Modifying Kooks race ls tri-y headers for g-body???

[jlcustomz]

Been wanting tri-y headers for years now. My 12 year old ls1 swap is not a kit, so may need some modification to anything anyways. Also, many premade headers aren't quite as optimum as could be hand built anyways, so I'm getting set up to do this sometime next year. Also just like being different. Make no mistake, I DO HAVE a pretty good idea on difficulty, but with the aid of pictures of premade g-body ls headers, f-body headers & custom headers, such as the discontinued ATS tri-y, I have a little side view layout help to go by. Already have a good idea of what to do on sideview layout to fit & be closer to equal length primaries than most production headers.

Picked up 5 damaged right side headers for pretty cheap at Daytona. Can later resell the 3 extra tri-y collectors. Here's a link to the original Nascar K&N series headers I got.http://www.ryr.com/headers-kn-pro-series-right/

Any advise other than don't try is appreciated. Also keep in mind I'm also the idiot also making his own ls intake. Guess I live for punishment.

[jlcustomz]

Got a little over an hour put in yesterday on cutting 1 header up into useable parts. Little bit of a pain trying to cut the welds back at the collectors without cutting into the pipes too much.

Pretty confident I can get close to what I need the new layout to be with a few patterns I made (tack welded only) for a test fit.

The scariest thing so far is I was quoted locally $350 to $400 to strip & re-ceramic coat a pr of tri-y's . Ouch

[jlcustomz]

Got a pile of parts cut up & a little better pattern jig setup.

Guess no one here so far wants to touch this subject with a 10 foot pole. I can understand why. The seeming difficulty of these projects always escalates once you really get into it.

[jlcustomz]

Got the pass side tacked together, ready for test fitting. All primary tubes right near 32.5" equal length.

[jlcustomz]

drivers side tacked together. Did large tack welds with little penetration so pipes can be cut apart easier if needed.

[no go nova]

Im at work and can't see the pics but nice idea. Now wouldn't this save you from having to run a X pipe or H pipe?

[jlcustomz]

Im at work and can't see the pics but nice idea. Now wouldn't this save you from having to run a X pipe or H pipe?

NOPE. An x or h is to balance the 2 sides of your exhaust. X is usually slightly more beneficial of the 2. The tri-y setup when done correctly, can increase low & mid range output, & sometimes still make more top end power than a 4 way collector. This is tricky to get right & I don't exactly own a dyno for repeat testing. I'm a little large on sizing for my current engine setup, but plan on changing that later anyway.

One idea I may do for decoration is have a small spear shaped (like Pontiac emblem) piece of polished stainless at the top of the collectors approx. 3" long. Just something to look cool that nobody else has.

[cornfedbill]

Looking good. I used to visit the Pratt & Miller ALMS team garage from time to time when my son worked for them. I used to drool over their tri-Y race headers.

Your modifications to fit your car are looking good.

[jlcustomz]

Thanks Bill. I've wanted tri-y's for years but I never thought I'd venture into header building myself. But after starting the intake project ( which I haven't touched since September), I have a little more pipe cutting skills.

Ton of different opinion & specing in header building here. I went 32.5" x 1 3/4" primary tubes into the Kooks 1 3/4 to 2 1/4 to 3 1/2 merges. Someone suggested speaking to Burns stainless, which spec'd using 1 5/8" x 27" primary tubes into 1 7/8" x 13" secondary tubes into 2 1/2". OUCH. They then said, since I started laying out with 1 3/4" tube , I could go 36" length into a 4-1 merge collector.

Discouraged by their answer, I figured to call Kooks & explain the project. They said it should be fine, go for it. Said it would loose a little low end over optimum, but tuning would take care of that. When I asked if I'd be better off with a good 4 -1 merge collector, they said NO. So back to where I was. I think the Kooks tri-y collector sizing works more like a really good merge collector than a sensitive to tune set of tri ends. ??? Who knows.

One thing I've done different here is I actually haven't fit them to car at all yet. I used a bunch of f-body & G-body header pics for side view reference next to the kooks headers. Then I did a bunch of 3-d measuring on my assembled vehicle, particularly noting the worst obstructions, such as lower suspension arms. Made wood jigs to lay out on & tried to get most of the pipe running hopefully extra clear of obstructions. The top of the tubes near the flanges in particular will be easy to angle the bottom in & out of before final tig or gas welding. I'm hoping for the best , with some backup plan in mind.

I'll also be getting rid of the pathetic 2 1/4" exhaust still I place that a local shop insisted in 12 years ago. Doing my own 3" setup with pypes x-pipe, race pro mfflers, some new straight 3" pipe & reconfiguring some used late model stock truck tailpipe with mandrel bends. Will reuse my cutout setup & 3" into 4 center tailpipe setup.

Lot of work, but should make a decent improvement over existing mid length headers which I measured @ 1 9/16 tube od & the 2 1/4" crush bent exhaust.

[cornfedbill]

I'm eager to see the finished product.

[Rwolf15241]

Don who did My g Body frame work, gets headers coated fro around $ 220, I'm looking for headers for my LS3