J's fc

iTrader: (1)

I have an s5 t2... My question is can you have the exhaust port ported and the intake ports stock? or do you have to port them both?


Has anyone ported the exhaust and left the intake without porting? and how did thier car run?

thanks guys

ajmacke

Porting the intake will net you better results. The stock exhaust port is already good sized, I think for most applications smoothing out the port openings without making them much bigger would be about all you should do. If you make the exhaust port lower, you will lose torque and if you open it up higher, you are creating more overlap which turbo motors don't like. Increasing flow on the intake side will give you better results.

J's fc

iTrader: (1)

But the car will still run, and would it affect the engines compression if i only port the exhaust?

ajmacke

It will still run, but the engine can only put out as much as it takes in. You will lose torque, lower exhaust velocity and in return have more turbo lag. Nothing extreme, but if you aren't making the intake ports bigger, I don't see any reason to do it. Porting the engine should not change the compression of the engine.

J's fc

iTrader: (1)

One more quiestion... If i got 75 psi on one rotor and 65psi on the rear rotor.. will the engine still run?

ajmacke

That is pretty low all around should be up around 90-110psi if I remember right. Probably would run, but that motor isn't going to last long at all. I had an engine like that some 10 years ago and it would be near impossible to keep it running after it got warm.

Anyone else have input on this topic?

Black Knight RX7 FC3S

iTrader: (7)

did you put in some oil in there to see if compression builds up?

also did you do the compression test with the engine out?
Try getting the engine to crank faster atleast to 200-300 rpms to get a more accurate test.

J's fc

iTrader: (1)

i used some 5w-30 cuz thats i had, and the engine was in the car test...

Evil Aviator

http://www.7parts.com/erikstrelnieks.html

J's fc

iTrader: (1)

OOOHHHH..... Dope so i does work.....

ajmacke

Anyone, including Evil have any input on this? A 20B generates more torque than a 13BT and would see more benefit from opening up the exhaust port for more free flow. With 50% more exhaust flow to the 1 turbo, it would be less of an issue. Is there an additional benefit I am not seeing?
I should have asked this earlier, J's fc, why are you wanting to only port the exhaust?

J's fc

iTrader: (1)

well its cuz i just ported the exhuast side only cuz i didnt want to mess with my timming..