Exhaust sizing question
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
2.5" true duals?
Too many competitive (damn fast actually) that are only running 3" with the single middle...then back to 2.25 or 2.5 (Y pipe) duals to the muffler.
I wouldn't worry about too much. There is a header formula that can be had with a web search....that should give you an idea of a sufficient diameter for 4 cyl...sounds like you;re there.
Too many competitive (damn fast actually) that are only running 3" with the single middle...then back to 2.25 or 2.5 (Y pipe) duals to the muffler.
I wouldn't worry about too much. There is a header formula that can be had with a web search....that should give you an idea of a sufficient diameter for 4 cyl...sounds like you;re there.
Race Director
Joined: Nov 2003
Posts: 12,221
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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Le Mans Master
Joined: Oct 2008
Posts: 9,758
Likes: 49
From: Houston Texas
I put LT1 exhaust on my 91.. It was cheap and effective.
http://forums.corvetteforum.com/c4-t...te-videos.html
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Very hard if impossible to make a 3" system quiet. Even with an X and 20" case mufflers mines still loud.
Keep the 2.5 unless you have one hell of a stout motor and running very high rpms/track only motor you simply dont need 3".
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Race Director
Joined: Nov 2003
Posts: 12,221
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Le Mans Master
Joined: Feb 2005
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From: Clearwater Florida
..... The what-you-need formula is always overuled by the what-you-want list ............. I have mandrel bent 3" tubes through an X-pipe with 24" glasspacks and 50 series Flowmasters ..... I think it sounds bad-a@@ .........
Last edited by C409; Feb 28, 2013 at 07:53 AM.
Drifting
Joined: Jan 2002
Posts: 1,403
Likes: 3
From: Columbia Maryland
Have to disagree with you on that one about being hard or impossible to keep a 3" system tame and liveable!
On my 415 car, have 2" Jeal's going into a 3" X pipe, 3" all the way back to Dynamax 3" Stainless VT mufflers and I can assure you this thing is very tame until you let it loose then it gets loud as chit.
Even all the way up to 80 mph or better, as long as you don't twist up the R's, it doesn't get loud. I can listen to the radio at normal levels or talk on the cell phone with no XS noise issues.
And the VT mufflers are guaranteed for life if they ever fail. Got the mufflers through Summit Racing for $160 bux shipped (they price matched AMAZON).
I went from a 2.5 Flowmaster to this system and it woke up the motor and now is seems to breath much better especially having the Siamease Plenum.
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
I had a big system with eliminators at the end and it was unbearable to cruise in...
the constant roar...droaning, made it more work than fun to take long drives. When I had to drive from Portland Ore to Phx...I stopped at a local muffler shop and had then hack the back end off and replace with something more civilized so I could get to my destination with some sanity...
Did that mod en-route it was so bad.
the constant roar...droaning, made it more work than fun to take long drives. When I had to drive from Portland Ore to Phx...I stopped at a local muffler shop and had then hack the back end off and replace with something more civilized so I could get to my destination with some sanity...
Did that mod en-route it was so bad.
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
few systems are actually "tuned" to the engine...most are just bolt on guessing or buying whatever sounded ok when there were funds available..
Advanced
Joined: Jan 2012
Posts: 78
Likes: 0
I AGREE with you,which means 3" with a 4oo hp sb,not so bad,but with 600 hp sb,very bad for noise,even with x pipe.He needs a res.or high flow cat. where the x would be.or stick with 2 1\2 and sligth restriction.john
Drifting
Joined: Mar 2009
Posts: 1,253
Likes: 4
From: East Wenatchee (2hours from n e where) WA
Race Director
Joined: Sep 2001
Posts: 14,676
Likes: 751
From: NEwhere Ohio
Cuisinartvette:
Have to disagree with you on that one about being hard or impossible to keep a 3" system tame and liveable!
On my 415 car, have 2" Jeal's going into a 3" X pipe, 3" all the way back to Dynamax 3" Stainless VT mufflers and I can assure you this thing is very tame until you let it loose then it gets loud as chit.
Even all the way up to 80 mph or better, as long as you don't twist up the R's, it doesn't get loud. I can listen to the radio at normal levels or talk on the cell phone with no XS noise issues.
And the VT mufflers are guaranteed for life if they ever fail. Got the mufflers through Summit Racing for $160 bux shipped (they price matched AMAZON).
I went from a 2.5 Flowmaster to this system and it woke up the motor and now is seems to breath much better especially having the Siamease Plenum.
Have to disagree with you on that one about being hard or impossible to keep a 3" system tame and liveable!
On my 415 car, have 2" Jeal's going into a 3" X pipe, 3" all the way back to Dynamax 3" Stainless VT mufflers and I can assure you this thing is very tame until you let it loose then it gets loud as chit.
Even all the way up to 80 mph or better, as long as you don't twist up the R's, it doesn't get loud. I can listen to the radio at normal levels or talk on the cell phone with no XS noise issues.
And the VT mufflers are guaranteed for life if they ever fail. Got the mufflers through Summit Racing for $160 bux shipped (they price matched AMAZON).
I went from a 2.5 Flowmaster to this system and it woke up the motor and now is seems to breath much better especially having the Siamease Plenum.
you sure you need that? what kind of power / rpm you have?
Drifting
Joined: Jan 2002
Posts: 1,403
Likes: 3
From: Columbia Maryland
You need room to move a lot of air volume at those kind of rpm's.
HP: Good question! Enough to violently spin a set of soft/sticky 335 30 18 R888's between shifts granny shifting.
Gibby
