it USED to be perfectly fine, on the bugeyes.

when stock cars are knocking, especially when run on 91 octane, why would you do anything to make it worse?

the situation does not manifest itself during dyno pulls, or when you floor it at 2k and take it to redline, because in those situations the delay times out before the boost comes up.

it occurs (and does damage) when you're sitting there at 4k rpms and low throttle angle, and then suddenly punch it. the boost hits quickly and will easily peak before the delay times out.

i run my car lean but i'm not going to run 14psi @ stoich fuel. you could/would be doing that on 91 octane which is even worse!

also, when gruppe-s says "the basics" does that also entail fitting an MBC? and if so, what is the MBC set to? an MBC set to 10psi will run stoich fuel all day long, whereas one set to 16psi will detonate and/or melt stuff at 14.7:1.

mike/mpjbecks at gruppe-s does know his stuff. are you giving him the full story though?

 

Another option for quicker spool-up is to upgrade your boost solenoid and the lines. A few different companies offer them, such as Perrin and GM. I know you can pick up the GM product for around 75 dollars. And they are really simple to install.

 

fwiw, most folks who have installed an interrupt style "3 port" solenoid (gm, perrin, grainger, etc) in place of the oem 2 port have required custom tuning to get the boost response stable. in fact, i only know of one who didn't.

 

Basic bolt ons would be ok on say a 02/03 WRX or 04+ STI but with the issues covered above (CL vs OP switchover) the 04+ WRX, FXT, LGT would/could suffer from issues with the new found flow improvements of say a free flowing exhaust or the faster onset of boost with a MBC/EBC.

Whoever you spoke to at Gruppe-S either missunderstood the question or didn't realize the car you were driving.

Mike

 

If you love your car just forget about using a MBC. I got a COBB AP and love it!!! Along with increasing boost safely to 15.78psi, the peak torque and HP kick in about 800rpms sooner than stock, you cant get that from any MBC.

 

this thread is strikingly similar to this one...........

https://www.i-club.com/forums/engine-management-66/safe-run-up-dp-cbe-without-cobb-ap-122961/

with the exception of using an MBC.

-Ted

 

thanks for clarifying.

i wasnt planning on using the mbc to raise boost, just for the quick spooling effect.