed here.

Boosted Performance

iTrader: (14)

Vas had the same issue after his install. The exhaust (header) bolts were not tightened all the way. I think he had a leak on the T4 flange as well.

Vas_Z33

iTrader: (39)

yeah that would be my best guess for the OP... either passenger or driver side.. I had a tiny leak... making me not hit fulboost till like 4-5 k lol

BCs350z

iTrader: (11)

should this leak be something i can hear when idling or when driving the car? Because i dont hear an exhaust leak. Or can a leak/leaks be small enough so i cant hear them but enough to have an impact on turbo spool and my laginess?

Vas_Z33

iTrader: (39)

the first time this happened to me, i heard it.. the second time I didnt but you could clearly see that the gasket was burnt on one side... and yes a little exhaust leak pre-turbo can make a difference

binder

iTrader: (8)

just because you can't hear it doesn't mean it's not there. Under no boost there isn't much backpressure on the exhaust. When you boost the exhaust starts to build backpressure which will push harder on the leaky gasket therefore causing it to leak.

BCs350z

iTrader: (11)

Im gonna have to check for exhaust leaks. I thought i would be able to hear one if there was one but i guess not. I understand that a leak would cause my laginess but does it effect the torque output also?

Andrei

iTrader: (7)

I like this kit. Keeps heat out of the engine bay. So does this kit have potential for 1000whp? Just curious.

str8dum1

iTrader: (11)

no because the biggest turbo that will fit is a 6765. a custom single kit with the turbo mounted by the washer tank could fit a 71+mm turbo though.

Boosted Performance

iTrader: (14)

This is true as far as Precision turbos go. However a T76 (76mm) does have an S compressor cover that would fit in that location.

350zion

iTrader: (58)

This guy has an answer for everything

str8dum1

iTrader: (11)

is that a 1000whp turbo though? the supra guys dont really consider the billet T76 a 1000whp turbo, let alone the cast turbonetics T76

Andrei

iTrader: (7)

It's okay. As long as it's near.
Great turbo kit again. Great welds and awesome bends with a clean look. I like it.

Resmarted

iTrader: (2)

I doubt you would hear it, I know someone who had a blitz twin turbo kit who leaked like a **** (1jz). He never knew it until he tore apart the engine. I mean you probably couldn't hear it, all the noise of the engine and the turbo spooling would probably cover it up, unless it is absolutely horrendous, and you weren't holding any boost....

Resmarted

iTrader: (2)

What else would be the point of getting a 71+mm turbo (as you claimed in your other post)? I really don't think the t67's are surging and aren't running out of steam yet, so no real reason to go bigger than for massive hp....