Boost Creep Contributor

[belize1334]

Maybe this is old news, but it's new to me.

I've known for a while that one of the main reasons that 14b's and especially 16g's creep is that the wg flapper doesn't open far enough (total of less than 45 degrees keeps it in the way of the exhaust stream). Common opinion has it that this is because the wg actuator doesn't throw far enough and there's even a mod you can do to make the wg actuator arm travel farther. I just had my exhaust housing off to switch o2 housings and I discovered another issue. On mine the wg arm itself COULDN'T open past about 45 degrees because it was getting hung up on a ridge on the outside of the housing itself. I ground down the ridge a bit to allow it to travel farther but since I also put on a tubular o2 housing, I can't be sure which (if either) affects the creep issue. My thought is that maybe even the stock wg-actuator would throw farther if the arm wasn't getting caught up on the housing.

So, if anybody wants to try this experiment, here it goes. If you have a 16g that creeps, disconnect the actuator arm and see if the wg arm gets caught up on the housing as it swings. If so, either grind down the housing a bit so that it clears, or bend the lever arm out a little so that it isn't so close to the housing. Once you're satisfied that it swings freely w/o ever getting caught, reconnect the actuator and test it out. Report back here with your results.

 

my jmf o2 housing + 3in tbe has never creeped. I dont even know what it is because ive never seen it.20-25-30psi once my e3 spools it stays right where i have it set. People usually port the crap out of the o2 housing to fix it but the JMF o2 housing has no issues with that.

 

[Nate]

I've always found that once a really free flowing exhaust was installed, the size and "shape" of the material right by the inlet of the wastegate flapper was much more crucial to port correctly. Make it easy for the air to get past the turbo without spooling it, and you won't have creep.

 

[atc250r]

+1

The most important part is removing some material right above the WG inlet inside the exhaust housing. From the factory the WG entrance is shrouded by this material and the exhaust gasses are directed away from the opening. While you're at it I would open up the hole that the flapper covers as well though.

John

 

[belize1334]

Well I was running an E3 exhaust housing ported by FP and a port matched 2G o2 and it creeps to 20psi now that I have a mandrel 2.5" turbo back w/ no cat. Anyway, I know that every setup is different and I'm not knocking things that have helped other people's creep issues; I just thought that somebody might be in a position to try this potential solution in particular.

 

[atc250r]

I'm not trying to knock FP but just because they ported it doesn't mean its ported enough or in the right place.

John

 

[Rausch]

FWIW: I had the Evo III ported and the 34mm flapper installed, never had creep issues (maybe 1psi) with the 3" exhaust. This was on the evo O2 as well.

[Porting was done by (gulp) Buschur.....I got a really good deal, this was in 2004, I think?]