Typical gains with Kooks 1 3/4" headers...

[bunk22]

...and x-pipe with cats? Having mine installed on Tues/Wed, along with a Steeda axle back. I've seen at least one shop results but average joe results, search came up with some stuff but curious for more.

 

[sambandit]

So am I. I have them on the way as well, with a catted H. Wont have results for a couple weeks though.

 

[alex12gt]

So am I. I have them on the way as well, with a catted H. Wont have results for a couple weeks though.

Let me know what ya put down

 

[sambandit]

Let me know what ya put down

:rockon:Tryin that 72mm pulley first!

 

[G2Mach1]

great question. Someone please post results!

 

[termie2590]

I did kooks longtubes and catted x , on a local mustang dyno that reads rather low and i have the peak numbers on my phone but i know it was almost 20 at the wheels in the upper middle 5300? but with cai , tune and gt 500 muffs my peak was 358.4 and after the header swap it was 372.8. I dont know where my sheets are but i can read the peak #s on my phone. i know my numbers seem low but it is an auto and this was done in third gear (not locked in fourth) and before headers it did run a 13.09 at 109 on a 4400 da evening but i have not been to a track yet this year so no current numbers yet. hope this helps!

 

[twistedneck]

with a tune 20-50 HP depending upon your mods, nice thing it makes way more torque also.

 

[scotmach]

I did kooks mid lengths and catted x , on a local mustang dyno that reads rather low and i have the peak numbers on my phone but i know it was almost 20 at the wheels in the upper middle 5300? but with cai , tune and gt 500 muffs my peak was 358.4 and after the header swap it was 372.8. I dont know where my sheets are but i can read the peak #s on my phone. i know my numbers seem low but it is an auto and this was done in third gear (not locked in fourth) and before headers it did run a 13.09 at 109 on a 4400 da evening but i have not been to a track yet this year so no current numbers yet. hope this helps!

Fixed it for you.

 

[BlackNDecker]

Can somebody explain the difference between 1 7/8 and 1/34 tube headers? Why choose one over the other?

 

[byeofcr]

I asked the sams thing and was told unless your laying down big numbers or boost by blower you dont need 1 7/8. But i like most people because we always want everything bigger

 

[BlackNDecker]

Pretty much every before / after dyno test of NA GT with ARH or Kooks headers I've seen used 1 7/8:shrug:...I honestly don't believe I've ever seen a magazine or internet forum test of 1 3/4 headers.

 

[Highway Star]

I made 60 hp from stock to cld air kit, kooks, x-pipes and axle back cans. 350 -410

 

[twistedneck]

I asked the sams thing and was told unless your laying down big numbers or boost by blower you dont need 1 7/8. But i like most people because we always want everything bigger

Plenty of write ups on 1-3/4" not only that most of the 6.2L GM aftermarkets are still 1-3/4". i agree given the choice for race car i'd go big but now that i'm stuck with 1-3/4" and read every study under the sun there simply is minimal difference. not even the theory about low torque gains with the smaller pipes holds up.

looks like with our engine 1-3/4" is already more than enough diameter if you have a well designed collector.

 

[BLK2012GT]

I went with BBK 1 5/8 and more then likely in the future I'll be swapping them out with Kooks 1 7/8.

 

[sambandit]

Well, I heard Kooks isn't doing 1 7/8ths anymore because of fitment issues. Don't know if it's true or not, but that's what I heard. I went with the 1 3/4.