Help me understand this boostcreep problem
#1
Help me understand this boostcreep problem
Ok In the past on my Evo8 engine i had the same mod's as far as exhaust goes, SS tubular manifold, SS o2 housing, 3" tbe.
Did a evo 9 engine swap.....
Put the bigger turbo and the new IX engine, and now i have boost creep.......... I though Creep was caused by lack of backpressure not more or im just confused please inlighten me
This is what is happening......
3rd gear, WOT..................... pegs 21psi~ around 3500give or take , holds until around 5800 then slowly rise's to around 24 but never goes over 24 to redline.
Could this be something besides creep because i though creep just keep rising?
Did a evo 9 engine swap.....
Put the bigger turbo and the new IX engine, and now i have boost creep.......... I though Creep was caused by lack of backpressure not more or im just confused please inlighten me
This is what is happening......
3rd gear, WOT..................... pegs 21psi~ around 3500give or take , holds until around 5800 then slowly rise's to around 24 but never goes over 24 to redline.
Could this be something besides creep because i though creep just keep rising?
Last edited by kaonashi; Nov 1, 2007 at 09:27 AM.
#2
Set a manual boost control to 11 psi and floor it slowly in high gear. It should go to 11 psi and hold it pretty well. If it starts to slowly climb over 11 psi as the rpm's get high, that's "creeping". The boost creeps higher at high rpm's because there's too much exhaust flow for the wastegate hole to bypass.
Going to try this and see what the outcome is.
Ok did this hits 11psi from lower RPMS and it rise's to 13-or 14psi doesnt hit the 15psi mark so i dunno guys its some weird *** creep
Going to try this and see what the outcome is.
Ok did this hits 11psi from lower RPMS and it rise's to 13-or 14psi doesnt hit the 15psi mark so i dunno guys its some weird *** creep
Last edited by kaonashi; Nov 1, 2007 at 09:53 AM.
#3
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Try taking any boost controller out of the equation all together and run the line from your boost source directly into the wastegate, ~12 psi. If it creeps then the W/G actuator is probably not functioning correctly thus the flapper door isn't opening to despell all the gases necessary out of the exhaust and in turn it's creeping.
#4
Try taking any boost controller out of the equation all together and run the line from your boost source directly into the wastegate, ~12 psi. If it creeps then the W/G actuator is probably not functioning correctly thus the flapper door isn't opening to despell all the gases necessary out of the exhaust and in turn it's creeping.
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Try it out if it spikes to a certain amount and holds to redline or dips off then your fine. If it spikes then slowly creeps up as rpm is increased then something isn't right as the exhaust gases aren't being directed out of the gate properly especially in the upper rpms as there is more exhaust flow.
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mine creeps on spring pressure with the green, and it is not the actuator, we have already loosened it till it is about 1 turn from sliding on the pin at rest. It has been verified to open all the way while on the dyno. My problem is the gate cannot bypass enough flow in the midrange.
This could also be related to the ebay 02 housing, if you look inside one there is a passage from the gate side where it joins the main side that could have some variation from unit to unit.
This could also be related to the ebay 02 housing, if you look inside one there is a passage from the gate side where it joins the main side that could have some variation from unit to unit.
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Not sure, I did not pay for the hd actuator, but I was thinking they shipped it with one because of the midrange creep, however, we took a couple turns out of the turn buckle so it will just about slip right on the pin. No change.
I really think the reason some of the greens have the midrange creep has nothing to do with the actuator, but rather the style of hotside used, since there are two choices, the dual flapper and single flapper.
To be honest, I don't recall which I have, but I do know If I wanted to stay with pump gas only boost levels, I would be pulling it off to hog out the wastegate port.
I really think the reason some of the greens have the midrange creep has nothing to do with the actuator, but rather the style of hotside used, since there are two choices, the dual flapper and single flapper.
To be honest, I don't recall which I have, but I do know If I wanted to stay with pump gas only boost levels, I would be pulling it off to hog out the wastegate port.