porting exhst manny, but not the turbo

[mitsugsx95]

I just took off my manny and turbo and plan to port the exhst. manif. If i just port the manny and not the turbo, will there be any problem with that, or will it run like crap? I plan on upgrading the turbo soon to match, but i dont want to take the time and port the t25. Any input?

 

[candela]

whtever, just do it... depending on how much you port the manny you will prolly have quite a restriction where the t25 inlet is... you should either wait til you get the new turbo or port just the lip of the t25 (even if its just to connect smoothly to the manny) so there isnt a bad bloackade there...

 

[jbillakdsm]

Yeah, if you port one side and not the other to match you'll end up with a lot of exhaust gas bouncing back off the extra metal and flow gets all messed up. Take the lip out of the T-25 and port the mani to match. That lip should only take 20 minutes tops to get out of the T-25.
If you're going to upgrade the turbo later, you can always go back and port the exhaust manifold more to match. I know this sounds like a bear, but you have the hardest part of job done (getting the exhaust manifold off the first time) so it should come off with ease the second time.

 

[P8ntBalla]

when it comes to porting, bigger is not always better. if there is a lip somewhere it can/usually will reduce the air velocity. so while you may be flowing more, you wont be flowing it as fast. i had my manifold ported and had the 16g port matched to it.