Exhaust Replacement

[76okievette]

I have looked up in past post for the answer but want to see what new info I can get. I am going to replace my exhaust system, at least the pipes from the stock manifold back to the mufflers, I know I have hole in one pipe but the mufflers seem good. Does this make sense of should I replace the mufflers at the same time. My car has had the cat removed and has true straight exhaust, I see no Y or X pipes just stright back to the muffllers. Also what size pipe's should I get most people talk about 2.5". I guess if I keep the mufflers that are installed now I will have to get the size pipe that fits those mufflers. I guess it would be best to go with 2.5" pipe and replace the mufflers at the same time. Does this make sense?

 

[Fishman]

2.5" has worked great for me... I'd go ahead and replace both mufflers regardless if one is still o.k.


Brian

 

[Robin7TFour]

Hello Brian, haven't seen you post in awhile. guess you've been on the road listening to your new pipes. finally got my sidepipes done. sounds really good, not as loud as i thought.
i have a set of dyno-max mufflers if anyone needs them

robin

 

[paintdaddy]

I would suggest buying a whole kit that includes mufflers and hangers.Since you dont want cats ,you might need to order for a 68-73.

 

[76okievette]

Update, I talked to the local performance muffler shop yesterday, and he is willing to replace the exhaust pipes from the manifold back to the muffler with 2.5 inch pipe for 90 dollars a side. That sounds pretty good to me what about to you guys?

 

[rponfick]

Have you considered chambered exhaust. Mid America has best deal at $299 for everything, no additional mufflers needed. Mine fit well.

 

[mvftw]

I posted this before, for what it's worth...I was told by 3 exhaust pros that a stock 350 is better with 2 1/4" then 2 1/2". Not enough HP. Also a H-pipe is better in a C3 then a X-pipe because of the location. I put in 2 1/4", H-pipe, no heat riser, & S/S Flowmater 50's.

 

[76okievette]

Interesting, all I have hear is 2.5 inch pipe. I have a completely stock 76 L-48 engine. Now I am confused, I though going with the 2.5 inch pipe would increase the horsepower, but what I understand you to say is that you have to enough horsepower to handle the 2.5 inch pipe?

 

[mvftw]

That's right...but ask exhaust pros yourself. Guys that deal in muscle cars.

 

[78SilvAnniv]

Have you considered chambered exhaust?

I'm glad someone else brought up chambered!
I love the sound and performance of my chambered exhaust. It is a very simple system and did I mention the loud rumble-y sound?

The problem with the stock L48 and its low horsepower is that it sort of needs the backpressure of the pipes and mufflers. If you change to chambered it will give you the sound...but you could lose some performance because there is less back pressure.
You can gain that lost hp back by making some mechanical changes, but do speak with an exhaust expert about what you could expect out of an L48.

My 78 was a California emission L48, about 160-170hp(?). I changed the engine to a GM crate in 1996 and that is the engine I have the chambered on. I don't know what the differences are between that block and the stock L48 I had.

Anyhow, if the exhaust system on your vette is nearly 30 years old, I'd replace it all, even the mufflers, so you get a clear and crisp sound.
Heidi

 

[Robin7TFour]

Me Okie, the $90 sounds very fair price. the local shop by ne was going to charge me $125 for the same thing. silly me, i put sidepipes on.
as to the size of the pipe. the local guy you talked to may be correct. sometimes too big of a pipe doesn't create enough back-pressure to effectively help in the scavenging of the exhaust gases. bigger isn't always better.


robin

Go Cowboys....OSU

 

[76okievette]

Thanks for all the good advice, I how feel I can make a better decision aobout how to go. I will let you all know what I did and how it worked out early next week. Thanks again.


Go OSU, man that's had to say for a SOONER Fan!!!!!!!!!!

 

[76corvette]

Hey, I got a MAD's chambered exhaust on my vette. I totally love it.. if you dont love the loud muscle car sound its not for you but just a suggestion. They are about 300 last time i checked.. http://www.madvet.com/shop?frame=4.36.1293http://www.madvet.com/ Its the best exhaust system i have ever heard. Good luck..

 

[GerryLP]

Interesting, all I have hear is 2.5 inch pipe. I have a completely stock 76 L-48 engine. Now I am confused, I though going with the 2.5 inch pipe would increase the horsepower, but what I understand you to say is that you have to enough horsepower to handle the 2.5 inch pipe?

Kievette,

All things being equal, the larger diameter pipe will allow for more horsepower (just how more is though to say without a before and after dyno run). But one has to realize that horsepower is a function of rpm, so this "gained" horsepower will most likely be at the upper segment of the horsepower band.

However, typically, a trade-off takes place, and the result is that torque at the lower segment of the band (usually refered to as "loosing or gaining bottom end") is reduced. The good news is that if your car could make the rear tires "bark" from a complete stop, then going from 2 1/4 to 2 1/2 probably won't be very noticeable. Again, only a chasis dyno can illustrate what you have gained or lost if the check is done before and after the modification.

 

[76okievette]

Great Info as always, I think I will go with 2 1/4 "no cat" true dual exhaust and possible new mufflers. I was looking at the car last night and it appears the mufflers are new they are still shinny and clean. I just have some pin holes in the exhaust pipes. I might also replace the chrome tips not sure because they are welded to the mufflers so if I keep the mufflers it make's sense to keep the chrome tips.

 

[curtis]

Maybe this is too late for you, but my 76 has Hooker headers that I wrapped and a mandrel bent 2 1/4 inch true dual system with Monza mufflers from Mid America (the cheap mufflers with no restriction. ) Headers and pipes from Summitt and fit great.MY engine really responded to these changes, other mods CompXE262 cam, vortec iron heads, performer intake, Edelbrock carburetor. Super Chevy built this exact motor and saw 390HP 430lb/ft torque. Blast to drive. Traction problem.

 

[curtis]

exhaust mods

Maybe this is too late for you, but my 76 has Hooker headers that I wrapped and a mandrel bent 2 1/4 inch true dual system with Monza mufflers from Mid America (the cheap mufflers with no restriction. ) Headers and pipes from Summitt and fit great.MY engine really responded to these changes, other mods CompXE262 cam, vortec iron heads, performer intake, Edelbrock carburetor. Super Chevy built this exact motor and saw 390HP 430lb/ft torque. Blast to drive. Traction problem.

 

[Bob Chadwick]

You are going with the set up I went with after talking to Dynoamx. They recommended 2 1/4 up to about 350 hp due to the loss of low end torque with bigger pipes.

 

[76okievette]

Just wanted to let everyone that posted to this thread know that I just drove the car home with the new exhaust system. I went pretty tame compared to some of the systems described here, I have 2 1/4 inch pipe from the stock manifold back to FlowMaster mufflers, true dual's no cat or Y or H pipe, with chrome tail pipes,(total cost $230.00) car looks good (no muffler hanging down everything is tucked up real nice) sounds good and runs good. I am sure its not as loud as some but I bet it sounds better that it did back in 1976, someone had put 2 inch pipe on before me so the 2 1/4 will help. Thanks again for all the info.

Next is new rear wheel bearings and parking braked, then a wheel alignment. After that its all road trips, I might even make the trip up to Auburn we shall see.

GO SOONERS

 

[bossvette]

I like Hooker Header side Pipes myself, but second choice would be chambered exhaust , I like the [URL=http://home.ripway.com/2003-9/23891/Corvette/vette2.wav]Sound[/URL] of Hookers.:cool