[DeTomaso] Headers/Exhaust

Daniel C Jones daniel.c.jones2 at gmail.com
Sun Feb 8 14:16:45 EST 2015


> Question for me is, what was the base HP, Dan Jones got 31 HP more? Was
it a stock engine or a highly modified? How many percent was it?

I've done a number of exhaust tests.  On the dyno mule 351C which is around
400 HP, the stock ANSA mufflers lost 50 HP to the Magnaflows using the same
headers.  the larger diameter aftermarket Euro GTS mufflers were also
tested on a 500 HP 408C and they lost 50 HP compared to the Magnaflows.
Later we tested Mike Drew's Mike Drew's modifed ANSAs (cans gutted and
filled with a perforated Y-pipe so no baffles) and they lost 38 HP on the
dyno mule 351C.  Finally, we tested the Wilkinson mufflers on a different
408C.  The details are summarized here:

 http://poca.com/pipermail/detomaso_poca.com/2012-December/066634.html

The relevant passages are below.  Given their size and design, the
Wilkinson set-up did pretty well compared to even Mike Drew's gutted
mufflers but weren't as good as open pipes or the Magnaflows:

"Several exhaust systems were tested with the following results (rounded to
the nearest HP):

1. Wilkinson stainless steel Pantera shorty 4-into-1 headers and exhaust (2
1/4" OD) with stock appearing mufflers:

 552 HP @ 6000 RPM
 518 ft-lbs @ 4500 RPM

That's really amazing power to be pushing through shorty Pantera headers
and mufflers with 2 1/4" tail pipes.  Compare to the following test and the
Wilkinson exhaust is worth 31 HP on this engine (perhaps more when we test
the Funnelweb intake manifold and 950HP carb).  Given the stainless steel
construction, low cost and HP increase, the Wilkinson exhaust are excellent
pieces.

2. ANSA Euro GTS headers and exhaust

 521 HP @ 6000 RPM
 500 ft-lbs @ 4800 RPM

These are the better flowing Euro GTS version of the Pantera ANSA mufflers
and matching headers. Down 31 HP and 18 ft-lbs to the Wilkinson version.

3. Mustang long tube headers without exhaust (no mufflers), specifically
Hooker Competition headers (part number HOK-6920HKR) with 1 3/4" diameter
by 27" long primaries, 3" diameter by 8" long collector with 12 inch long
collector extensions

 564 HP @ 5900 RPM
 546 ft-lbs @ 4600 RPM

4. The above Hooker Mustang long tube headers with 3" inlet/outlet
Magnaflow stainless steel mufflers.

 555 HP @ 5900 RPM
 535 ft-lbs @ 4800 RPM

Only 3 HP peak more than the Wilkinson exhaust but 17 ft-lbs more peak
torque due to the long primary headers.  Open headers were worth another 11
HP and 11 ft-lbs so I'd bet a cross-over would be worth some power when
running mufflers.

Dan Jones

On Sun, Feb 8, 2015 at 12:57 PM, R.J <willibillie at live.de> wrote:

>    Question for me is, what was the base HP, Dan Jones got 31 HP more? Was
>    it a stock engine or a highly modified? How many percent was it?
>    Roland
>
>    Am 08.02.2015 um 12:07 schrieb Mike Drew via DeTomaso:
>
>    In a message dated 2/7/15 21 24 31, [1]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][2]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
>
>
> _______________________________________________
>
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> the li
> nks above.
>
> References
>
>    1. mailto:mghibli7 at hotmail.com
>    2. http://www.precisionproformance.com/ex1015.php
>    3. mailto:DeTomaso at poca.com
>    4. http://poca.com/mailman/listinfo/detomaso_poca.com
>
> _______________________________________________
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>
-------------- next part --------------
   > Question for me is, what was the base HP, Dan Jones got 31 HP more?
   Was it a stock engine or a highly modified? How many percent was it?
   I've done a number of exhaust tests.A  On the dyno mule 351C which is
   around 400 HP, the stock ANSA mufflers lost 50 HP to the Magnaflows
   using the same headers.A  the larger diameter aftermarket Euro GTS
   mufflers were also tested on a 500 HP 408C and they lost 50 HP compared
   to the Magnaflows.A  Later we tested Mike Drew's Mike Drew's modifed
   ANSAs (cans gutted and filled with a perforated Y-pipe so no baffles)
   and they lost 38 HP on the dyno mule 351C.A  Finally, we tested the
   Wilkinson mufflers on a different 408C.A  The details are summarized
   here:
   A [1]http://poca.com/pipermail/detomaso_poca.com/2012-December/066634.h
   tml
   The relevant passages are below.A  Given their size and design, the
   Wilkinson set-up did pretty well compared to even Mike Drew's gutted
   mufflers but weren't as good as open pipes or the Magnaflows:
   "Several exhaust systems were tested with the following results
   (rounded to the nearest HP):
   1. Wilkinson stainless steel Pantera shorty 4-into-1 headers and
   exhaust (2 1/4" OD) with stock appearing mufflers:
   A 552 HP @ 6000 RPM
   A 518 ft-lbs @ 4500 RPM
   That's really amazing power to be pushing through shorty Pantera
   headers and mufflers with 2 1/4" tail pipes.A  Compare to the following
   test and the Wilkinson exhaust is worth 31 HP on this engine (perhaps
   more when we test the Funnelweb intake manifold and 950HP carb).A
   Given the stainless steel construction, low cost and HP increase, the
   Wilkinson exhaust are excellent pieces.
   2. ANSA Euro GTS headers and exhaust
   A 521 HP @ 6000 RPM
   A 500 ft-lbs @ 4800 RPM
   These are the better flowing Euro GTS version of the Pantera ANSA
   mufflers and matching headers. Down 31 HP and 18 ft-lbs to the
   Wilkinson version.
   3. Mustang long tube headers without exhaust (no mufflers),
   specifically Hooker Competition headers (part number HOK-6920HKR) with
   1 3/4" diameter by 27" long primaries, 3" diameter by 8" long collector
   with 12 inch long collector extensions
   A 564 HP @ 5900 RPM
   A 546 ft-lbs @ 4600 RPM
   4. The above Hooker Mustang long tube headers with 3" inlet/outlet
   Magnaflow stainless steel mufflers.
   A 555 HP @ 5900 RPM
   A 535 ft-lbs @ 4800 RPM
   Only 3 HP peak more than the Wilkinson exhaust but 17 ft-lbs more peak
   torque due to the long primary headers.A  Open headers were worth
   another 11 HP and 11 ft-lbs so I'd bet a cross-over would be worth some
   power when running mufflers.
   Dan Jones

   On Sun, Feb 8, 2015 at 12:57 PM, R.J <[2]willibillie at live.de> wrote:

     A  A Question for me is, what was the base HP, Dan Jones got 31 HP
     more? Was
     A  A it a stock engine or a highly modified? How many percent was
     it?
     A  A Roland
     A  A Am 08.02.2015 um 12:07 schrieb Mike Drew via DeTomaso:
     A  A In a message dated 2/7/15 21 24 31, [1][3]mghibli7 at hotmail.com
     writes:
     A  A  A  A I have finally decided to switch back to normal exhaust
     on my
     A  A  A Pantera.
     A  A  A  A  I will keep the 180's.
     A  A >>>Why would you keep them?A  Seems to me you should either
     keep them
     A  A and use them, or switch and sell them to fund the switch?
     A  A  A >A  I want something that looks stock, but flows better.A
     My car has
     A  A  A been
     A  A  A  A through a few stages.A  The one that I enjoyed the most
     was
     A  A  A slightly
     A  A  A  A modified over stock.A  It is currently in the
     too-modified
     A  A  A condition.
     A  A  A  A It feels like a race car slightly detuned for the street.
     A  A  A  A I've been thinking about GTS headers like these:
     A  A  A  A [1][2][4]http://www.precisionproformance.com/ex1015.php.

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

     _______________________________________________
     Detomaso Forum Managed by POCA
     Posted emails must not exceed 1.5 Megabytes
     DeTomaso mailing list
     [3][5]DeTomaso at poca.com
     [4][6]http://poca.com/mailman/listinfo/detomaso_poca.com
     To manage your subscription (change email address, unsubscribe,
     etc.) use the li
     nks above.
     References
     A  A 1. mailto:[7]mghibli7 at hotmail.com
     A  A 2. [8]http://www.precisionproformance.com/ex1015.php
     A  A 3. mailto:[9]DeTomaso at poca.com
     A  A 4. [10]http://poca.com/mailman/listinfo/detomaso_poca.com
     _______________________________________________
     Detomaso Forum Managed by POCA
     Posted emails must not exceed 1.5 Megabytes
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     [12]http://poca.com/mailman/listinfo/detomaso_poca.com
     To manage your subscription (change email address, unsubscribe,
     etc.) use the links above.

References

   1. http://poca.com/pipermail/detomaso_poca.com/2012-December/066634.html
   2. mailto:willibillie at live.de
   3. mailto:mghibli7 at hotmail.com
   4. http://www.precisionproformance.com/ex1015.php
   5. mailto:DeTomaso at poca.com
   6. http://poca.com/mailman/listinfo/detomaso_poca.com
   7. mailto:mghibli7 at hotmail.com
   8. http://www.precisionproformance.com/ex1015.php
   9. mailto:DeTomaso at poca.com
  10. http://poca.com/mailman/listinfo/detomaso_poca.com
  11. mailto:DeTomaso at poca.com
  12. http://poca.com/mailman/listinfo/detomaso_poca.com


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