What kind of gains (rwhp) can be expected from LT headers? I've heard as much as 40, sounds a little too good to be true. I'm dynoing the car on Friday, just trying to get some early predictions. BTW the headers are Kooks 1 7/8 with 3 inch merge collectors & a 3 inch x-pipe with metal substrait cats. TIA

 

I never did a before dyno with my Kooks 1 3/4" headers. I did run the 1/8 mile, a week apart in similar weather. The DA was about 2500-3000' and my best pre-header (cat-back, tune, cai) was an 8.7@86.4 (2.1 60-ft) while after the headers, a best of 8.41@89.39 (2.1 60-ft). My only dyno with the above mods and headers was 378rwhp/358rwtq SAE.

 

Thanx for the info. Have you run the car through the 1/4, curious about your mph? BTW 6spd or auto?

 

Aric,

Will be interesting to see what it will do with the headers. Maybe 117 mph? Your car flies already for stock. I hope mine will do even almost as well.

If you are installing headers with cats be sure to clean everything out of the ID of the headers and pipes upstread of the cats. Although I have not seen any Kooks pieces, almost every other brand I have seen had metal shavings, weld slag, grease and other pieces of crud that will at least block some of the cats flow capability. Keep in touch!

 

Oops, it's a mn6, Z51 option. The best 1/4 mile with just cai (Halltech), cat-back, tune and headers was 12.91@111.9 (2.1). The weather was not good on that run however....the DA was 4500' with the outside temp was 101-103 degrees. My other 4-5 runs just went downhill with the DA topping 5000' and the temp peaking at 106 The 1/8th mile on that run was no where near my best posted above, it was arond 8.6@86-87.

 

If you see 25 at the wheels, I think you'll be doing pretty well.

 

I dynoed at 375RWHP/365TQ with the mods in my signature. If anyone is getting 25RWHP more on just headers and tune, they are doing damn good!

 

I'll find out for sure on Mon. I'll post results when I get them. I'm more intrested in the gains @ the track than the dyno anyway. Thanx for the info & replies.