replacing exhaust system on the 73
Thread Starter
Burning Brakes
Joined: Jul 2001
Posts: 1,051
Likes: 0
From: Inside every color vette there is a blue one trying to come out!
replacing exhaust system on the 73
getting ready to take the vette to the shop and have the exhaust system replaced. It has stock exhaust manifolds. Can 2-1/2" pipes be run from the manifold? I believe that stock manifold has 2" outlet, can muffler shop get 2-1/2" pipes to fit? also thinking about getting some flowmaster 40's from ebay.
Melting Slicks
Joined: Feb 2003
Posts: 2,330
Likes: 6
From: Long Island NY
Re: replacing exhaust system on the 73 (Skruball73)
If you have a stock low compression motor like me ('78 L82), then consider 2 1/4" pipes. There are better if you have less then 300hp. The manifolds are 2". I'm going with Flowmaster 50's stainless...
Thread Starter
Burning Brakes
Joined: Jul 2001
Posts: 1,051
Likes: 0
From: Inside every color vette there is a blue one trying to come out!
Re: replacing exhaust system on the 73 (mvftw)
Enigine was just replaced with rebuilt engine bored 40 over with flat top pistons, can't remember off the top what the cam is, should be producing somewhere around 250 horses. Why would 2.25" be better than 2.5" under 300HP? I thought that less restriction would give better HP. :confused:
Burning Brakes
Joined: Apr 2001
Posts: 752
Likes: 1
From: Springfield Oregon
Re: replacing exhaust system on the 73 (Skruball73)
If you're replacing the exhaust system, I would strongly reccomend getting a set of headers on that motor. If you spent $220 on Dynomax ceramic's, I'd bet you could expect at least 1 HP/TQ for every $10 spent. That is the cheapest power you'll ever buy. Plus, header back exhaust will probably be a bit cheaper than manifold back, offsetting at least partly the cost of the headers. Ceramic coated headers will also reduce under hood temps, another bonus.
Safety Car
Joined: Jul 2002
Posts: 3,770
Likes: 3
From: St Louis MO
Re: replacing exhaust system on the 73 (Skruball73)
I just took the 40s off my 74 and put Dynomax Bullets on it. I will sell you the 40s for $75 + shipping. They are in really good shape and have turndowns welded on the ends. I can post pics if you're interested.
Brett :thumbs:
Brett :thumbs:
Melting Slicks
Joined: Feb 2003
Posts: 2,330
Likes: 6
From: Long Island NY
Re: replacing exhaust system on the 73 (ORVette)
You need backpressure. I went to 3 exhaust pro's, and all 3 said 2 1/4". I'm also debating headers. Since your motor isn't stock maybe 2 1/2" is Ok. Go to shops that do high performance exhaust and ask...
[Modified by mvftw, 4:39 PM 5/30/2003]
[Modified by mvftw, 4:39 PM 5/30/2003]
Safety Car
Joined: Jun 2001
Posts: 4,004
Likes: 2
From: Severna Park Md
Re: replacing exhaust system on the 73 (Skruball73)
2 1/4" pipes are better than 2 1/2" in some cases. If you want to maintain better power on the bottom end go with the smaller pipes. Now if you plan on screamin yur 350 beyond 6000rpm then the 2 1/2 will help out there, but only on the top end, with the sacrifice on the bottom end. my setup works great with 2 1/4" pipes.
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
I don't know anything about the ebay sellers of Flowmasters, but I would familiarize myself with the parts and part numbers before buying, especially on eBay. Flowmaster has a very informative website. For example, Flowmaster 40 series mufflers part # 42441 are $59.95 from Summit, but the Delta flow 40 series part#942441 are $72.95 from Summit. The Delta flow 50 series 942451 are $89.95. You can see there is a big variation. MJ
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Instructor
Joined: Jan 2003
Posts: 222
Likes: 0
From: Ventura CA
Re: replacing exhaust system on the 73 (Skruball73)
Can 2-1/2" pipes be run from the manifold? I believe that stock manifold has 2" outlet, can muffler shop get 2-1/2" pipes to fit?
[Modified by BB73Chris, 5:56 PM 5/30/2003]
Melting Slicks
Joined: Feb 2003
Posts: 2,330
Likes: 6
From: Long Island NY
Re: replacing exhaust system on the 73 (BB73Chris)
Right, they start out 2" at the manifolds. Some poeople get fooled when they say that L82's came with 2 1/2" (they did). After '74 they used Y-pipes, converting to true duals means more pipe is needed, that's why 2 1/4" is better...
Melting Slicks
Joined: Feb 2003
Posts: 2,330
Likes: 6
From: Long Island NY
Re: replacing exhaust system on the 73 (redwingvette)
Right, the kits are 2 1/2". That's why I'm having it done by a shop (2 1/4"). Plus if you get a kit, you should bring it to a shop anyway to install a H-pipe. Plus I'm having the manifold studs replaced with stainless...
Melting Slicks
Joined: Dec 2000
Posts: 2,198
Likes: 2
From: Eastern Connecticut
Re: replacing exhaust system on the 73 (mvftw)
Go with 2-1/2 inch (the first couple of inches have to be 2" to fit the manifolds). That's what fits thru the crossmember. The manifolds will give you all the backpressure you need, and headers don't like backpressure. There is no advantage to 2-1/4, except it is easier for the shop to bend. Get aluminized pipe (or stainless), not cheapo Midas pipe. Joe
Melting Slicks
Joined: Feb 2003
Posts: 2,330
Likes: 6
From: Long Island NY
Re: replacing exhaust system on the 73 (GREGG-73)
Like I said...go to a pro and ask him...if you have a hot engine with headers, use 2 1/2", but like I said, stock engines, run better with 2 1/4".
Instructor
Joined: Jan 2003
Posts: 222
Likes: 0
From: Ventura CA
Re: replacing exhaust system on the 73 (GREGG-73)
There is a complete system- SS ON E-Bay today for $670.00. :cheers:
Burning Brakes
Joined: Apr 2003
Posts: 844
Likes: 0
From: Central KY
Re: replacing exhaust system on the 73 (BB73Chris)
More thoughts:
The Dynomax headers seem ideal for a small block. Too bad they don't make them for the big block - or have I missed them?
Your exhaust tips are peculiar to the 1973 cars - lead pipe is centered in the rectangular tip. Earlier (70-72) cars had the pipe offset in there. Your muffler shop will have to accomodate our special tips. I would suggest you consider Dynomax Super Turbo mufflers instead of Flowmaster. The sound is perfect! Of course, then you have to deal with a muffler designed for 1972 car brackets and tips, so they say...
Anybody got the 1973 parts from Dynomax to go with 1973 brackets (stock) and tips?
Thanks!
The Dynomax headers seem ideal for a small block. Too bad they don't make them for the big block - or have I missed them?
Your exhaust tips are peculiar to the 1973 cars - lead pipe is centered in the rectangular tip. Earlier (70-72) cars had the pipe offset in there. Your muffler shop will have to accomodate our special tips. I would suggest you consider Dynomax Super Turbo mufflers instead of Flowmaster. The sound is perfect! Of course, then you have to deal with a muffler designed for 1972 car brackets and tips, so they say...
Anybody got the 1973 parts from Dynomax to go with 1973 brackets (stock) and tips?
Thanks!