cengles at cox.net
Mon Jan 7 19:29:11 EST 2019
Thanks for the comprehensive factual review.
You're building a 390 stroker as the dyno mule engine? No 351C mules?
Warmest regards, Chuck Engles
From: DeTomaso [mailto:detomaso-bounces at server.detomasolist.com] On Behalf Of Daniel C Jones
Sent: Monday, January 07, 2019 6:06 PM
Cc: detomaso at detomasolist.com
Subject: Re: [DeTomaso] headers
> IIRC, the Euro GTS headers-exhaust were considered the best although
they lost a reported 50 hp
It was the ANSA muflers that lost the 50 HP (compared to both Magnaflow mufflers and open headers. Surprisingly, the GTS headers weren't too bad on peak power but gave up a bunch of peak torque (25 to 35 ft-lbs depending upon the engine combination) due to the short primary and collector lengths. That's compared to a conventional Mustang long tube 4-into-1 headers with 1 3/4" diameter primaries and 3" diameter collectors.
> I need to purchase a new set for a 4v. Tri wye or big bore.
The Euro GTS headers aren't really tri-y headers. They are just 4-into-1 headers with a short tri-y collector. They have primaries that are too big and a collector that is too small but, in our testing, performed a little better than the other 4-into-1 shorty headers we tested with (also too
short) conventional collectors. Note that we did not test the Mind Train
4-into-1 headers. I'd stay away from the Hall big bore which had the worst collector.
I believe a real 4-2-1 tri-y full length header would gain back that peak torque without sacrificing the peak power. I've got a design that looks like it will fit the Pantera chassis and something I think I can use to test the concept on the dyno but when I'll find the time to complete the project is unknown.
> I have heard a handful of anecdotal stories of problems with
Those were the best of the off-the-shelf Pantera exhaust systems we tested due primarily to the mufflers working much better than the original ANSA units. Kelly Coffield's custom stepped 180s were probably the best Pantera exhaust we tested:
Note the small ID collector works on the 180s because no adjacent firing pulses are paired together in the same collector. The of-the-shelf Pantera 180s I've seen have had way to large of a collector.
> I have a pair of headers for 2v heads is someone needs them.
I've been slowly gathering 2V parts to test on the dyno. If no one snags them, I might have a use for them once the new dyno 390C is built.
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