TD05H 34mm or oem 28mm?

[Black99GST]

ok so i got the bolts taken care of on my Exhaust housing... now i'm in the process of porting, and stumbled across something that seemed quite interesting. i'll try to find the link again, but they where talking about how the 34mm wastegate mod was great to about 17psi, then after that, they start to leak, and in the long run, with a good port job the OEM 28mm flapper is better then the 34mm flapper, because the 28mm wont leak at boost higher then 17psi. now what i am asking is "is this true?" because i have the 28mm flapper still installed and i want to finish up my port and get the car up and running as fast as possible, but i do not want anymore boost conrole problems... anyone know anything about this?

[SilvrEclipse]

I would only upgrade to the 34mm flapper if you still have a problem with boost creep. If not then no reason to upgrade. I have never heard of the 34mm leaking at 17psi.

[Black99GST]

well i do not want to wait untill i find out if it still creaps to fix it, once i put it back together, i want it to work perfect. so what would be my best option? i have an External Dump O2 housing.

[SilvrEclipse]

I dont think you would have a problem with the 28mm wastegate, specially if you had 02 dump

[Black99GST]

well i used to... bad.... it creeps up past 20psi... i'm trying to port the shit out of the inlet side of the Exhaust housing, to allow the exhaust easier access to the wastegate (by taking out that little "wall" that blocks it) i'll get some pics up here so you all know what i'm talking about

EDIT: pics found here

[kjewer1]

I've posted in the past about larger WG flappers limiting boost capacity. It is a very real problem, one which I have measured and documented extensively on EVO16g sized turbos. If you plan to max the turbo out, you will blow the 34mm flapper open. I've also found that with the proper porting, there is no boost creep issue with that turbo on the stock sized flapper, so I have always recomended people run the stock flapper. This is assuming you're not trying to run 15 psi or something gay. Looking quickly at your setup, there is no reason for you to be running less than 20 psi.