check my sig, i have a II 62/12, running just the perfomance tune in diablo, if i floor it from a stop, i get 40 psi and holding, then when i get to od, it spikes to 50 psi. do you think the wastegate is opening at 40 and then i'm just overdriving the turbo when it shifts because of the load of od? i know a 62/12 is a luittle small for a ho, but i want quick spool, which it does. i'm just wondering if switching to a 14 exhaust housing will give me more consistent boost? i'm thinking with the small housing even with the wastegate open, its still overspeeding the turbo? or maybe 40 psi is all it will make because i'm only running a small tune and the wastegate doesn't open until 50? i think it is supposed to be preset for 40, but maybe i shouldn't trust that

 

I know this isn't about what you asked but I have been looking at getting the same turbo for my truck and was wondering if you would mind telling me what kind of ext temps you see with that turbo.

 

i think i would get the ps 62/14, but i don't know if it lags more. with a 100 hp tune in, it holds 1300 in the manifold until it shifts into od, then it climbs a bit, but i maybe need to set it up a bit, not sure. i'll report back when i get it set up, some people say they can run a 170 hp tune under 1250, but mine doesn't seem to do that, like i said, maybe i just need to tweak abit

 

1300 is still good on a wot run.I probly wont go much over 100hp tune I just want guick spool ant to be able to pull a little with good egts.hey thanks for the info

 

Overdrive creates more load on the motor. This makes the turbo work even more. You can actually push more air than the wastegate can keep up with.

 

that what i though was happening. there maybe a 14 cm exhaust hsg in my future