TheAnalogKiddd

iTrader: (2)

I'm trying to get this straight.. I've got an 88 TII that has the full 3" Racing Beat exhaust and stock airbox. Before I ported the wastegate, the boost was shooting straight up to fuel cut. As a temporary fix I stuck a plastic restriction in the airbox which seemed to keep the boost at 6 psi. It got colder and again started to move up in the fuel cut range slowly. Recently I ported the wastegate to the max and removed the restriction. What I'm seeing now is the same slow creep as I did before but without the plastic restriction in the airbox. Does this mean if I were to put a fcd and manual boost controller on and set the mbc to ~9 psi, it would shoot up to 9 and then creep further? Without the mbc would the boost cap off somewhere in my situation? I was under the impression that if it's creeping past ~5 psi now, then it'll creep anywhere.. or could this be wastegate creep that goes further than ~5 psi due to the ported wastegate?

kep0ne

if you're boosting to fuel cut already, an mbc wont help creep. you may have to do a little more porting to cure your creeping problem, and if that still doesnt work, trying getting the turbine wheels clipped.

faster7

I would never be 100% certain about how far it might creep, lots of variables involved.

If it slowly would creep up to 8-9psi in 4th, a boost controller set at 7-8psi shouldn't change the severity of creep. Either way you're at a certain point (8psi) with the wastegate all the way open, it's going to go from there whether the boost controller let it get right up to 8psi or whether it slowly crept there. Now same scenerio, if it would QUICKLY creep to 12-14psi and climb higher until you let off...The boost controller could make that peak worse since it lets it get higher earlier=more time to creep further.

Every configuration should only creep to a point. That point might be really high and it might get there slow or fast.

It's pretty easy with a stock S5 wastegate setup and freeflowing intake/exhaust to creep well past 12-14psi in higher gears. Keep making the wastegate flow more, only way to fix it. Unfortunately at a point that means you need a REAL wastegate!

Do whatever you need to do to provide the motor with the fuel it needs and see where your combination lands you.

Hope to be of some help....It's a big subject with lots of variables! Yell/pm me if I could be of more help.

Scott 89t2

it will creep to the same point as it creeps now. if it creeps to 10 now, and you set the MBC to 9. it'll shoot to 9, then slowly to 10. if it creeps to 8 now, and you set it to 9, it won't creep past 9.

faster7

Unless it only stopped at 10 before because you ran out of revs.

Find the "wall" (once you have the fuel...) in 4th/5th gear.

Small wastegates suck...

NZConvertible

In reference to your thread's title, wastegate creep isn't the issue here, that's a completely different problem than the boost creep you're experiencing.

As has already been mentioned, a boost controller (pnuematic or electronic) won't have any effect on boost creep. It'll just boost up a bit faster. Increasing the flow through the wastegate port is the only solution for boost crepp other than restricting the airflow into or out of the engine as you're already done. Sucks I know...