Exhaust 1 1/2 or 1 3/4

Ces 140 · #1 12-13-2016, 07:10 AM

Question on future exhaust purchase? 7 with O-360 carb. with FP prop. Is there going to be a difference from using the 1 1/2 rather than 1 3/4 dia. tube coming from the cylinders to the mufflers?

RetiredRacer · #2 12-13-2016, 03:02 PM

Search "dyno pulls on Vettermann exhaust" here on VAF. Larry compares the 1.5" & the 1.75" pipes. Plus the 1.5" are a lot lighter than the 1.75".

lr172 · #3 12-13-2016, 08:31 PM

properly sized pipes can increase velocity and improve scavenging. Properly sized sized exhaust pipes are good for a few ponies at the top end. Neutral anywhere else.

I see no reason not to get the 1.5" (especially for a 320) and that's what I did.

Larry

219PB · #4 12-14-2016, 06:09 AM

I ordered the 1.5" for my 360. Clint's test showed an ever so slight HP improvement. I did not order it for that. Less weight and more component clearance. The fit-up was superb.