I have an '88 IROC-Z with a temporary 305 TBI that will soon become either a 383, or a 350 (either way it'll be carbbed), and a 5 speed trans. I currently have a stock exhaust system with a Flowmaster 80 series that sounds good, but is far too quiet. When I went and had in istalled, I asked my exhuast man about true duals and he told me either I can run it the way it runs now, but only be able to run about 2" pipes, or I can run one the way ot goes now, and the other down the center, but i would have to remove the torque bar and re-route the fuel lines. Now I would like to run a good powerful motor, so I'd like to keep the torque arm. My question is does anybody Know of any alternatives to these two options? Also would it work for the curret 305 and if i put the 383 in? I plan on pulling all the smog equipment out, as inspections are not done in my area. Any and all input would be greatly appreciated. Thank you in advance.

 

You can either buy an off-the-shelf dual kit that runs in the stock location (or have your local guy custom fab it).

Or run "true duals" (1 pipe per side just like the older cars) but you cann't just remove the Torque Arm without totally redesigning the whole rear suspension. If your exhaust says you can? Tell him to stick to exhaust only. Suspensions are definitely not his thing!

You will hafta mod the tranny crossmember (or buy a pre-made custom one) or have LOW ground clearance on the Driver's side due to no room to run it higher because of the Torque Arm which cannot just be removed.

 

Where does one aquire a true dual kit?

 

Better off to buy one than acquire one. Too many legal issues for acquiring things.....

Dynomax dual kit 82-89 Camaro/Firebird part #wlk-89009 was listed on Summit for $167.95 at one time, but I don't see it there anymore. Maybe it has been Discontinued? Dunno.

 

So far as I know a off the shelf true dual kit is not in existance anymore. I could be wrong.

I would let a local guy do it. Run both pipes in the stock location next to one another and then split them at the rear. Use SLP bullet resonators or something of that size and you might need a panhard relocation bracket. And don't lower the car.

 

I'm curious as to why you would want to put "true duals" on your car?

 

it flows better=more power on all engines but really helps with a modified engine. the more air you can move in and out the engine the more efficently it will run and the more power it will produce. Of course that is a nut shell explaination

 

Have you tried looking at the dual exhaust picture thread in the sticky section? Lots of options on how to do it. I wouldn't trust your exhasut guys opinion on the subject if he has never done it before, or thinks you need to start re-arranging everything underneath the car.

 

With shorty headers its easy to fab a dual system with x pipe in stock location. I have dual 3" on my car with x pipe and 4 mufflers

 

Hey blackenedbird that picture with the duals in the stock location with the x pipe do you know what size the exhaust was and what kinda ground clearance that had by any chance?
Orr89RocZ do you have pictures of your set up somewhere on here? Lol I would like to see how yours looks especially with 4" mufflers.

 

I dont have 4" mufflers i got 4 total mufflers

https://www.thirdgen.org/forums/post...6-post118.html

 

No clue. Just a pic I saved from back when I was on that "dual exhaust is better" kick, which isn't exactly true. Not enough you are cranking some SERIOUS horsepower. Not worth the extra weight of the extra pipes & muffler for just a different sound.

 

Yep a single 3.5-4" will handle most builds. Good single 3" with cutout will hold 430's whp but its considered a restriction by then. Dual 2.5 would cost more and may likely be heavier but would definately sound nice. Reallly depends on the motor and layout tho. Ive heard bad sounding duals and some great sounding singles.

 

Here is how I did it on my 87 Iroc

Pretty much stock location and I have a half inch less clearance then stock, never have scraped or bottomed out.

Hooker shorties and x-pipe from Jegs.

Made this entirely out of 90,45,30 degree turns. And some U's

 

And pretty much listen to this guy lol.

I wanted duals just because I am working on a 355 from my fathers old race car to put in there.

But then again when I get on it this thing is loud as hell, been pulled over multiple times for to much noise.

 

Well afr195 heads, cam and hsr intake is what I got and I need a good flowing exhaust for what in pulling in now. I wanted go with duals because with an x pipe I heard scavenging is best lol

 

Im not positive, but I think a single piple would scavenge better than an x pipe...

Scavenging is a big deal because you're splitting each bank into separate pipes. The X and H pipe are bandaids to make that happen. If you just run into a single pipe then it scavenges perfectly...

 

I did it in a 91 z. It was a pain in the *** but it's possible. I used hooker 2210s, flowmaster 40 series and a 3" universal exhaust kit from flowmaster. It even comes with an h pipe. It sounds awesome. Too bad I recently upgraded to a big block. Now I have no use for a custom exhaust system. It fits tight to the floor and goes over the axle. I didn't take any pics but I got a lot of compliments from my local speed shop.

 

assuming all pipes are equal length, each primary, then each pipe to the Y pipe. I don't think scavenging is as effective on a street car with a full exhaust as people believe.

 

IMO, I see no point in adding true duals to these car unless you are pushing 500 hp. Im running a 383 HSR setup that puts down about 420 hp and all I use is Hooker LTs with a custom made 3" Y pipe, Mufflex 3" cat back piping (minus the cat) and a cheap Hooker muffler. I do not need to run true duals to get more power out of my setup.
Besides, my car is lowered so even IF true duals free up HP for me, they still wouldnt go on my car.

 

. .

I pretty much run the same setup... Hooker 2210 supercomps, Muffex Y pipe to 4" pipe through a spintech exhaust.. It is definetly loud and I receive noise violation tickets all the time. But I have very litte restriction. I absolutely can't lower the car any..

 

Like said duals with shorties are easy and good clearance. Any exhaust with long tubes will have issues unless you have a custom tranny xmember or manual trans. Most autos are wide and dont have alot of room to pass pipes. Even y pipes have to clear them and sometimes that requires you to go under subframe rails and lose clearance. I know my car had issues with longtubes.

 

I have "been there and done that" on exhaust with these cars, I wish I had more pics of some of my setups but here is my experience:

Shorty headers with y pipe - The best ground clearance, not only for the headers, but for the exhaust behind it as well as they leave room for the driver's side pipe to make an immediate 90* turn towards the passenger side of the car and run down the stock exhaust channel.

Long tube headers - Loved my Hooker Super Comps, hated the ground clearance. Not necessarily with the header collectors as it always seemed like, at least for speed bumps they lined up with the tires enough that they both went over at the same time. Just the exhaust behind the headers, that height sucked.

Dual exhaust "Down the transmission tunnel" with bullets - Had this done at an exhaust shop, I didn't even have hangers my 2.5" exhaust was literally bolted to the bottom of my tranny cross member. I bottomed out on everything, it was embarrassing. There is not enough room under these cars to lose an additional 3" of ground clearance, and my car wasn't even that low. I do have old pics of that. I must say that setup made great power though :





Single 4" with long tubes - This was the best of all worlds, although my fab guy had to modify my frame for the driver's side exhaust pipe to pass by. He also modified the floor pan on the passenger side and we put a big stainless magnaflow muffler in it's place. This combination had great ground clearance and made great power. It also cost over $1,000 to have done.