Hey guys, I plan on doing a dual exhaust setup for the winter and this is what my idea is. My original idea is to hack up the original y-pipe and fabricate downpipes that would lead underneath the car on each side. as many of you know, there is not much room underneath these thirdgens. I though of a new and relatively simple way to do a dual exhaust. no i do not want to put headers in, i TRIED... i have long tubes and short tubes, neither of them fit. what i plan on doing is where the original cat was [for cars that had single cats] put in place a cherry bomb 2.5" single inlet dual outlet center 2.5" muffler. i forget what the exact name of it is, its in my jegs magazine and it is about $57.00. I then plan on ordering the 2.5" hotrod exhaust kit which is about $219.00 and includes alot of piping in order to do custom exhaust. i plan on having the pipes run along each other on the passenger side of the frame, over the axle and then exit as dual exhaust. one tip will extend to the rear drivers side and the other will continue to the rear pass. side. let me know what you think. i currently have a flowmaster 80 series muffler 2.5" to dual 2.5" tips, but since i did not order the complete kit, i had forgotten when i had my original exhaust piping fixed, the stock exhaust is 2" or 2.25" so i am getting a farly nice sound considering i have no cats, but maybe 5 to 10 hp at max from this setup. my goal is to get a louder, deeper and more agresssive tone while increasing my hp & torque just alittle bit more without having to break the bank. let me know what you guys think! thanks-matt!

 

1. That's been done many times (dynomax even sold a similar setup for years).
2. That's not true duals if it's a single inlet at the muffler.
3. Installing headers and single exhaust will increase the power much more than having log style manifolds and duals.

Some headers fit well, some don't. You get what you pay for.

 

There's really no need for a true dual exhaust, anyway. It's not worth the extra expense.

 

here is my setup before they were installed of course. a guy had them in his shed with a ton of other car parts he wanted to part with. they were originally on his iroc with headers. stops right before the axle. just a template for ya.

 

My goodness, that guy went to autozone and wiped out their supply of bends and extensions! At least he welded it up.

 

lmao thats what i said lmao but its welded pretty darn good. no leaks

 

In my opinion, a lot of work for no gain. If it were a 1000 horsepower car then maybe it would be worthwhile to go true duals. Talk to Don on these forums...he builds headers for our cars....he's been building exhausts for decades

 

what do you have?

 

I don't have it yet, but I will have a 383 stroker, when it is finally finished here soon.

I talked to Don aka "dyno Don" and he said with my 383 even at 550 horsepower, a single system is more than ample and works great. He hasn't noticed any worthwhile gains running a dual exhaust on engines in this horsepower range.

I think he told me he picked up 3 horsepower running long tubes and true dual exhaust.

 

well thats great and im sure "dyno Don" knows his stuff but maybe statistics and charts just dont cut it for everyone. maybe its just something someone wants to have. even if a car isnt 1000hp, im sure a true dual setup would fair better than the stock y pipe setup as far as breathing goes. in my case, i got the pipes for free so i didnt lose a thing. just had to buy the headers that i had already planned to buy in the first place. and not to call you or your friend a lie but installing long tubes AND a dual exhaust should have given you more than 3hp..that engine must have been HEAVILY HEAVILY on something.

 

I could be mistaken. He said either 3 or 9 horsepower. I do know that it wasn't much of a gain.

 

yea, maybe 9 sounds a little more like it. when you get your 383, will you be running a single or dual setup? cat?

 

There's a reason that almost every name in exhaust offers a single 3" exhaust for our cars, and only one offers a dual exhaust system. It's not needed. Especially not on a 150hp 305. A mandrel bent 3" setup with a good aftermarket muffler is going to flow better then a hack-job, crush bent true dual system that reduces ground clearance.

Our cars all sit low as it is, every dual exhaust illustrated in other threads on here cost ground clearance. It's fine if you don't mind rubbing on everything, or pulling over to go pick up your mufflers that just fell off, but if you want a system that fits, maintains ground clearance, and is emissions legal, just pick one of the MANY stock style cat-back exhausts that are available.

 

well most people that go for a true dual setup doesnt have ground clearance as a priority in the first place. and a hack job crush bent exhaust for free is wayy better than a $300+ single exhaust which i started with. and its only on the 305 until i finish my vortec 383 but heyy, thats just IMO. like i said earlier, maybe its just what someone wants, piece of mind if you will. if the numbers dont add up to you, then heyy, save yourself some time, money, and GROUND CLEARANCE by not getting duals..simple. the OP wanted a "simple dual exhaust concept" as the title clearly states, not a class on why duals arent necessarily or a number crunching horsepower course. ok?

 

The only reason to do dual exhausts is long tubes. The only advantage of long tubes is that although they dont make that much more peak power, they do make more power earlier in the RPM range. The increase low end torque and therefore horsepower and as you get closer to peak HP, the gain is pretty modest. At high RPMs LTs and shorties are theoretically about the same as far as performance.

If you dont have long tubes that necessitate the driver's side bank staying on the driver's side of the car, there is NO REASON to go duals, IMO. Running duals along the stock location is fine, but I dont think you'd gain anything from going from a single mandrel bent 3 inch catback to a 2.25 inch (thats what I usually see) dual setup, especially with all those tight bends in it all the way through the car.

I have long tubes and I run a single 3.5 exhaust. I did the dual 3 inch deal for a little while... hated it.

So to address the OP's idea. That's pretty much the worst of both worlds. The farther back from the engine you get, the less your power gains are. The farther back from the engine the slower the exhaust is, the cooler it is, the more insignificant it becomes to the engine way up in the front. Im not saying there are no gains in a good catback, but I am saying that MOST of the gains come from headers and a good y-pipe. The catback is there just to make sure the headers and y-pipe flow to their potential.

What you're doing is the equivalent of attaching a garden hose to a culvert and expecting the hose to flow more water. Worse than that, all the bends and piping cost money after a while - dual 2.5 pipes and mandrel bends all the way out the back - ouch. Plus extra friction that comes with more piping. It'd be not so bad if it was just a straight shot out the back of the car, but you're gonna try to follow the stock routing.

I dont think it's going to accomplish much in performance or sound or cost. you've got the performance of log manifolds and factory piping and the effort and expense of a complicated dual exhaust system with no performance gain.

 

WOW. Thats a horrible exaust system. Look at all those bends in the pipes.

 

oh, why thank you. he followed the stock route.

 

Hmm... Make excuses for your flea market exhaust much? Did you read the OP's post? Do you understand the concept of a discussion forum?

OP asked for opinions. I gave mine.

 

A single 3" is my opinion.

 

okay so it probably wouldnt be worth the money, but i atleast want to change the cat-back piping. the piping from the muffler to the cat is 2". would i have buy the whole entire kit all over again if i want to upgrade to 3"? the muffler is 2.5". Also Another neat idea i want to fab up, is 2nd gen trans am exhaust tips. i want to fabricate them so they exit the same way on 2nd gen, onto a 3rd gen. considering now I am going to stick to single exhaust, dual outlet

 

One thing is for sure. Your gonna have to get a mandrel bent 3" cat back. That'll cost you under $400. Then you would have to buy shorty headers with matching y pipe. I myself have the Edelbrock TES header and y pipe system but it's not as good as other header systems because the y pipe and headers are crushed to fit in the collector. Still it is better than OEM. So regardless, it's cheaper to buy a complete system from Summit Racing than to have one fabricated at a shop. Talk to DYNO Don about the header and y pipe. Header system and y pipes are also made by flowtech that is pretty much plug and play.

 

i have the right tools to fabricate it myself. i just want to get the best sound& performance to money ratio. ill figure something out. thanks guys for the suggestions and help!

 

Well if you what hard aggressive sound, I suggest you get a header and y pipe system. And then get an electric motor cut out system in between the cat and motor.

 

http://www.google.com/search?tbm=isc...0&bih=208#i=14

http://www.google.com/search?tbm=isc...0&bih=208#i=32

 

There isn't a lot of power to be gained from a cat-back exhaust. The choke points in the stock system are the manifolds, Y-pipe, converter, and muffler. The LG4 exhaust is basically the same as the V6, tiny pipes from start to finish. A 3" cat-back isn't going to bolt up to the existing cat, and it's not going to address the restrictive manifolds and Y-pipe.

If you want louder you can just change the muffler. If you want more power, I'd start by finding a set of high output manifolds, matching Y-pipe (either single or dual converters), and then bolt up a matching cat-back. It'd fit, sound good, and increase performance.

 

I would take Drews advice. Drew is a no Bull Dung type of guy. Drew knows his stuff.

 

single 3in will b just fine u can even fab up up an adapter from 2.5 to 3in
sleeve in order too retain your current ehaust that flowmaster flows great take it to a muffler shop and have em sweg the inlet to three in cheap and btw dont listen to no one do what u like thats what matters the most check the system i just built on the post one off long tubes cackles and flames

 

I have to stick up for the Edelbrock headers. I have had a few sets of them over the years, and even though they aren't the best flowing design, they are fine for a stock to mild engine. What I love about them is they fit great and seem to be a very good quality, I've never had problems with any of them.

 

First, I'm glad you didn't spell it "Duel". Second, take everyone's advice.

 

thanks for the advice guys! i actually have a set of edelbrock TES headers. I tried to fit them in and i couldnt get them to fit. I only tried the drivers side and then gave up. is there a special technique to get them in. I.E raise the block?? & yeah Drew, you're right, there are alot of restricting components on the LG4 like as you stated the exhaust but also the cam, compression and heads. the stock intake isnt too shabby & the carb is imo a great piece of equipment. but the parts that are necessary to gain power from, GM had greatly de-tuned the motor by putting in more restrictive parts. So yeah just let me know if any of you guys had any problems using the edelbrock TES headers. The ones i have had the air tubes, but i had just recently cut them off and welded up the holes since i have no more emmisions equipment on the block. thanks- matt

 

I can't wait to get my single 4" on!

 

I'm satisfied with my flea market exhaust, thank you very much. And yes I understand the concept of a discussion forum. I was participating in the discussion by giving the OP an example of a dual exhaust and apparently a couple people wanted to bash my exhaust cause its not a professional $400+ exhaust. Who cares what it looks like. Its on my car and it was free. If I had a problem with what it looked like, I obviously wouldn't have even took them. Sooo, if that's all you and your people have to say about my exhaust then whoopty doo. Hope your sheepish comments keep your lungs pumping. If not, PLEASE, get off my d**k before you over ride it.

 

IIRC, the instructions said that it may be necessary to remove the driver side valve cover to slide the header in. Of the four I've put in, I never had to remove the cover (one was really close though). Maybe your mounts are a bit worn.

 

 

You will find the instruction sright here...
http://static.summitracing.com/globa.../edl-68723.pdf

 

 

That crinkle system looks fine to me. Ive seen FAR FAR FAR worse come out of real exhaust shops.

A mandrel bent y-pipe setup would clearly be better, but I dont know how much he paid for that setup either. could be a great bang for the buck. Unless he's racing at the drag strip all the time I dont see it as a huge encumberance. The crinkle bends are bad, but still I've seen way worse.

Far worse that cost a friend of mine WAY too much money:
https://www.thirdgen.org/forums/exha...e-exhaust.html

 

i actually just got finished installing the Edelbrock TES headers. i had to remove my valve covers because i have the tall edlebrock valve covers. and the reason why the driver side wouldnt fit before is because the steering column was wider when it was horizontal compared to when it was verticle. i turned the steering wheel slightly and bam! the fit right in. i just ran the car and it runs great and doesnt sound half bad. i just need to find a y pipe for the Edelbrock TES headers. any suggestions?

 

Yup. It only cost me $127 dollars about a year ago. Hold on while I search for it.

 

here is the part number.... Edelbrock 65930
your gonna have to search and destroy because this part is discontinued. Summit no longer carries it nor other stores....
http://performanceparts.com/part/Edelbrock/65930

 

Thanks man! i really appreciate it! thanks for all the help! -matt

 

Glad to help out a fellow member. Ur welcome.

 

thanks man. nope, no drag strip. just was something i was replacing my stock stuff with. i KNOW its no where near a beauty and its not there to stay. but like i said, it was FREE so no weight off my wallet. and wow, a shop actually made that y pipe like that?? crazy. i dont even like the muffler/exhaust shops around here. every time you go there, they never had a situation like that before and they dont know how much it will cost and they want you to leave your car to come back to a surprise $500 bill. and its with normal non f body cars lol

 

Single.

I'll be running no cat (don't need it in Wyoming) and 1 3/4" Dyno Don shorties with a 3.5" collector to a single 3.5" exhaust pipe most likely to a Magnaflow dual exit muffler.

My other idea is the Hawk's "Sinister" single 4" exhaust. Rather than just pipe, however, I would add a straight through Magnaflow round muffler about 2 to 3 feet before the exit tailpipe, to mellow out the sound a bit.

I am leaning more towards the Magnaflow because A) it is a frickin' good exhaust for the money and B) it'll have dual exit pipes which is appropriate for an American muscle car.

My 383 will have a choppy idle, and I want it to be muffled enough to not sound too nasty, but I don't want a restrictive exhaust on the beast, so whatever muffler I use, it will be a "straight through" design.

I admit that I love the sound of Flowmaster mufflers but have not heard great things about actual flow performance from a lot of people, but a few people swear by Flowmaster "technology."

And guys who want a dual exhaust, let me tell you that I am no expert, but I HAVE done a TON of research by reading, in person, and via forums and the internet, and a dual exhaust is NOT NECESSARY on our cars.

I guess if you are into serious drag racing and need to squeeze every last bit of hp out of the darn engine, then FINE....go crazy and add a few horses to your 9,000 horsepower top fuel drag car by going long tubes and true dual exhaust.

I used to love wasting Subaru STIs, Vettes, Camaros, etc. in my little SRT-4 (yes, I did lose a lot of races to 600+ hp Vettes and 750 hp STI's and the like), and I had a single 3" Billy Boat exhaust on it coming off of a log style manifold, and many of the V-8 cars I beat had "true dual" exhausts and long tube headers. Big deal!!

The most important thing is to build your engine right and set up your drivetrain and suspension to handle the power.