88mazdarx7turbo

ok well i take my car out and i end up getting into a lil race with a 99 gt mustang on the highway.. and basically i cant keep it floored cuz the boost will keep climbing.. only thing i can think of is a vacuum leak somewhere.. but i checked the wastegate line and its fine.. so now im not real sure where else to check.. itll cut out in every gear except 1st..

ErikTheDead

the 87 and 88 wastegate is too small

https://www.rx7club.com/2nd-gen-archive-72/serious-s4-wastegate-porting%85-352816/

powrdby13B

i see you have a boost controller... but no FCD... that will be a problem... so you can't set your boost higher than like 7.6 PSI or whatever... does it ever go higher than your boost controller is set? and is your gauge electronic or mechanical

Wankel7

The fact that boost keeps building is because your wastegate is undersized.

What are you using to measure boost.

There are a few ways to stop the creep. You can restrict intake or exhaust to stop the creep. Or you can port the wastegate. http://fc3spro.com/TECH/HOWTO/ZWG/zwg.html

There is no boost controler than can be used to stop the creep. Period.

James

SevenDreamz

Yeah a full 2.5in exhaust and boost controller w/ no FCD.....you might just be asking for trouble. Your car sounds nice and I wouldnt want to hear of another TII biting the dust. I say either port your wastegate or have someone do it for you b/c restricting the exhaust system will only slow your car down...and thats no fun. Its not hard at all to port the wastegate...hardest part is removing the turbo....but if u just search there are TONS of threads about porting the S4 Wastegate. Be safe and keep the boost down as much as u cn till that has bn performed....then after the ported wastegate and a FCD go find the GT Mustang again and remind him why he should of bouught an RX-7....LOL

88mazdarx7turbo

ok i hav recently takin off the boost controller and the boost gauge is a mechanical faze boost gauge.. every once in a while it cuts out still but not near as much..

Aaron Cake

iTrader: (1)

You NEED to port your wastegate.

BLKTOPTRVL

If your turbo system is stock, I would be cautious about porting the waste gate. I see that you have recent modifications. Did the problem start as soon as you installed the mods, or did it happen later.

If later, the wastegate did not suddenly get to be to small for the turbo.

Careful examination of the rats nest (on my 3rd gen - may be a differetn issue) showed that one of the hoses to an actuator had expanded and was therefore loose fitting - not passing enough signal pressure.

Go through your hoses and replace them... Sooner or later, you may come across the one that is too loose, or is kinked, or has collapsed altogether.

If the problem started instantly after the mods, then I have no advice.

NZConvertible

There is nothing wrong with the car other than a poor combination of mods. On an unmodified turbo a full exhaust and a pod filter will always result in enough boost to hit fuel cut. The only way to avoid fuel cut with the stock ECU is to fit a FCD. But you will still have dangerous boost creep, and the only way to cure that while keeping your intake and exhaust mods in place is to port the wastegate. Read my how-to.