CATS OR NO CATS

A pro-chamber is a type of X/H cross between the two made by MAC. I have one on my car. I haven't seen any number comparisons between the two but when I put one on over stock, I saw a very noticeable gain.


Does ANYONE have PROVEN dyno difference between cat and NON-cat?

Here's something I found from a co.called www.bieberfever.com - stock stang with shorty headers:

a. MAC high flow catalytic h-pipe: 6-8 rear wheel hp gain over stock
b. MAC high flow off-road h-pipe: 9-12 rear wheel hp gain over stock
c. MAC high flow Pro Chamber™: 23+ rear wheel hp gain over stock

hmm... so a high flow pro-chamber and shorty header with Off road h-pipe = 23rwhp? Incidently what is a pro-chamber? and is that :bs: ?

Based on below b. and c. look like :bs:

Ok...finding more... Below is a 2001 GT:
"We left the stock mufflers in place so as not to get the awful drone associated with "cat back" muffler systems. On the dyno the restriction free X-pipe showed a 6-8 horsepower gain from 3000 to 5000 rpm, with a 2-3 HP loss on the low end. Torque was up a max of 10 lb. ft. at 4400 rpm."

http://www.fordmuscle.com/archives/2004/12/Xhale/index.php

Looks like 6-8rwhp gain is about right WITH low end loss of 3rwhp. Is that enough worth to blow me ear drums out and scare neighboorhood cats? No.
 
A while back my friend dynoed his mustang with both a high flow catted H pipe and a off road H pipe .The off road H pipe only made 4 more horsepower than the high flow but lost low end torque .I have both the high flow catted and the off road H pipe and I feel my car stronger with the high flow catted H pipe and the sound is almost the same between the two .

:nice: Thanks for the input. Always nice to know real world examples!
 
i ran an off-road one for a while. the car sees maybe 500 miles a year. my conscience got me and i just put some catco universal 2.5" converters from summitt ($54 each, rated for up to 5.9 liter engines) on my h-pipe. the car feels NO different to me and is still loud as hell. only difference is the smell of the exhaust