34MM flapper overkill on 14b?

[Enraged78]

Hey all,

You've all been pretty good about helping me before, I'm hoping that this will be another easy one for you... I've got a '95 TSi AWD, with a ported 14b, 2.5" to 3" downpipe (only 2.5" for 10"), 3" high-flow cat, and 3" cat-back (Check sig for all mods). I am having one hell of a time controlling my boost creep. Installing the cat helped a little, but it's still WAY out of control. Boost is set at 12 PSI, and I'm hitting 19PSI in fourth at WOT. Third hits 18, and second only hits 15. So far, everything in the turbo is gasket match ported, EXCEPT the wastegate hole. O2 housing is gasket matced, step and ring are removed from turbo, and a little light porting of the compressor outlet. Exhaust manifold is gasket match ported also. Now, I am planning on ripping the system apart and porting the wastegate hole, but while I'm in there, should I install a 34mm flapper? Is this overkill on a 14b, or just insurance? Any ideas on where I should get this flapper? I don't like not being able to boost hard. I would like to just get this thing to hold 15PSI rock solid. Any ideas are welcome.

Thanks in advance,
Matt.

 

[jbillakdsm]

I'm installing a 34mm flapper on my 14b soon and I would recommend it while you are in there. I'm dealing with similar amounts of boost creep on a 2g 6.6cm ported manifold, matching exhaust housing, ported 2g O2 housing and RnR 2.5 turbo-back with cat. I'm making my own flapper from an old Chevy valve that I cut off and machined to fit perfectly. Check around and see if anyone will sell you a kit to install the flapper. I know Slowboy makes them, but I don't know if they will just sell them without installing it.

I'm not sure if the turbo will take full advantage of this big of a flapper, but I've never heard anyone complain about their wastegate being too big and causing problems. Think of it as justified insurance.

 

[Enraged78]

jbillakdsm, thanks for the reply, that pretty much answers my question. I wound up giving Extreme Turbo a call, and they were more than happy to help me out. The only flappers that they had in stock were the 39mm flappers, which from my understanding, are too big for the 14b's wastegate assembly. So, they offered to machine it down to 34mm free of charge. It comes with the mushroom head on it, so I should be able to just drill the old flapper out, and press the new one in. The whole thing came out to only $30.00, including machining. I needed it by this weekend, so I opted for the incredibly expensive 2-day air for $20.00. Grand total: 50 bucks. Not bad for custom machine work. I'll post my results when I'm done with it.

Thanks
Matt.