#10165, "im getting bad boost creep, even though i have an o2 dump"
installed the 16g and ran the j-pipe connection to the wastegate and it would boost to about .5 bar till about 5k rpms and creep up to about 1.3 bar by 6500rpms. i dont understand why it would creep if i have an o2 dump
#10167, "RE: im getting bad boost creep, even though i have an o2 dump" In response to Reply # 1
Mine crept a little at first but stopped for some reason. Installing a larger flapper will get rid of ANY creep but then you run the risk of it blowing open if you start running high boost. Could always go external...
__________________________________________________________ -Tony <--- NOT asian. '06 Wicked White EVO IX
Originally posted by Avenger When I raise the BS flag ... it's a really big fucking flag and I raise it really fucking high too.
"Never whistle while your pissing." ~The illuminatus Trilogy
#10168, "RE: im getting bad boost creep, even though i have an o2 dump" In response to Reply # 2
Did you port the crap out of the wastegate hole on the turbo? An o2 dump is worthless if the air can't get out of the turbine housing in the first place.
Get the larger flapper and port the hole to match it. It will take care of the creep.
#10170, "RE: im getting bad boost creep, even though i have an o2 dump" In response to Reply # 4
how would a bigger flapper stop boost creep? wouldnt a bigger flapper if anything increase creep because it would block more flow out of the chamber? im thinking maybe my 14b actuator is at fault.
#10171, "RE: im getting bad boost creep, even though i have an o2 dump" In response to Reply # 5 Aug-04-04 09:51 PM by eclipzGST
A bigger wastegate hole will let more air out. The bigger flapper is needed to cover the bigger hole. edit: Another thing you could try would be to tee into the line running from the intake mani to the BOV for your boost source. Then from there to MBC and then to wastegate actuator. The nipple on the J-pipe should go to the lower prong on the BOV (if there is one) or capped.
__________________________________________________________ -Tony <--- NOT asian. '06 Wicked White EVO IX
Originally posted by Avenger When I raise the BS flag ... it's a really big fucking flag and I raise it really fucking high too.
"Never whistle while your pissing." ~The illuminatus Trilogy
#10173, "RE: im getting bad boost creep, even though i have an o2 dump" In response to Reply # 7 Aug-05-04 08:20 PM by eclipzGST
Originally posted by BigBald Do you know what creep is and how it happens?
BOOST CREEP 101 Internal or external wastegate opens to relieve pressure when you get to a set boost level determined by the BCS or MBC/EBC. Creep happens when the pressure isn't relieved fast enough and pressure keeps building (creeping). External usually elimintaes creep because it gets rid of the pressure at the manifold where an internally gated turbo relieves it at the turbo itself. O2 dumps are sometimes better than because there's no restriction from the o2 housing. A bigger flapper lets the air out faster than the smaller one but when running high boost can sometimes blow open because of the increased surface area of the flapper.
__________________________________________________________ -Tony <--- NOT asian. '06 Wicked White EVO IX
Originally posted by Avenger When I raise the BS flag ... it's a really big fucking flag and I raise it really fucking high too.
"Never whistle while your pissing." ~The illuminatus Trilogy
#10174, "RE: im getting bad boost creep, even though i have an o2 dump" In response to Reply # 8 Aug-05-04 08:25 PM by chrysler kid
the spring inside the actuator pushes the lever that is connected to the flapper open, so the more psi coming out of the turbo, the more the pressure is on the spring, the more the wastegate opens up. a boost controller tricks the actuator by releasing some of the air pressure through a bypass valve. the ball inside of the mbc is pushed backwards to a cartain point and then lets air out. the more compressed the spring inside the mbc is the less air is recieved by the actuator.
thats why i thinking my actuator is mis calibrated. because if the wastegate is fully open there wouldnt be any creep in a normal situation
#10175, "RE: im getting bad boost creep, even though i have an o2 dump" In response to Reply # 9 Aug-05-04 08:48 PM by eclipzGST
Originally posted by chrysler kid because if the wastegate is fully open there wouldnt be any creep in a normal situation
Lots of people get creep under normal situations... BTW, Mine still creeps and I have a o2 dump. It's not as bad as it was before but, it still does in the high rpms. edit: why not try a different MBC, maybe it's leaking.
__________________________________________________________ -Tony <--- NOT asian. '06 Wicked White EVO IX
Originally posted by Avenger When I raise the BS flag ... it's a really big fucking flag and I raise it really fucking high too.
"Never whistle while your pissing." ~The illuminatus Trilogy
#10176, "RE: im getting bad boost creep, even though i have an o2 dump" In response to Reply # 10 Aug-05-04 09:59 PM by Vandy420a
which 16g are you running? the evo?
I had an in depth discussion about this with one of the guys at slowboy. Basically, it summed up to this:
1) the evo 16g is gated to run about 18psi and is very stubborn about it. using an unported 02 housing (ESP. from a 2g) isn't going to help things at all. <<this one i'm not 100% on, but they have alot more experience than I do with the turbo>>
2) A larger flapper is the first step to controlling creep, but will probably not eliminate the problem
3) Externally gating it is another solution that probably will control the problem.
4) Another option, although rare/expensive, is to "deviate the septum", i.e. have someone machine away the separation from the wastegate and the turbine in the turbo. This will help with creep ALOT and is good for racing under certain rules, but most choose to just externally gate.
5) All of these options cost alot (besides the 34mm flapper) and you need an FMIC eventually anyways, so you may as well just bite the bullet and buy one now and stay internally gated, then just use a higher boost level.
good luck!
(also, using a good quality MBC will help vs. using an EBC)
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