Is their really a point in using pipe that has a larger ID than the exhaust ports on the motor? Wont the exhaust only go as fast as the ports allow? If anything it will speed it up no? Reason im asking is im wondering if its worth upgrading my log mani to something bigger but not equal length cause im a cheap lazy ----. Its been so long i cant remember but this is my mani, and im not sure cause it was like 3 years ago and the cars in storage but i think its sch 10 with a 1.25" id. I remember them matchup really well, I also remember reading they shouldnt be to close or gases will revert.

I remember seeing dynos comparing equal length to log manis, and the increase in top end was substantial. IIRC somewhere around 20whp, but building an equal length turbo is lenghty and expensive, I can use that money to take my girl out for a nice OC dinner and be rewarded with a slap n tickle.

IIRC the ports are 30mm ( 1.25") and im thinking of going to 1.5"
maniweld.jpg?t=1231222483

 

If your pipes are bigger than the ports you will only loose airspeed and gain ---- all.

 

The answer i was looking for.

 

Before you go LOG just remember a Proper Tubular manifold should be able to match the spooling time as a log, give better flow more topend & more power...

 

This is HMT not Popular Mechanics.
Run what you got.

 

I'm already logged, and uber lazy therefore i will remain logged.