I Hate Creep

b00stingsx · 04-11-2004

ok with my ported big 16g turbo and a 34mm flapper (with all supporting mods), i am getting boost creep really bad. i thought that it was my boost controller acting up, but its not the case. I bypassed it and the turbo spooled to 9psi, but then as i got higher in the rpm range, it would shoot to 19-20 lbs and i get fuel cut (possibly because its really cold out now??).

now heres my question. my turbo is ported, my o2 housing is ported, I have a open 3" exhaust, but my 1g exh manifold is not ported. is this the reason that i am getting creep? i do have a boost leak in the tb gasket, could this possibly be the problem?

let me know as i am sick of driving untuned :headache:

john · 04-11-2004

A ported manifold would increase the chances of creep as it would flow air through it quicker. With the maft setup shouldn't you be able to eliminate fuel cut? My guess would be a kinked or a vaccum line with a hole. Since you checked it already I don't know. You should be able to tune for 19-20 psi though. I was running that before. You would want to set your mbc up to 19 or 20 so it isn't so laggy.

When I was running that, I was in 40* weather and had my fuel pressure raised so I wouldn't fuel cut. I tuned for 0-1 count of knock.

b00stingsx · 04-11-2004

well with the maft, i can turn fuel cut off, however i want to be safe by leaving it on, and figureing out what is causing the fuel cut and fixing that. I might borrow todds extra wg actuator, to make sure mines not broken.
Your safc ettings were all around -8 on your setup right john?

john · 04-11-2004

No, at 20 psi I was + on the SAFC. Probly around +5 (~4000rpm) up to ~+12 or something at 7500 rpm. I was using my hacked 1g MAS and higher fuel pressure to avoid fuel cut and make the injectors a little bigger at my SAFC settings. I would fuel cut when I hit 22 psi. You may need to make the SAFC settings higher than mine (bc of fuel pressure) bringing you closer to fuel cut though. If you cannot figure it out, I would turn fuel cut off but just monitor knock and timing. That would be more of a last resort type thing. hopefully someone can come up with a solution. The wg actuator isn't pinched is it?

**Shane@DBPerformance** · 04-11-2004

The fuel cut elim stuff in the MAFT is kinda crap, I wouldn't try to use without some careful tuning and monitoring.

Creeping to 19-20psi is safer than run 19-20psi from the get go though. Running 20psi at 4000rpms is much more likely to knock then having it slowly creep to 20psi at redline where you might be able to get away with it.

If you really want to cure creep, then get an external wastegate.

b00stingsx · 04-11-2004

ok i logged today, and i had no knock at all, good o2's, timing was 17-18 the whole time. it pulls fine, feels great. in first i dont get any fc. 2nd gear i dont get fc. but in 3rd gear and up, it cuts fuel.

I would get an external wastegate, but i was just hoping to use the internal one, that should work. Its got to be a line pinched somewhere (ive looked and looked but have not found any) or else its the wg actuator thats toast. cause no matter what level of boost i set it at, it still creeps.

im going to look at it tomorrow at tech with james and todd, maybe they will see somthing that i havent.