Anyone tried different header types in the SLC? I don't have the car yet, but from everyone's images it looks like there's no room for long tube or anything exotic like 8:1 or 180s, but how about 4-2-1 tri-y or other types? Thinking of trying to shift the exhaust note up a little, not easy to do on an LS engine.


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There isn't an issue doing long-tube headers if you plan it out. It's been done multiple times. A Daily dry sump will allow you to cross primaries under the oil pan. I had an 8:1 mocked, but I was worried about heat concentration. So, I did the following for my built LS7:

*Equal-length long-tube headers
*180-degree cross under
*Merge collector tubes fire in correct sequential rotary pattern (one is clockwise and the other is counterclockwise)
*Primaries step from 1-7/8" to 2"
*321 stainless steel
*Sparkplugs are easy to remove
*Like many exotics, engine must be removed to remove the headers

Requires four of the 2" x 2" chassis tubes to be scalloped and a Daily Engineering dry sump which requires you to relocated the A/C compressor. I'm working on the cat-back system now. Post cats everything is 3.5" titanium. There are cutouts and an x-pipe. These pictures don't show it, but four primaries cross under the pan.




That's a fantastic setup. Don't know if I'll go so far as to dry sump for a 180, but I'm definitely cosnidering an H or X for the exhaust if I go more conventional. Without seeing it, what was the heat issue with the 8:1? Just 4 big heat radiators a side?


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I did the dry sump so that I don't risk blowing the engine when running slicks on a track day. If it was a race car, I would have lowered the engine several inches, but it's a street/track car so I kept the engine at the stock height and crossed primaries under the pan.

Note that my x-pipe fits under my Albins transaxle. If you look at the pictures above, it has a lot more space under it than most. That location wouldn't work with a Ricardo and I assume a Graz, but I'm not sure about Porsche, etc.

To fit an 8:1 within the bodywork you will need to cross 4 primaries from one side to the other. With and LS the only way that I could figure to do it was under the engine which requires a dry sump. Then you need to do some gymnastics with the long primaries on the other side to create equal length header and stuff it all into the merge collector. The correct way to do it is to have all of the primaries firing in a sequential radial pattern. I spent a lot of time with icengineworks and I was able to achieve equal length primaries with proper sequence with 1-7/8" tube (I didn't get around to attempting to step up to 2" at 17" or so which is necessary with my power level). Two primaries crossed under the dry sump and two under the transaxle.

Here a couple of pictures or an early iteration - there were many. Note that you'll need a lot of icengineworks blocks (i.e., more than one of their largest packages) because you must model both sides at the same time. As you can see I had a plastic engine block and a mock bellhousing and transaxle case all mounted to some plywood. I can't imagine trying to model something this complex on the car.



You will note that the merge collector was aft of bellhousing. It would have been nice to stuff a bunch of tube into the triangular section to the right of the engine above (i.e., outside of the angled billet pieces), but as shown below my cold air box is in that location. I was able to get it to fit but it would have been difficult to get in and out and there would have been a lot of tube in one concentrated area which would have generated a lot of heat.

As I was mocking it, I kept thinking of the "A Bridge Too Far" movie which didn't end well for the Allies...

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I think Shane at Vraptor Speedworks is a site sponsor? He would know, he does Kooks header group buys for other mid engine cars, has built SLCs among other things. Nice guy.