EFI for big inch BBC

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apm
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EFI for big inch BBC

Post by apm » Fri Nov 23, 2018 8:17 pm

Hi everyone , I'm trying to find a self learning EFI system for a 750 inch BBC that currently uses 2 x 1250 dominators .Its 4.9 BS with profiler heads , 12:1 , solid roller 270/284 @.050", runs on 98 octane pump gas (we are in Australia) , has a really short sheet metal intake to keep it low for hood clearance ,it makes 1100hp and 1000ft/lb.
I love the idea of a system like the Holley sniper stealth EFI, it will work with the power level we make but it only comes in a single throttle body version , we have spent a lot of time on the dominators but they aren't the greatest carb on the street, the engine is in a 67 impala with a turbo 400 and we try to drive it once a week , car will never be raced it's just a radical street car that we built just because we wanted to . I know we could pull the intake, fit injectors to the runners , make fuel rails etc and then use 2 throttle bodies and use any ECU but I'm trying to use something as simple as possible .
Any idea please let me know , thanks in advance

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Re: EFI for big inch BBC

Post by racear2865 » Fri Nov 23, 2018 8:35 pm

look at FiTech--has double throttle bodies. I have 6 sets running and doing 2 sets now both on 540 BBC . One on 600+nitrous and other on 540 blower.
reed

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Re: EFI for big inch BBC

Post by Newold1 » Fri Nov 23, 2018 8:42 pm

My serious suggestion is to get a Holley EFI Dominator ECM controller. This unit is probably the finest big engine performance ECM and it has a pretty decent self learn feature and an incredible tuning and programming capability. Here in the states the acceptance and usage of this ECM is more widespread and in use of most serious performance engine and racing users. If the features and cost of this particular unit is not the ideal choice then keep in mind that Holley has a smaller less expensive unit called the HP which is also the same architecture of the Dominator ECM but with just a few less racing features. Holley also has all the engine harnesses, sensors, O2 sensors, injectors and wiring needed to put together a complete operating system. Take a look online at all the Holley offerings in this area and see if they will work for your project. I have personally used these Holley ecms's on quite a few engine builds and I can say it's the only system I will use for efi builds.
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Re: EFI for big inch BBC

Post by Keith Morganstein » Fri Nov 23, 2018 9:21 pm

racear2865 wrote:
Fri Nov 23, 2018 8:35 pm
look at FiTech--has double throttle bodies. I have 6 sets running and doing 2 sets now both on 540 BBC . One on 600+nitrous and other on 540 blower.
reed
I was looking at the Fitech 2x4 systems. They rate the part number 30064 up to 1200 HP.
Automotive Machining, cylinder head rebuilding, engine building. Can't seem to quit #-o

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Re: EFI for big inch BBC

Post by Racing68 » Fri Nov 23, 2018 11:02 pm

I was looking into the fitech systems as well til i learned the throttle bodys are only 850 cfm no matter what hp level they are advertised as.

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Re: EFI for big inch BBC

Post by racear2865 » Sat Nov 24, 2018 8:59 am

Keith Morganstein wrote:
Fri Nov 23, 2018 9:21 pm
racear2865 wrote:
Fri Nov 23, 2018 8:35 pm
look at FiTech--has double throttle bodies. I have 6 sets running and doing 2 sets now both on 540 BBC . One on 600+nitrous and other on 540 blower.
reed
I was looking at the Fitech 2x4 systems. They rate the part number 30064 up to 1200 HP.
Keith
I have used at least 20 on engines in my shop. No problems. Got 4 engines in shop now to run on dyno with including the 2 I spoke of.
reed

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Re: EFI for big inch BBC

Post by Keith Morganstein » Sat Nov 24, 2018 9:40 am

The fitech 2x4 is the only thing I've found like it. One of the two throttle bodies has the ECU, and it controls the second one.
Automotive Machining, cylinder head rebuilding, engine building. Can't seem to quit #-o

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Re: EFI for big inch BBC

Post by gmrocket » Sat Nov 24, 2018 11:12 am

The couple single Holley snipers I've used on street builds were not driver friendly... can't imagine how bad it would be with two of them on there..

Holley admits there is a problem and will send you the tiny progressive linkage for an extra $20 and then you reflash it.

This was up till a couple months ago.. so if you get them, tell them you want the upgrade correction done by them

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Re: EFI for big inch BBC

Post by racear2865 » Sat Nov 24, 2018 2:03 pm

As I stated, I have at least 20 engines. Every customer, to my knowledge, loves theirs. We tuned all on the dyno and then made any changes after in the car. Have used on trucks and cars. One thing we learned, if we make a large change in adjustment, we wipe memory clean and let it relearn from there. We have run down to 6 inches of vacuum and got it to run. I even put a 400 unit on a 1955 Cadillac. I tried the Holley and Fast and went back to the FiTech. Ive got a 525 hemi with 2 units on it and performs super nice. We dont let it off the dyno until we are satisfied and we then have each customer bring vehicle in after installation. I dont expect them to make adjustments. That my job
reed

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Re: EFI for big inch BBC

Post by Cutlassefi » Tue Nov 27, 2018 8:47 pm

It changes things on the "self learning" systems when you have lots of camshaft.
The Holley Dominator is a pulse width, lbs per hour system. Very simple but also gives up some on the tuning/drivability side. Remember their focus is drag racing, not wild street applications where you drive them daily.
Read the Holley manual for yourself and you'll see they recommend to drive the vehicle for "a few hundred miles" to "self tune". By that time you could easily datalog a session with other systems and do the rest yourself.
But if the FITech has the features that will help compensate for big camshaft characteristics then go for it. Just remember none of these systems are magic, they all have limitations.
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Re: EFI for big inch BBC

Post by RednGold86Z » Wed Nov 28, 2018 1:09 am

If you do go FiTech, I often look at the control software and calibration engineer in the mirror, and sleep with his wife :mrgreen:

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Re: EFI for big inch BBC

Post by peejay » Wed Nov 28, 2018 7:22 am

I have never seen a "self tuning" computer that was worth a crap.

It's simpler and easier to learn to do it yourself. It's not really all that difficult to get better results than what a "self learning" system will do.

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Re: EFI for big inch BBC

Post by racear2865 » Wed Nov 28, 2018 9:09 am

peejay wrote:
Wed Nov 28, 2018 7:22 am
I have never seen a "self tuning" computer that was worth a crap.

It's simpler and easier to learn to do it yourself. It's not really all that difficult to get better results than what a "self learning" system will do.
This is a broad brush to paint. The same could be said of carburetors out of the box. Can you please elaborate as to "why" their not worth a crap and please tell me which units you have tried and what changes did you make during the setup and any changes as you read the data tables while running. Im all ears as I totally disagree and I can elaborate bothe with dyno data aand data tables and HP/tq outputs. Or are u speaking of driveability. Im not trying to dismantle your statement, but I would love to learn more because I feel that I am not the sharpest knife in the drawer and my paint brush only cover a small area. Sorry do not take this negatively. We have enough of that on here already
reed

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Re: EFI for big inch BBC

Post by Roundybout » Wed Nov 28, 2018 1:38 pm

Self learning is basically what all efi systems do. You give the engine parameters and the parts to match and done. Now too big of an injector for the application or various other mis-matched parts and it’ll run like crap, it can only compensate for so much. But match the system to the application and it only has to compensate for a narrow band and becomes much better.

Now combine ease of use in the menu screen along with powerful software. I’d like the option to set and forget along with the option to tune to my hearts content in one application.

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Re: EFI for big inch BBC

Post by GRTfast » Wed Nov 28, 2018 2:06 pm

RednGold86Z wrote:
Wed Nov 28, 2018 1:09 am
If you do go FiTech, I often look at the control software and calibration engineer in the mirror, and sleep with his wife :mrgreen:
:lol: =D>

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