Well this is the second time I experienced a boost creep, all under the same time and place and circumstances. I'm coming home from school car is warmed up its about 85 outside and I decide to open her up on the highway. I'n 3rd I punch it build boost up to 10 psi at around 6k rpms i go from 95% to WOT and the boost climb beyond 10 to 12 then to 15 so I get off of it checked my a/f recall and I never dropped lean my Greddy Rubics did a full cycle.

I hardly ever get these boost creeps but is creeping up to 15psi dangerous???

i running a street port, hi flow turbo's, greddy rubics, aux fuel pump, full 3" turbo back exhaust, PF SMIC, and a PF tuned PF ECU

 

What PSI is your PF ECU tuned for?

Dave

 

10psi low 13 med 15 high ( race gas )

 

bump,

Ok I heard that a ported waste gate or external waste gate or a exhaust shim should solve the problem. whick would work best.

 

You can't run an external wastegate.

A restrictor plate is just that, it restricts exhaust flow. They work, but I don't see how you are going to make much more power than just running a hi-flow cat.

Ported wastegate is best....unfortunately requires removal of turbos and is a general all around unpleasant task.

 

I disagree with my bud rynberg on this one. a 1/8 or 1/4" length of restriction is not nearly going to be same as a full cat in place. It will add just enough exhaust turbulance to control boost, but it won't add the same amount of restriction as a 10" long catalytic honeycomb.

 

Sorry everything, this is really that relevant to the topic, but do FD's have 5 psi per turbo? Or 10 per turbo? THank you.

 

I have ported wastegate thats polished out, and I still get nasty boost creep. I think the stock wastegate is just too small for a really high flow exhaust.

 

What did you cut your wastegate to, and what boost are you running?

I suppose if you didn't port it as large as possible and ran your boost really low (less than 10psi) you could still get creep. Or, if the wastegate actuator isn't opening the door completely.

"Nasty" boost creep suggests you may have a leak or malfunction in the wastegate actuator lines.

Dave

 

It's opened to 33mm, any bigger and I need a flapper. I run 12psi and it creeps to over 15 if im not careful when it's under 60F outside. In the heat it doesn't creep. Could it be the boost controller I'm using?

 

On an FD?!?!?!

 

33mm = 1.30".

It's probably nothing wrong with the boost controller, I'd just make sure the flapper door is being opened 100% (check the reach of the actuator vs. the swing of the door). I have a Mityvac - I'd just tee both actuator nipples together and see that 8psi is enough to move the actuator all the way, and that it's enough movement to swing the door completely open.

Dave

 

windom,

There have been several people in the past that even with a ported wastegate, they couldn't stop boost creep in some situations. You basically run into only two options:

1. Larger port with a new/larger flapper door
2. Restriction plate in the exhaust

I believe Garfinkle does the larger flapper door if that's an option for you.

 

Well I think the restricer plate would be the best option for me, Mahjik where do you think I could get one.

 

You can either make one, or bug someone on the forum who has made one (and has a template to use). I believe "JyRO" here on the forum has a few templates to make them easily.

 

hmmmm i just ported my wastegate to 1.3 as well. we will see what happens with mine. good to see i didnt have to post a thread that has already answered my question

 

I am now down to one set of plates. Once they're gone I will not make another batch of them unless someone "orders" (not formal) at least one set. Turn around time ... approximately 2 to 3 weeks on the new batch. Turn around time on the last remaining set ... 1 day.

- JyRO