34MM flapper mod pics and results...

[Enraged78]

Hey all,

After dealing with insane amounts of boost creep on my 14b equipped 2G (21+PSI!), and trying multiple ways to deal with it, I bit the bullet and called up Extreme Turbo. I had them machine a 34mm wastegate flapper, and they shipped it to my door via priority express for $50.00 including shipping. I ripped the turbo off of the car on Friday, brought it to a friend's shop to use his compressor, and hogged the wastegate flapper port out to about 26mm. The old flapper just about fell through the new port work when I was done. The new flapper does not have a mushroom head to compress, so I did what the vfaq advised, and cut a slot in the top of the flapper with a hacksaw. I pushed it out on top of the washer with a flat blade screwdriver and a hammer. Put the whole thing back on the car, and the MBC set to 10PSI for the first two days. It creeps to 15-16PSI now, depending on the gear your are in. I spent a few days tuning the car, and now have it set to 15PSI, with just a little bit of spike and creep. The datalogger showed some very interesting results. With just a fuel pump re-wire (4-gauge competition wire split down to 8 gauge for a small amp, and 10 gauge competition wire for the pump), the 14b@16 PSI in 4th at redline, the datalogger showed 18 degrees of timing advance @ WOT at 7,000 RPM. O2 readings are between .96-.98. A little rich, but I think that's OK for now. The car pulls like a motha, and has never run this well. One strange thing, though, is my timing is being pulled between 3,000 and 5,000 RPM. It dips down to as low as 9 degrees advance. Is this the phantom knock I've been hearing about? Anyway, here are the pics. Enjoy.

Matt.

 

[Enraged78]

Pic 1 34mm mod...

 

[Enraged78]

Pic 2 34mm mod...

 

[kpt4321]

You obviously didn't try enough ways to deal with it, because that turbine housing isn;t ported nearly enough, if at all. You need to port the area between the WG outlet and the turbine outlet, on the WG side, so that the gassas have an easier path to leave the wastegate. If you had done that instead of buying a 34mm wastegate, you probably would be fine.

 

[Enraged78]

Originally posted by kpt4321
You obviously didn't try enough ways to deal with it, because that turbine housing isn;t ported nearly enough, if at all. You need to port the area between the WG outlet and the turbine outlet, on the WG side, so that the gassas have an easier path to leave the wastegate. If you had done that instead of buying a 34mm wastegate, you probably would be fine.

Could you please be a little more specific? I gasket match ported the Exhaust manifold, removed the step and ring from the manifold and turbo, and gasket-match ported the O2 sensor housing. Other than the inlet and wastegate passage, no other porting was done on the exhaust housing of the turbo. I was told that opening up anything else would contribute to more creep, not less. If this is incorrect, please let me know. I've been looking at this for four months, and an answer other than a wastegate mod have found no other solutions. Please post back.

Thanks,
Matt.

 

[ChicagoGSX]

The 34mm flapper is by far the best way to eliminate boost creep. I have mine set to 10 psi right now, and could probably go lower if I wanted to.

 

[mitsugsx95]

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=43430

Look, Listen, Learn....

 

[Enraged78]

Not bad... I wish I would have known about the removing the divider a week ago. I would have hit it up while I was porting to completely eliminate any signs of creep. As of right now, I really have no creep (maybe 1PSI), so I think that the 34MM flapper was the way to go anyway.

Matt.