[DeTomaso] Dogbone airfilter questions

[cengles at cox.net]

Dear Mikael,

You wrote:

> Thanks for answers. After Summit'ing a bit, I found that I can actually get
> an offset 14" base, needed to clear the rear lid. It's almost as if it was
> designed to help Pantera owners, but it's actually to clear the GM HEI.
$$$$$$ Hmmm. Pretty neat discovery.

>
> If I combine that with just a 2" tall filter element and a filtered top, I
> get approx. 220 square inches of area. The dogbone with 2 filters give
> approx. 110 sq ", and with 4 filters 220 sq ". And I get more visibility out
> of the rear window, plus it's adjustable (by buying 14" filters of different
> heights). Plus I save $200. And since some of the air comes from above
> instead of all of it having to turn 90 degrees to enter the carb, I'm sure
> it's less restrictive than the dogbone. Maybe not enough to see even one HP
> on a dyno, but still :-)
$$$$$$$ I have the same type of top filter from K&N. It was quite obvious that it would permit more airflow and, therefore, produce more horsepower. Uh-oh, Wrongo. After buying into that literally and figuratively for two engines, I learned that in the real world, it doesn't work. On the SpeedTalk website in their Engine Forum, where actual machinists and engine builders converse on multiple topics, this filter was mentioned a few months back. Multiple engine builders noted a 5 to 10 HP *decrease* using the trick filter top over a conventional top!! It would seem that the obvious benefit doesn't happen and my humble guess is that it may work so well that it harms laminar air flow into the carb by producing too much turbulence. Perhaps this is similar to the phenomenon of a normal air filter on a carb producing more HP than a bare carb in the situation of a hot rod with an exposed engine referenced in David Vizard's booking Making Horsepower Volume II. So........maybe save a few bucks and use a conventional lid that might make a few more HP over the trick top. FWIW.

Warmest regards, Chuck Engles

>
> So here's what I ended up with:
> http://www.summitracing.com/parts/SUM-239142/
> http://www.summitracing.com/parts/TRD-2231/
> http://www.summitracing.com/parts/TRD-2430/
> Total cost $115
>
> Mikael
>
> -----Oprindelig meddelelse-----
> Fra: Will Kooiman [mailto:wkooiman at earthlink.net]
> Sendt: 3. november 2011 14:24
> Til: 'Roland Jaeckel'; 'Mikael'; detomaso at realbig.com
> Emne: RE: [DeTomaso] Dogbone airfilter questions
>
> I have seen this discussed several times since I've been involved with
> Panteras (~10 years). Some say it is restrictive. Others say it isn't.
>
> We tested the dogbone during a dyno day in 2005. The top dog made 347 HP at
> the rear wheels. We removed the dogbone air cleaner, and the power jumped
> to 348 HP. This was on a 377 stroker, dogbone, no spacer between the air
> cleaner and carb, and single filters on each side.
>
> It was also in Houston in the summer (hot).
>
> I've seen too many people say that it is restrictive, though. I'm guessing
> that it depends on the application.
>
> -----Original Message-----
> From: detomaso-bounces at realbig.com [mailto:detomaso-bounces at realbig.com] On
> Behalf Of Roland Jaeckel
> Sent: Thursday, November 03, 2011 4:41 AM
> To: Mikael; detomaso at realbig.com
> Subject: Re: [DeTomaso] Dogbone airfilter questions
>
> I had it on my 427 stroker.
> It was restrictive even with two filterelement on both side.
> It sucks hot air from the engine compartment, whitch also limits the power.
>
> I had a big airfilter housing from a Mercedes G 400 CDI diesel in my right
> wheelhouse and an air openig to the side.
> That did the trick. Quite on full throttle and no power loss when warm.
>
> Roland
>
> ----- Original Message -----
> From: "Mikael" <mikael_hass at mail.tele.dk>
> To: <detomaso at realbig.com>
> Sent: Thursday, November 03, 2011 10:09 AM
> Subject: [DeTomaso] Dogbone airfilter questions
>
>
> >I know this has been discussed, and on the PI Forum I searched and got a
> >lot
> > of info, but no real conclusion. First, the reason I want it is not bling,
> > it's so I can look out my rear window. But I don't want to restrict
> > performance.
> >
> >
> >
> > Here are some of the questions that are still open for me:
> >
> > -Who has it, are you happy with it?
> >
> > -Is it restrictive, I need air for a 600HP 408 engine, using a single
> > Holley
> > 850?
> >
> > -If the filter area is the restriction, can I just double filter it, two
> > on
> > each side?
> >
> > -If it's the distance above the carb, how far is it from the top of the
> > vent
> > tubes?
> >
> > -The distance over the carb could be remedied by a carb to air cleaner
> > spacer?
> >
> >
> >
> > Of course if Holley has done the work properly, it won't restrict flow on
> > the biggest 5 1/8 neck carb, and won't be too close to the vent tubes.
> > Have
> > they?!
> >
> >
> >
> > Summit has Holley version for a whopping $300
> >
> > http://www.summitracing.com/parts/HLY-64280/
> >
> >
> >
> > Mikael
>