EVO III Boost Creep Problem Solved!

[Boiler2]

Originally posted by twistedtsi
i have an evo 16g not yet installed and from seeing all this i wanna do this mod before putting anythign on but im still confused on what part of turbine u guys r talkin bout.. one is talkin bout looking into the 7cm part and the other is talkin bout the other side wheer the o2 housing meets the turbo.. can someone please explain what part and post some pics before i really need halp hea guys thanks fella's

To answer your question ... I am talking about both.
Priority order is as follows to eliminate boost creep (with my setup):

1. Port the watsegate hole larger
2. Port just above the wastegate hole in the 7cm housing part so the air has a smoother path to the wastegate hole
3. Port the step away in the wastegate exhaust side in the section where the wastegate air is just about to enter the O2 housing so the wastegate air does not hit a 90 degree wall when the flapper opens
4. Port the O2 housing wastegate path and port away some of the divider on the side where the O2 housing meets the downpipe

There are some good pics above of this. Good luck!

 

[myblack98gst]

here are the pics from my port job... it now holds a steady 10 psi to 4.5k I have not gone any higher because the motor now has about 30 miles on it.

 

[myblack98gst]

note that you can see the wastegate entrance now... before there was a large hump that kept it blocked

 

[myblack98gst]

see the turbo was opened up to match the o2 housing... then some.. and the o2 hous was matched the stock gasket was used to mark the holes... they are near a perfect mirror image of each other for smoother flow.

 

[myblack98gst]

on the exit side of the o2 housing.. go up in there and open up the hole where the wastgate comes into the main flow. and from that hole to the exit I opened it up to 2.5"

 

[myblack98gst]

on the manifold... it was opened up to match the turbo (2.5") and after that was done I beveled the runners where they have a smoother flow into the turbo and thinned out the divider wall.

this manifold took more time that almost everything combined.. it is ALOT harder metal that the turbo..

all in all I am VERY pleased with the results. although I will be running 20+ after the motor is broke in this will allow much more air flow to help max out the "big" 16g.

 

[twistedtsi]

hey thanks guys those pics really helped out alot now i kno what everyone is talkin bout thanks gain and wish meluck

 

[Boiler2]

Originally posted by myblack98gst
on the manifold... it was opened up to match the turbo (2.5") and after that was done I beveled the runners where they have a smoother flow into the turbo and thinned out the divider wall.

this manifold took more time that almost everything combined.. it is ALOT harder metal that the turbo..

all in all I am VERY pleased with the results. although I will be running 20+ after the motor is broke in this will allow much more air flow to help max out the "big" 16g.

Myblack98gst ... Thanks for the help and support. I am glad you took the time to post the pics. I believe this thread will solve a lot of peoples issues with boost creep.

Nice summary!

 

[Maximuscr31]

i may try this with my turbo.......i was about to buy a external wastegate and tubular o2 to try and solve it. I have a evo3 16g. I have been having creep bad.....on the dyno i found out how bad. I held 12psi from 3200-3600 rpms.Then i went from 3600-5600 rpms in that time it took 1.9 seconds to go from 12psi-28psi. It is crazy creep.......i may try this and see if it helps.Thanks for the writeups and pics

 

[Tarantula]

Well thanks to this thread I learned alot. Heres my port job I did to the O2 housing wastegate exit. I removed the hump near the O2 sensor as well. Opened up the hole with a Dremel and an aluminum oxide grinding stone. (orange stone) took roughly 2 hours on and off.
This pic is the opening of the hole and cutting of the divider.

 

[Tarantula]

This pic is the comparison of my old O2 housing and the new ported O2 housing (Forced peformance)with my divider port job. You'll notice that I tested the griding stones first on the old housing (which is why it looks a little ported) and the red markings are the marks in which I used to cut and shape the porting on the other housing. It was my guide. There was also a hump near the o2 sensor that I ported down flat, which made the opening bigger. I went deep inside the hole to open it all up.

 

[Boiler2]

Originally posted by Tarantula
This pic is the comparison of my old O2 housing and the new ported O2 housing (Forced peformance)with my divider port job. You'll notice that I tested the griding stones first on the old housing (which is why it looks a little ported) and the red markings are the marks in which I used to cut and shape the porting on the other housing. It was my guide. There was also a hump near the o2 sensor that I ported down flat, which made the opening bigger. I went deep inside the hole to open it all up.

Tarantula ... Thanks for the pics. Keep them coming. I am glad my post helped you.

 

[Tarantula]

Well I bought the EVO III 16G and had it ported from FP. I did the additional porting of the area above the wastegate and mirroe polished all openings. Hers the result.

 

[ShapeGSX]

I just wanted to post that I solved my boost creep issue as well, but without any porting.

I bought a 2.5" tubular O2 housing from Andy at www.122performance.com . The only difference was that he used a 1 3/4" wastegate tube. And he plumbed back it in farther from the turbine.

That is it. That one piece solved my boost creep issue. My 2G O2 housing was choking off the wastegate.

Andy told me that he can build more of these. I had to bend my heat shield to fit over the larger wastegate tube. But that was the only fitment issue.

You can contact him at [email protected] . His web site appears to be down at the moment.

 

[RiceKiller_TSi]

How much $ Shape? ^^^
Got pics?

 

[ShapeGSX]

I don't remember what he is charging for them. I think it was under $200, but don't quote me on that. Nice thing is that you don't have to port it.

I can upload a pic tonight. It doesn't look all that pretty compared to the stainless models that are out there, but it works.

 

[RiceKiller_TSi]

Cool, see if you can get some pics up. I dont care about looks, as long as its functional. Nobody should be looking under there anyhow.

 

[ShapeGSX]

Outside, out of focus.

 

[ShapeGSX]

Outlet

 

[ShapeGSX]

Outlet 2

Told you it wasn't pretty.

 

[ShapeGSX]

Inlet

 

[RiceKiller_TSi]

Dang, I'd buy one if it looks like that. I wish his webpage worked. And you got "no" boost creep at all?

 

[ShapeGSX]

I only tested it at 18psi. So I don't know about lower. I actually don't care about lower.

 

[Zex4g63]

That's odd Shape, because I had a tubular O2 housing with a dump instead and the wastegate dump tube was 1 3/4 too. I still creeped till I ported around the wastegate entrance. I thought for sure mine would not creep with the dump but it did. Anyhow how does it work now without the creep? Will we see some quicker times this year?

Tim

 

[ShapeGSX]

We will see tomorrow night. If I can't maintain boost, I may swap the 2G housing back on. But I don't think that will be an issue.