Header Size Calculator
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Header Size Calculator
I remember somebody posting a link to a calculator that told you the optimum size for the primaries and collectors (not the length but the diameter) but I can't seem to find it anymore. Can somebody help me out. Thanks
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Car: '89 Trans Am GTA
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Re: Header Size Calculator
Gee, this is ONLY about 3-1/2 years late, but maybe it'll help someone out...
HeaderDesign.com
(I found this thread while doing a related search...)
HeaderDesign.com
(I found this thread while doing a related search...)
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Car: '90 Trans Am-12.45@110.71
Engine: 355 w/AFR 195's Elem. 400/430 HP/TQ
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Re: Header Size Calculator
If you subcribe to that jargon to determine what header to use on a street car, then you have way to much time on your hands.
That info is just for an allout max output race situation.
That info is just for an allout max output race situation.
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Car: currently a 91 G92.
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Re: Header Size Calculator
Do you really want to go with the 1 5/8" header in a camed lb9, or is the 1 5/8" header sufficient for most street applications both in 305s and 350s? I have been sort of trying to figure this out for sometime since I am trying to select a set of headers for my car. I know that many people here have chosen the hooker 2055s, which have 1 5/8" primaries.
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Car: '82 Camaro
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Re: Header Size Calculator
My choice for the '82 is 1 3/4" to 1 7/8" step headers, 34" tube length and a 3 1/2" collector---only other thing I'm considering is using a merge collector but I haven't really found any good test data on them other then the usual manufacturer's hype...???? But, this will be a 383 solid roller cammed, AFR 195 heads, 12.8 CR on E-85... Obviously a whole lot more header then the average 350 with a mild cam would ever need....
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Re: Header Size Calculator
Do you really want to go with the 1 5/8" header in a camed lb9, or is the 1 5/8" header sufficient for most street applications both in 305s and 350s? I have been sort of trying to figure this out for sometime since I am trying to select a set of headers for my car. I know that many people here have chosen the hooker 2055s, which have 1 5/8" primaries.
1 5/8" are fine for most guys. I ran 1 5/8" headers for a number of years when I had a thirdgen and trapped 119-120mph in the 1/4.
Some guys at the time, such as Traxion if I recall, were running 1 3/4" long tubes, but I was running 10mph faster than them so I often wonder if it was overkill. Then again, they had better heads than me.
There is some merit to primary length tuning, but not with the camshafts you guys are running.
-- Joe
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Re: Header Size Calculator
My heads are pretty much stock, with comp cams xr258hr12: 206*int/212* exh. @.05" tappet lift .480"int/.488"exh. lift with 112* LSA?
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Re: Header Size Calculator
So would it be worth the money to invest in a set of hooker 2055s, which are tuned, vs lets say the hooker 2460s, which are not tuned? Also, since Dyno Don's headers have 1 3/4" primaries, will that be overkill for my engine and kill performance?
My heads are pretty much stock, with comp cams xr258hr12: 206*int/212* exh. @.05" tappet lift .480"int/.488"exh. lift with 112* LSA?
My heads are pretty much stock, with comp cams xr258hr12: 206*int/212* exh. @.05" tappet lift .480"int/.488"exh. lift with 112* LSA?
I don't think 1 3/4" primaries are going to do much for you. And the tunes vs not tuned, if you are referring to the length being equal or not it doesn't matter. Whats worse, having 8 primaries equally the wrong length, or 8 primaries of slightly different lengths? Neither.
I don't know about Dyno Don's headers. I'd compare price, and go from there.
My 119-120 mph thirdgen strip car ran hedman 68470 headers. I had swapped to SLP 1 3/4" with zero improvement. This is on sportsman II heads with a somewhat lazy exhaust port. IF you had say, AFR 195s and a 224+ degree camshaft I'd opt for 1 3/4".
-- Joe
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Re: Header Size Calculator
What do you have now?
I don't think 1 3/4" primaries are going to do much for you. And the tunes vs not tuned, if you are referring to the length being equal or not it doesn't matter. Whats worse, having 8 primaries equally the wrong length, or 8 primaries of slightly different lengths? Neither.
I don't know about Dyno Don's headers. I'd compare price, and go from there.
My 119-120 mph thirdgen strip car ran hedman 68470 headers. I had swapped to SLP 1 3/4" with zero improvement. This is on sportsman II heads with a somewhat lazy exhaust port. IF you had say, AFR 195s and a 224+ degree camshaft I'd opt for 1 3/4".
-- Joe
I don't think 1 3/4" primaries are going to do much for you. And the tunes vs not tuned, if you are referring to the length being equal or not it doesn't matter. Whats worse, having 8 primaries equally the wrong length, or 8 primaries of slightly different lengths? Neither.
I don't know about Dyno Don's headers. I'd compare price, and go from there.
My 119-120 mph thirdgen strip car ran hedman 68470 headers. I had swapped to SLP 1 3/4" with zero improvement. This is on sportsman II heads with a somewhat lazy exhaust port. IF you had say, AFR 195s and a 224+ degree camshaft I'd opt for 1 3/4".
-- Joe
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