I had this done back in 1993. Its custom for my 1 3/4" SLP headers. It uses 2 1/2" tubing and has high flow cats to dual flowmaster mufflers. It run in the stock location and ride at the same height as stock. It can be done by a good exhaust shop. This system is 100% legal and pass emissions with flyin colors. I did have any modification to rear panhand bars to make it fit either. Its a tight squeeze but can be done. Also I have Spohn sub frame connectors with no problems. P1010959.jpg P1010960.jpg P1010964.jpg Eric

more pics

Dynomax sells a kit very similar to your setup. I think that's what I'm going to get soon. I have a cheap dual setup without mufflers. Here is the kit on Summit http://www.summitracing.com/parts/WLK-89009/

not quite similar, its crush bent crap and no cats, not legal.

although it was a nice try... im sure you prob hurt performance with that exhaust system... the tubing bends are crushed so much it prob was less than 2.25" at the bends.

both these setups are not optimal. valent efforts but not the way to do it. you would have been better off with a single 3" system.

im running headman LTs with 3" header extensions into a 3" xpipe then into 3" force mufflers with turndowns. i got good ground clearance and its mandrel bent. and will flow enough for more than 600hp.

Like I said this exhaust was done in 1993. I've just read posts saying that it can't be done legally, and I wanted to show that it can be done. I'm planning on getting it redone with mandrel bent tubing. As for power difference, I notice a big difference from going from Thrushs cat back system to duals, back than that was the only cat back kit available. I always go to the flow amount, 3" flow to 5" or if the bends goto 2"(which I measured and the smallest is 2 1/4") in spots, still 4" is better. Also the sound is so much better.

has anyone ever seen the setup on an 82 firebird se with the 305 mine had the reg single small crap till it got to just before the rear end and it split into two 2" pipes that went over the rear end nicely then they both fed into a larger pipe that T into 2 seperate smaller mufflers on each side wish i could find that cus it would be a great platform to build a simple dual setup off of... i may start lookin in the bone yards theres got to be one out there........

its not a stock setup.

Not legal. Must retain stock routing, which is a single pipe. Fed laws on converters say it cannot be replaced unless it fails, and must be replaced with the same size and type for application.

With that said, I doubt any inspection station is going to look that closely at a 20+ year old car.


-- Joe

Actually THAT was a stock setup, and it was horrible. I've seen a few in person, and if you look in the books it is shown as an OE exhaust for '82-83 I think.

-- Joe

yes thatr was run for 82-83 only it was not available in 84+ models

It would only be legal on a vehicle originally equipped with dual cats.

The EPA- and C.A.R.B.-types don't care what you do after the cats. DOT takes over from there for safety and noise aspects.

f**ck carb and the EPA, i dont even have a cat, never a problem

My Formula came with dual cats from factory.

Eric

Correct me if I'm wrong, but once the car is 25+ yrs or older, don't they stop caring?

wow, nice kink pipe.

No. The regulations on the books start with the 1975 year model and don't change with age.

Enforcement is local/regional/state, but the rules are Federal (except California is allowed to make and enforce their own standards).

There was a TGO member a few years ago that related his story of trying to import a Canadian export model car to the U.S. At first he was told it had to be converted to U.S. configuration. In the end, they waived everything because the car was more than 20 years old.

BUT, if the car was originally sold in the U.S., there is no exemption from the regulations.

Clearly a double standard.

Emissions testing stops, but the parts must remain for the visual portion. Take something off & you should still fail visually.

guys, its simple

http://www.summitracing.com/parts/MPE-94008/

that cat and some cherry bomb glass packs and you are fine

How is that "simple"? It wouldn't be legal.

Besides, 2" is small.

ok, almost nothing is legal anymore.

and you can just use a reducer and an expander thing on either end and have 2 1/2 inch pipes. and its easier than dual cats would be in my opinion

We don't have any emission here nor an inspection of any kind. I see a 500 Caddy and a 4l80e in my near future lol

3" exhaust has 7" of area
dual 2" has 6.3" of area

Dual 2.25" has just under 8" of area, so it would seem if one were to go from a normal 3" catback, you would want at least dual 2.25".

Now, the 90 million bends it takes to work could result in lots of little losses as well.

-- Joe

thats why i said use reducers and expanders so that in general the system 2 1/2 except for the cat. plus i couldnt find any cat with dual in/out other than ones with 2" in/out/

lol @ the cadillac 500 comment!

was at the local bone yard and found one of them on an 83 camaro just as i remember it though yes it is a flow nightmare cus of how they bent the tubing but it would be good for a real setup template... i have pics here they are....

fiew more........goin back tomorrow to get new headlight switch and may take that with me too lol....

i dont see the big ordeal with dual exhaust on our cars.
a single setup fits, and you dont need any modifications for it to bolt up.

Did you subtract the wall thickness from those calcs? I don't feel like going through the math right now, but as I recall when I did go through it a few years ago, when you account for wall thickness, dual 2.25" has less flow area than single 3".

Good point, and no. Exhaust pipes are measured in OD, not ID, so perhaps the rule of thumb should be single 3" or dual 2.5" ..


-- Joe