[DeTomaso] efi horse power gain

michael frazier red3644 at hotmail.com
Wed Aug 12 00:07:04 EDT 2009


I'm finding out I have one of the very earliest IR units from Dennis Quella and have only put a little time into it with the help of Kirby but the drivability is greatly improved over my

carbed cars.  As far as cams go, I had a Motorsport M6250-A342...  .580"/.606"  296/306 (248/258 @ .050" lift)  "Very radical-race only camshaft" according to Ford.   I don't think a carbed engine would hardly run under 3000rpm with that cam.  I could get it to idle smoothly (and cool) at 900-1100rpm.  It still needed some tuning.

 

Michael Frazier
Gruppo Rompiculi Corsa 

 

 





 
> From: kirby.schrader at gmail.com
> To: boyd411 at gmail.com
> Date: Tue, 11 Aug 2009 21:59:09 -0500
> CC: detomaso at realbig.com
> Subject: Re: [DeTomaso] efi horse power gain
> 
> 
> Ahhh.... I understand now.
> 
> Actually, the only sensor I know of that uses vacuum is the manifold 
> pressure. And that is used to control injector on time in conjunction 
> with throttle position, if necessary.
> 
> Whether it be normally aspirated or under boost with a supercharger or 
> turbo, you select a pressure sensor that fits the bill.
> 1 bar, 2 bar, etc.
> 
> The other sensors are crank trigger (magnetic or Hall effect), cam 
> trigger (magnetic or Hall effect), manifold air temperature (inlet 
> air), coolant temperature, knock sensor, etc. etc.
> 
> Most controls and sensors are operated electrically; very few or none 
> with vacuum, to my knowledge. All ECU's that I know use a 'pull to 
> ground' system. You supply power to a relay and when the ECU detects a 
> condition that has met the criteria set, it grounds the relay and 
> activates it. For example, turning off your A/C compressor clutch at 
> high rpms, turning on your cooling fans when the coolant temperature 
> reaches a given value and then turning them off when it drops below 
> another value, turning on an idle air controller motor, etc. etc.
> 
> As for being confused, like most things, if you bite off a little at a 
> time, it's easier to chew.
> :-)
> 
> Later,
> Kirby
> 
> On 11 Aug 2009, at 9:06 PM, boyd casey wrote:
> 
> > If I said sensors are useless with out a vacuum that's not what I 
> > meant. What I meant to say was the Fast XFI has so many sensors and 
> > optional controls (that are presumably actuated by a vacuum after 
> > the sensors indicates a condition exists that requires one of the 
> > optional controls to kick in.) If these "controls are in fact 
> > vacuum powered and you have no vacuum or insufficient vacuum you are 
> > SOL.. The dam thing is so complicated I can't even talk about it 
> > without getting confused. I would hate to see what would happen if I 
> > were actually using it. As I have said numerous times I am not a 
> > mechanic. I can take most shit apart and put some shit back together 
> > but I usually have something extra left over when I'm done. I had a 
> > 6cylinder 280 ZX and I tried to do a tune up. When I was done it was 
> > a 7 cylinder!!
> >
> > Boyd
> >
> > On Tue, Aug 11, 2009 at 9:24 PM, Kirby Schrader <kirby.schrader at gmail.com 
> > > wrote:
> > Boyd,
> >
> > You know a lot already.
> >
> > It seems like you are well on your way. I really don't think you'd 
> > be happy with anything but the FAST XFI.
> > :-)
> > Just kidding.... go for it. It does seem like the latest and 
> > greatest. As you indicate, I assure you that it will have more 
> > features than you will use, but it will certainly be flexible, just 
> > like the TEC3r and others.
> >
> > Regarding vacuum... it depends. As I pointed out in a previous 
> > email, I use ONLY the #2 runner with my IR EFI on my Pantera for the 
> > brake booster. I was told by many experts that this would NOT work, 
> > but it does. Now... if I had a really radical cam with next to no 
> > vacuum at idle, then maybe it would be another story.
> >
> > My recommendation is try it first and if it doesn't work, then you 
> > have two options.
> > Tie all the runners together in a plenum (which you should do anyway 
> > with a decent IR system), which has been discussed ad nauseam, or go 
> > with a small electrical vacuum pump to give you enough vacuum. If 
> > you're going to use a 'street' cam, I'll bet you'll be fine.
> >
> > Sensors are useless without 'vacuum assist'? Hmmm... I don't know 
> > what that means....
> >
> > Should you go with a throttle body and injectors or an individual 
> > runner manifold? Up to you...
> >
> > At the risk of repeating everything...
> >
> > 1) Low and mid range HP and TQ will be better
> > 2) Drivability will be better, even with a radical camshaft
> > 3) DON'T FORGET THE BLING FACTOR!
> > 4) It looks really cool
> > 5) Everyone (well, almost everyone) will be jealous
> > 6) Your air cleaner will cover up the single throttle body and 
> > nobody will every know what kind of cool sh*t you have underneath!
> > 7) It'll start and you can drive away without blipping the throttle 
> > or wondering when the choke is going to shut off
> >
> > I really think you're getting your head around the whole issue. Keep 
> > asking questions if you've got any.
> >
> > Regards,
> > Kirby
> >
> >
> > On 11 Aug 2009, at 6:53 PM, boyd casey 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
> >> "
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >> 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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