tri-y headers and smaller exhaust system

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Re: tri-y headers and smaller exhaust system

Post by 77cruiser » Mon Apr 15, 2019 10:37 pm

Gaskets for track 1 heads by Felpro are close & the holes need to be slotted on them. I put mine back on with Hi Temp RTV.
These.
https://www.summitracing.com/parts/fel- ... /chevrolet
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Re: tri-y headers and smaller exhaust system

Post by steve cowan » Tue Apr 16, 2019 3:51 am

i scraped the flange plate idea.
i cut some 1'' x 1'' x 5/16'' flat plate and welded into floor of header,i have left the square edge into the pipe as a AR ?? comments
these headers seem to be centered in the middle of the port height wise,i slotted holes so roof and sides line up pretty close.
the photos are not pretty but i think it will work,the Dart 178 cc i have on the moment is a 1444 felpro opening size as standard 1.38'' x 1.38''.
i will need to fabricate a new gearbox cross member as well,i want to keep the collectors running true and straight.
i have done 2 flat plates only 6 to go. :D
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Re: tri-y headers and smaller exhaust system

Post by cjperformance » Tue Apr 16, 2019 4:07 am

The look does not matter , no one will see it ! :lol:
The 'AR' square edge may or may not help,, hows that for a decisive answer?!,, in any case it definitely wont hurt at cruise/lighter throttle loads, most likely wont hurt mid range/tq. Only testing will prove it for your combo , maybe just moving that mismatch down stream that little bit will help it everywhere.
Good work.
Craig.

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Re: tri-y headers and smaller exhaust system

Post by steve cowan » Tue Apr 16, 2019 4:30 am

:D
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Re: tri-y headers and smaller exhaust system

Post by steve cowan » Thu Apr 18, 2019 7:42 pm

tri-y 001.JPG
updates-
finished welding in all plates and hand finished one side.
i am unable to use the flowmaster merge pipes (bummer) the inlet angles are spread to wide.i cut one of my secondary pipes to try and compensate for better transition but makes the pipes to wide and fouls on the starter,front end.
my options were slim so i did the best i could into the merge area.
i welded in some AFR bungs at the merge - the sensors are facing up in the 11 oclock position.
collector length ???
i have slip on extensions i can add later
i am looking for a starting point 15'' ?? maybe having slightly shorter.
if these pipes show potential i would consider getting a copied set made in stainless with corrected CSA at the flanges and merge areas.
comments appreciated.
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Re: tri-y headers and smaller exhaust system

Post by cjperformance » Thu Apr 18, 2019 8:17 pm

Steve, if you want a very easy , quick and cost effective way to play with collector length just cut what you have back to say 6" - 9"
Make up several collectors in different lengths and have an exhaust shop pump out one end to slip over your short collectors.
You can then 'slice and clamp' the slip join or 'hook and spring' the slip joint into place.
This makes a collector length swap a 5 minute job.
Good work.
Craig.

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Re: tri-y headers and smaller exhaust system

Post by steve cowan » Thu Apr 18, 2019 9:58 pm

cjperformance wrote:
Thu Apr 18, 2019 8:17 pm
Steve, if you want a very easy , quick and cost effective way to play with collector length just cut what you have back to say 6" - 9"
Make up several collectors in different lengths and have an exhaust shop pump out one end to slip over your short collectors.
You can then 'slice and clamp' the slip join or 'hook and spring' the slip joint into place.
This makes a collector length swap a 5 minute job.
Good work.
thanks Craig,
if i cut the collector back to 9'',what would you recommend as a good extension length 6''-8''-10 ? 6''-10''-14''
probably answering my own question here lol- have as many different lengths as possible and test them all :D
i have a local guy who is helpful - exhaust shop
i figure test with short and then change to a long extension and see the differences,
what does make me leery on this is because i am track testing only -there are so many variables - i have to be careful i dont chase my tail on collector extension tuning for 6 months :lol:
appreciate your help mate.
steve c

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Re: tri-y headers and smaller exhaust system

Post by MadBill » Thu Apr 18, 2019 10:16 pm

You're not limited to a single extension; with the right lengths, you can easily stack up several as required to get virtually any length +/- 1".
Felix, qui potuit rerum cognscere causas.

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Re: tri-y headers and smaller exhaust system

Post by cjperformance » Fri Apr 19, 2019 2:04 am

Good point Bill ! That cuts down on the ammount of test pieces you need.
Yes Steve you could endlessly play with collectors. Dont go nuts. Just cut yours at lets say 6". Take a 12 , 6 and 3" extension with you. Or pipemax some collector options as some baselines, your pipes wont match exactly what pipemax says but you'll be close enough to experiment.
If the car is consistent already just do a quick and dirty test,, 1 clean run on each length. Pick the best looking mix of 60'(indication of TQ/response) & e/t (indication of average mph/hp) then tune for the best on that collector. Then try the lengths again maybe just to 're average' it. You will see a trend quickly. Basically after 5 or 6 clean runs you will have a pretty good idea what the car and pipe combo likes. Then do a few runs and usual tune checks etc to test consistency. Its hard sometimes when you dont get many in a given meeting. Or find a nice backroad and have some fun!!
Craig.

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