Boost Creeping

[ARTSUPRA]

Thankx guys lots of usefull info here, I am sure you answered a question for many people here and pictures say 1000 words!

 

[Tarantula]

Hell yeah that was some good info. I just received my Evo III 16G (ported) from FP and going to get to work on porting above the wastegate passage in the turbine inlet. The wastegate is the standard one and FP stated that theres not enough material to put a 34mm flapper on it. And from looking at it, well they are right. Its totally different and theres a hole going inward on the side of the flapper. It looks as if you try to enlarge the hole, you will not seal. So I think porting above the wastgate door in the inlet will help alot. (Since I can't put a bigger flapper.)

 

[Tarantula]

well heres the result...

 

[DSM mechanix]

I ported my 14b much like that and it still crept to 16psi, still an improvement considering I was creeping to 18-19psi though not as I was hoping for.

 

[coltboostin]

Looks good

Did you port anything besides that? Another key, as far as my experience with protign and creeping is enlarging the wastegate exit to the size of the flapper. This also helps greatly.

 

[DSM mechanix]

I ported the WG hole bigger, but not as large as the flapper itself.

 

[Tarantula]

Originally posted by coltboostin
Looks good

Did you port anything besides that? Another key, as far as my experience with protign and creeping is enlarging the wastegate exit to the size of the flapper. This also helps greatly.

Yes I did... On the EVO III 16G, there was a step under the center divider of the turbo in the newly designed wastegate area. Well I removed the step and smoothed out the center divider. I felt that the step would create turbulance on its way out by the way the step was a small notch under the divider the length of the divider. There was also a hole deeper in the wastegate area that I rounded off to permit smooth flow. I left the Wastegate hole untouched. There does not seem to be any way to add a bigger flapper so I figured why bother. If it causes problems later on, I'll probably enlarge it. I just can't see how 2-3 mm bigger under the original flapper would do a world of difference. What I did also was "Mirror" polish all the openings. (turbine inlet, entire turbine outlet and Wastegate area)I can actually see my reflexion.

 

[Tarantula]

Update: No boost creep whatsoever. Not even spikes! Boosted 9 psi straight to redline and 15 psi straight to redline. I installed a custom boost source right on the compressor cover of the Evo III 16G.

 

[ShapeGSX]

Looks good

Did you port anything besides that? Another key, as far as my experience with protign and creeping is enlarging the wastegate exit to the size of the flapper. This also helps greatly.

Don't port the wastegate hole itself or you will have issues with boost falling in the upper RPMs. It makes the car feel like a slug.

 

[Tarantula]

I totally Agree. Theres no reason to do a flapper mod or enlarging of the wastegate hole. Leave it as it came. It does it job perfectly.

 

[coltboostin]

I did that to mine and I have not issues with fall off, and I also can hold 9 psi till redline. It is not a problem, just be careful!

 

[DCsGST]

Think this technic will work on a 20g? I plan to hog the hell out of it this weekend in hopes it will solve my boost creeping from 15psi to 25psi (I haven't had the balls to see how high it will go)

 

[oldman]

This is a great post. Extremely helpfull. I'll be working on the same thing this weekend, got a couple of question.

1. I just ordered a die grinder and one carbide bit, I should have it by tomorrow. Do I need any other tools?
2. Some of the picture on this thread did not load, it would be very help full if I can see all the pics.
3. I also have a boost leak at the intake gasket so I was planning to gasket match both the intake and exhust manni runners. Can I do this without porting the head at the same time? Will it hurt flow?

BTW Someone else earlier had mention mbc being a factor but was quickly shot down, here's my story: I use to hold 19 psi to 7k with my old boost controller (Some guy installed it for me long ago), it look kinda like the turbonetic vbc with the turning knob. I think it's the bleeder type. I thought it was leaking when I did the leak test after fmic install so I bought a hallman rx pro (ball and spring) and now it creeps to 22psi @5k where I hit fuel cut. I did notice the car spools quicker with the hallman so I think my old mbc contros boost by bleeding air out to reduce pressure to the wastgate actuator, that is why it didn't creep before. What do you guys think?
Sorry about hijacking.

 

[ARTSUPRA]

This downpipe was made by me and fixed my boost problem, car was boosting strong and holding @ 16.5 PSI without boost controller and boost creep. Final 1/4 Time is 14.4sec @ 95miles and 1.901 60'foot, with full 3" exhaust Upper hardpipe, rewired pump everything else stock.

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Pictures of the car before it was sold

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[beat90tsi]

this thread has a lot of useful information, but i'm confused on one issue

how much porting, and of which areas is safe...without hurting the turbo's ability to hold high boost (~22/23psi)?

 

[kiknturbo17]

Hey guys I am having creep problems but im guessing its from the 3" Buschur racing exhaust. Its the turbo-back and i have the stock turbo,mani,and o2 housing. If i got a ported or 2 and 1/2" o2 housing with a dump would that help me out at all? I cant afford a new turbo and such so i want something that will help temporarily. Any suggestions would be appreciated...Oh by the way my mods are the exhaust,UICP,dejon intake pipe,and boost controller set to 14lbs. But it creeps to 20 in the upper rpms.Thanks again

Joe

 

[coltboostin]

The dump will help, but porting of the O2 housing will do nothing. Porting to eliminate boost creep is done at the wastegate inlet of the turbine housing, as shown above.