s4 wastegate mod
 

Hey guys, I saw the basic "bolt on" turbo upgrades for my s4. I am really low on cash right now, so I was thinking of jsut taking apart my turbo and getting the stock wastegate enlarged.

Who sells the bigger wastegate door so I can do it myself? I am aware the hole needs to be enlarged.

Is there any machining involved to put in 360 degree thrust bearings?

from what i know, porting the wastegate will just let it flow like the S5, and thats about it. but i could be wrong..

I was looking at the BNR upgrades, and I saw the stock wastegate size compared to the ones they rebuild.

Is there anything I can do??? I want to get my car tuned very soon. Its got a street port, greddy FMIC, ss autochrom header, and a turbo back exhaust with a megasquirt ecu setup. Im getting 160 miles ona full tank!!
P.S> im aware rotaries will never get good mileage, but I know mine can be tuned a little better for reliability, some more gas mileage, and power

BTW , how is the s5 turbo compared to the s4? no boost spike?

Here is Aaron Cake's site... this is what I did:
http://www.aaroncake.net/rx-7/s4wastegate.htm

a valve from a piston engine and something to port it with, and a welder works good

Great link. Do you know how big they port the wastegate? I have a Mil at work and I can just drill the hole.

Does teh s5 turbo have the same size turbine? Im thinking about just getting a s5 housing from someone and bolting it on my s4 turbo.

Or an actual wastegate puck for $5 online and do it right. Waste of money to go S5 over S4. Just keep the S4 and port the WG

Im gunan search that on the internet, "wastegate puck". Do you know of any places?
I was thinking of using a s5 housing because the guy I got my car from had put a tubular header made for a s5 turbo already. The turbo is a s4 though. DO you know how much bigger you port the stock 16mm wastegate?

It would almost be easier to just purchase a s5 turbo. You can probably get a used one for $100 shipped from someone the forum. i'm running a stock s5 turbo on my car at 15psi and I'm putting ~250whp down currently.

Are the s4 and s5 compressor sizes differnt though? Im just curious.

Im pretty new to the rx7 scene. I jsut got one for 1 week. I was suprised noone makes a tubulat manifold for the s4 turbo. What is the type of flange on a stock s4 turbo? I would consider making a manifold at work to try out.

Sorry for being such a newb. I jsut found out about this site http://www.fc3spro.com/main.html

Its easier to locate a used turbo and spend $100 than it is to port the wastegate and weld on a new puck? The guy said he has the tools to do it at work, so why not

I searched "wastegate puck", but did not find anyone selling those. You got a link? Im pretty low on cash right now. I will look for a better turbo in the future.

I did a quick search and only found this flapper

http://store.forcedperformance.net/m...ode=Acc-Gasket

not $ 5 , but im sure someone will link you with a cheaper option.

Jesus, $35. I was thinking they sold new for cheaper. Not $5, I was exadurating a bit. Best bet might be bringing it to a local performance shop or turbo building shop, if you have any local. I had a local guy install me a larger puck from a different turbo he had laying around. only charged me $20 for part and labor (with consisted of a little grinding and a small weld to re attach the washer (the part on the end of the stem/neck to hold it onto the arm, and allows it to move and pivot) to the puck "neck" thing.

The S5 turbo's biggest advantage is the fully divided manifold set-up, which improves turbo response and reduces lag. Given how cheap thay are, and the fact that you can sell the S4 turbo, it's not a waste of money.

thanks for the input guys. Great info

ok then. IMO its a waste of money. I dont see the point of buying another stock turbo just because of its devided manifold and larger wastegate design. Too much trouble for me to go through just for that little gain.

(((((((((((((((Is there any machining involved to put in 360 degree thrust bearings?(((((((((((((((

No