Factory efi
 

Might take a crack at racing a Ford 4.6 in stock . Do I keep the factory EFI set up or is there an aftermarket unit? Change out the computer from the factory unit with what? I've seen the set ups with the FS cars and I don't think I can use this stuff.

Re: Factory efi
 

Reading rules regarding my ImpalaSS you run the existing EFI.
Nothing wrong with it..Lot of good ODB2 tunes to make it run.
In fact run as light as a P/SA car...give Mike E in his Caprice a tough run.

If you build it..want a heads up run against my Pure Stocker ;-)
Bet you a whole $1 and dinner..

Re: Factory efi
 

You can use the stock computer with a TwEECer.
www.tweecer.com

Re: Factory efi
 

Save yourself a ton of grief, switch to an aftermarket system. It will pay dividends in the long run.

Re: Factory efi
 

fast xfi!

Re: Factory efi
 

Holley EFI!!

Re: Factory efi
 

I have tuned several with both FAST XFI & Holley. I would certainly disagree. I can & do make the FAST system do things the Holley can not. Besides the Holley ECU failures I have seen.

Re: Factory efi
 

I have five cars running Holley. I have never had one issue.

Re: Factory efi
 

Can you give specific examples, and describe the impact of those things?

Re: Factory efi
 

While I only have 1 jeep running the Fast XFI2, I am quite happy with it. Bought used on EBAY - (replacing the obsolete silver FAST - no longer supported). It is still a work in progress - not a lot of Jeep 4.0 support (on anything!) but no tech problems at all over 2 years.
1051 StK

Re: Factory efi
 

LOL, I am with you on this Rob. I hear this from time to time while at the Track. You would be surprised at how many people haven't scratched the surface with the capabilities of the more recent EFI units available today.

Robin

Re: Factory efi
 

Most, in fact just about all the issues with the Holley is installation, and piss poor map set up. Actually its amazing how bad they can be and still run half way decent. Had a guy come over to our pits last summer and wanted me to look over his stuff. He said it ran fine, didn't miss or bog or anything, but the engine builder kept telling him he thought it should be faster. He says its a seven under car, he's happy with that, but lets have a look at it ..First thing I noticed was his data log showed crazy things going on with his TPS signal. And the better I adjusted the fuel map (which was a mess) the worse the signal got. I contacted Robin and he tells me a few areas to look at. Turns out, the units main voltage inputs did not go directly to the Battery. It was not set to the right parameters in the crank trigger settings. And the tune needed alot of work. We were both amazed when the car picked up THREE tenths. One solid tenth in 60 foot. Holleys are killer units, I think they have over 35 thousand of them out in service ( Right Robin?), but GIGO, Garbage In, Garbage Out, is absolutely the thing to watch on them....

Re: Factory efi
 

One thing is something I was doing with my old Jr Stock ‘56. Running more timing in low & second gear. Something Jere Stahl put me onto over twenty years ago. I now run different timing in each gear. Easy 5 hundredths there. Jere told me he and Bill Jenkins had done that for years. Used to do it with our old dual point distributors & a toggle switch. “Turn on” the second set of points to retard the timing. I had re-drilled the breaker plate in my ‘56 Corvette distributor to move that one set of points to adjust the amount of retard. Spent most of a day on my Sun “distributor machine” working that deal out. Had the toggle switch mounted where my Hurst shifter tripped it going to high gear. I was much younger then, could usually remember to flip the switch back on the return road. LOL My FAST ECU does it all for me now. I do have a toggle switch now that shuts that function off, to help slow the car down when I don’t need it. The FAST XFI ECU can hold 5 “tunes”, I just use two.

Re: Factory efi
 

Was just talking about doing the retard points deal with someone this morning.

Re: Factory efi
 

First I ever heard of it was from Jere Stahl. Then I bought the book by Bill Jenkins showing how to do it. He was flipping the retard switch with the shifter in his Vega.
The NHRA World Finals was held in Tulsa a few years. I saw a switch in Monster Mash that I assumed was for retard.
The Ronca Brothers had a ‘56, same combo as mine, but MUCH faster! Took the winds out of my sales. LOL 25 years old, and thought I was bad fast. Evidently I held the record because they let me. LOL Never had the nerve, and was too embarrassed, to talk to them.

Re: Factory efi
 

You should be able to create a secondary table to control the timing like that through Holley as well. Can’t remember off the top of my head what the actual terminology for the table is. But you can create a secondary table based off whatever input you’d like. Such as time or transbrake release etc. I just recently started messing with this on my turbo 275 car where I can pull extra timing down track if the track isn’t as good. Not saying the fast system isn’t great but for a relative newbie to efi I love the simplicity in Holleys system.

Rick Ryan

Re: Factory efi
 

What else you got Ed? 😎

Re: Factory efi
 

You can do this with the Holley also. If you want to have multiple tunes inside the ECM to switch between you need the Dominator ECM. There is so much that can be done with the Holley that people just don't even know about.

Re: Factory efi
 

OP. The factory ECM is great for Stock class cars. All you need is a hand heild tuner or a lap top programer.

Re: Factory efi
 

Many factory ECUs don’t run well at higher RPM. Most GM stuff won’t trigger the injectors well past 7000 RPM. Not sure how high you need to spin your Stocker.
1996/1999 Vortec trucks hit that just barely past 6000.

Re: Factory efi
 

Pardon?? Could you be more clear about what I’ve done?

Re: Factory efi
 

You can switch “tunes” at shifts, going down the track?

Re: Factory efi
 

You can modify your timing and fuel going down the track for each gear.

It seems a lot of people have their own opinions on this website and they are the final authority on all matters.

If you are hell-bent on running small injectors at higher than normal fuel pressure, go ahead. You can still run a large injector at higher fuel pressure and limit the pulse width, but you must already know this.

I come on here to help people, but I see you have it all covered. Robin Lawrence and I should just go-away and let people like you help the rest.........

Enjoy.

Re: Factory efi
 

WOW! I have no idea who you are, but I apologize for offending you.

Re: Factory efi
 

Ed,

You are a highly regarded member of this site. You are a smart guy and usually have very good points.

I feel that your comments in regard to Holley EFI lack sufficient supporting evidence.

I got my start with Accell Gen 6 DFI. I have had the old FAST, Accell Gen 7, and even stock ECMs. I currently have Holley on all my COPO cars. I have nothing bad to say about any of the systems I have run. At the time they were cutting edge or required by the class rules.

I have also never had an electronic failure in any of my cars. I am sure that I will have something happen at some point. Am I just really lucky? I don't think so. A lot of my time is spent installing modern electronics into older textile machines. There are good practices for installing electronics. The failures that I have witnessed in other peoples cars could be traced to a failure to respect those practices.

As an example. Never cable tie any part of your EFI system to any other battery source. The Holley installation requires that the power supply be "clean" all the way to the battery.

You have hit some good points lately. One is the idea of changing the timing on the shift. My old "Gump" Firebird has a first gear switch on the shifter for that purpose. I put it on there more than 20 years ago. The second is running smaller injectors. I have never had an issue running a smaller injector at a slightly higher pressure. In my experience they idle cleaner and have better throttle response. My 2012 COPO came from Chevrolet with 42 lb injectors at 90 PSI!!

No hard feelings here,

Daren

Re: Factory efi
 

After dialing my air/fuel numbers back to the same, 60 psi & smaller injectors was a solid 5 hundredths quicker. The reason I was given by the most knowledgeable guy I have ever known, was it reduces misfires, and promotes more complete combustion. We never hear all the misfires taking place all the time.
Larger injectors require much shorter pulse widths, at idle, light loads, and decel. When you get much below one mili second pulse widths, it gets inconsistent. My knowledgeable friend works for GM, doing the original calibrations (“tunes”) on Corvettes. Absolutely knows more about this than anybody here.