To Port The Wastegate Or Not
 

ok i just picked up what will be my 4th stock turbo to go on my 89 tII. it is an s5 turbo i got for 75 bucks. there is some shaft play up and down but i cant feel anything in or out, so i figure it will do untill i send in one of my s4 turbos to bnr. the wastegate flapper bushing is a little work and allows the wastegate to open a little on the far side and it will allow it to leak a little. so the question is even though the wategate arm bushing is worn do you think i should still port eh wastegate holes a little. oh and BTW has anyone ever like port matched the exhaust manifold. thanks for the help.
Rob

p.s. the car is a 89 TII with JIC spec 90 exhast from the turbo back, full emission removal, upgraded TID, oh yea i also have an SAFC II and a rewired walbro 255

4th turbo?!? How long have you owned this car for? Is it possible that your PCV valve/crankcase ventilation is not operating correctly?

well with the whole emission removal i have a open pcv system with breathers on them. like the how to showed. ive had the car four about 2 years. but im pretty shure my problem lies with the BOV. it is a TurboXS RFL. i may have had too may washers in it tighenting it up too much causeing compressor surge. im not too worried abou that right now im just trying to decide if i should port it or not casue i dont want ti to leak any worse than it may now.. but than i dont want a shit load of creep from the big exhast

[QUOTE=mort2002] the wastegate flapper bushing is a little work and allows the wastegate to open a little on the far side and it will allow it to leak a little.


Im not sure what you mean by this, but it sounds like your talking about the diaphram that moves the arm to open and close the WG? Theres no bushings involved with the WG. Theres the flapper door that is controlled by the arm then the arm which goes to the diaphram.
I would not go crazy with the porting because what happens is when you have an open exuast and allow more flow through that turbo while keeping the boost down your putting a hell of a lot of stress on the internals of that turbo. There only designed to flow a certain amount of exaust gases and with an open exaust its just going to melt the seals in the turbo. This might be why youve already blown 4 of them. I have the same set up as you in terms of emissions and exuast and ive gone through 2 turbos so far. An s4 and a s5. The s4 was not ported and was boosting to 15psi (dident last long) and the s5 maintained 8psi but lasted 6 months.
Conclusion; for a modified rotary do not use stock turbos even if there ported to maintain low boost. Get into a turbo that is made to handle the flow/mods.

well im actually talking about the arm that goes into the turbo housing. it is worn and you can grab th flapper and that little tab on the other side and wiggle it. i plan on going with a bnr stage 3 and like 14lbs of boost. also ive been trough 2 s4 tubos and 1 s5 turbo. and ive only ran like 12 to 13lbs max.

is your motor rebuilt or just factory with electronics and bolt ons

its just a stock JDM that has like 50k on it.

oh yeah if the flapper is loose than its gonna leak exaust which would probably cause it to be more laggy than anything. Itll prob keep the boost lower than if it wasent like that.
Im in the same boat again also by the way i just bought another s5 turbo that has like 50k on it. Is it me or does every used s5 seem to have 50k on it? lol
Well even though i know this turbo is going to blow in short time, im putting it in cuz i cant afford the BNR yet and i NEED to drive my car.

i know exactly what you mean there. i know ill blow it up even though ill only run 12lbs of boost. but when i get my bnr turbo ill get it as a S4 not an S5. when i talked to him on the phone he told me that he can port the S4 better than the S5. but that will be a little while down the road. i need to get 2 720cc hi imp. injectors still. does your wastegate on your S5 do the same thing too? thanks
Rob