EFI for big inch BBC

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Olds455
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Re: EFI for big inch BBC

Post by Olds455 » Wed Nov 28, 2018 3:05 pm

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.
First one I ever saw was a stock GM ecm with rewritten code and self-tuning. It actually worked quite well for what it was. Used the 7749 ecm. This was back in the mid 00's, IIRC.

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Re: EFI for big inch BBC

Post by mk e » Thu Nov 29, 2018 2:00 pm

The problem with self learning is always getting it to learn the right stuff. At cruise it's not bad...but anywhere else.....
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Re: EFI for big inch BBC

Post by Newold1 » Thu Nov 29, 2018 7:52 pm

That's why any good EFI system needs to have user programming in the ECM above and beyond self learn tuning!
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Re: EFI for big inch BBC

Post by gmrocket » Thu Nov 29, 2018 8:03 pm

I'm installing FItech six pack this week on a 71 challenger 440...original 6 pack car.

It's the first one FITech built, according to them...so we are the guinea pigs on this deal.

I'm interested on how it will progressively bring in the outboard throttle bodies...which they told me it will

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Re: EFI for big inch BBC

Post by induction apprentice » Fri Nov 30, 2018 8:54 am

apm wrote:
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
Message this to Tom Kise at holleys forum.
He is the best authority on this and will direct you correctly.

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Re: EFI for big inch BBC

Post by jmarkaudio » Fri Nov 30, 2018 9:10 am

Carbs can be made to work right. Stock Dominators?
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Re: EFI for big inch BBC

Post by Newold1 » Fri Nov 30, 2018 9:49 am

I hear your concern and thoughts jmarkaudio:

I have a suggestion that with your excellent knowledge, offerings and service on performance carb fueling systems that if you are already not you should also start moving into the current efi performance fueling systems and provide the same expert service and offerings in that arena.

Your future business will probably depend on that in my opinion. :wink:

The growth in performance efi aftermarket systems has had HUGE growth in the last 3-5 years!
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Re: EFI for big inch BBC

Post by racear2865 » Fri Nov 30, 2018 8:16 pm

i guess Ive been at this as long as any one here and longer than most. I finally realizes on day, there were no more carbureted cars being built. I swallowed my pride and started learning efi. Doesnt matter if I liked it or not but the future was upon me and more and more people were coming in the shop as asking. I can do systems as complicated as I want and yes I do but for the general public I knew I had to pick a self learn system. All of them has their strong points and weak points but after testing I picked one and went. Doesnt mean I want change but this is where I am now. I have no idea what I will need as the future progresses. Ill take it as I go.
reed

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Re: EFI for big inch BBC

Post by peejay » Sat Dec 01, 2018 9:33 am

Roundybout wrote:
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.

No, not at all. You might have a window that you can allow some adjustment (both temporary or permanent) but I haven't worked on any EFI system that Playskool. It always boils down to mapping the engine.

At least the modern systems allow you to play with engine paramater numbers like volumetric efficiency, instead of having to hardcode injector pulsewidths.

The biggest issue I have with "self tuning" systems, besides the fact that they are tuning for an assumption and not what the engine actually wants, is that they use a sensor that measures oxygen in order to estimate fuel. It is common to get a rich situation that misfires, which the oxygen sensor reports as lean (high oxygen content), so it adds more fuel... And then of course anything with a hot cam is not tunable by oxygen sensor, it must be tuned manually. And if it doesn't have a hot cam, then why bother with EFI? You can get great drivability with a carb if you have a mild cam.

If you are starting with an already well-mapped system, then having a degree of self-adjustment is great, as long as it is kept confined and there are some sanity checks in place.

Quite some time ago there was a system that placed a MAF element above a throttle body, kind of like the Nissan TBI systems in the early 90s. That would be the ideal way to go, since you are measuring airflow directly. No real "tuning" needed aside from compensating for intake manifold volume for acceleration-enrichment purposes, and defining when and how much power enrichment to use.

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Re: EFI for big inch BBC

Post by Olds455 » Sun Dec 02, 2018 11:42 am


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Re: EFI for big inch BBC

Post by RednGold86Z » Mon Dec 03, 2018 4:25 am

gmrocket wrote:
Thu Nov 29, 2018 8:03 pm
I'm installing FItech six pack this week on a 71 challenger 440...original 6 pack car.

It's the first one FITech built, according to them...so we are the guinea pigs on this deal.

I'm interested on how it will progressively bring in the outboard throttle bodies...which they told me it will
Who told you that? It's definitely not progressive. PM me if you have questions.

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Re: EFI for big inch BBC

Post by gmrocket » Mon Dec 03, 2018 4:31 am

RednGold86Z wrote:
Mon Dec 03, 2018 4:25 am
gmrocket wrote:
Thu Nov 29, 2018 8:03 pm
I'm installing FItech six pack this week on a 71 challenger 440...original 6 pack car.

It's the first one FITech built, according to them...so we are the guinea pigs on this deal.

I'm interested on how it will progressively bring in the outboard throttle bodies...which they told me it will
Who told you that? It's definitely not progressive. PM me if you have questions.
That's what they said when we asked about using the factory progressive linkage and why it will be interesting. We have the first one they made.

It didn't cone with any paperwork, nothing.

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Re: EFI for big inch BBC

Post by RednGold86Z » Mon Dec 03, 2018 5:07 pm

gmrocket wrote:
Mon Dec 03, 2018 4:31 am
RednGold86Z wrote:
Mon Dec 03, 2018 4:25 am
gmrocket wrote:
Thu Nov 29, 2018 8:03 pm
I'm installing FItech six pack this week on a 71 challenger 440...original 6 pack car.

It's the first one FITech built, according to them...so we are the guinea pigs on this deal.

I'm interested on how it will progressively bring in the outboard throttle bodies...which they told me it will
Who told you that? It's definitely not progressive. PM me if you have questions.
That's what they said when we asked about using the factory progressive linkage and why it will be interesting. We have the first one they made.

It didn't cone with any paperwork, nothing.
I'm the engineer for FiTech, so I can say for sure it's not progressive. PM me, and I'll email you those instructions.

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Re: EFI for big inch BBC

Post by gmrocket » Mon Dec 03, 2018 5:38 pm

RednGold86Z wrote:
Mon Dec 03, 2018 5:07 pm
gmrocket wrote:
Mon Dec 03, 2018 4:31 am
RednGold86Z wrote:
Mon Dec 03, 2018 4:25 am


Who told you that? It's definitely not progressive. PM me if you have questions.
That's what they said when we asked about using the factory progressive linkage and why it will be interesting. We have the first one they made.

It didn't cone with any paperwork, nothing.
I'm the engineer for FiTech, so I can say for sure it's not progressive. PM me, and I'll email you those instructions.
Great...we were sure it wasn't. Should be firing it up this week.

pm'd you

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Re: EFI for big inch BBC

Post by midnightbluS10 » Tue Dec 04, 2018 3:37 am

gmrocket wrote:
Thu Nov 29, 2018 8:03 pm
I'm installing FItech six pack this week on a 71 challenger 440...original 6 pack car.

It's the first one FITech built, according to them...so we are the guinea pigs on this deal.

I'm interested on how it will progressively bring in the outboard throttle bodies...which they told me it will
There's already been others installed and running, though. That sort of makes you not a Guinea pig if others have already done it. No? Henson's 68 Roadrunner had it at the Power Tour around July and Mark Rollings has it on a 71 Challenger already, as well. Done long enough ago to write and publish an article about it in Hot Rod this month.

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