Advancing Camshaft
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From: Pacifica CA
2 - 2 &1/2" (mandrel-bent pipes only) into a single 3 1/2" is exactly what we used on a restricted class stock car.
With a high-flow cat it can be far better than an OEM original exhaust if there is room for it. IMHO
Would this flunk a visual inspection ?
We had to use iron manifolds too and 'vette ramhorns filled the bill nicely.
Do you any options for better manifolds or exempt headers ?
You may not make great improvements - but you may be able to make some.
With a high-flow cat it can be far better than an OEM original exhaust if there is room for it. IMHO
Would this flunk a visual inspection ?
We had to use iron manifolds too and 'vette ramhorns filled the bill nicely.
Do you any options for better manifolds or exempt headers ?
You may not make great improvements - but you may be able to make some.
Burning Brakes
Joined: Nov 2012
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From: Indianapolis IN
I believe Hedman makes a set of full length headers which are CARB legal, but just how effective would they be going through a 2-1-2 exhaust system? As far as the visual inspection is concerned, I think that depends on the smog tech's experience. I don't think many smog techs today know much about older (carbureted)cars. That may be a bit of an advantage for us.
It has potential to be better than duals in some respects.
Go here to learn more about two into one exhaust:
http://www.castheads.com/2into1_systems.php
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From: San Jose CA
I believe Hedman makes a set of full length headers which are CARB legal, but just how effective would they be going through a 2-1-2 exhaust system? As far as the visual inspection is concerned, I think that depends on the smog tech's experience. I don't think many smog techs today know much about older (carbureted)cars. That may be a bit of an advantage for us.
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From: anchorage ak
I believe Hedman makes a set of full length headers which are CARB legal, but just how effective would they be going through a 2-1-2 exhaust system? As far as the visual inspection is concerned, I think that depends on the smog tech's experience. I don't think many smog techs today know much about older (carbureted)cars. That may be a bit of an advantage for us.
oops!
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From: Pacifica CA
OH yes, full length headers with a great two into one will be very effective - if sized correctly.
It has potential to be better than duals in some respects.
Go here to learn more about two into one exhaust:
http://www.castheads.com/2into1_systems.php
It has potential to be better than duals in some respects.
Go here to learn more about two into one exhaust:
http://www.castheads.com/2into1_systems.php
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From: Millington Illinois
St. Jude Donor '08-'09
If you used larger mandrel bent pipes and high flow cat and high flow muffler it sure would help. I think dougs try y's are carb legal. The trick in your case is getting the most through the induction and out the exhaust with approved parts while passing a pipe test, if the exhaust were larger with high flow accessories would it pass the visual provided it were run in the same places? Would the high flow cat do enough to pass the pipe test? I think with the combination and placement of parts you could get an honest emmisons legal 375 to 400 horse. my vette passed the pipe test with 260 rwhp, but i had to take it to the ref station because it didn't pass the visual and this was with a flat tapper cam, not the best edelbrock heads and the Wieand action plus that was crappy but made hood clearence all through Hooker comps as 2.5" duals. With Afrs and a roller it might have made 280 or 290.
oops!
oops!
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
just a thought, you could cut the A.I.R tubes off of a late c3 with tubular manifolds , drill some holes and weld them to a set of long tubes.
that would make them look right at least . no reason it wouldn't work.
that would make them look right at least . no reason it wouldn't work.
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From: anchorage ak
oops!
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From: Millington Illinois
St. Jude Donor '08-'09
Burning Brakes
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From: Indianapolis IN
This is the Flowmaster setup I have on now; the collectors look very similar to the Brzezinski 2 into 1 exhaust system and all the pipes are mandrel bent as well. It is a very well made system, the pipe diameter is 2 1/2" throughout. I like the idea of a better rams horn or shorty headers, but I have to be able to install the A.I.R. plumbing as well.
http://www.summitracing.com/parts/flo-y250350/overview/
Smooth bends and transitions !
What is the intermediate pipe and cat diameter ? I'd consider 3 1/2" to be a minimum, if using 3" - you'd be best to make it and the cat as short of a run as possible, ( and that would still be a cork !).
Those "shorty" style headers are not much better than manifolds - if any, I'd always want full length and even use them on work trucks when possible.
Last edited by 68post; Sep 18, 2014 at 09:43 AM. Reason: more