01 MidMet WS6

iTrader: (4)

I am wondering what kind of differences and recommendations that anyone out there running Kooks headers has on primary diameter selection. I am looking to put a set of Kooks headers on my 01 ws6 m6 and am curious what size primary would be best suited for my application. The car will have full boltons shortly and will most likely end up with heads and a cam within the next two to three years. As for right now when I purchase the headers I will also be installing a Kook's ORY and Corsa exhaust. Will I be buying new headers later if I go with the 1 3/4" now. Or if I buy the 1 7/8" will the car have issues until more modifications are done? Are there any drawbacks to running the stepped headers aside from cost. Are there clearance issues with running the larger tube headers. Any info/ Dyno/ performance results would be greatly appreciated. Thanks in advance!! Also I have been shopping around and it looks like Marylandspeed. com has the best pricing, anyone purchased from them before?

I also put in a pic of the car they will be going on, I just picked it up on Sat. and can't wait to start "playing with it" any mods will be docummented as I have access to a Mustang Dyno.

bigcraig987

1 3/4" - usually bolt-on cars h/c cars
1 7/8" - usually strokers
1 3/4" to 1 7/8" stepped - usually BIG cam, supercharger or nitrous
1 7/8" to 2" stepped - pretty much "race car headers" your going to be running a big cubs and spraying alot of nitrous to take advantage

That is what it typically seems for the uses. I am currently running the 1 3/4" Kooks with ORY and corsa catback and love them. Great clearance, sound, and performance. I have not had it dynoed or tuned yet since I am waiting for after the cam I am going to get, but it will give more performance after tuning since it will be a bit rich after the install. As for install, it went alright, passenger side easy, thing to watch for is when doing the driver side header, if you cant get the car high enough to go in vertically with the header like its designed for you may have to unbolt the motor mount and rock the engine or fully unbolt the mount and push it forward to get the header it in there. Almost forgot, as for running the 1 7/8 with just bolt ons, I have not heard much from people doing this but they said it didn't really hurt the low end torque too much, but I have not heard of it helping that much more either. Maybee others have more experience with it.

bigcraig987

I just noticed there is a sale on them in the group purchase / sales section so you might want to see about getting them from that

01 MidMet WS6

iTrader: (4)

Thanks for the input, did you notice a performance gain after your install? Any driveability issues afterwards?

TheBlurLS1

iTrader: (8)

The 1-3/4" will probably work best for you, they will handle a H/C car easily. The 1-7/8's require you to grind the k-member, and they are a bit harder to install. People have also reported a few lost bottom end ponies, but I didn't feel any loss when I swapped. One of our other mods did a back to back comparison between his 1-3/4's and 1-7/8's on a bolton car and the power was within 1-2hp throughout the entire curve.

You're really going to be pleased with the Kooks headers/y-pipe, they tuck up VERY nice. That car looks awesome.

PS - As always, I'll suggest you to put in poly motor mounts while the exhaust is out. You can do a little searching/reading and find enlightenment.

gollum

iTrader: (1)

Quote:
Originally Posted by 03 BUSA
I just got done installing last week. With Poly mounts I still had some issues with the right side just touching the K-member. I pulled header back off and with a BFH and the use of a dremel got it to clear. That was with the 1 7/8 long tubes. I think with the 1 3/4 it would have cleared no problem.



Regarding Kook's 1 7/8 headers

Read here also:https://ls1tech.com/forums/showt...ok%27s+pictures

bigcraig987

I did notice gains after the install. The only real thing after install was that it is a bit rich, that happens after any lts really and will be fixed with a tune

ChocoTaco369

i've heard from a lot of people that even on H/C cars, 1 7/8 headers don't even show gains over 1 3/4 headers. it's just extra spent money. of course, that's hearsay. IMO, stick with 1 3/4 headers. i don't see a point on on running 1 7/8 headers unless you like spending more money for headers that are A LOT harder to install and will have many clearance problems. of course, again, that's my opinion. don't take it as gospel.

01 MidMet WS6

iTrader: (4)

Thank you all very much for your replies, it looks like I will be ordering the 1 3/4" in the next couple of days, the car is heading down to the dyno on Friday with just a lid and a flowmaster for a baseline. I will post before and after results if anyone is interested.

MarylandSpeed

iTrader: (11)

You can't go wrong with Kooks. The stepped headers are mostly for stroker applications IMO. They are also custom made to order and take a while to get (we are one of Kooks top 2-3 vendors...so I know too well). Unless your doing a stroker I see no need for the added cost and complication of stepped headers.

I say it comes down to 1 3/4" vs 1 7/8". They both will fit the same so that is not really an issue. 1 3/4" will be good for up to about 450-470 rwhp according to the tuners we send our customers to. From there on up, there will be flow need to run 1 7/8". That being said...a lot of GTO guys run 1 7/8" headers on stock car's with no ill effects...they may bog on a stock LS1 however.

If you have any questions give us a call at 443-730-9428 and we will help you out. We spend a ton of time helping people make header decisions all day long. We have always sold a lot of F-body parts and have fantastic feedback on the other large forums we sponsor.

Thanks!

01 MidMet WS6

iTrader: (4)

Thanks for the input MarylandSpeed. I have already placed the order through you guys. The Corsa Cat back showed up and it is installed, I absolutley love it! Can't wait for the 1 3/4" headers and ory!!

greatskiiiier

iTrader: (10)

I have QTP 1 7/8 untuned until the 30th, not the power i was expecting... My friend's claim a nic ehit to my torque

If you could post that chart/ link so I can compare to my car in the next 2 weeks, it'll be greatly apperciated.

TheBlurLS1

iTrader: (8)

Search posts/threads by SUX2BU, he's the one who did the comparison.

99blancoSS

iTrader: (115)

Heres something that doesnt happen very often taco is wrong.
The 1 3/4's and 1 7/8's are the same price.



Its the stepped headers that are more expensive. (1 3/4 stepped to 1 7/8)

Also when I ordered my stepped Kooks from Texas Speed they were in stock. They also installed easier than the SW's came out. All you need to do is remove the oil filter is what the instructions say. And they do tuck up very tight. The y-pipe was of much better quality and construction as well.

01 MidMet WS6

iTrader: (4)

Finally recieved headers and ORY y-pipe. The headers are beautiful, installation was a breeze. Y-pipe took a little more persausion to get everything to fit right. The Corsa cat-back bolted right back into place with a little adjusting. I am suprised by how LOUD this setup is, the tone of the car changed completely. Below 2500 with the windows up you can't even hear it in the car, from 2500-2900 it has a strange gra-gra-gra-gra noise that I am not completely sold on, from 3000-4100 it starts to come to life and anything over 4200 sounds orgasmic! Definitly a power increase, overall very happy with results, will post dyno in near future.

SSpdDmon

iTrader: (10)

I believe 1 7/8's is just too big for any stock cubed LS1. There's write-ups on the net if you search Yahoo!, there have been tests done on engine dynos, and the results seem consistent. They're just too big. Go with the 1 3/4's and don't look back.

93TAWicked1

iTrader: (28)

I agree, the problem is someone like me with who actually made 500rwhp (well 473 on a mustang dyno through a 9inch) with old Grots and catted QTP Y, I needed to go with a new setup and chose the 1 7/8's I don't know if they are too big for the 388 I have but I figure they will be just right if the block holds up and I go to a 427... I'm going to do a dyno afterwards but there are really too many variables to know if the 1 7/8's gain or loose anything....hopefully made the right choice!

ino

iTrader: (1)

Sweet looking car and when my warranty expires I think kooks is the way to go.

01 MidMet WS6

iTrader: (4)

Oh and another thing I forgot to mention. The car rides on Sportlines and with the headers and ory tucked up as tight as they are ground clearance is not an issue!

99blancoSS

iTrader: (115)

No regrets what so ever with my stepped. All the car does is go.