Undercar exhaust exiting ahead of rear wheel

[Tom Wells]

Lippy,

I have'em and I love'em. The only snakebite I ever got was while working on another Cobra guy's car...

Here's a shot of the passenger side with the body off:


You can see the notch in the front outrigger support that E-M put there to allow some ground clearance.

And here's the finished product:


Spintech made the mufflers for me. Their stock ones proved a little too wide and made one of the world's loudest rattles. After they made some for me about 3/4" narrower, they've been on there ever since. They are not SS so they are coated.

I have SS headers and pipes. This was another series of learning experiences, as the routing and fit of the pipes needs to be done correctly. If they're hanging down a bit too low, well, let's just say it makes a noise that's a lot louder than a rattle!

The pipes are 3" all the way. If you have a smaller engine (mine's a 521) you could likely use 2-1/2" and not eat too much hp.

There's a standard rubber hanger (sort of elongated O-shaped) just before the exit bend, holding onto the the pipe using a piece of 3/8" rod welded onto the pipe, and a similar hanger under the frame.

I would have taken them out to the back bumper to make it quieter on 400-500 mile days, but there wasn't any space for the tailpipes.

Enjoy,

Tom

[HealeyRick]

Originally Posted by Tom Wells

Lippy,



Spintech made the mufflers for me. Their stock ones proved a little too wide and made one of the world's loudest rattles. After they made some for me about 3/4" narrower, they've been on there ever since. They are not SS so they are coated.

I have SS headers and pipes. This was another series of learning experiences, as the routing and fit of the pipes needs to be done correctly. If they're hanging down a bit too low, well, let's just say it makes a noise that's a lot louder than a rattle!

The pipes are 3" all the way. If you have a smaller engine (mine's a 521) you could likely use 2-1/2" and not eat too much hp.

There's a standard rubber hanger (sort of elongated O-shaped) just before the exit bend, holding onto the the pipe using a piece of 3/8" rod welded onto the pipe, and a similar hanger under the frame.

I would have taken them out to the back bumper to make it quieter on 400-500 mile days, but there wasn't any space for the tailpipes.

Enjoy,

Tom

My Austin-Healey probably has one of the least amounts of ground clearance on a production car. When I did the small block Ford conversion, I really had to search for a suitable muffler that would save me from tearing out the exhaust system on any kind of bump. I went with the Spintech Cruiser series, which looks a lot thinner than the model you have. They measure 2 1/4" thick and come with oval inlets up to 3" Here's the link: SpinTech Cruiser Series - Mufflers - Street Mufflers - LOW PROFILE STREET MUFFLERS - 7000 CRUISER SERIES OVAL OR ROUND COLLARS - SpinTech Performance Mufflers

Here's what they look like on the Healey:



I have 2 1/4" pipes on a 345 crank horsepower motor. You can also see the self adhesive DEI Reflect A Kool aluminum covered insulation that I installed above the mufflers: Reflect-A-Cool 010460 | Purchase DEI, CryO2, Ny-Trex, Boom Mat & SPA Turbo Products | Design Engineering, Inc. - Thermal Performance Products

And this is what the mufflers sound like:



(The system is a dual system with the right side pipe crossed over behind the axle to give the look of the stock twin pipes)

[DanEC]

Originally Posted by Tom Wells

Lippy,

I have'em and I love'em. The only snakebite I ever got was while working on another Cobra guy's car...

Here's a shot of the passenger side with the body off:


You can see the notch in the front outrigger support that E-M put there to allow some ground clearance.

And here's the finished product:


Spintech made the mufflers for me. Their stock ones proved a little too wide and made one of the world's loudest rattles. After they made some for me about 3/4" narrower, they've been on there ever since. They are not SS so they are coated.

I have SS headers and pipes. This was another series of learning experiences, as the routing and fit of the pipes needs to be done correctly. If they're hanging down a bit too low, well, let's just say it makes a noise that's a lot louder than a rattle!

The pipes are 3" all the way. If you have a smaller engine (mine's a 521) you could likely use 2-1/2" and not eat too much hp.

There's a standard rubber hanger (sort of elongated O-shaped) just before the exit bend, holding onto the the pipe using a piece of 3/8" rod welded onto the pipe, and a similar hanger under the frame.

I would have taken them out to the back bumper to make it quieter on 400-500 mile days, but there wasn't any space for the tailpipes.

Enjoy,

Tom

How do the spintek mufflers sound on your car? I've heard they are pretty loud. I have 2-1/2 inch ones mounted on my ERA with 2-1/2 inch pipes all the way out the back end, but I'm some ways off in my build from being ready to fire up the motor.

[DanEC]

Did either of you have any problem with the passenger side ERA collector placing the muffler a little too far to the outside to where it interfered with the body rocker area? I had to take mine down to an exhaust shop and have a 2 degree bend put in it to center the muffler in the proper area for clearance. I hate having that slight kink in it but it will only be visible from underneath. It looked to me like the shop they have fabbing up the exhaust headers and collectors isn't allowing for the 1 inch offset of the motor to the passenger side. Or maybe it was something just unique to mine.

[Tom Wells]

DanEC,

Hmmm...

Don't really have a lot of sound bites. Here is a link to a couple from Daytona: First Coast Cobra Club • View topic - Tom at Daytona - two videos

I guess the closest to what it actually sounds like would be the second clip just as I'm passing the Mustang.

Overall, the sound is nice! Sets off car alarms if you're into it but reasonable if the throttle is not too far down.

There's a lot that determines the overall sound, so yours is probably different. My guess is you'll like it!

Tom

[DanEC]

Tom - wierd deal - I couldn't get any sound off of those clips. Must be something in my computer. But thanks for the commentary.

[Tom Wells]

DanEC,

That is strange - I tried it again and it worked fine.

There's a sound volume slider on the bottom left of the Youtube picture and also one somewhere on your PC. Maybe one of them is all the way down, or one of them has the MUTE function on.

Either way, Spintech are they guys who started the high performance muffler designs for (gulp) dragsters to minimize noise while not hitting HP too much. I'm sure there must be others as good by now.

If you can, post some sound from your car when it is making some!

Tom

[DanEC]

Originally Posted by Tom Wells

DanEC,

That is strange - I tried it again and it worked fine.

There's a sound volume slider on the bottom left of the Youtube picture and also one somewhere on your PC. Maybe one of them is all the way down, or one of them has the MUTE function on.

Either way, Spintech are they guys who started the high performance muffler designs for (gulp) dragsters to minimize noise while not hitting HP too much. I'm sure there must be others as good by now.

If you can, post some sound from your car when it is making some!

Tom

Tried it again and this time I had sound. Hard to tell but with the background wind noise but in the second one there is a period when your accelerating past the Mustang that comes through pretty clear and it sounds nice. Thanks.

[tkb289]

Originally Posted by DanEC

Did either of you have any problem with the passenger side ERA collector placing the muffler a little too far to the outside to where it interfered with the body rocker area? I had to take mine down to an exhaust shop and have a 2 degree bend put in it to center the muffler in the proper area for clearance. I hate having that slight kink in it but it will only be visible from underneath. It looked to me like the shop they have fabbing up the exhaust headers and collectors isn't allowing for the 1 inch offset of the motor to the passenger side. Or maybe it was something just unique to mine.

Dan,

I did have some fitment issues on my 289 car.

When I first installed the headers, the collector on the driver's side was very close to the brake / clutch hard lines. Talked with Bob P. and we determined due to a tolerance stack up, the motor was sitting too low. Made some 1/4" thick steel plate shims that were powder coated and put between the frame and motor mounts. Next step was to level the motor in the car, used a straight edge on top of the motor as a sightline to a horizontal seam in the firewall.

Then to get the pipes / muffler to align and sit properly under the car we wound up cutting off about 1" from the length of the collector on the passenger side. The driver's side we took off maybe 3/8". A little tweaking here and there does the trick. Sounds like you have everything lined up on your setup. I would not let the 2 degree bend bother you, seems like a good solution to the problem. Be sure to add the insulation under the floor and above the muffler if ERA did not already install that for you.

I have about a 3/4" space between the top of the muffler housing and the floor insulation. No heat issues so far.

There are bound to be a few things here and there that need to be tweaked with installing parts, but overall I have to say things go together pretty well on the ERA.

When you are finished, take some photos would be interesting to see what you have done.

[terry251]

I have the under car on my Superformance, but the exit is under the rear bumper hoops. It is easier on my ears, but still sounds high performance. Most of the real Cobra's on the street back when they were new came with under car exhaust - the small blocks and the big blocks. It was years later when everyone started emulating the competition look with roll bars, side exhaust etc. The under car system is a great look! There are some pictures in my gallery.
Terry