[DeTomaso] efi horse power gain

Ken Green kenn_green at yahoo.com
Tue Aug 11 13:43:23 EDT 2009


The FAST system also includes a different wide band sensor.  I don't recall the detials, but I think it has a faster response which is suppose to be important in closed loop operation.  They a two or three times the price, so you don't want to burh them out too soon.  I think the FAST guys said the ACCEL system also uses the differenct wide band sensor.  If you look at the FAST web site, they list both the sensor for the older FAST systems, and one for the newer "XI" systems.
 
Ken

--- On Tue, 8/11/09, Kirby Schrader <kirby.schrader at gmail.com> wrote:


From: Kirby Schrader <kirby.schrader at gmail.com>
Subject: Re: [DeTomaso] efi horse power gain
To: "boyd casey" <boyd411 at gmail.com>
Cc: "De Tomaso List" <detomaso at realbig.com>
Date: Tuesday, August 11, 2009, 9:20 AM


Boyd,

I would be curious to know _why_ the machining of the Cleveland
manifold is substantially more. I'm sure there is a good reason, but
it would be nice to know since it is not obvious to me. I used one of
Kelly Coffield's blocks, just like MD, and it was machined to fit my
9.5" block. I also decided to machine off the bosses that Kelly puts
on the manifold for port injection since they got in the way of my
valve covers.
Otherwise, I don't know why the two engines would be different in this respect.

Thanks for the confirmation of the inside rails vs. outside rails/good vs. bad.

I've done some reading about the FAST XFI and it does seem to be the
most recently released system. Thus, the processor is most likely
faster than older systems and it would allow them to throw more
sensors at it. I don't know that advertising having more pins on your
connector as a reason to buy their stuff is a good spin though...
:-)
Not having used their software either, I can't comment on how easy it
is (as their website claims), but I've read that kind of stuff a lot
from other vendors. It's called marketing... I believe it when I see
it.

As I mentioned previously, the software I've used requires some
learning. The Haltech F9a is DOS based, but runs in a window. Since it
is fuel only and is 'old' and has limited capabilities, it is pretty
easy to use, but works well. It has a couple of general purpose
controls. I use one for the A/C clutch at high rpm.

The Electromotive software is not what I'd call user friendly, but is
very flexible and lets you control 'everything'. In addition to fuel
control and ignition control and fuel pump control, warm up
enrichments, acceleration enrichments, cold weather starting, as you
would expect, it has, among other things, four general purpose inputs
and four general purpose outputs which you can define and use as you
require. I use one to shut my A/C compressor off at high RPM's, I use
one to acquire a wideband EGO for loop control, I use one to turn my
radiator fans on and off. I've still got 2 GPO's and 3 GPI's
available. I may find something to do with them in the future.
The TEC3r also does wastegate control, idle air motor control, dual
injectors per cylinder, timing adjustment for individual cylinders,
etc. etc. etc. Pretty darned flexible.

The 'four or five MAP sensor' acquisition is interesting. My initial
reaction to that would be that it would allow you to do barometric
pressure compensation and measure manifold pressure with or without
boost at the same time. Something I can't do with the Haltech, for
sure. The TEC3r... dunno... have to check.

As mentioned by many, you may see a HP gain; you may not. There are
just too many variables.
You seem to have it figured out though.... IR definitely will give you
more HP at low and mid range rpm's.

As for the Weber carb vs. throttle body EFI difference... based on
what little I know about Webers... I think they have 3 different jets
for low, middle and high range. Correct me if I'm wrong, somebody!
You should still be able to fine tune the EFI to give you better
response across the entire rpm range.
And honestly, EFI is really a set it and forget it affair once you've
got it tuned. Turn on the EGO loop and it will continue to correct
automagically.

IDA vs IDF? I don't have a clue....

The most important thing up front is to make sure you've got enough
CFM to deliver the required air and fuel to the engine size/power you
plan to use. Too small or too big a carb is a problem. Too small EFI
is a problem. Too large EFI might be 'tameable'. Depends.

Seems to me like you're having fun with all this stuff!

Regards,
Kirby


On Mon, Aug 10, 2009 at 7:54 PM, boyd casey<boyd411 at gmail.com> wrote:
> Gary at TWM said that he uses weber carb manifolds and he specifically said
> "from Hall Pantera" I asked him if a manifold from another source would be
> okay and he said he wouldn't know until he saw it . I didn't know there was
> a difference. He also said it took a substantial amount of machine shop work
> to modify the manifold  for the Cleveland and that's why the Cleveland set
> up was more money then the Windsor. Anyway Hall has several Weber manifolds
> currently  at the machine shop ( I assume being cleaned up after being cast)
> their price is $650. They said they would have some ready in two weeks.
> As far as the "inside fuel rails"   I should have specified that the reason
> I was given for the fuel rails to be "inside" the stacks was for the optimal
>  placement of the injectors and their being pointed in the correct direction
> in  reference to the intake valve location.
> On another point if I remember correctly the Fast XFI has the ability to
> utilize  4 or 5 MAP sensors. As well as numerous optional sensors and
> controls. I had made earlier mention of the benefit of a "fast " system
> meaning a fast processor not the brand name "FAST."
> The "FAST XFI" has been designed with software that has more optional
> sensors and controls then any other sytem I am aware off. But just like
> trying to multi task with an old Pentium III you will over load your
> processor if you push it to hard. You need a system where the hardware can
> keep up with the software. According to what I have read the new FAST system
> has the ability to handle all the potential tasks possible to assign to it
> through the software interface with processor power to spare. The way I
> understand it , the faser the engine is running( the higher the RPM's) the
> faster the other  engine parameters are changing and the faster the system
> needs to be able to respond . This may be nothing more then a sales pitch
> but it made some sense to me.
> I have two MSD 6al units and two blaster coils and the automatic coil
> selector. t Iallows you to attach the two coils to a common distributor wire
> so you can switch from one MSD set up to the other in the event of a failure
> of one of the MSD modules. The only things I am missing is the selector
> switch , the correct  distributor and the tach adapter. I have an MSD small
> cap distributor and after a crummy mechanic told me my MSD6al was bad I
> bought a replacement MSD 6al for close to $300.00 ( if memory servers me
> correctly) . It turns out the MSD was not bad so now having two  MSD 6AL's
> and knowing MSD's reputation for dying at inopportune moments I decided to
> go with the dual switchable ignition set up. It was only after buying the
> extra coil and the MSD automatic coil selector  that I realized I wasn't
> able to use my distributor with the switchable set up ( this may not be
> factualy correc , but the sales rep at MSD seemed to think I needed to buy a
> different one! ( no surprise there!). I had just spent a few hundred dollars
> on the MSD small cap distributor in addition to the auto coil selector and
> the extra Blaster II coil and I didn't   feel like springing for another
> distributor (or anything else with the name MSD on it!) everything was now
> working and my Pantera  and my "To Do " list was already longer then my
> budget!  So now I keep the spare MSD6AL and the spare coil in my in car tool
> kit ( along with the unused automatic coil selector) .
> So in case of a coil failure or an MSD 6AL failure I can still make it home.
> It is certainly not as easy as flipping a switch but it beats walking or
> calling a tow truck. One of these day ( If I don't switch to a coil on plug
> with a crank trigger) I will get the rest of the correct parts to utilize
> the MSD switch set up. I still have to decide if I am going to bite the
> bullet for the efi and if my ignition setup is compatible with whichever ECU
> I wind up with (if I wind up with an EFI.) I know that many people go with
> EFI for a number of reasons besides performance HP Gains  (which seems to be
> a subject of some contention ) they have reasons like reliability, easier
> starts, better fuel economy, but if all you were only considering  HP what
> is the consensus on the difference in horse power between a weber carb set
> up  and a weber "style" Stack EFI setup ? I know it's hard to make a
> statement based on a "style "of EFI because there are so many variables. But
> to simplify matters (if that is possible) Hypothetically if you had Weber
> IDA's with the correct venturis and tuned to perfection  and you had  an
> equally well tuned Weber style EFI (like a TWM) do you think there would
> still be a HP difference between the two? Also The Weber IDF is supposed to
> be more "Street able" than the IDA besides the absence of a choke on the IDA
> what are the other differences?Does an IDF have two venturis to the IDA's 3?
> The Lamborghini Miura had 6 Weber IDL's I believe this carb had 4 venturis (
> as opposed to three on the IDA) Is this information correct?  Are the 4
> venturis on the IDL the reason they had a reputation for being so difficult
> to tune? (I suppose a 12 cylinder with 6 webers and 4 venturis each as
> opposed to 4 webers  with 3 venturis each didn't help to make it any easier)
> Are IDL's still available? Do people use them on Cleveland's or other push
> rod ,lower reving engines (lower then 12 cylinder Itailian  DOHC , 48 valve
> exotic engines) I know these are allot of questions and I want to say how
> much I appreciate the feed back and opinions of those of you who have taken
> the time to contribute your ideas or opinions. The only way Novices progress
> to the next stage is by learning and it makes much more sense (to me) to
> learn from the experience of those that have travelled down this road before
> rather then try to go through my own trials of hit or miss experimentation.
> I don't have the financial resources to try a plethora of different carbs ,
>  manifolds, heads  etc. With EFI there is the added choice of style (tunnel
> ram, weber stack style , 4 barrel throttle body, then the ECU, then choosing
> between batch or sequential injection) You could spend years and a small
> fortune if you relied on trial and error.
> II know there are allot of members of this list that have forgotten more
> then I will ever know about this subject and automotive engineering in
> general . I learned early in life that it was not necessary to become an
> expert in every subject you were involved in to achieve success in it. It
> was necessary to be able to recognize the talent and expertise in others(
> and to listen to them). So by identifying the people who were masters of the
> subject you were interested in you could actually achieves more then you
> could by attempting to master them all yourself.  I really appreciate the
>  efforts and patience of those of you who have taken the time to share your
> knowledge, experience and secrets.  I'm sure to some they must at times seem
> like redundant and or stupid questions. I have  always believed not asking
> the question was the stupid thing. So thanks to all of you for your help and
> camaraderie, it is truly appreciated.
>
> Boyd
> PS. I forgot to mention Thanks for not  'grinding me into the asphalt' for
> occasionaly ( or more often) making a mistake or misstating facts. I
> sometimes forget to mention that I am esposing an opinion or repeating
> something I have read or heard and I am looking for confirmation  or denial
> of the information so I know if I'm on the right track and I am  not
> pretending to be an "Expert" or :know it all" If I have an idea of my own or
> a hypothesis it's a good way to find out if I have understood the concept or
> theroy of what ever subject we happen to be discussing.  I don't just want
> to know what works, I want to know why it works or why it is better. If I
> never put forth one of my own ideas I will never know if I am still as
> clueless as I was when I started. If I am repeating something that I have
> read or that was told to me by a vendor or a self proclaimed expert I want
> to know if I have been sold a "bill of goods" or if the information is "on
> the money"
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