[DeTomaso] Headers/Exhaust
MikeLDrew at aol.com
MikeLDrew at aol.com
Sun Feb 8 06:07:20 EST 2015
In a message dated 2/7/15 21 24 31, mghibli7 at hotmail.com writes:
> I have finally decided to switch back to normal exhaust on my Pantera.
> I will keep the 180's.
>
>>>Why would you keep them? Seems to me you should either keep them and
use them, or switch and sell them to fund the switch?
> > I want something that looks stock, but flows better. My car has been
> through a few stages. The one that I enjoyed the most was slightly
> modified over stock. It is currently in the too-modified condition.
> It feels like a race car slightly detuned for the street.
> I've been thinking about GTS headers like these:
> [1]http://www.precisionproformance.com/ex1015.php.
> Any recommendations on mufflers? Do any of the vendors sell ANSA style
> mufflers that flow better than stock?
>
>>>All the vendors sell the factory GTS exhaust system. They all source
their ANSA GTS mufflers from Hall, who is the exclusive north American
distributor for them, and sell them for about the same price. The headers are
perfect copies of the ANSA originals but made in the USA.
The mufflers are fantastically expensive. The original GTS mufflers are
also quite restrictive; Dan Jones dyno tests showed they knocked a full 50 hp
(!) off from an optimized system (Mustang headers and conventional
non-Pantera mufflers) in back-to-back tests.
I gutted my GTS mufflers to improve them, and shipped them to Dan for a
back-to-back test with unmodified GTS mufflers and was sad to learn that I only
picked up 12 hp; it wasn't worth the effort to modify them. I concluded
that the culprit is the four tips, whose center holes are not nearly large
enough. The new-production mufflers no longer use resonators; they have
chrome tips with an unnecessary restriction inside, but they are at least larger
inside diameter than the old ones were.
Wilkinson's copy of the GTS exhaust system is brilliant. Dan dyno-tested
them and found that they picked up a whopping 31 horspower over the factory
GTS system. It comes as a complete system (headers and mufflers) and costs
barely more than the ANSA GTS mufflers alone. It's designed to mimic the
appearance of the originals, and does a fantastic job of it. The outside
diameter of the tips is 1/4 inch larger than the original ANSA tips, barely
noticeable (3 inches versus 2 3/4 inches). But the inside diameter of the
resonators is 1 3/4 inches versus the 1 1/4 inches of the original ANSAs (the
new ANSAs are 1 1/2 inches, splitting the difference).
A quarter inch might not sound like such a lot, but don't forget the whole
Pi-r-Squared thing.
So, the original GTS muffler tips have an area of 3.92 inches each, the new
ANSAs are 4.71 and Wilkinson's are 5.49. Multiply each of those by two
per pipe, and you start to see a significant difference in potential flow:
7.84 inches versus 9.42 versus 10.89 inches, per muffler.
All three have the same inlet pipe size, 2.34 inches; that gives an area of
7.35 inches.
Wilkinson's system was available in either mild steel or stainless steel,
but he told me he doesn't intend to carry them in mild steel any longer.
Personally I like the way mild steel exhausts sound, and given that they are
significantly cheaper, I would opt for those if possible.
Note that he had the mufflers made to accomodate the one-piece L-model
bumper (a mistake, in my view), but he will modify the angle of the tips to
replicate the jaunty upward stance of the original ANSA exhausts for a nominal
fee (I think he charges $75 extra). That's a must for any car that has
anything other than a one-piece L rear bumper.
My car still wears the original ANSA GTS system, but we got one of
Wilkinson's mild steel systems for Lori's car and that will be going on once we get
her engine back from Dave McLain....
Mike
-------------- next part --------------
In a message dated 2/7/15 21 24 31, mghibli7 at hotmail.com writes:
I have finally decided to switch back to normal exhaust on my
Pantera.
I will keep the 180's.
>>>Why would you keep them? Seems to me you should either keep them
and use them, or switch and sell them to fund the switch?
> I want something that looks stock, but flows better. My car has
been
through a few stages. The one that I enjoyed the most was
slightly
modified over stock. It is currently in the too-modified
condition.
It feels like a race car slightly detuned for the street.
I've been thinking about GTS headers like these:
[1]http://www.precisionproformance.com/ex1015.php.
Any recommendations on mufflers? Do any of the vendors sell ANSA
style
mufflers that flow better than stock?
>>>All the vendors sell the factory GTS exhaust system. They all
source their ANSA GTS mufflers from Hall, who is the exclusive north
American distributor for them, and sell them for about the same price.
The headers are perfect copies of the ANSA originals but made in the
USA.
The mufflers are fantastically expensive. The original GTS mufflers
are also quite restrictive; Dan Jones dyno tests showed they knocked a
full 50 hp (!) off from an optimized system (Mustang headers and
conventional non-Pantera mufflers) in back-to-back tests.
I gutted my GTS mufflers to improve them, and shipped them to Dan for a
back-to-back test with unmodified GTS mufflers and was sad to learn
that I only picked up 12 hp; it wasn't worth the effort to modify
them. I concluded that the culprit is the four tips, whose center
holes are not nearly large enough. The new-production mufflers no
longer use resonators; they have chrome tips with an unnecessary
restriction inside, but they are at least larger inside diameter than
the old ones were.
Wilkinson's copy of the GTS exhaust system is brilliant. Dan
dyno-tested them and found that they picked up a whopping 31 horspower
over the factory GTS system. It comes as a complete system (headers
and mufflers) and costs barely more than the ANSA GTS mufflers alone.
It's designed to mimic the appearance of the originals, and does a
fantastic job of it. The outside diameter of the tips is 1/4 inch
larger than the original ANSA tips, barely noticeable (3 inches versus
2 3/4 inches). But the inside diameter of the resonators is 1 3/4
inches versus the 1 1/4 inches of the original ANSAs (the new ANSAs are
1 1/2 inches, splitting the difference).
A quarter inch might not sound like such a lot, but don't forget the
whole Pi-r-Squared thing.
So, the original GTS muffler tips have an area of 3.92 inches each, the
new ANSAs are 4.71 and Wilkinson's are 5.49. Multiply each of those by
two per pipe, and you start to see a significant difference in
potential flow: 7.84 inches versus 9.42 versus 10.89 inches, per
muffler.
All three have the same inlet pipe size, 2.34 inches; that gives an
area of 7.35 inches.
Wilkinson's system was available in either mild steel or stainless
steel, but he told me he doesn't intend to carry them in mild steel any
longer. Personally I like the way mild steel exhausts sound, and given
that they are significantly cheaper, I would opt for those if possible.
Note that he had the mufflers made to accomodate the one-piece L-model
bumper (a mistake, in my view), but he will modify the angle of the
tips to replicate the jaunty upward stance of the original ANSA
exhausts for a nominal fee (I think he charges $75 extra). That's a
must for any car that has anything other than a one-piece L rear
bumper.
My car still wears the original ANSA GTS system, but we got one of
Wilkinson's mild steel systems for Lori's car and that will be going on
once we get her engine back from Dave McLain....
Mike
More information about the DeTomaso
mailing list