My setup is a 2.3L H22 with 9:1 compression pistons and a sc61 clone turbo, drag2 manifold, tial 35mm wastegate 6psi spring, 2.5" dp that flares to 3" no cat, no resonator, and a straight thru muffler.
I went to the dyno yesterday but the odd thing is when they made a run, it would go to 10psi fine but the problem comes when I try to boos t higher then that, say 12psi. It would spool to 10psi fine, but it would stay there for ~1000rpms then jump to 11psi and stay there and finally at the last 500 rpms it would hit 12psi and the run ends. At 14psi run, it would go to 10psi fine, stay there for a bit, jump to 11psi, and towards the last ~500rpms it would finally hit 14psi.
Also, the 6psi spring is what I have in my wg but the lowest I boost with the boost controller off is 10psi- whats with that?
Is there a problem I need to address? The power curve is nice and straight but I think I would make more power if I could build the max boost earlier and not at the last 500rpms. Any suggestions?


Modified by Wo-Nelly at 2:15 PM 2/23/2004

 

any opinions?



Modified by Wo-Nelly at 2:16 PM 2/23/2004

 

i wanna be fast too

 

What Boost controller are you using? That can make a difference..

I've set my SBC Spec R so that it builds boost at a certain point to peak on a gradual level so I can save my tires even on highway runs..

Just curious....

 

What boost controller are you using? Are all your vacuum lines secured and in the right spot? Have you tested for boost leak at all?

 

And what wastegate are you using?

 

It's a tial 35mm wastegate- 6psi spring, the boost controller is a Greddy profec b- the older version. All the vacume lines should be in the right places. I just find it kinda wierd that it'll build 10psi fine but then stops there when I try to go higher

 

Try disconnecting the boost controller, and see what psi it is running. If it's still @ 10psi, then i doubt that you have the 6psi spring.

 

the whole wg hasn't changed since the first setup, and on the first setup 6psi is what it made. I'm pretty sure it is a 6psi spring

 

I's try it anyways. Sounds like it might be sticking, or tha boost controller is crapping out.

 

is that boost controller the fuzzy logic one?

eew, i hate fuzzy logic boost controllers, nothing but $1.00 boost controllers made at hardware stores for me... or if im really feeling bold i'll be biased towards the turbo XS dual stage manual boost controller.

My bet is the boost controller is going wacko. Might want to mess around with the settings, or temporarily disconnect it and replace with a manual one, see if that solves the prob.

 

Make sure you dont have any pressure leaks from the turbo to the throttle body! you might want to consider building an inexpensive pressure tester.

 

I tried to check for pressure leaks, added some liquid gasket to all the couplings and none of them bleww out or anything. I don't know how else to check. But if that was the problem, shouldn't I have a problem building boost everywhere and not just after 10psi?

 

Possibly a small rip or tear in a coupling that only leakes when your boost gets up near 10psi???

I had that at ... couldn't get past it for nothing, then found a small tear in a coupling that was sealing untill pressure was on it. It did that same as your describing... flew to 5psi then stayed and crept slightly to 6 that i was set for.

Just a suggestion

 

I went out today and examined all the couplings very carefully but didn't see and cracks or rippage on them. How can i pressure test the pipes/ic?
Any other suggestions?