[RED77]

I'm looking for a pre bent dual exhaust system for my 77SJ.
Any one have any info they can share?
Not having much luck finding anything.
I've checked with the local shops and none do mandrel bending.
From some of the work I've seen and what I've been told getting a quality job is hit or miss.
The car is a low milage custom ordered that I purchased from the original owner.
I really don't want to waste time and money putting crap parts on it.
I did come across a company called Torque Tech. anyone know anything about them?

[carsmymistress]

Interesting question. I just went through this on my 76 as I am converting it to duals now. I have the double hump cross member so I am good to go. Given how the aftermarket kit fit my GTO, I decided to have a local shop custom build my exhaust. You are correct that a good pipe bender is hit or miss and fortunately the guy doing mine did my GTO exhaust after I couldn't stand the fit. I am confident he will make this fit like a glove and for less than I could buy an aftermarket kit
One question. I understand you like the flow characteristics of a mandrel bent exhaust however if you have the stock 77 engine, it is likely that you will not notice a difference in performance between the two. Either one will flow better than the factory exhaust.
Two other potential challenges.
1) Do you have the double hump cross member? If not , a stock dual exhaust from a 73-4 will have clearance issues on the drivers side.
2) From a pipe builder, you will likely have issues with them not installing cats to replace the one that is on the car as there are pretty stiff penalties if they remove the cat and do not reinstall.
You probably already know this however thought I would thow that info out there in case you are unaware.

Good luck with the project

[jdon88]

I'm going to have a shop near me put duals on my '76, can you provide more detail about clearance issues on the drivers side? I have one of the tubular dual hump crossmembers from 73-74 that I'll have the shop install. If necessary I'll take the old cat off. I have PA classic registration so cat is no longer required.

[rexs73gto]

jdon88, I don't want to upset you but fed. law over see your local PA law. If the car came with a cat as all 75 cars did, the shop is required to reinstall your converter on all car so equipped. But some shops will do it any way. But you will need to put the crossmember on yourself as they can't by law convert any exhaust system either. But some do as we all know. Your best bet & I'm not saying you can do this , but install the double hump cross member pull off the cat & all the exhaust off including the Y-pipe as thats a dead give away. Then tell them your car is a 74 & you want new duel exhaust installed as the old system rusted off. Drive it in noisy. Don't let them see the vin as they will have to follow the letter of the law then. The fine for not reinstalling the cat is now up to 50K. Thats for the first offense. The second is lose of licence. But again I can't tell you to do this but it will help if your going to attempt it. As stated before if your engine is stock or mostly stock you won't if you get it done won't notice any difference in a reg. or mandrel bent system.

[carsmymistress]

Originally Posted by jdon88

I'm going to have a shop near me put duals on my '76, can you provide more detail about clearance issues on the drivers side? I have one of the tubular dual hump crossmembers from 73-74 that I'll have the shop install. If necessary I'll take the old cat off. I have PA classic registration so cat is no longer required.

Agree with Rex73GTO. The double hump cross member will address the clearance issue on the 75-7 cars. What he described is exactly what I have done for my conversions and have done with my current one as well.

Good luck!

[2002Z4CSS]

Seems like you should be able to order prebent 1973-1974 dual exhaust systems.

[Pontiacdaver]

This sidesteps the legal issue since you could install it yourself (and maybe take it to a shop for final aligning and permanent attachment).

http://www.ebay.com/itm/1973-1974-PO...0e5d66&vxp=mtr


I've been wondering, since this was posted, if a system from Inline Tube could be tweaked to fit, it is mandrel bent. Rex, or anyone else, know?

Dave

[rexs73gto]

I think if you go to the INLINE Tube site you will be able to find out . I do think tho that the system from them is mandrel bent.

[jdon88]

Thanks for the info, I didn't know there would be issues like that. My inspection station seemed to think it is not a big deal. If the exhaust shop won't do it then I will.

[jmt455]

Inline Tube, Waldron's, Classic or Gardner systems are not mandrel-bent.

The aftermarket performance systems like Pypes are (usually) mandrel bent.

[Bull]

Are exhaust shops near you guys actually refusing to install custom exhaust setups for customers because of cat converter or other "conversion" concerns?

[RED77]

Originally Posted by Bull

Are exhaust shops near you guys actually refusing to install custom exhaust setups for customers because of cat converter or other "conversion" concerns?

The problem around here is lack of people doing exhaust work and the haphazard quality
of the ones who do.
I wish someone would step up and make a decent system for the 74-77 GP's, even if running dual cat's was required.

[ScootinGP]

I just picked up a one owner 75 with 53K original miles. One thing I will need to address is the exhaust. I never expect the car to be what my 69 HO car is as far as performance, and this one will go to the wife for a cruiser anyhow. So with that said, I just want to ditch the converter and toss on duels that will sound decent. I will have to go peek at it but is the cross member on all 75's single hump? Where is a good place to dig up a duel hump and what years did they use the duel? I assume the GTO was the same cross member? Lastly, have any of you finished your exhaust and if so what did you end up doing? There are a few shops here I know would do it without the converter, but I may just run it in with it off anyhow. I already cut everything else off as it was shot anyhow and I wanted to pull the tank on the car.

[carsmymistress]

As for the double hump I believe it was 73-4 only. Grand Am should work as well. They pop up here quite often and Pontiacman had one listed a few days ago.

http://forums.maxperformanceinc.com/...ix+crossmember

As for the exhaust shops, I have a good relationship with a great exhaust guy here in FL. As long as I do not ask him to remove the cat (gone before it arrives at his shop) he builds a nice system. He did my 76 a few months ago and it turned out beautiful.

[fireprix]

I know that Summit Racing sells a mandrel bent dual exhaust. You can get it in either 2 1/4 or 2 1/2" piping. It is a header back system that exits in the rear below the bumper as a stock style exhaust would. I also believe Jeg's has the same. I put the 2 1/4" one from Summit on my 75 and it fits like a glove. But it is a header back system and 75-77 should have a 74 or back double hump transmission crossmember for proper fitment. I think they also sell down pipes from the manifold separately. I also at the same time installed a pair of Summit 4 tube headers. They required some denting to fit on the driver's side but they were cheap. The exhaust system comes with all hangers, clamps, hardware and 2 turbo mufflers. It even sounds decent on the low compression 400. I did the install in a 1 car garage with a floor jack, ramps and jack stands. It was fairly easy as far as the exhaust goes but the headers were another story. It was easier to put headers on my 89 Formula 350 than it was on my G.P. Pontiac V8 and bolt on headers don't exist in the same language.

[7t7gp]

Hi all, I have a 77 Grand Prix and like so many here I wanted true duals. Luckily for me I was working at a muffler shop at the time so I was able to bend up my own. But I was going to point out that the stock cross member can be modified to accept a dual exhaust. I took a piece of 4"pipe(hold a section of exhaust pipe inside it to make sure it fits first) and cut its length to the width of the cross member. I then cut it in half so from the end it resembled a u. I took this piece and used it to mark the cross member and once you are happy with the markings, cut this section out. Then put your u shaped piece of pipe into the cut out and if it fits weld it in. After that, grind and paint as necessary. Obviously this is all assuming you have a welder and other fabrication tools on hand. I now have a Grand Prix that sounds great and I have a minimal amount of money invested in it.

[ScootinGP]

Does anyone know if there are down pipes available anywhere? I do not want to mess with headers on this 75, and Summit said they do not carry them. I really wish there was a bolt on system. OR anyone know a decent muffler shop in the Chicago western suburbs area that can bend up a decent system reasonable and likes cash? lol

[jmt455]

Try Waldron's Exhaust.
(800)-503-9428

They might even have aftermarket NOS stock pipes.

[rexs73gto]

The down pipes for the GTO that all the companys sell will fit your G/P. Summit sells them to.

[RED77]

Summit sells Pypes down pipes that go from the manifolds to the crossmember.
They also sell header (crossmember) back dual exhaust kits that supposedly fit mid 70's GP's. They also have fabricated dual hump crossmembers which you will need.
you would probably be better off buying a factory dual hump from a forum member as the fab'd ones are expensive. Also check at Jegs. They often have the same products as Summit.