Underbody Exhaust Help...ERA 427 Street

[lippy]

Originally Posted by strictlypersonl

There are outriggers from the main chassis rail with 19.25" longitudinal distance between them.

4" from the floor surface to the bottom of the chassis rail.

The box containing the brake master cylinders (in front of the muffler cavity) extends out from the main rails 5", so that the muffler "In" must be offset to the outside. The muffler "Out" must be centered or in-line with the "In" pipe. It cannot be on the opposite side.

Bob - what about the MagnaFlow 11376 (http://www.magnaflow.com/02product/s...ain&id=10390)? It is 11" long, with a 4" x 9" oval cross section and 2.5" circular inlet/outlet. This model has both inlet and outlet offset/aligned, but it can be configured several ways.

[DanEC]

Originally Posted by lippy

Bob - what about the MagnaFlow 11376 (http://www.magnaflow.com/02product/s...ain&id=10390)? It is 11" long, with a 4" x 9" oval cross section and 2.5" circular inlet/outlet. This model has both inlet and outlet offset/aligned, but it can be configured several ways.

You really need a center outlet if running a tailpipe. You might be able to use an "S" shaped adaptor on the outlet to adjust the tailpipe. If exiting in front of the rear wheels it might work. At 4 inches depth it will hang down more than my Spintechs - but no more than most.

Here are a few pictures from my mock up. No - my tailpipes will not be PVC.

[strictlypersonl]

I found some Magnaflow mufflers that look close. Note that they are 4" tall, so they will hang below the chassis a bit. Also note (in case there are some lurkers with other than our late 427 model), that early (pre-731) 427s, FIAs and Slabsides only have room for a 14" long muffler.

Universal design
XL Series

I don't know the performance difference between those designs, but the second one is available in a longer case. I'm also assuming that the oval XL series can have the flow in either direction.

[RodKnock]

Originally Posted by DanEC

No - my tailpipes will not be PVC.

Well, you never know. I think Patrick used PVC for his roll bars, though it's hard to tell with the PVC insulation wrap around them.

BTW, Dan, really nice work.

[Bruce M]

I have a Contemporary with 3" out of the collectors through 3" Flowmasters up and over the rear with 3" stainless tips. No headaches or burnt legs. I built the car in 1982 with a big block Chevy.

[DanEC]

Originally Posted by RodKnock

Well, you never know. I think Patrick used PVC for his roll bars, though it's hard to tell with the PVC insulation wrap around them.

BTW, Dan, really nice work.

Thanks - I hope to have some pictures of the complete system in a few weeks.

[mdross1]

When building our car knowing we were going go with undercar exhaust used 1/8" plate welded flush with floor making for solid feel and never feel any heat from the mufflers.We used Stainless Specialties custom made stainless chambered mufflers 2 1/2" out the back.They sound just right.

[427 Street]

I'll try to get some pictures up tomorrow of my current Dynomax system.

[racco]

great looking car.

I just went through the same process on a 427 so ccx, I used cast iron manifolds and
full tail pipes.

I have photos but they take forever to load.

[427 Street]

Some side shots...I took some close ups of the pipes/muffler with my other camera. I will post them as soon as I download them. The muffler is currently 3.75" thick and 14" long:

[JBCOBRA]

Hi 427 Street!
Awesome car!!!

[my427cobra]

A few pics of my Street Roadster undercar exhaust as I was putting it together.

My car is an NAF and I'm running a 351C with Edelbrock Al heads and a custom made 2X4bbl carb set-up.

2 1/2" Polished 304 SS from headers to exhaust tips.

Tucked along side frame rails, over the rear axle to muffler under rear quarter panel and tips out past rear bumper.

Mufflers are Stainless Specialties (I need to polish them yet) 4"OD and 2 1/2" inlet/outlet.

Blue tape where the cut and mitered pieces were to be welded.

Also a pic of my ceramic coated headers (Schoenfeld IMCA headers that come of the heads horizontally instaed of pointing down so I had no frame clearance problems) and SS down pipe.

Greg

[DanEC]

I wonder if anyone has come up with an aftermarket shorty header for an FE that will fit in an ERA? I suspect not, but maybe. . .

[427 Street]

I went to a custom exhaust shop today. Since my mufflers are already hanging below the outriggers, he said that I can put any muffler in there.

He was a hardcore hot rodder, and his shop logo is a Cobra, which I thought was pretty cool. AND, his name is James Dean. He really knows his stuff, and he is one of those older hot rodders that you hope never retires.

He recommended the 18" Magnaflow oval muffler with 2.5" inlet/outlet. He also said that he can run it out the back and not be limited to side exiting pipes. I kinda like the side exiting but he said we can always change that later.

I think a tubular/glasspack shaped muffler will look better, and I was thinking of the Chambered Classics. Eric said he can make them any length and diameter.

Thoughts? Magnaflow? Has anyone heard the Chambered Classics?

Thanks.

[mickmate]

That's the Classic Chambered. I wonder how these would fit Search Results : Acton Custom Enterprises, Custom Metal for Cobras

[427 Street]

Yes...Classic Chambered...I was finger tied.

So, anyone with experience with either Magnaflow 18" (or longer) oval mufflers or Classic Chambered?

[DanEC]

Not exactly - but I have a Magnaflow cat back on my 2003 Lightning Pickup and it is a nice sounding unit. I like them much better than the Flow Masters that everyone seems to want now-a-days.

[mickmate]

I like Classic Chambered so much I carry inventory of their product. It gives a nice exhaust tone I think. I haven't used it under car, only on side pipes.

[DanEC]

Originally Posted by mickmate

That's the Classic Chambered. I wonder how these would fit Search Results : Acton Custom Enterprises, Custom Metal for Cobras

These undercar headers look pretty nice Nick. A viable option. I guess they clear underbody pedal boxes like ERA (and others) have? If I didn't already have my ERA headers coated and ready to go I would have considered those. Nothing wrong with the ERA headers however, the individual header pipes make clearances for installaion fairly simple.

[my427cobra]

A few more pics of my Stainless Steel under car exhaust exiting out back past the rear bumper over riders/loop.

Greg