silverblue66

Can somebody clear up the concept of exhaust pipe size? is bigger better or do you need some back pressure? is there some formula for the right pipe size?
Kip

Gun Jam

some back pressure is good.

if your running around 200-300hp then 2.25 inch pipe should be about the right size.

if you around 400 to 475 hp then 3" pipe is about right.

Gun

JamesW

https://mustangforums.com/m_982319/tm.htm

JMD

Too much exhaust size is a waste of money at best and a power stealer at worst.

Also, exhaust that is too large tends to be more prone to be damaged orripped from the bottom of a car by debris, speed bumps, etc.

67mustang302

Dual 3" pipes can support upwards of 600ish hp before they become restrictive. Most street cars that run upwards of 450hp can do fine with 2.5" pipes. And bigger doesn't necessarily mean it flows more, a smaller wel designed system will always beat a larger poorly designed one.

dozierstang

Bigger builds more HP but drops the torque. Backpressure is good and helps with the torque. I have 2.5" on both my stangs. Seems like a good size to me.

mySAVIOReigns

Here is a chart

JMD

Awsome man!

I like following the photos showing the progression of your ride!!


Keep it going Steven!

Sorry to steal the thread...... but...

To get back on track, it looks like we are a bit undersized on the 66 acording to the chart...

We are running 2 1/2"... IMO it will do the job...