[Will]

Looking for advice on the lowest restriction exhaust I can install on my Formula that will still have pipes that exit at the rear bumper.

Thinking of a Torque-Tech 3" system with X-crossover, but don't know what mufflers are best, and am also concerned about ground clearance on my lowered car. Never had much luck putting mufflers under the back seat...

The car currently has a Flowmaster 2.5" system with X-crossover and crossflow muffler, but I want something that flows better.

Noise control isn't as important as flow where the mufflers are concerned, the pipes exiting under the back bumper seem to tame down most obnoxious exhaust systems.

Any recommendations or ideas greatly appreciated.

[Will]

Looking for advice on the lowest restriction exhaust I can install on my Formula that will still have pipes that exit at the rear bumper.

Thinking of a Torque-Tech 3" system with X-crossover, but don't know what mufflers are best, and am also concerned about ground clearance on my lowered car. Never had much luck putting mufflers under the back seat...

The car currently has a Flowmaster 2.5" system with X-crossover and crossflow muffler, but I want something that flows better.

Noise control isn't as important as flow where the mufflers are concerned, the pipes exiting under the back bumper seem to tame down most obnoxious exhaust systems.

Any recommendations or ideas greatly appreciated.

[Brian Baker]

Well, mounting 2 conventional mufflers under the car is going to limit your choices if you want to retain some kind of decent ground clearance. I have twin 2-chamber Flomasters on my 79 T/A and they're a tight fit. I tried mounting 3-chambers but they were just too long.

[Half-Inch Stud]

I have the short [ 14" ] length Walker Super DynoMax Turbo mufflers on my 69 Bird in front of the rear Axle. 2.5" exhaust with 2.5" tails.
Low 12's with a 3.31:1 rear gear may suggest that they flow adequately.

I suspect the 18" [or is it 22"?] long mufflers are better, but would not fit as well as my 14" Muffs.

[Old Man Taylor]

Will – I have a system like Half Inch on my ’64 GTO. The engine is a tri-power nitrous fed 428. The headers are stepped headers from 1 7/8-2” going into a 3.5” collector. I then have a full 3” system with an H pipe. The mufflers are the short Dynomax Super Turbos. However, the only ones that were a true 3” inside were the stainless ones, so that is what I have. The tail pipes are also 3”, and they point out and down towards the front of the rear tires. I had one opportunity to have the noise checked at the National High School Car Club Association’s street legal drags at Qualcomm stadium in San Diego. At 3500 RPM and a distance of 50 feet, the noise level was 80.7 dB. At the races the noise at the 60 foot mark of the track and 50 feet away was 89 dB. Unfortunately, the track was not a standard length. The baseball stadium was too short to have a full 1/8th mile. The measured distance was 540 feet. With the hard compound M&H DOT street tires, full exhaust and a 4 speed (therefore no full throttle starts), it did 89 mph in 7.0 seconds. I calculated that this would convert to a 7.89 at 97 mph in the full 1/8th. That tracks pretty well with past ¼ mile performance.

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Jim

[Rashionality]

Dynomax Bullet mufflers...nothing less restrictive then them but straight pipes.

[Rashionality]

Right now I am running this setup
But I am switching to the Dynomax bullets. What you see in the picture is a 3 1/2" custom Flowmaster system from http://www.mufflex-performance.com/ and will be for sale once it is removed...any takers?


[This message has been edited by Rashionality (edited 01-30-2001).]

[Old Man Taylor]

As always, muffler sounds are extremely subjective and a matter of personal preference. IMHO with a large cam the Dynomax bullet mufflers are too loud. With a small cam they sound great. The Super Turbos have a quieter, throatier sound. Especially with a large cam. Greg Minor has the Bullets on his Puttytat, which does not have a huge cam. They are close to being too loud on the street. That engine is a dual quad 421 with a hydraulic roller. The car is a 62 Catalina.

[Rashionality]

I just noticed in his original post that noise was not an issue...without a doubt those bullets are almost as loud as no muffler at all...

[PHILLYGOAT]

Does it show true love if you are willing to take a bullet for your cars performance???

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Too stubborn to do it the easy way. What else would I spend all my $ and time on?

[Will]

OMTaylor, I'm confused...

I've been poking around Dynomax's website, and they don't even offer their stainless mufflers with a 3" in/out configuration. The biggest is 2.5". You have to go to the Ultraflow welded mufflers to get 3" in/out.

Looks like the Ultraflows are about the best deal. 14" long case, 3" in/out, 2200+ cfm flow per muffler. Don't see how you can beat that, and the price is right.

I just REALLY wish they were available in stainless steel as I'd like to install a full stainless exhaust. The desire for stainless might lead me to install a set of Borla "Hemi" mufflers. Same basic size and configuration as the Dynomax Ultraflows, but all stainless construction (and you pay for it too).

[Old Man Taylor]

Will - Maybe they quit making them. I had to go with 2.5" when the 3" system was first put in until the 3" SS mufflers were available. They are a true 3” inside. I think the number on the case is 17774, but I would have to check to be sure. The outside dimension is about 15.5”, so I assume it is a 14” case. There was a noticeable difference going from the 2.5 to the 3 inch mufflers. You might want to give JBA a call. They were the ones who built and installed my system. B/T/W, they said they would never do another set of headers for a Pontiac A-body. It would be worth checking with them on the 3.0” SS Super Turbos. They sound great and perform very well. Again, I have a large cam, which makes them louder. The cam is a 257/264 at 0.050 in a 428. JBA’s number is 619-265-3056. Before I finished this note I confirmed with JBA that this muffler is real. The last one they put on a car was November 2000, so they assume they can still get it.

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Jim

[Bigred455]

Rash, Would you mind explaining how your exhaust system is set-up? I mean How are the mufflers mounted behind the axle? Becuase it is behind the axle does that limit the driveability of the car? thanks