I want to start the ultimate stainless steel LT header thread. Maybe it can eventually become a sticky so it can help out many people like me who have done their research but still can not decide what to go with (I DO NOT have headers yet). Even if it doesn’t come to a clear consensus, I hope a lot of info can be posted to help people out.

Although I am still a newbie, I have put in a lot of time searching and gathering info before posting this. There are a lot of threads that I have read through, and a lot of information. But the more info, the better right? This is a big decision (money-wise) and I want all the info I can get before I make a decision. Hopefully, most people feel the same way. So any and all comments are welcome.

Before I get any further, I want to highly suggest newbies and anyone else that is looking into headers to check out the post in JRP’s sig. There are pictures of all of these headers and a write-up about most of them. It is VERY helpful for starters. Here is a direct link:
https://ls1tech.com/forums/showthread.php?t=139142

From what I have found, the available brands of stainless headers are Kooks, QTP, Stainless Works, Dynatech Supermaxx, and Hooker (I just found these at speedinc.com). Bassani also makes stainless headers, but I do not think they are LT’s (Correct me if I am wrong please). Kooks and QTP seem to be the most highly regarded, but Stainless Works and Dynatech are fairly new and have had positive reviews. While Kooks and QTP are a “Grott” design header, SW and Dynatech are not. Whether or not this makes a difference in power is disputable, but I would love to have some info on this. Kooks and QTP offer a 3” collector and y-pipe, while SW and Dynatech offer a 2.5”. The smaller will obviously tuck up better. I have read varying arguments on which will make more power (comments?). QTP is the only one that offers a flowmaster merge in the y-pipe. In theory, this should be more free flowing, but that is also debateable. The stainless Hookers must be very new. I know they don’t offer a catted y, but QTP offers one with a merge collector, and TSP offers one that will fit as well. One thing I noticed about these is the placement for the O2 sensors is on the outside of the headers, which might be more difficult to deal with (I don’t know).

I have also learned quite a bit from talking to TTP (regarding Kooks via pm), QTP (phone), and Stainless Works (email). I will try to sum it up in the paragraphs below:

Kooks:
Kooks CAN put on high velocity merge collectors for $400 but they are only needed if trying to get every last bit of power. And about the y-pipe: He said that a customer put on a flowmaster merge on a Kooks y-pipe and lost about 7 rwhp. Kooks uses Magnaflow stainless steel hi-flow cats.

QTP:
This info is the hardest to remember because it has been a while and it was over the phone. Anyway, I remember QTP saying that the high velocity collectors will add power, but it’s basically whether or not you are willing to spend the money. It will be substantially more on a heads/cam car than a bolt-on car. The y-pipe comes in pieces and most of the trouble as far as the install has come from people trying to install it themselves. They said if you take it to a shop it should not be a problem. I can’t remember what kind of cats they use, but I am thinking Magnaflow/Carsound. Does anyone know for sure?

Stainless Works:
They use random tech cats in the y-pipe, which is 2.5” in diameter (similar to Dynatech but smaller than the 3” from Kooks and QTP). They can weld on a 3” collector but don’t offer a y-pipe to fit this (must be custom). The only other thing is that they are supposed to fit very well. They sent me some pictures which will be attached in a reply to this post.

Some links to more pictures:

Link with a lot of great pics of QTP headers and y-pipe (courtesy of Blacker):
https://ls1tech.com/forums/generation-iii-external-engine/173707-qtp-headers-installation.html

Link with some good shots of Kooks headers and y-pipe (courtesy of 99PTA):
https://ls1tech.com/forums/generation-iii-external-engine/220403-kooks-finally-installed.html

Link with pics of Kooks (courtesy of LawmanSS) and Stainless Works (courtesy of glennhl):
https://ls1tech.com/forums/showthrea...1&page=2&pp=20


After a lot of research, I still have some questions. I would appreciate it if I could get ANY comments that might help me with these questions:

1. Have there been any dyno or track results that show that certain stainless header/y-pipe combinations are better than others? In other words, has it been proven that the “Grotts” headers make more power than others?

2. Does a 2.5” collector/y-pipe lose or gain power over a 3” setup when going into a 3” cutout or catback, or is the 3” cutout/catback the main restriction?

3. Would a y-pipe like QTP’s containing a merge collector work with a cutout in the I-pipe, or would it go too far back?

4. What is the best choice for headers/y-pipe on a heads/cam car that will still run a catted y-pipe?


I have attached some pictures I have found of headers and y-pipes. These are just some more pics that hopefully can help out. Unfortunately, these are just saved on my computer and I do not know who to credit with the picture (except one, which has the username in the title). I will reply to this post with another set of attachments containing pictures that Stainless Works sent me.

Please help out with the info for this thread by posting more questions, answering questions, comments, reviews, providing links with info, pictures, dyno graphs, etc. I hope this helps some people, and I hope that some questions I have, along with others questions, can hopefully be answered in one spot.

 

The other 3 Stainless Works pictures that I have are too large to post, so if someone can tell me how to fix this or post them, that would be great. Here are the two that were small enough to post:

 

Great thread.
I like the QTPs the most personally.

 

I wish I still had my website up; I've got pics of the SW headers installed. They do tuck up real nice; I'm lowered 1.5". I had FLP's before these, and always had trouble changing oil; not with these, they are fine. I'm not thrilled with the SW merge collector, I may go duals soon.

 

Good job!

 

Anyone have any pics of the new stainless steel LS1 Hookers, just curious what they look like.

 

Thunder sells them for a G note. At that price, it might take a lil while. You can still pick up Kooks 1 3/4 SS for ~$750.

 

Very true, and even QTPs for $725.00, at those prices I can't really see anyone going with Hookers when the QTPs and Kooks are likely much better made and cheaper anyway.
I just wanna see if the Hookers look decent at all and if they're even using 304 stainless.

 

Thanks for the positive feedback so far. Does anyone have any feedback on any of these systems? How about more pictures or dyno graphs? Answers to my questions? More questions? Like I said, I've got 3 good pictures of Stainless Works headers installed, but they are too big. They were sent to me from Stainless Works. If someone can tell me how to resize them, lower the quality, etc. so that I can post them, that would be great.

Viper, you said you didn't have your website, but do you still have the pictures that you could post in this thread? Can you tell us anything more about your headers/y-pipe? For example, do you think you are giving up any power with a 2.5" collector? Is the "bad merge" just based on it not having a merge collector like flowmaster's in the y-pipe? Any info would be appreciated.

 

I would think that on a stock internals (bolt ons only) car that the 2.5" collector and Y pipe combo could be a potentially better set up over a 3", the only thing that might concern me is the way that the Stainless Works are 'stepped down' to 2.5" so abruptly at the collector, and even having such a short collector (the one thing I don't like about FLPs, Supermaxx's and SLPs as well).
It's argueable that even 1 3/4" header primaries might be giving up some velocity over 1 5/8" (or 1 5/8 - 1 3/4 stepped) primaries on a stock internals car but nothing has been proven there yet either so I'd still suggest a quality 1 3/4". But for a big cammed, heads and cammed and stroker motor I would think a 2.5" set up could hurt you...and of course that's the point when one considers a 1 7/8" (or bigger) header as well.
As for merge collectors, it makes sense to go with a Flowmaster (or even that Magnaflow version) style but plenty have made good power with the Kooks or Hooker style 'one pipe attached to the other' style as well.

 

Hope this helps. As far as power, hard to say. They pull hard up top but I feel the FLP's had more for down low. Bad merge - you be the judge by the pics.

 

Awesome pictures, thanks for posting them!

I think if a company would make 1 3/4 "Grotts" style stainless headers smoothly merging into a 2.5" collector and y-pipe (for better clearance), into a flowmaster merge going from dual 2.5" inlets to a single 3" outlet (to fit most catbacks), these would sell great. I guess that is at least what would be the best for my situation. And I bet that this would work great, even with heads/cam cars (which I plan to eventually have). I could keep my 3" cutout, have great ground clearance, excellent power, and more. Someone start making these!!!

 

I totally agree.

 

I'm installing some 1 3/4" QTP High Velocity Merge collector LTs tomorrow (replacing SLP's). I'll re-dyno, but it won't be apples to apples in comparo due to the addition of a 90mm lsx intake.

 

SouthFL.02.SS: Please post the results in this thread, that would be great to see. Thanks.


I was wondering, does anyone that has the QTP headers and y-pipe use a cutout in the I-pipe? I would like to keep my cutout, but from the looks of the installed pictures from the link in my original post (by Blacker), it looks like the Flowmaster merge goes back too far. This leaves no room for my cutout, which is approximately 12" long. If someone could tell me if they have made this work or have had problems with it, that would be great. Thanks!

 

I'm going to be purchasing Stainless Steel Kooks 1 3/4 stepped to 1 7/8 headers here in a month or two, simply b/c I'm going to be running a stock cubed LS1 that will be H/C/S eventually. I don't need full 1 7/8 headers, but I do think I will benefit from the stepped design on the spray. Plus the fact that I'll be running 3" true duals will help

 

T T T

 

So seriously, nobody can answer ANY of my questions? And nobody can do a quick review of their stainless headers and y-pipe? Or is there just that few people with Kooks, QTP, Stainless Works, or Dynatech headers? Come on guys, at least tell something.

 

SLP LTs are stainless and are coated. I could give you a quick review of those if you wanted...

 

My stainless works are not coated. The heat is much higher than the FLP's put off, that's for sure. Even with air running full blast, you KNOW you have headers. Now that my engine and tranny are out, I may get them coated locally.