C-1 Performance Mufflers:
Thread Starter
Race Director
Joined: Jan 2005
Posts: 11,053
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From: Milford Michigan
C-1 Performance Mufflers:
Does anyone know the details of the C-1 special performance exhaust option? The undercar exhaust with the round mufflers? (Like what was the piping diameter & muffler dimensions).
Thanks, -Eric
Thanks, -Eric
Former Vendor
Joined: Aug 2006
Posts: 76,656
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Eric,
I have some at my shop NOS. In the 80's I loaned a set to Allens so he could make them. I can get the muffler dimensions for you. It seems to me like the muffler had a large round edge to them but I won't swear to it.
Email me at Willcoxcustomerservice@Willcoxcorvette.c om and I'll see if I can get someone to measure them for you. It may take a few days if that is OK.
Willcox
I have some at my shop NOS. In the 80's I loaned a set to Allens so he could make them. I can get the muffler dimensions for you. It seems to me like the muffler had a large round edge to them but I won't swear to it.
Email me at Willcoxcustomerservice@Willcoxcorvette.c om and I'll see if I can get someone to measure them for you. It may take a few days if that is OK.
Willcox
Race Director
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From: Mustang OK
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If the car came with the regular exhaust system (oval mufflers), there were TWO pipes forward of each muffler.
If the car came with the offroad exhaust system (round mufflers), the piece of pipe on the forward end of the round muffler was welded to the muffler. Thus, with the round muffler system, there was only one pipe forward of the mufflers, which is also the same forward pipe as used with the oval mufflers. As a result, with round mufflers that have the short piece of pipe welded to the front of the muffler, they are L&R. SOME manufactures of repo mufflers make the round mufflers and the short forward length of pipe as a one piece and some make the round muffler and short piece of pipe as a 2 piece.
If the car came with the offroad exhaust system (round mufflers), the piece of pipe on the forward end of the round muffler was welded to the muffler. Thus, with the round muffler system, there was only one pipe forward of the mufflers, which is also the same forward pipe as used with the oval mufflers. As a result, with round mufflers that have the short piece of pipe welded to the front of the muffler, they are L&R. SOME manufactures of repo mufflers make the round mufflers and the short forward length of pipe as a one piece and some make the round muffler and short piece of pipe as a 2 piece.
Race Director
Joined: Nov 2002
Posts: 12,142
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From: Taylor Michigan
The C 1 High Performance System was RPO 441 the Direct Flow
It appears the Off Road Exhaust system RPO N 11 started in 1963 to 65 available extra at a cost of $37.37. Probably only ordered with the HP engines. Before that only the 1962`s had a Direct Flow Exhaust system available RPO 441 that starts with the 2 1/2 in ram horn manifolds and immediately the pipe was reduced to 2 in to the muffler with a 1 1/2 balance tube crossing from side to side facing forward a few inches below the manifolds. Inlet on the round straight through mufflers is 2 in. and the outlet to the tail pipes is 1 7/8 in. Round mufflers were exclusive to the 62 in the RPO 441 package which was a no charge {$ free} system on the Vettes with the 360 HP 327 ci. fuel injection engine. The round mufflers were also used on either the 56 or 57`s. then skipped to 1962. Between those years only the oval mufflers were used on all Vettes regardless of the HP.
Melting Slicks
Joined: Sep 2006
Posts: 3,194
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From: Monroe Twp, NJ
It appears the Off Road Exhaust system RPO N 11 started in 1963 to 65 available extra at a cost of $37.37. Probably only ordered with the HP engines. Before that only the 1962`s had a Direct Flow Exhaust system available RPO 441 that starts with the 2 1/2 in ram horn manifolds and immediately the pipe was reduced to 2 in to the muffler with a 1 1/2 balance tube crossing from side to side facing forward a few inches below the manifolds. Inlet on the round straight through mufflers is 2 in. and the outlet to the tail pipes is 1 7/8 in. Round mufflers were exclusive to the 62 in the RPO 441 package which was a no charge {$ free} system on the Vettes with the 360 HP 327 ci. fuel injection engine. The round mufflers were also used on either the 56 or 57`s. then skipped to 1962. Between those years only the oval mufflers were used on all Vettes regardless of the HP.
Burning Brakes
Joined: Mar 2001
Posts: 1,203
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From: dalton ma
Although it is not listed in the Corvette Black Book, those round "off-road" mufflers came stock (also free) on my NEW 1960 270 HP Corvette. Also one of the relatively unusual items I had were the wide wheels with the dog dish hubcaps. Bob
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Former Vendor
Joined: Aug 2006
Posts: 76,656
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Eric,
I have some at my shop NOS. In the 80's I loaned a set to Allens so he could make them. I can get the muffler dimensions for you. It seems to me like the muffler had a large round edge to them but I won't swear to it.
Email me at Willcoxcustomerservice@Willcoxcorvette.c om and I'll see if I can get someone to measure them for you. It may take a few days if that is OK.
Willcox
I have some at my shop NOS. In the 80's I loaned a set to Allens so he could make them. I can get the muffler dimensions for you. It seems to me like the muffler had a large round edge to them but I won't swear to it.
Email me at Willcoxcustomerservice@Willcoxcorvette.c om and I'll see if I can get someone to measure them for you. It may take a few days if that is OK.
Willcox
If you can wait until tomorrow, I should be able to get all the measurements for you.
Edit Saturday: I went to the office today and forgot to measure them, I'm sorry. I'll do this on Monday for you.
Willcox
Last edited by Willcox Corvette; Jan 17, 2009 at 10:34 PM.
Drifting
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From: Rochester Hills Michigan
Melting Slicks
Joined: May 2000
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From: Chuckanut WA
According to Corvette News of the day the straight though mufflers were used on all 1957 Corvette engines and with all 1958,59,60,and 61 Corvettes with special camshaft engines. They were offered as an option (RPO 441)on all 62 Corvettes. 
Melting Slicks
Joined: Sep 2006
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From: Monroe Twp, NJ
Former Vendor
Joined: Aug 2006
Posts: 76,656
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
The mufflers appear to be about 13” in circumference, about 4.15 in diameter. The muffler is 23 ½ inches long. The pipes are 2” inlet and 1 ¾ outlet. I should be able to post pictures this evening.
Willcox Inc.
Willcox Inc.
Former Vendor
Joined: Aug 2006
Posts: 76,656
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Eric,
Email rec. (actually two of them) I've been having a problem with the office emails bouncing to my laptop. I think you're going to have a problem if the diameter is any larger, if you look at Fdreano's tumbs you'll see it may be tight. I'll talk with you about this later.
Willcox
Email rec. (actually two of them) I've been having a problem with the office emails bouncing to my laptop. I think you're going to have a problem if the diameter is any larger, if you look at Fdreano's tumbs you'll see it may be tight. I'll talk with you about this later.
Willcox
