Git Er Dun

The car is a 99 FRC that I am putting a 442ci LS-7 into. Horsepower should be around the 700hp mark at the crank normally aspirated. I am building this car for the Cannonball run:One Lap of America, NASA Super Touring Unlimited, and HPDE road racing.

I am looking at the KOOKS Long Tube 2" race headers with no AIR/EGR and the LS-7 D-port flange. Seen here: http://marylandspeed.com/kooks-2-lon...r7-p-2237.html

Then I am looking at KOOKS X-Pipes that are 3"X3" bit it looks like they all might neck down to 2.5" at the end of the X-pipe. Does anyone know if this is true? See here: http://marylandspeed.com/kooks-3-x-3...07s-p-990.html

I would be getting them coated with Jet Hot 2000 coating rated to 2400 degrees (flat black) seen here: http://marylandspeed.com/jet-hot-i-7.html

I am wondering what the largest diameter pipe that you can fit under a FRC is? I am wondering if I but just the X-pipe without the tubes to the headers seen here: http://marylandspeed.com/kooks-3-x-3...11s-p-993.html

if I could have some 3 1/8" or 3 1/4" or possibly even bigger made up to connect the headers to the X-pipe.

I am not very familiar with C5 stuff because I just bought the car and am in Iraq and have not seen the car yet. Does the X-pipe connect right to the over axle pipes that connect to the mufflers in the C5's so that is why the X-pipe would neck down to 2.5" at the end of it? Do any companies make 3" pipes to go over the axles or is that going to be something that needs to be custom bent for me? Are there many good C5 mufflers that have 3" inlets?

What would you guys recommend as a muffler for a car with this set up? I am not really to concerned about DB limits and emmisions stuff as the car is going to be loud regardless. I am also thinking about adding electric cut outs just for fun but with 2" primaries and a big diameter exhaust it might be loud enough without cut outs for when I want to play around on Friday nights cruising with a few car buddies. I know I want some restriction in the exhaust system but I figured that with the 2" primaries and at least 3" exhaust that by adding a good flowing muffler it would be just about perfect. A little more restriction than straight pipe racecars but pretty much perfect for a car with a muffler.

So what are your guys experiences or knowledge on this subject matter? Thanks a lot guys.

AU N EGL

Contact Kooks. They should make anything you need or advise you.

Aardwolf

I'd use Swain tech over Jet hot. http://www.swaintech.com/

Git Er Dun

It's actually for this deal: http://forums.corvetteforum.com/c5-z...save-more.html and if you order the x-pipe it looks like you get a free coating. I don't know if that includes the 2000 coating but I would see if I could pay the difference between the coatings offered. This is another coating they offer for free: http://marylandspeed.com/pmfl-header-coatings-i-8.html

but it I thought the Jet Hot 2000 coating looked better. I looked at Swain's site and they look pretty good but if free coatings are included with that deal them I think I would rather buy an X-pipe and get free coatings...just a thought though. Any other opinions on Jet Hot coatings or Precision Motorsports of Florida coatings or on the first questions I asked?

trackboss

Not to derail your thread, but it sounds like you want to build a wicked race car. You really need to choose between race or street car. If its gonna be a race car I'd suggest you go to a large diameter single exhaust with a proper "Y" merge. You can get those from SPD exhaust. That will limit you to either dumping the exhaust underneath or cutting a hole in your frame with proper re-enforcement and going out the side.

spazegun2213

You might want to contact American Racing headers. They built me an exhaust for my race car, without any problems. They love helping out racers!

But a 2" would probably be fine, although are your exhaust ports 2"?

also, if its a race car and you are not concerned with DB limits, why have mufflers with cut outs??? seems a little needless to me.

Git Er Dun

Yeah I thought about that option already but I really need to have some sort of muffler. For the Cannonball Run:One Lap of America you still have to drive around 5,000 miles on public roads to get to the next race course. To do that I wanted to be somewhat street "legal" and not as blantantly obvious as a straight pipe racecar with side exit exhaust. I also will still have a passenger seat in because you need a co-driver for the One Lap and I sometimes take passengers on track at HPDE's. My buddy has a World Challenge car (C5Z) and has side exit exhaust but the pipes run through the passenger side floorpan a little so I don't think I would be able to run side exit and a passenger seat and I won't be able to fit a flowmaster 40 series or anything underneath the middle of the car I don't think. Keep the comments coming guys.

gkull

I don't quite have that much power out of my 434 ci, but I use dual 3 inch with "H" pipe into 3 1/2 in and out stainless packed race mufflers. So sound is very acceptable until you floor the gas petal.

I also have a friend with near a 1000 hp with N2O 565 ci and he is running a 4 inch oval setup with 4 inch race mufflers

With 2 inch primaries you might have a 3.5 inch collector. You would want to use 3.5 inch pipe

Git Er Dun

What race mufflers do you have and do you have any good companies you would recommend for race mufflers? Do you think I could fit 2 race mufflers underneath the car somewhere? The collectors go to 3" at the end so I would run a 3" pipe most likely I guess since the X-pipe is 3" also. Any videos of your car running on track or with your exhaust set up?

Git Er Dun

What is a good axle back set up that is 3" they all seem to be 2.5"?

0Randy@DRM

LGM and stainless works both make 3 inch pipes over the axle.

Randy

Git Er Dun

Thanks Randy. I have been thinking a bit today about that race muffler idea. If I put the Kooks headers on with the 3" primaries and then had a small pipe on the headers to a small race muffler per side and then dump them underneath the car or would I have to go out the side. Does anyone know a good race muffler that will fit under the car somewhere close to where the headers end? I know a lot of race guys run the exhaust out the side. Is there any advantage to going out the side vs dumping underneath right after the mufflers?

I did a simple search for race mufflers on JEGS and found out that most of their cases external dimensions (total footprint of the muffler) is anywhere betwen 3.5" wide to 5" inches wide...some are wider but most are roughly around 5" diameter. Stainless works makes the smallest diameter one at 3.5" wide and 24" long. See it Here: http://www.jegs.com/p/Stainless+Works/755753/10002/-1 or a chambered round muffler that looks to be near the same dimensions but is 30" long and possibly louder seen here: http://www.jegs.com/p/Stainless+Works/758762/10002/-1 . I am guessing the 5" case dimension mufflers will not work under the car but I am guessing that the stainless works race mufflers that are only 3.5" X 24" or 30" would work under the car right after the headers. Would it work to just dump from the end of the mufflers there or would it be an advantage to dump out the side of the car? I am thinking that the end of the muffler would be somewhere clost to the center of the car and almost as far back as the rear tires. If the only issue with this would be heat inside the cockpit would a heat shield (like those flexible silver blankets some people have) work to keep heat out of the inside of the car?

Thanks for any imput guys. -Eric