Exhaust Questions

[Mike M.]

I have a nice '65 Coupe that got a 2nd Flight last Nov and will be judged again this Nov. I have done much work (lacquer paint, many new correct parts, etc) trying to move up to TF. I bought some mufflers last year from Corvette Central after doing some research on getting correct mufflers. I had a local muffler shop put these on they are not mounted totally correctly (were welded in spots where they should have been clamped, and vice versa). So I need to get the exhaust system installed correctly. I have all of the old original exhaust pipes (and I have new correct exhaust tips) that a good shop could copy. My question is whether or not it is best to have a local shop 'build' the system or am I better off to buy a system from someone like Corvette Central (or other good vendor)? I am told that a local muffler shop's metal bending will not be as original and there will be deductions for such. Please advise me on this question. Thanks,
Mike

[Keith B.]

Re: Exhaust Questions

a local muffle shop wont have the correct shape pipes. I heard good things from these guys http://www.gardnerexhaust.com/

[Doug L.]

Re: Exhaust Questions

I don't think you are going to be able to get an as-original exhaust system. I went through this debate with myself a few months ago. What I found was that any system that is available has something that is not like original. I got information from Gardner and although they have a very nice system, it is not correct. As I recall, one problem was the exhaust pipe is not welded to the muffler as it was on original systems. I think I got mine from Corvette Central. It is welded where the Gardner is not but it does not have mandrel-bent pipes. I could have had the Gardner system welded but they were more expensive and still not correct. I finally decided that if nothing I could buy would be as original, I may as well get an aluminized and welded system at the lower cost. The fit was excellent.
Doug

[John H.]

Re: Exhaust Questions

It is welded where the Gardner is not but it does not have mandrel-bent pipes. I finally decided that if nothing I could buy would be as original, I may as well get an aluminized and welded system at the lower cost. The fit was excellent.
Doug

Doug -

The original pipes weren't mandrel-bent either; they were bent with external die shoes, just like they are with muffler shop benders and the pipes on today's cars.

I made the same decision you did, for the same reasons.

[Mike M.]

Re: Exhaust Questions

I appreciate the advice. However, should one not have the system installed as per the original (that is clamped/welded/clamped-I hope I have that right) instead of welded entirely? I remember that I received point deductions for having the exhaust tips welded instead of clamped.

[William C.]

Re: Exhaust Questions

Yes, the tips should be clamped. I believe the reproductions are made to accept the clamped tips.

[Tom R.]

Re: Exhaust Questions

Buy yourself a good two piece welded system from Corvette Central with the installation kit. There are a couple of videos on YouTube how they copied the N-11 off road muffler and got the bends and flattening of the pipes as close as your going to get for judging I think. They offer stainless, aluminized and plain steel that will rust quickly but mimics OEM. The fit and installation is easy by one guy.

[Paul J.]

Re: Exhaust Questions

Mike, this should help. There's lots more in the archives.

https://www.forums.ncrs.org/showthre...ardner+exhaust

Paul

[Doug L.]

Re: Exhaust Questions

Going back to my last comment, the Corvette Central system is correct in that the front pipe from the exhaust manifold gets clamped to the main pipe. This connection is just in front of the crossmember under the seats. I believe the Gardner is the same. The main pipe from CC is welded to the muffler and has a stub outlet that accepts clamp-on extensions. That is how the original systems were assembled. The Gardner system has a clamp where the rear pipe meets the inlet of the muffler and this is not like original. So you can pay more for the Gardner system and either leave it as a clamped connection or you can spend more $ to have it welded. Neither system is correct for judging so if you are having your car judged you will receive deductions on both systems. Given you will loose points and there is no way to have a new "original" system, to me the decision comes down to cost. I can't speak to the fit of the Gardner system but I imagine the pipes are bent correctly and there is no problem with the fit. I know the CC system fits as it should.

Stainless, aluminized or mild steel? Pretty much your choice. If you are having the car judged you will have already received deductions no matter which system you chose, so the material can be whatever you want to pay for. I have had SS exhausts on other cars. I chose aluminized for my '64 because it is less expensive than SS and still provides some resistance to corrosion.

[Joe L.]

Re: Exhaust Questions

I appreciate the advice. However, should one not have the system installed as per the original (that is clamped/welded/clamped-I hope I have that right) instead of welded entirely? I remember that I received point deductions for having the exhaust tips welded instead of clamped.

Mike-----


There are NO systems that are "completely welded". Such a system would be absolutely impossible to install in a Corvette. The original PRODUCTION factory systems were CLAMPED at the juncture between the front and rear pipes (i.e. at the transmission crossmember). The exhaust extensions ("tips") were also originally clamped although if they had been welded it would have created no problems of installation. The factory-original rear pipes were welded at the muffler. This was the only welded connection in the original systems.

GM (and aftermarket) SERVICE mufflers and rear pipes were designed for a clamped connection at the rear pipe/muffler juncture. So, the SERVICE mufflers had a welded-on extension for connection to a shortened rear pipe accomplished at the time of muffler replacement. SERVICE rear pipes were also shorter than original so that if a rear pipe were replaced at the time of SERVICE muffler installation it would be the appropriate length. SERVICE mufflers for N-11 systems were supplied with a welded-on rear pipe identical in configuration to the PRODUCTION installation.

[Mike M.]

Re: Exhaust Questions

Doug: I think that although the Gardner systems are evidently excellent, they also cost a bunch. I have already spent a small fortune on getting this car to what I hope will be a TF. That in mind I am going to have a local muffler shop that I have used extensively make the system out of aluminized materials using the old pipes as a model. It will be clamped/welded/clamped like original and that will have to do. Thanks for all the good advice. Mike

[Joe L.]

Re: Exhaust Questions

Doug: I think that although the Gardner systems are evidently excellent, they also cost a bunch. I have already spent a small fortune on getting this car to what I hope will be a TF. That in mind I am going to have a local muffler shop that I have used extensively make the system out of aluminized materials using the old pipes as a model. It will be clamped/welded/clamped like original and that will have to do. Thanks for all the good advice. Mike

Mike-----


My guess is that this is going to cost as much or more than a complete system from a source like Corvette Central.

[Daniel Y.]

Re: Exhaust Questions

the other issue for point deduction is the muffler. Originals only had an "A" embossed on them. Anything else indicates a replacment /Configuration issue. Not to mention that the seam on all after markets are on the opposite side. I even asked Gardener if they could change the seam - no such luck.....

the best you can do is get the welds as close as possible where they should be - most judges will onky dedcut 2 points for the mufflers then. assuming the tips have a seam and the muffler has "mitting"


good luck!

[Mike M.]

Re: Exhaust Questions

I took the '65 to the local muffler shop that i have used in the past. I took all the old original exhaust pipes. They copied these as best they could with me standing there telling them exactly how I wanted it to look.. The result looks good, very much like the original. It is an aluminized system using the Corvette Central mufflers and correct extensions. The shop charged less than $250 to do all this which was not enough (although I stayed quite on that subject!) This car is going to be a driver. hopefully a TF driver, so I needed a muffler system that looked pretty much as it should but one that also should be dependable on a driver car.
Thanks for the help.
Mike