Hey guys. I did a pretty extensive search and lots of reading. I learned a lot just nothing about this problem. Right now my mod list is as follows. Apexi intakes, hard intake pipes, 3 inch down pipe, hks cat back. The mid pipe is still stock. I put a .64 holley carb jet in the waste gate vacuum line and a .59 in the precontrol line. I have all the vacuum lines hooked up properly. I am thinking that maybe i need to make the precontrol restrictor a little smaller like a .57. Let me know what you guys think.

Thanks
Hank

 

carb jets aren't ideal when trying to tune seq twins.

try getting two MBC's...then you can get as close to a 10-9(+)-10 boost pattern. Sure it's more expensive but then you won't have to fiddle with jets anymore...like you are done modding your car

 

You would want to make the precontrol jet larger. Larget jet = larger volume flow rate into actuator = higher net pressure in the actuator = precontrol door open more = less primary boost and stronger transition.

Good luck though. Tuning with jets IME has been difficult at best.

 

IMO, 11-8-xx indicates that as dgeesaman said, that the PC jet needs to be slightly larger to get, say, 10-9-xx. However, he is also correct that tuning PC w/ a pill is touchy, at best, and may not be consistant with varying weather conditions. A ball-spring controller will work much better.

The 8-psi after transition, however, may indicate a flow restriction (intake or cat) that can't be remedied with a pill size change.

 

I agree with this. How many miles on your cat?

 

There are 86k on my cat. When i got the car it had split boost hoses, most all of the vacuum lines were broken, and many of the check valves were bad. So there is a good chance that the car was running rich. However (and i know this is not real test) but at the back of the car at idle the exhaust flow feels strong. It just might be toast. What will a high flow cat do to my current set up? Will i need to go with something like the power fc? Or will my stock ecu be ok with a high flow cat? Thanks for all your help guys.

 

A high flow will be ok if you install a manual or electronic boost control and keep things at 10psi.

To check the cat, just unbolt it from the car, and shake it. If junk rattles or falls out, then the element is disintegrating.

Dave