i want to make my exhaust a true dual loudmouth WITH dual cats. but, unlike other true duals, i dont want an X or H pipe. I've attached a picture of what I want exactly. (the black circles are meant to represent the tires, in case you were wondering). is this setup possible, or would it be an unequal distribution of the exhaust, or create serious clearance issues, etc.? the pipe all the way through is 3" in diameter, and the tips will come out right under the side skirts in front of the rear tires on their respective sides. the only other alternative i can think of if this is too hard to get the tips in those locations, is to have turndown tips right after the loudmouths. feel free to make any comments, recommendations or anything. I want to get this project moving ASAP.

Thanks,

-Rich

Click to view attachment

Plenty of people have turn downs after bullit mufs right in front of the rearend.

Your duels to the side may be possible with the new oval pipe from muffex.
The reason for the "X" is to build more bottom end torque but it isnt necessary in an exhaust system.
Lots of old muscle cars had the design you drew

so which one in your opinion would be a better, or more unique system? would the turndowns underneath the car cause for a lot more heat and noise inside the car, or would it not be that much? similar thing for the side exit exhaust, would it cause more heat/noise to go into the windows?

whats the mufflex oval pipe? i tried to google it, but found nothing on it.

thanks.

Mufflex owns Spintech muffler

Click HERE for Spintech

You need to get the info and do some measureing. Maybe tape a chunk of foam the size of the tips to where they will go for a look and drive around places you may think you'll have clearance trouble and see what you think.

If you dump in front of the axle it will be a lot louder in the car and there is exhaust fumes that may get in - CO poisoning is a possibility. Some guys on another forum have dumps but I'm not sure if they are street cars. If I couldnt go out the side I go out the back - but thats me. I've had side exit pipes on other cars before and didnt have any problems. Not on a f-body tho.

If you are running a true dual without a crossover, you do not want 3" unless you are using a twin turbo setup. You would actually want closer to 2" or a 1 5/8" to keep some of the back pressure. That is where most people go wrong and let too much out and hurt performance.

As Formyla stated, Spintech would be a good choice to keep the clearance issue at a minimum.

Matt

Why do you want "back pressure"? Exhaust back pressure it a myth that arose because of the need to retune carbureted engines when you opened up the exhaust system and improved volumetric efficiency, leaning out the A/F ratio. A simple adjustment of the carb restored the lost power, and then some. Not an issue with a modern closed loop EFI engine.

Back pressure reduces flow. Reduced flow reduces HP. You do not want or need back pressure. Suggesting that you could effectively push the exhaust from an LT1 through a pair of 1-5/8" pipes is ridiculous. The stock intermediate pipe is 2.75"...... equivalent in area to a pair of 1.95" pipes, and the stock exhaust is a restriction to stock HP levels. The typical 3" catback nets 10-12HP on a totally stock engine. More flow area, less back pressure = more HP.

If you were talking about the primary tube in a set of headers, 1-5/8" is marginal for a stock LT1. Any sort of mods, and the 1-5/8" primary will choke the engine. 1-3/4" is a better choice.... but that's for the primary tubing, not anything from the collector on back. I wouldn't put anything less than a 2-1/2" diameter dual exhaust on a stock LT1, and a 3" dual setup will produce good results on a modified engine.

I run basically what the original poster is after, except for the side exits. 3" collectors on AS&M headers, Borla XR-1 straight mufflers bolted to the extended collectors, and 3" pipes dumping in 90-deg turndowns near the rear axle. The system was custom built by Mufflex in their shop in Trenton, NJ (I wasn't aware that Mufflex owned Spintech, at least Denny, the owner has never mentioned it to me.) Denny was considering going bigger than the 3" duals, because of the 300-shot. Before the duals, I ran CarSound cats, a custom built Mufflex 3" Y-pipe, and the 4" Mufflex catback... a 4" intermediate pipe has the same area as a pair of 2.82" dual pipes.

Injuneer, How was the sound level? and did you have any fume getting into the car problems?

my bad "Distributor Of SpinTech™ Exhaust Products" not owner of

Rico, dont you live up near there?

I think Dr Gas also sells some flat tubing for exhaust but do a search before you quote me.

I posted a photo and a link to a dyno pull in this thread:

http://www.theformulasource.com/forums/ind...showtopic=14574

Sounds good-n-strong

How loud is it in the car on the street?

Comfortable?

I just want to remind Rico that while all here have given some great info, '82 and newer f-bodies were not designed to accomodate a true dual set-up underneath the floorpan. No matter how you do it and what tubing you use, ground clearance will decrease. I am fully aware that plenty of people run given systems, but the fact remains so how worthwhile it is to any one person depends on intended use of the car and where. Flat open rural roads and highways it wouldn't be as much an issue, but if you spend any time on city streets with transitions to parking lots and side streets or speed bumps, pipe will scrape sooner rather than later.

Not trying to rain on the parade, just figured the point was valid enough that it needed addressed

I also want a dual design like the drawing. For other clearance issues on the muffler back and out the car, you could run boom tube piping. (like Nascar uses)
it is a wide flat pipe about 1.5" thick by 8" wide to equal a 3" pipe. DR gas boom tubes...here... www.DRgas.com