Greg 99ACR Red and Silver
Enthusiast
When I recently attended the Socal Dyno Day with my '99 ACR, I was disappointed with my 404.5 RWHP run (basically a number that bone stock ACRs attain).
My mods...Borla Headers, Light Flywheel, Mopar/Borla 3" exhaust...should have delivered more.
I have been very suspicious of the stock cats, since my speed at the drags had dropped by 4-5 MPH over 1 year at the same track and conditions.
Dan Cragin ran an exhaust back pressure test, which revealed a plugged left cat (10psi). Instead of replacing with stock cats, I had him drop in some Hi-Flow Cats from Jon B., and the results were much better.
Base Run at Socal Dyno Day: 404.5 RWHP/445.2 RWTQ
Best Run with the New Cats: 435.7 RWHP/474.5 RWTQ
The link below to my Dyno slip shows the Baserun and the improvement in HP. It improved clear across the curve. Don't assume that "Cats are OK", especially if you sense a power drop-off.
http://viper.epikos.com/Uploaded/1951739PM1092.jpg
My mods...Borla Headers, Light Flywheel, Mopar/Borla 3" exhaust...should have delivered more.
I have been very suspicious of the stock cats, since my speed at the drags had dropped by 4-5 MPH over 1 year at the same track and conditions.
Dan Cragin ran an exhaust back pressure test, which revealed a plugged left cat (10psi). Instead of replacing with stock cats, I had him drop in some Hi-Flow Cats from Jon B., and the results were much better.
Base Run at Socal Dyno Day: 404.5 RWHP/445.2 RWTQ
Best Run with the New Cats: 435.7 RWHP/474.5 RWTQ
The link below to my Dyno slip shows the Baserun and the improvement in HP. It improved clear across the curve. Don't assume that "Cats are OK", especially if you sense a power drop-off.
http://viper.epikos.com/Uploaded/1951739PM1092.jpg
