Do I need a new tune with these changes?
Thread Starter
Instructor
Joined: Jun 2005
Posts: 120
Likes: 2
Do I need a new tune with these changes?
I just bought a cammed Vortech supercharged C5 that is making 10 lbs of boost. There are two changes that I'm considering making to the car.
First is changing from off road to high flow cats. I know most people are against this but I'll probably go that route due to the smell of the exhaust. Would that require a new tune? I'm guessing it wouldn't.
Second is I might change to a larger pulley to go down from 10 lbs of boost to 8 lbs of boost. Would this require a new tune or would the computer read less air and make adjustments?
First is changing from off road to high flow cats. I know most people are against this but I'll probably go that route due to the smell of the exhaust. Would that require a new tune? I'm guessing it wouldn't.
Second is I might change to a larger pulley to go down from 10 lbs of boost to 8 lbs of boost. Would this require a new tune or would the computer read less air and make adjustments?
Drifting
Joined: Oct 2006
Posts: 1,724
Likes: 23
From: Minnesota
The high flow cats will likely increase the AFR a little but the drop in boost will decrease the AFR significantly. Depending on how good the existing tune is, the computer should do a fairly good job adjusting the fuel trims in closed loop. However, your open loop AFR will be rich.
Get it tuned.
Get it tuned.
Last edited by reactor2; Feb 24, 2016 at 11:55 PM.
