SMR#002

iTrader: (9)

I have a 99 Camaro and has nothing but a borla catback, and its very quiet. Im looking into a set of longtubes. ive been looking at kooks 1 7/8 primaries to 3in collectors, is that too much for a stock car? I hear only get 1 7/8 if you have 500+hp. My other question is should I get the headers with O2 bungs because I have to do emissions. For my mustang the O2 are turned off but apparently the new emissions updated program can detect O2 when they're turned off. I saw some O2 sensors relays that send the right signal back as if the O2 were functioning correctly, are these worth it? or can that be done in a tune and pass emissions? I want to do a x pipe setup to dumps when I get the longtubes. thanks for any help

BrntWS6

iTrader: (7)

Unless your getting 1 3/4" for a hell of a deal go 1 7/8". Its not too much even on a stock car and you'll be better off the more you modify.

JOHNNY59

iTrader: (398)

pm sent

SMR#002

iTrader: (9)

That's what I was thinking. Headers aren't exactly cheap, id rather spend the money on them once.

big hammer

1-7\8 ftw

big hammer

I remember seeing a dyno comparison of 3 different headers on a stock ls3. 1-3\4, 1-7\8 and 2". the 2" made the most power.

SMR#002

iTrader: (9)

What about the emissions aspect? Do I need to buy one of those O2 sensor relay things, or will I be able to pass on a tune?

NolaTA

iTrader: (4)

You'll have to hook your front o2's into your headers, you'll probably need a catted y or true duals with cats so you can hook up your rear o2's in order to pass emissions.

SMR#002

iTrader: (9)

So I cant go catless with a tune and pass emissions?

JOHNNY59

iTrader: (398)

have a set of polished stainless steel Kook's 1 3/4" headers and their high flow catted y-pipe for sale less than a year old.

z28SSilvest

Congrats on the decision to go with Kooks. You won't regret it, 20k later and mine still hold up perfectly as well as the gaskets that come with them. If you have to keep your air and EGR as well as pass a smog test when it comes time for DMV, get the Headers with air and egr as well as a catted Y pipe. Trust me, it will be plenty loud. Here is a youtube video I uploaded right after getting my headers on:
Disregard all the rasp, I had a small exhaust leak that a local exhaust shop fixed for me the next day. Keep in mind you will also want to get a tune, as it differs from LS1 to LS1 whether it runs rich or lean; a dyno tune, or street tune if you can't find any nearby dyno shops, will make it just right. As far as deciding between 1 3/4 and 1 7/8, honestly go with the 1 7/8. I convinced myself I would never cam my car and bam, 10 months later threw a new camshaft in there and am now looking at heads to go with it. Just remember, once you start modding, there is no ending

PM me if you have any other questions about Kooks, I am extremely happy with mine.

SMR#002

iTrader: (9)

Thanks a lot for the responses! I still want to go catless, is there no way around emissions testing? would something like these http://www.ws6project.com/user_stor/...oducts_id=1599 help me pass emissions? thanks for the help guys

z28SSilvest

Yea those will work or you can just have the rear o2 sensors tuned out. Like I said it depends on your states' DMV laws. In Delaware we just have OBD II checking, so I go catless and have all the codes tuned out.

BoricuaHec01

OP, if you live in Chicago then you should be fine catless if you get the rear o2 codes deleted, you'll pass emissions.

Holloway5

If not you can also buy 02 simulators. Speed inc sells them, or if you get a tune you can have them deleted. As long as it doesn't throw a code, you're fine for Chicago.

SMR#002

iTrader: (9)

This has worked in the past, but some guys on the mustang forums went in for emissions and I guess the new program knows when the O2 sensors are turned off and they failed. So the O2 simulators will remedy this?

BrntWS6

iTrader: (7)

The older hi-flo cats would only cost you 2-3hp, these new ones I've read don't lose any power and you won't have to deal with any stank in your car.

SMR#002

iTrader: (9)

Everybody likes a little stank in their cars thanks for the input guys

RedDeadG8

iTrader: (3)

you will probably lose some topend torque and gain a few HP where you sit now. I went with the 1 3/4 when i first started modding my Camaro, now with a 383 I have 1 7/8. So if you're going to do headers, do it once and be done, otherwise you'll pay twice.

z28SSilvest

OP, I just found this, might want to check it out.
https://ls1tech.com/forums/generatio...xperience.html