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True Duals?

Why do you want true duals? With Duals, you need an H or X pipe to equalize the exhaust pulses. With a single LARGE pipe dow the middle, you have Ultimate H/X pipe!

You can install a late model gas tank in your '90 & run the late model exhaust. Much less restrictive than the early model exhaust. I did this on my '89 XR-7 & it's Great!

I run the SCPI Big Dawg (3.5") exhaust, No Cats, No Resonator. It's kinda buzzy without the resonator, but you can't make a 6 sound like an 8!

68COUGAR
 

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What is the best exhaust for a 1990 supercoupe?
First of all, since you own a 1990 SC, you will need to replace the tank with a 1992 or above to run TRUE DUAL.

What kind of price am i looking at for a shop to bend straight dual exhaust?
I had my exhaust custom made from local shop , I got 2½ duals running from Cat's back with H pipe for 300USD! Very quiet with super turbo mufflers! Lost some low end, but will be installing a 10% pulley soon!!

Cheers,
Calvin
 

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I'm running 2-1/2 true duals from the cats back into dynomax turbos, and I love it! Have a 5%pulley in the s/c and I'm still pegging the boost gauge. I paid $450 Canadain dollars(I'm friends with the guy at an exhust shop).

687 COUGAR what do you mean, by equalize the pipes? Will one flow better than the other? How can tha be measured??
 

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Formula 1 Freak
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I'm running a pair of Borla mufflers on a 2.5" system with 3" center, mangaflow resonator, a pair of high flow cats, and 2-1/4" downtubes, I might be a bit biased because it's on my car, but I have to say it's one of the best sounding, no drone systems I've ever heard on an SC. The Borla's cost about a hundred bucks each, but they're well worth it IMO. I also installed a 92+ fuel tank, and replaced the fuel pump with a 190 LPH while the tank was down. Most any decent high-flow exahust system on an 89-91 SC will require the fuel tank swap if you want a straight shot under the tank, not just the "true dual." The X, or Y pipe equalizes the back pressure, and will improve the sound, and flow as well.
-Jeff

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save one heck of alot of money

get new down tubes with cutouts just infront of cats i had my cats moved back six inches put cutouts that go to super trap mufflers next to cats when I pull cable they open and run through all four exh . stock and cutoutsyou could use soliniods to activate cutouts at high boostor low vac
 

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true duals

i got 2 1/4 inch true duals on my 91 model. heck of a difference! instead of all going through 1, 2 inch behind the resonator i have 2, 2 1/4 pipes all the way back to the turbos. they welded them to each other where they go around the tank but i have no x or h they are 2 seperate pipes. i think i gained on the low end cause it spins a heck of a lot more and on the freeway you can just tell the motor is a lot less stressed i think it even idles better. cost me 250 usd's best money i spent since i bought the sc. also looks very impressive to all that get the privliage of seeing the bottom of my ride.
 

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I have 2.5" downtubes, no cats, to a magnaflow resonator. This goes to a single 3" pipe then bach into dual 2.5" pipes. Oh yeah...two turbo mufflers.

I love the way it sounds and feels.
 

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true duals

im gonna be running true duals without an x or h pipe im using the magnaflow resonator dual 2.5 in and dual 2.5 out so ill have great sounding exhaust with true dual performance just as soon as i can get the parts that is and the fact that im goin to do the exhaust myself since the exhaust shop wants 700 to do it lol
 

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Re: true duals

scmaniac said:
im using the magnaflow resonator dual 2.5 in and dual 2.5 out so ill have true dual
How is it TRUE DUALs if everything flows through a single chamber resonator?

Curious 68COUGAR
 

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magnaflow res

The magnaflow resonator actually is prety much an X pipe inside a mufler. I got one on my 94 with dual 2.5''. I do have to say the super turbo muflers really don't cut the sound enough. But I guess that may be because of no cats. On my previous car I had high flow cats and a terminator 2.5 in 3" out resonator, no muflers and it was quieter than the current setup.
I have been happy with the top end pickup with the new exhaust, but as mentioned, a considerable amount of low end torque is lost. I got a ESM raised blower top that is to be installed soon.
-John
 
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