High boost no mbc??? What is my wastegate doing?

[brainlessher0]

I have a big 16g turbo and every time i boost my guage shoots all the way up to around 20 and then i shut it down so i dont damage anything. I am running no mbc and the hose is connected from the wastegate to the j pipe. I have no idea what the problem could be. Any suggestions would be appreciated.


1998 eclipse gst

mods
- fmic
- 190 fuel pump
- bov
- 2.5 downpipe 3 in all the way back
- boostguage

 

[talontd92tsi]

Check to see if your wastegate hose isnt cut, clogged, or even something stuck in the end of the actuator, or if something is interfering with its movement.

 

[THE REAL DEAL]

i'm willing to bet the flapper isn't opening

 

[brainlessher0]

i lengthend the rod on the wastegate and now i am building 10lb of boost then it seems to creap to 15 at wot. normal?

 

[blazebolt]

Yes that is normal if you don't have the inlet and wastegate passage ported.

http://www.dsmtuners.com/forums/showthread.php?t=186525

 

[brainlessher0]

i ported both my manifold and my 02 housing, Not much but i took any burs any carbon and stuff like that out of it and polished it. If it was my wastegate creating the problems what would be some key symptoms. And how do i check and see if my wastegate is performing like it should.?

 

[blazebolt]

You can check your wastegate actuactor by connecting it to a vaccum pump. It should open at around 7-10psi

 

[brainlessher0]

is it worth going external with the big 16g?

 

[blazebolt]

An external wastegate will work but for a 16G you don't need it. It is the easy, but more expensive route. Porting isn't that hard.

 

[brainlessher0]

im already ported

 

[blazebolt]

I see that your manifold and o2 are ported, but you didn't mention the wastegate passage on the turbo was ported. You may also want make sure the flapper opens up all the way and shave off any material blocking it from fully opening.

If you don't have a vaccum pump, you can directly connect the wastegate actuator to the j-pipe nipple or where ever your boost source is and see if it opens during a boost leak test. This method is hard to see and be accurate.

 

[oldman]

im already ported

No it isn't, read the link above.

i lengthend the rod on the wastegate and now i am building 10lb of boost then it seems to creap to 15 at wot. normal?

You can't just lengthen the arm because your flapper will not close properly causing boost lag, unlengthen the actuator arm and port your turbo properly.

Lastly, you might want to check the shift key on your keyboard, seems to be malfunctioning.

 

[brainlessher0]

Im almost 100% my turbo was ported ahead of time as well as coated. The wastegate area was extremely open compared to the 14b i have and the flapper was a a lot bigger. The part of the turbo where the exhaust enters from the manifold appeared to be ported as well It was very open and unrestrictive.

 

[oldman]

Im almost 100% my turbo was ported ahead of time as well as coated. The wastegate area was extremely open compared to the 14b i have and the flapper was a a lot bigger. The part of the turbo where the exhaust enters from the manifold appeared to be ported as well It was very open and unrestrictive.

Most vendor port jobs focus only on enlarging the inlet flange to 7cm^2 to increase flow and better spool which does nothing for boost creep, in fact it worsens boost creep. Porting for boost creep requires porting of different areas of the turbine inlet, if you read the linked thread in the tech article, you would know that the author started off with an already ported EVO3 as well and it took me 2 pages to convince him otherwise, much like the conversation you and I are having.

Here the thread. http://www.dsmtuners.com/forums/showthread.php?t=183108&page=1&pp=25

 

[ArcaineGST]

Oldman, I just spent the last couple hours reading both the tech article and the original thread, and I just wanted to say wow to both you and Chad .

This is definitely something I need and want to do. I'm on the stock t25 still though. Would you recommend waiting until I upgrade or would it still be worth it to port and line everything up now anyway?

 

[oldman]

This is definitely something I need and want to do. I'm on the stock t25 still though. Would you recommend waiting until I upgrade or would it still be worth it to port and line everything up now anyway?

Unless you're creeping with the T25 which I doubt, I would just wait.

 

[brainlessher0]

awesome link oldman def going to keep that in mind.