1971 C3 Exhaust Tips
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
Oh I am definetly going to do something with the tips when I install my new motor and new exhaust. The guy with the 1000hp black C3 told me his tips are custom made 3". THATS what I am looking for.
The gibson tips are a true 2.5" but I am really looking to do a 3". PLUS they are pretty expensive. You can get the 73, 2 3/8" tips on ebay for about $50 a pair. The gibons are about $150 a pair.
There is definetly a restriction, especially on bigger, more powerful motors.
On my dad's 59' vette, we had a 70 LS6 454 with about 450-475 crank HP running through 2.5" all the way to the rear but they had to go through 2" openings in the rear bumpers. So we went 2.5" to the muffler, then 2.25" out of the muffler up to the bumpers, then 2.0" out of the bumper. The total length of the 2.0" section was maybe 3".
The car sounded like total $hit. It was really poppy and just did not have a good tone. We left it like that a few months then ended up redoing it, going 2.5" to 40 series flowmasters, then 2.5" out of the mufflers, going over the axle and just turning them down right under the bottom of the trunk and slash cutting the pipes. You can not see the outlets at all without crawling under the car and it sounds 100X better. It now has just a ZZ4 so its not near as dramatic.
My 71 is 2.5" muffler shop special crinkle pipe until right before the rear end, then it goes down to 2.25" under the axle and into 40 series flowmasters. Out of the flows its 2" into the stock 2" tips. It sounds ok on my car because my motor is a basically stock, low compression smog motor with a L79 cam. On a real motor it would be poppy as hell.
The gibson tips are a true 2.5" but I am really looking to do a 3". PLUS they are pretty expensive. You can get the 73, 2 3/8" tips on ebay for about $50 a pair. The gibons are about $150 a pair.
There is definetly a restriction, especially on bigger, more powerful motors.
On my dad's 59' vette, we had a 70 LS6 454 with about 450-475 crank HP running through 2.5" all the way to the rear but they had to go through 2" openings in the rear bumpers. So we went 2.5" to the muffler, then 2.25" out of the muffler up to the bumpers, then 2.0" out of the bumper. The total length of the 2.0" section was maybe 3".
The car sounded like total $hit. It was really poppy and just did not have a good tone. We left it like that a few months then ended up redoing it, going 2.5" to 40 series flowmasters, then 2.5" out of the mufflers, going over the axle and just turning them down right under the bottom of the trunk and slash cutting the pipes. You can not see the outlets at all without crawling under the car and it sounds 100X better. It now has just a ZZ4 so its not near as dramatic.
My 71 is 2.5" muffler shop special crinkle pipe until right before the rear end, then it goes down to 2.25" under the axle and into 40 series flowmasters. Out of the flows its 2" into the stock 2" tips. It sounds ok on my car because my motor is a basically stock, low compression smog motor with a L79 cam. On a real motor it would be poppy as hell.
Advanced
Joined: Dec 2004
Posts: 98
Likes: 3
From: West Chester OHIO
SO I guess 2.5" is the absolute max then.... I really want to build a 3" mandrel bent system with 3', 40 series flowmasters and 3" square tips. I wonder if we can oval bend the 3" pipe to fit the stock tips better? I will go find the gibson tips I was talking about and see the ID.
3" mandrel bent pipes into Super 40s (3" inlet -3" outlet)
Had exhaust shop ovalize 3" one end of pipe, cut-off 2" inlet into square tip , cut oval hole and weld up
went together great!
Tips look original, But from a slight distance you can see 3" pipes going under rear diff - tells you its not stock ( I also wrapped the pipes going under the rear diff and rear spring region to be sure the spring doesnt over temp - you dont want the spring to get to 200F, even locally)
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
That exactly what I did
3" mandrel bent pipes into Super 40s (3" inlet -3" outlet)
Had exhaust shop ovalize 3" one end of pipe, cut-off 2" inlet into square tip , cut oval hole and weld up
went together great!
Tips look original, But from a slight distance you can see 3" pipes going under rear diff - tells you its not stock ( I also wrapped the pipes going under the rear diff and rear spring region to be sure the spring doesnt over temp - you dont want the spring to get to 200F, even locally)
3" mandrel bent pipes into Super 40s (3" inlet -3" outlet)
Had exhaust shop ovalize 3" one end of pipe, cut-off 2" inlet into square tip , cut oval hole and weld up
went together great!
Tips look original, But from a slight distance you can see 3" pipes going under rear diff - tells you its not stock ( I also wrapped the pipes going under the rear diff and rear spring region to be sure the spring doesnt over temp - you dont want the spring to get to 200F, even locally)
DUDE....can you get pics of your exhaust??? I am having a hard time proving to people 3" will fit in the cross member and under the rear end assy. Any pics of your 3" system would be GREATLY appreciated...
Especially of the tips!
Advanced
Joined: Dec 2004
Posts: 98
Likes: 3
From: West Chester OHIO
Side view of super40s w/ 3" exit transitioning to the tips
Looking into rear of exh tip showing ovalized 3" pipe welded into tip
backside view of ovalized pipe welded into tip
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
DLR502, THANKS A LOT FOR THE PICS!!!!
Man you don't have much clearance under the rear end huh? My car is stock height so I think I will be ok but...damn, those 3" pipes eat up some real estate. I like the tips to. Thats the way to go....
Man you don't have much clearance under the rear end huh? My car is stock height so I think I will be ok but...damn, those 3" pipes eat up some real estate. I like the tips to. Thats the way to go....
Thread Starter
Heel & Toe
Joined: Mar 2007
Posts: 23
Likes: 0
From: Redmond WA
Oh I am definetly going to do something with the tips when I install my new motor and new exhaust. The guy with the 1000hp black C3 told me his tips are custom made 3". THATS what I am looking for.
The gibson tips are a true 2.5" but I am really looking to do a 3". PLUS they are pretty expensive. You can get the 73, 2 3/8" tips on ebay for about $50 a pair. The gibons are about $150 a pair.
There is definetly a restriction, especially on bigger, more powerful motors.
On my dad's 59' vette, we had a 70 LS6 454 with about 450-475 crank HP running through 2.5" all the way to the rear but they had to go through 2" openings in the rear bumpers. So we went 2.5" to the muffler, then 2.25" out of the muffler up to the bumpers, then 2.0" out of the bumper. The total length of the 2.0" section was maybe 3".
The car sounded like total $hit. It was really poppy and just did not have a good tone. We left it like that a few months then ended up redoing it, going 2.5" to 40 series flowmasters, then 2.5" out of the mufflers, going over the axle and just turning them down right under the bottom of the trunk and slash cutting the pipes. You can not see the outlets at all without crawling under the car and it sounds 100X better. It now has just a ZZ4 so its not near as dramatic.
My 71 is 2.5" muffler shop special crinkle pipe until right before the rear end, then it goes down to 2.25" under the axle and into 40 series flowmasters. Out of the flows its 2" into the stock 2" tips. It sounds ok on my car because my motor is a basically stock, low compression smog motor with a L79 cam. On a real motor it would be poppy as hell.
The gibson tips are a true 2.5" but I am really looking to do a 3". PLUS they are pretty expensive. You can get the 73, 2 3/8" tips on ebay for about $50 a pair. The gibons are about $150 a pair.
There is definetly a restriction, especially on bigger, more powerful motors.
On my dad's 59' vette, we had a 70 LS6 454 with about 450-475 crank HP running through 2.5" all the way to the rear but they had to go through 2" openings in the rear bumpers. So we went 2.5" to the muffler, then 2.25" out of the muffler up to the bumpers, then 2.0" out of the bumper. The total length of the 2.0" section was maybe 3".
The car sounded like total $hit. It was really poppy and just did not have a good tone. We left it like that a few months then ended up redoing it, going 2.5" to 40 series flowmasters, then 2.5" out of the mufflers, going over the axle and just turning them down right under the bottom of the trunk and slash cutting the pipes. You can not see the outlets at all without crawling under the car and it sounds 100X better. It now has just a ZZ4 so its not near as dramatic.
My 71 is 2.5" muffler shop special crinkle pipe until right before the rear end, then it goes down to 2.25" under the axle and into 40 series flowmasters. Out of the flows its 2" into the stock 2" tips. It sounds ok on my car because my motor is a basically stock, low compression smog motor with a L79 cam. On a real motor it would be poppy as hell.
Racer
Joined: Apr 2007
Posts: 364
Likes: 1
From: Dane Wisconsin
after you get past the cross member use some of this and it will fit the tips and give more clearance.
http://burnsstainless.com/OvalTubing/ovaltubing.html
http://burnsstainless.com/OvalTubing/ovaltubing.html
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