convert to undercar exhaust?

[Tom Wells]

Hi James,

How hot does the floor get under your seat where the box is? Did you cover it with some sort of heat guard?

The floor stays cool. We've gone 450 miles + in a day without any heat problems at all. Everett Morrison supplied a thin, aluminized flexible heat barrier - kinda looks like fiberglass with a reflecting material adhered to one side. The reflective side faces the mufflers, and it's glued to an aluminum sheet which rests on the frame under the floor of the footboxes.

Did you do the cutting through the frame components to get it through?

The E-M has three outrigger supports. The factory relocated the center one to the front, and then put the notch there to accommodate the headpipe.

Tom

[JBCOBRA]

SPF rear exhaust cars have Stainless Steel panels with acorn nuts holding them on to insulate the body from the heat from the pipes and mufflers. There is a little space inbetween the panels and the bottom of the body. Looks nice and finished. I am sure it could be duplicated for not too much money. Just a thought.
You can feel some heat through the floor after a while, but when it is cool out any and all heat is appreciated. When it is hot out, just go faster! LOL

[Maricopa]

Works on FFRs too. 3" ovalized pipe and Spin Tech mufflers. Exits in front of the rears but can be run out the back. I only lost about 1/2" of ground clearance compared to the 4" tubes so the same set-up should work on most makes.

[jolsen42]

I've also done this to a Factory Five. I'm very pleased with the way it cameout. Whadayatink?





John O

[Maricopa]

Show off!

[jolsen42]

Thank you Michael, now go finish yours. Ha Ha.

John O

[jolsen42]

I think I have this thing figured out.

John O

[JBCOBRA]

Very Nice!
Looks familiar
JB

[Dinobyte]

Probably one of the nicest FFR Cobras I have ever seen.

I like it without the rollbar and with the solid old school color.

[G.R.]

BRG ...needs tan seats...just kidding. great looking ride, John O. my favorite color for a 50's-60's vintage roadster

[NKOTB]

Originally Posted by Dinobyte

Probably one of the nicest FFR Cobras I have ever seen.

I like it without the rollbar and with the solid old school color.

DITTO! Nicely done.

[Aussie Mike]

I've just about finished an underbody system for my car. Our strict rego laws down here mean that a hand built Cobra is considered to be a new car and must meet all the current design rules. that includes noise and emissions so the system needs to be quiet i.e 90dB @ 2/3 operating RPM measured at about 2 foot from the exhaust tip.

My underbody system uses modified factory dual layer pressed steel headers from the Corvette (LS1 Powered) that run into 2.5" collectors then into cat converters. Out of the cat converters the pipes taper down to 2" and then Y together into a single 2" pipe. This runs into a heavily baffled muffler and then into another resonator before exiting the rear of the vehicle.

we also have to have a minimum of 4" of ground clearance so the suspension gets wound up a bit too.

Not real good for performance but should knock the noise down to legal levels. Needless to say the whole system is designed to be quickly and easily un bolted and be removed so I can bolt my side pipes on (Honestly, I only bolt them on for for track days Officer).

Cheers

[Ant]

jolsen42

Nice job!!!


Mike,

We have just had the noise decibel test passed in NZ, I think we are a bit easier here with 95db at .5 meter (your 2ft) and a V8 @3000rpm, and if you hold a race license add 2dba, and another 2dba for a mechanical engine = 99DBA. The bottom line is I aint revving my 8000rpm engine up to 75% for any **hole, I think in your case over there I would limit the engine to 5000rpm and that would make 3750rpm, stuff plenty of mufflers baffles etc and then take it off after you get the OK.

We dont require this at certification time, but if the Police pull you over and measure it/green sticker the car, you have to go to a Warrant of Fitness depo and get it tested and make it pass the test.

I think its just stupid of your govt to make excessive rules, with the small percentage of retro sports cars etc on the road, most using old engine technology, and you arent allowed to use a Carb, must use EFI! wind the fuel injection up and it will still billow unburnt fuel emissions. Have you still got the silly rule where the Smiths gauges have to be non-glare like no chrome bezels, I suppose you have to blacken out the chrome windscreen as well.

My car has original type door latches (MGTF) and they dont allow them here, so I told the certifier I am using them period, the doors will have the latch handle immovable/doors fixed at the time of certification, he said I dont know about that, the doors will have to be permanently fixed, ........rubbish, I said if the door isnt used to entry/exit the car it doesnt have to open, providing the car has no roof. As you can see I have got a very short fuse for bulls**t regulations!!

[Aussie Mike]

I think they have let up on the chrome in the drivers view rule i.e. chrome bezzels on the guages etc. Most people were putting black tap on the back of the wind screen frame and painting the bonet handles black but it seems to come off pretty quickly after rego (You just can't get good quality paint and tape these days). I think the let up on this rule has happened because a few production cars have come through with chrome in their interiors and the big manufacturers can put a bit more pressure on.

Door latches have to be burst proof design. I'm using XF Falcon items and they are one of the few Ford bits in the car.

It used to be 95dB at 0.5 meters but they dropped the noise limit a few years back. The drive bey test can be hard to pass too. Many have to close up the side vents and bonet scoop and even run a tray under the engine bay to get reduce the mechanical noise. Even wheel and tyre noise can present problems.

You would think the government expects the cars to float by with the sound of Motzart gently playing whilst the scent of daisies and new born babies wafts out the exhaust pipe.

Cheers

[Ant]

Aussie Mike,

Drive by, gee thats a bit rough, how do HD motorcycles and trucks get on. I have a Jerico transmission, I reckon a cop would pick on that here....so when they get rid of all the straight gear boxes in the trucks, which are a major environmental problem ........not, I going to stop now because it just gets silly with beurocratic nonsense!
Getting back to under car exhaust, I have a guy who travels the ditch and is in big demand for work on Aussie Supercars exhausts, he built a system for a GT40, and its as long as the transmission, and almost "too quiet" - so we will have a real quiet road system to keep a low profile, and as we are still allowed at certain events, the straight pipe big noise system! Problem is room so it should be a clever system.

Make to most of motoring, as I think we can still do it the same as the 70's 80's etc still, but I reckon thats all going to change in 20 - 30 years, and I wont be concerned about it so much then!

[Jim Doak]

When I initially built my car I had the FFR 4-into-4 headers and side pipes. Sounded good but LOUD. I put about 3100 miles on my car with the original side pipe setup. But a 375-mile drive to Steamboat Springs, Colorado, in June of 2004 is what really prompted me to go with an under car exhaust system. A 300 plus mile drive will give your hearing a workout. Especially if you didn't wear earplugs.

Anyway, version 2.0 of my car, shown below, has an under car exhaust system built by Dr. Gas. I like the sound a lot better and I really like the look, too. Plus I don't need to worry about my 3-and 7-year-old daughters burning themselves on sidepipes.

[aldersonjames20]

I know this is an old thread, but I was reminded about it last Saturday. I was at Olthoff Racing in North Carolina and was dropping my car off for some service. They were delivering somebodies car and when they went to move it they started it up while we were all standing around. My ears, as well as a couple others, were expecting to hear the exhaust note coming from the sidepipes that were right there in front of us, but that never happened. It was coming from the rear of the car. They told me they have built a few cars now that have sidepipes, but just for looks, and the actual exhaust system runs under the car for rear exit. This is obviously not something that would be worthwhile for me to do now, but I thought it was VERY cool. Unfortunately I didn't get a picture before it was loaded into the trailer.

James

[superschwan427]

dont all superformance coupes have exhaust as described above? i really hate that.

[aldersonjames20]

I am sure its not for everyone (on the Cobra), but I thought it was kind of cool. Its hardly noticiable on the Cobra, betcha 9 out of 10 people wouldn't see it unless they heard it up close. What is it that you don't like, the looks, or the idea?

James

[mj_duell]

How about something like this? Don at D&D did this for an EVO 5 customer in Quebec.





--Mike / Turn Ten Racing, Inc.