Header help

[mikesyellocobra]

Hey guys, how do we feel about Pacesetter longtubes? I was interested in maybe tossing some on the car for a boost. Is a tune necessary? I know its going to give the best gains tuned, but just until I can get it tuned would I have any issues driving without one? How hard is the install? I've heard its a lot easier with a tubular k member.

Thanks for the help!

 

[mwolson]

There is a parameter in the tune called "O2_Transport_Delay_in_Revs" that tells the PCM how long it takes for the exhaust to get from the exhaust port to the O2 sensors. When you install long tubes, you increase that delay significantly. Without changing the tune, at idle and part throttle the PCM tries to control the AFR, but it is getting data from the wrong combustion events. So it assumes that it knows the AFR it was trying to hit, and tries to compensate based on data from a different AFR it was trying to hit. This confuses the PCM and makes it really hard for it to maintain a stoich burn at idle and part throttle.

Could you drive it that way? Yes. Would it be running correctly? No. Would you tell it was not running correctly without datalogging? probably not.

I would recommend getting it tuned ASAP after the install.

 

[04DeadShort]

I look at some Pacesetters awhile back, specifically the ceramic coated ones. Pacesetter told me they are only coated on the outside so i would have to send them off to get the inside coated. I've read that the fit is great. My main concern is they are made out of mild steel. Mine is a DD so I'm just gonna hold out for some stainless and not worry about them rusting out.

 

[ImThatGuy]

Ive known Pacesetter to make some good stuff, but I have read more than a few complaints on their fitment. But then again some people dont know what the hell they are doing. When I installed my Bassani headers, I took my front wheels off and lowered my K member. Its pretty tight in there to work, unlike a pushrod motor.

 

[04DeadShort]

Yea I dont think it matters which header you choose, its gonna be tight. Search "headers" on here for more info.