I need to rethink the muffler system on my Hemicuda racecar, as it hits the ground on the Nurbrugring way too often. What low profile muffler would you recommend behind a HEMI that revs up to 7,500 rpm ? Which mufflers flow the most ?

We currently have Borlas with 3" inlet and outlet and a pair of Supertraps exiting both on the right side of the car, but they are both too low.

I'd like to put the muffler under the rear seat and then exit at each side without using the Supertraps anymore, but just an oval 3" stainless steel tube. To achieve that, the mufflers need to reduce sound more than the current ones, but without affecting flow.

Any idea is welcome

Do you have a crossover pipe? if not that will help a little. Lengthening the pipe will help a little as well. Can't comment on which muffler would be best though. Borla's are reckoned to be one of the best IIRC. Dynomax as well.
Do you have a db limit to adhere to?
Edit: Found this but principle is the same. http://www.pontiacstreetperformance.com/psp/exhaust.html
HTH's

Thanks :-)

Think you are going to need to raise the mufflers and pipes into cut sections of the floor boards and frame.

Any pics of the car at the 'ring?

Dynomax Ultraflow SS. Straight through muffler that does not effect power. they are quiet at idle, but they do tend to make some noise behind a healthy Hemi.
You can get them in a size that should fit under the back seat.

Ive have your style as well as some magnaflows 3 inch in/out and your on the right thoughts on tucking them under the back seat area.

The newer the magnaflows the quieter they are. I spin over 7200 in a street car and really all I can say in a respectful way is what the are you expecting with that kind of rpm?

There is one muffler that has a 3 inch in/out on the front side and your also correct about running the oval or rectangular pipes out in front of the rear tires.

With a little patience you can get a full size magnaflow on each side and they can be flush with the lower frame rail.

With tti-s and a 3.5 collector into a X pipe my lowest point is the deep trans pan and from the side the car looks like it has no mufflers on it.

Here is a couple ideas.

This system is almost 15 years old and from time to time I will pull it and run 1500 wet sanding paper over the pipes and polish them up good and they last 3-4 years.

I just replaced the magnaflows and the newer ones are the same specs just in SS.

They look closer to the floor in the pics then they are, a good 1/2 inch and you can see no melted rust proofing and they also work as good nitrous bottle heaters if you mount the tanks inside over them.

I see there is room on each side of your fuel cell, you could also run 3 inch tails out the back and run a second set of mufflers if needed.

I feel the magnaflows are a bit more quiet then the borlas I have but both bark at wot.

Everyone has there preference clearly, but ive found no drone
Issues with either.

I have one rig with, um dammit I cant think of the name but they are the 2 chamber ones that have too much of a ting to the note. There the ones you see on most chevy guys love so much.

Also as mentioned a X pipe is nice, I have a bit bigger then normal one with flanges on the header side as well as the muffler side so its an easy drop to pull the trans if needed.

But I do like hearing the sound of each cylinder going through the headers.

They are the std full size universal muffs.

Good luck, which ever way you decide to go.

Cool.............do they come in 3 1/2"...............?

If you put flanges on both ends as you can see the in the edge of this pic each pipe unbolts from the backside of the X and the others at the header flange and the trans drops right out.

Maybe not the best overflowing system but if you want to tighten things up underneath you got to give a little.

One other idea is a guy in ebay always selling 70-s era show tubes that are a 4 inch diameter. For about $150 a pair.

A fenderwell header or a made shorty header or some creative oval pipe work and you could run 4 inch pipes down the side. With one good benefit.

The guts come out so the can be cut to fit you noise level and also be repacked if needed.

GUTS I drilled each hole to 2x the diameter then started to shorten and cut the packing.

Another plus is you can easily take out the inserts and run a wide open system that everyone will hear.

More guts.

Just noticed the pipe under the middle of the exhaust. I think you need to cross over near the tailshaft and get both mufflers on one side of car.



You can weld Spintech mufflers side by side. Then put a box in your passenger floor for them.

http://www.circletracksupply.com/product.php?productid=4386&page=1

I have been kicking around the same issue with my Dart, tailpipes are not an option (fuel tank to wide), and to have the muffler tucked up in the back seat recesses I would need some T/A Challenger style S abortion that I don't want. Just dumping it is how the car has been since day 1 but traveling in the car with wife and kids gets noxious. I plan to use these Spintech mufflers that do what a T/A exhaust does but they do it inside the muffler case which saves a huge amount of room.
http://www.spintechmufflers.com/sportsma...i23o7mek051iv95
http://www.spintechmufflers.com/images/uploads/STREETMUFFLERS/349sct%20web.jpg

Have you considered oval pipes? I'm really not sure who makes them but I've seen them and there's mufflers available also that have cases that are not much bigger than the pipes. I believe Pype's and Spintech make these.