[DeTomaso] efi horse power gain

[boyd casey]

Finally like the prophet returning from the mountains after 10 years with
the ten commandments and smashing the golden lamb. The prodigal son has
returned. So Mike , is the twm still your recommendation for the starting
point as far as the basis for building a weber styled  EFI?  Do you think
that starting with  a weber intake manifold from Hall is also the way to go?
And What about the computer. Do you like the fast XFI system ? or do you
recommend something else. What if someone wants to go with a super charger I
would assume that the stack system is no longer the optimal choice. Would
you recommend  a tunnel ram throttle body  or what. I don't want to inundate
you with questions but I don't know if you are going to fade back into the
back ground and disappear before I can get  the information I would like.
Your reputation precedes you! One last thing (for now) From a standpoint of
looks there is no question that the Weber stack system has the other EFI set
ups beaten hands down. But lets  say that esthetics's appeal has nothing to
do with my choice. ( and it may be the superior choice based solely on
performance) I would be surprised if the best looking was also the best
performing. So if it's not the best from a standpoint of horsepower what
design is the best performing ?
Thanks,
Boyd




On Tue, Aug 11, 2009 at 7:53 PM, boyd casey <boyd411 at gmail.com> wrote:

> When it comes to vacuum I am like Sgt. Schultz, "I know nothing!"  But from
> what I have read there seems to be a a very Strong correlation between
> deficiencies in Vacuum and Weber stack style efi Units. I don't understand
> the mechanical processes involved with  generating and maintaining a
> sufficient level of vacuum but something to do with the design of the Weber
> stack setup interferes with having sufficient vacuum to operate some of the
> various devices that require vacuum. The Fast XFI ecu has the largest
> number  optional  devices  and sensors ( that I know of) that can be run or
> controlled by the fast XFI and   apparently  a number of them are useless
> without sufficient  vacuum assist. I have even read that one may( literally)
> run in problems  with braking  due to insufficient vacuum for the brakes. I
> can't remember where I read it and I hate quoting something without be able
> to cite the source but I seem to recall a brake vacuum booster being highly
> recommended if one was considering a weber style  stack EFI setup.I have
> nominal vacuum powered items on my car so I know even less then the average
> Pantera owner, but apparently the fast XFI has among its optional interfaces
> ( automatic transmission interfaces,  waste gate controls, ac controls ,
> Idle controls ) here is a partial list from one of their web sites : Quote
> from Hot Rod magazine "
> This is a list of some off the other optional features and sensors. This is
> not a comprehensive list and some of the items are not really relevant  to
> Pantera applications.
> The partial list is as follows:
>
>
>    - Fast XFI Dual Sync Distributor
>    - Fan - Fuel Pump and control Harness
>    - XIM Ignition Module
>    - TCU Transmission controller and adapter harness.
>    - Fuel Injectors
>    - Fuel Pump
>    - Throttle body
>    - Coil on Plug ignition applications
>
> Some of the popular options are:
> Traction Control
> PC Free  "Internal Channel Data logging up to 30 Minutes of  data recording
> with out a computer.
> Additional PC Free data logging of accelerometer, EGT,  Fuel pressure and
> oil pressure.
> (it is almost like an aircraft's black box)
> It also has an available Digital LED touch screen. With this module
> installed in your dash board or glove compartment  you would be able to
> adjust  and calibrate the operating parameters by touch right from the
> drivers seat while you are driving  instead of having to plug in a lap top
> to make adjustments.
> With the addition of the XIM Ignition module  it can be adapted to the Ford
> Modular transmission,  GM LS1 and new Hemi transmissions.
> And with the addition of the  Transmission control unit ( obviously not  a
> benefit to  a Pantera  owner) it can be utilized to work with GM, Ford, and
> Chrysler  electronically controlled transmissions.
> I know there is more I am missing and all this taken in conjunction with
> the ability to control  up to 16 injectors and 5 map sensors makes me
> believe the biggest problem would be coming up with an engine advanced
> enough to be able to use theses optional sensors and controls and the PHD in
> tuning you would need in order to utilize it all!
> It would be great for a supercharged or twin turbo  DOHC  32 valve  16
> spark plug 16 injector 12,000 rpm  engine. with  a six speed paddle shifter
> and  F1 trans axle ( and a complete pit crew and bank roll to keep it all
> running).
>  Either that or just buy it like most other american consumers and have ten
> times the power that I could ever use but be able to brag about it even
> though they never drive it
>  I guess it's still better to have allot more then you need then a little
> bit less then you need. Especially if the price is the same.  Apparently if
> you don't buy all the extras the price is close to the price of the average
> systems on the market.  And it is human nature to want the latest and
> greatest  even if you will never use it.
> I have to admit is sounds like a bad ass set up.
>
> Boyd
> "
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> On Tue, Aug 11, 2009 at 4:42 PM, Kirby Schrader <kirby.schrader at gmail.com>wrote:
>
>> Well, what can I say...
>>
>> It works to combine them. I can _prove_ it by measuring the manifold
>> pressure at the plenum on my car.
>>
>> Why are companies like TWM using this technique if it doesn't/shouldn't
>> work?
>>
>> Either the explanation is wrong or the conclusion is wrong. Or both.
>>
>> Let's not ignore the proven facts. If I did that in my job, I'd have
>> been fired decades ago.
>>
>> Kirby
>>
>> On Tue, Aug 11, 2009 at 2:59 PM, <JDeRyke at aol.com> wrote:
>> > In a message dated 8/11/09 8:02:16 AM, kirby.schrader at gmail.com writes:
>> >
>> > I have no idea how each cylinder's vacuum pulse can cancel out each
>> other.
>> > That
>> > means one pulse would be negative (vacuum) and the other positive
>> > (pressure).....
>> >
>> > Correct- the strong pulses going back & forth thru an IR manifold are
>> indeed
>> > positive and negative, as the pressure wave oscillates between the
>> intake
>> > valve and the ram-tube top. As one intake opens and starts a negative
>> wave
>> > downward, the preceding cylinder has just closed and starts a positive
>> wave
>> > back out. I found the net from combining cylinders is zero. It's so
>> > prevalent that experts suggest using a fairly long piece of rubber
>> tubing to
>> > connect a single intake port to a vacuum advance, so the rubber's normal
>> > pliability will dampen the pulses. Using metal lines is the worst- as I
>> > found. My vacuum with Webers wouldn't accumulate until I added a check
>> valve
>> > like is in the power brake booster. But maybe the rules change with EFI-
>> > dunno; haven't tried it yet. FWIW- J Deryke
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