[DeTomaso] efi horse power gain

Ken Green kenn_green at yahoo.com
Tue Aug 11 00:35:48 EDT 2009


My "obsolete" C3 heads flow 360 at .600 lift and have fairly small ports.  D3 heads flow over 400.  While the CHI heads may win a competition where C3 and D3 heads are not allowed, I don't think that proves they are the best Cleveland heads.  Also, because the race teams move to a new design if they can make just a few more HP, you can buy some really nice retired heads for a lot less than buying and ports most the aftermarket heads.  The one additional cost C3 and D3 heads is the shaft rockers they use, but at the end of the day, I think they can still be cheaper than most the other aftermarket heads.
 
Ken

--- On Mon, 8/10/09, Julian Kift <julian_kift at hotmail.com> wrote:


From: Julian Kift <julian_kift at hotmail.com>
Subject: Re: [DeTomaso] efi horse power gain
To: boyd411 at gmail.com, notstock at yahoo.com
Cc: kenn_green at yahoo.com, wkooiman at earthlink.net, kirby.schrader at gmail.com, "De Tomaso List" <detomaso at realbig.com>
Date: Monday, August 10, 2009, 7:58 PM



Boyd,



I'm not sure I understand TWM's statement for the Cleveland system costing a lot more. The TWM throttle body is the same no matter whether Windsor or Cleveland and Hall sells Cleveland specific IR IDA style Weber manifolds in either 4V or raised intake port style that the TB's bolt right up to.



The IDF style manifold is no longer available for the Cleveland, but adapters are available to convert an IDA style to IDF, raising the height and runner length whilst doing so. There was a guy in Asutralia that got the rights to the old Cain IDF manifold and was going to recast it, but I haven't heard anything on that for a while now. The plus with that manifold is that using it would permit IDF's to sit below the deck lid, so no cutting/notching of the decklid, which you will have to do with Weber IDA's or most EFI independent runner systems. IDF's are accepted as more streetable, easier to tune and to maintain in tune than IDA's, but there is nothing wrong with a well tuned IDA set up.



My rationale for going with EFI on the Pantera is that 48mm Webers are generally accepted to run out of steam at ~500HP and high air demand. I have a 620+HP Cleveland stroker that is designed to spin to 8000 rpm I'm dropping in......flame suit on and awaiting the "it won't last", but it'll be fun while it does ;>) and I got it for a real bargain price.



If new heads are in your future you may want to decide that now as it may affect your choice of IR manifold if you go Aluminum raised port heads. The CHI (Cylinder Head Innovations) heads out of Australia are generally accepted as the best Cleveland heads you can buy www.chiheads.com Available in 2V, 3V and 4V styles, their pricing includes shipping to you door.



Julian

> Date: Mon, 10 Aug 2009 20:54:25 -0400
> From: boyd411 at gmail.com
> To: notstock at yahoo.com
> CC: kenn_green at yahoo.com; wkooiman at earthlink.net; kirby.schrader at gmail.com; detomaso at realbig.com
> Subject: Re: [DeTomaso] efi horse power gain
> 
> 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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