Chicago Crew UnderBoss

iTrader: (1)

My TPIS headers on my 98 C5 A4 are now almost 3 years old and with the awesome MTI Group Purchase going on i can upgrade to the KOOKS 1 7/8 headers for my C5R Based 427 Motor and i figure it should be good for at least 10 rwhp/torque increase throughout the rpm band. The whole cost for this however with install, etc, and even after figure i can sell my TPIS headers will probably be around $900.00 or so.
I appreciate all informative info/opinions regarding what power estimate increase you think i will pick up throughout the entire rpm band and at peak by just making the header swap (not upgrading to LSX intake yet) and whether you think its worth the $900.00 for the expected power gains.

Pro Stock John

iTrader: (34)

What size headers are you running now?

You would be going to 1.875 full length headers wtih 3" collectors?

Chicago Crew UnderBoss

iTrader: (1)

JOHN,
Don't know a ton on the specs on the common TPIS vette C5 headsers i have been running for almost 3 years now but they are full length and i believe 1 5/8 vs the Kooks 1 7/8!

ram-it

I think your estimate seems reasonable. Are you sure 10rwhp is worth the time, money and effort considering where your at already?

jeffrey G

I dont think it would be worth the cost or money, just slap on a nice 50 shot on there!

11 Bravo

iTrader: (3)

I would spend the money on a FAST 90mm intake and MTI 90mm tb. MTI says that combo has picked up @ 25rwhp on a 427.

Scalpel

iTrader: (4)

The TPIS LTs for the C5 are 1 3/4" AFAIK.

14u2nv

I thought LG Motorsports had the best design C5 headers

Pro Stock John

iTrader: (34)

I'd be looking at how to make more HP and not TQ. I'm not sure, maybe the intake and throttle body might be more worth it but maybe ask Tom Izzo how he's making 550rwhp with his 427 Z06.