16G Overboost, what options do I have?

[Chicken Patty]

Hello,

I just installed a brand new MHI 16G. I am running a line directly from my wastegate to a boost source teed of my BOV vacuum line that goes to the Manifold.

I hit about 9 psi, then at about 4k RPM the boost starts to creep and creep and by 5k I am at about 20lbs and climbing, but I let off.

I know it is common on these turbos, but I want to see what are my options before I go ahead and fix it the most common way which is seal the flapper shut and put an external wastegate.

What options do I have guys, thanks in advance!!

BTW, i disconnected the WGA and opened the flapper, and with the WGA disconnected I still saw about 6 psi at about 6k RPMS. This pretty much confirms it is not the wastegate.

 

[Dsmj89]

Your best bet would be to port the wastegate exit and turbine housing.
Like we discussed it will sacrifice a bit of low end power but then again, the difference won't be that big, thus still relieving the creep issue.
It's pretty much the only option you have other than going with an aftermarket external gate.

 

[gorf]

never heard of boost creep that bad

With your WGA disconnected and the wastegate flapping in the wind, you still hit 6 psi?
Sounds like you have a restriction in your O2 housing on the wastegate side? Did you #### the gasket in between the turbo and the O2 housing?

 

[Chicken Patty]

never heard of boost creep that bad

With your WGA disconnected and the wastegate flapping in the wind, you still hit 6 psi?
Sounds like you have a restriction in your O2 housing on the wastegate side? Did you #### the gasket in between the turbo and the O2 housing?

What were you trying to say about the gasket? It says #### instead of the word?

I still hit 6 psi with the WGA off and the flapper open. I have a dumped o2 housing and a 3" turbo back.

 

[Chicken Patty]

What about getting a different turbine housing for the turbo, like for example a Hahn Racecraft 10cm housing, does anybody know if it bolts up???

 

[jrohner]

I would recommend you just get the supporting mods to run 20+ psi. You've got a great turbo for some really good power, so you might as well put it to use.

 

[gorf]

What were you trying to say about the gasket? It says #### instead of the word?

I still hit 6 psi with the WGA off and the flapper open. I have a dumped o2 housing and a 3" turbo back.

Site bleeped my word - try crooked - partially blocking the exhaust flow from the waste gate.
are you sure the flapper is actually opening all of the way?
When you manually operate the flapper, does it move as far as it did on the turbo without the O2 bolted on?

 

[Chicken Patty]

Site bleeped my word - try crooked - partially blocking the exhaust flow from the waste gate.
are you sure the flapper is actually opening all of the way?
When you manually operate the flapper, does it move as far as it did on the turbo without the O2 bolted on?

naw the gasket is fine, no exhaust leaks anywhere niether. The flapper seems like its opening a good amount. I think the turbo just needs porting.

What do you think of maybe using a Hahn Racecraft 10cm back housing on the turbo, should lag more but this turbo still spools pretty quick? Of course I dont even know if the back housing fits directly into my turbo, it should though right?

 

[50trimmed1g]

They all do it from my experiences. Mine right now will hold 9 psi until about 5000rpm and then it shoots up to infinity and beyond. I recommend getting an external gate or porting the waste gate passage. I think the angle of the waste gate opening causes the exhaust to take the easiest route out and that is straight through the turbine rather than the 90 degree bend through the wasegate passage. Shitty design IMHO.

 

[T9S1i]

I tried many things to remedy the boost creep on my 16g.

The best bet was an external tial 38mm wastegate off the o2 housing.

I did have the bullseye exhaust housing with internal 38mm wastegate, which was a very nice piece, and DID cure the boost creep, but after a while the flapper failed and boost was not able to be controlled, so i upgraded to the external off the o2.

 

[Chicken Patty]

thanks for the all the help guys.

However I am really interested in knowing if the Hahn Racecraft turbine housing is compatible with my turbo and if you guys think it will cure creep?

 

[hairybeanbag]

Even with the flapper door opened up, you will still see 6-9 psi on a 16G. It just go's to show you how restrictive the 16G exhaust housing and Internal WG setup is. The only way your going to get rock solid boost control is going to an external WG, Why fool around with another exhaust housing? Your just beating around the bush.

 

[Chicken Patty]

Even with the flapper door opened up, you will still see 6-9 psi on a 16G. It just go's to show you how restrictive the 16G exhaust housing and Internal WG setup is. The only way your going to get rock solid boost control is going to an external WG, Why fool around with another exhaust housing? Your just beating around the bush.

I'm just going through my options here.

If I do end up with an external WGA setup, do you guys recommend getting another manifold or just having the factory 2g mani tapped for a 38mm???

 

[gorf]

Interesting - everyone saying this is common on 16g....

I have a 2.3 with E316g and I always see 1-2 lbs spike but the preasure settles down to where it is set and holds. I ran the actuator straight from the source and saw 10 psi which held solid. With my mbc in I am running 18, it spikes to 20 and settles.....

I do have a ported 2g O2 - that I ported the bejeezus out of, and the 16g is ported but not the wastegate, other than making sure it was free to open 90 degrees - which was a waste of time because it never opens that far.

 

[2slow4utsi]

Isn't there an option for a wg flapper?

 

[silvreclips]

thanks for the all the help guys.

However I am really interested in knowing if the Hahn Racecraft turbine housing is compatible with my turbo and if you guys think it will cure creep?

Hahn turbine housings are T3 flanged. So it will not bolt up. Just port the hell out of it and you will be good.

 

[ArticNemesis]

http://www.dsmtuners.com/forums/art...oler/186525-how-cure-boost-creep-porting.html

A good port job does wonders.

 

[Chicken Patty]

Interesting - everyone saying this is common on 16g....

I have a 2.3 with E316g and I always see 1-2 lbs spike but the preasure settles down to where it is set and holds. I ran the actuator straight from the source and saw 10 psi which held solid. With my mbc in I am running 18, it spikes to 20 and settles.....

I do have a ported 2g O2 - that I ported the bejeezus out of, and the 16g is ported but not the wastegate, other than making sure it was free to open 90 degrees - which was a waste of time because it never opens that far.

I have a 2.5" dumped o2 housing. The flapper seems to open a good amount.

Hahn turbine housings are T3 flanged. So it will not bolt up. Just port the hell out of it and you will be good.

Thanks, I figured that out last night, forgot to post. Thanks anyways

http://www.dsmtuners.com/forums/art...oler/186525-how-cure-boost-creep-porting.html

A good port job does wonders.

Thank you, i'll read this a bit later on and revert.

 

[siceclipse]

just get the supporting mods

if you dont want an external then dont get it.

i got the evoIII expecting creep (yet it doesnt cause i ordered it from FP) and made my setup for 20+psi

 

[Chicken Patty]

just get the supporting mods

if you dont want an external then dont get it.

i got the evoIII expecting creep (yet it doesnt cause i ordered it from FP) and made my setup for 20+psi

after reading the post that ArticNemesis linked me to. I will go ahead and try to port it myself over the weekend. I got nothing to loose.

 

[Chicken Patty]

well guys, thought I'd provide an update.

I ended up buying a 2g manifold with an HKS 50mm wastegate already mounted. The deal also included a TD06 20G, another manifold with wastegate mounted, same HKS wastegate.

I went ahead and installed one of the manifold and wastegates. I welded the flapper shut as well. I have no fuel mods at all so I set the 16g at around 13-14 psi and I must say this little turbo has some balls. Car feels really good, a/f ratio stays at about 11.8-11.9 in the upper power band.

I have set the 20g aside to put it on later when I beef up the motor a bit. What you guys think?

 

[Dsmj89]

Teh sex chicken.

 

[Chicken Patty]

Teh sex chicken.

No, I don't have sex with my car