headers saves gas
Team Owner
Joined: Aug 2003
Posts: 38,314
Likes: 35
In my case, about the same gas mileage. But increased valvetrain noise because the headers are thinner than the stock cast iron manifolds. Exhaust note changed and is louder at WOT but the same or less at cruising.
Team Owner
Joined: May 2004
Posts: 26,345
Likes: 232
From: SoCal
Originally Posted by tramminc
after install headers did you guys notice a increase in mileage, i would like to buy them but not looking for a lot of noise. 
Race Director
Joined: Sep 2001
Posts: 13,292
Likes: 0
From: Hockessin Delaware
Originally Posted by EB20003
In my case, about the same gas mileage. But increased valvetrain noise because the headers are thinner than the stock cast iron manifolds. Exhaust note changed and is louder at WOT but the same or less at cruising.
Drifting
Joined: Sep 2002
Posts: 1,614
Likes: 7
From: South Florida
Didn't get the car tuned yet. I'm waiting on HPs wideband. But the gas mileage definately decreased. I used to get 31 mpg highway, now I get 24 mpg highway. Around town is less of a difference. The car is running super rich.
Team Owner
Joined: Mar 2002
Posts: 47,647
Likes: 1
From: Queens, New York Life begins at 183 mph....
St. Jude Donor '08-'09
Originally Posted by EB20003
In my case, about the same gas mileage. But increased valvetrain noise because the headers are thinner than the stock cast iron manifolds. Exhaust note changed and is louder at WOT but the same or less at cruising.
That's funny because I was about to make a post about this today. Over the weekend, I got to drive my vette for the first time with the windows closed since I installed my Kooks headers in August. I had noticed a bit more noise under the hood but with the windows closed, no AC and a smooth road, you can really hear alot of valvetrain noise. I thought maybe I might have to have that checked out. So is that one of the reason why GM doesn't offer longtube headers as standard equipment. I actually noticed a slight increase in gas mileage although lately, I've been really stepping on the gas so it's probably decreased a little.
Race Director
Joined: Feb 2003
Posts: 11,133
Likes: 1
From: ~The DARKSIDE Group~
Originally Posted by EB20003
In my case, about the same gas mileage. But increased valvetrain noise because the headers are thinner than the stock cast iron manifolds. Exhaust note changed and is louder at WOT but the same or less at cruising.
Me too!
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Le Mans Master
Joined: Feb 2001
Posts: 6,777
Likes: 358
From: West "By God" Virginia
CI 7-8-9-10 Veteran
Originally Posted by Smokin Joe
Didn't get the car tuned yet. I'm waiting on HPs wideband. But the gas mileage definately decreased. I used to get 31 mpg highway, now I get 24 mpg highway. Around town is less of a difference. The car is running super rich.
No tune either, but soming soon!! I went from ~29mpg down to about 25 on the interstate. But, I think the sound and power makes up for the loss. I would say once my get the a/f's adjusted, mpg will be back up.
Burning Brakes
Joined: Jan 2004
Posts: 811
Likes: 0
From: RPV CA
Originally Posted by alex1217
That's funny because I was about to make a post about this today. Over the weekend, I got to drive my vette for the first time with the windows closed since I installed my Kooks headers in August. I had noticed a bit more noise under the hood but with the windows closed, no AC and a smooth road, you can really hear alot of valvetrain noise. I thought maybe I might have to have that checked out. So is that one of the reason why GM doesn't offer longtube headers as standard equipment. I actually noticed a slight increase in gas mileage although lately, I've been really stepping on the gas so it's probably decreased a little.
valvetrain noise, i would say sound, became more noticable....