Accel DFI VS. FAST EFI

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Jul 9, 2003 | 07:06 PM
  #1  
Alright, It's time for me to come to a decision here, this is the last "BIG" item I need to finish my motor (the smaller items are pushrods,fuelpump, lines, and intake gaskets, thats all.) Anyways I keep running back and forth between Accel and Fast like a begging puppy trying to eat the best treat first. So here is the Delima, FAST has a their bank to bank system for 1,850 with a wideband. to go to sequential it will be more like 2,500. then to get a data logger it will be another 400 or so. All fine and dandy. Thats a heck of a lot of money for me now. The only other pro I can think of for fast is that there seems to be more real world applicationS of it. No onto Accel. 1,389 gets me a base unit with harness and sensors, another 800 for a wideband O2, so around 2,100 for a complete setup. Accel's unit already provides 30 minutes of datalogging potential, can go bank to Bank or sequential already and otehrwise seems to offer the same kind of features as fast. I don't know the the bit rating on the accel, I think fast is 32. Issue, people say that the O2 for accel is not very good, and cannot handle alternative fuels. they also say you cannot get as percise in the map manipulation "I think this is only dependent on the bit rating, thats why I am curious", and I have not seen hardly any realworld sucess storys. But then there is this 3rd part option. Haltech.. one of the originals in custom ECU's got really outdated with their systems, and people say they work, just not that well. I tend to think that perhaps they have not tried their new system, thei E11 which has a windows based programming system just like DFI or FAST.. except this one is able to control wastegates, nitrous, throttle delay, darn near anything, is 32 bit with over 100 different maps that can be instated at any time. It can be bank to bank or sequential, can be changed to handle anywhere from 1 to 16 cylinders, and low impedance injectors "nothing big when comparring to fast and accel". price 1,400 for flying lead kit, and a super low 650 for a wideband "cheapest yet". I am honestly extreemly impressed with the Halwin software. Only problem, again, I have not seen any big dogs use this. just Imports and oddities, Other than that, the wiring is much more cumbersom, which you have to terminate each end to the sensors.
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Jul 9, 2003 | 11:20 PM
  #2  
Re: Accel DFI VS. FAST EFI (WashingtonRacer)
Why not go with the same system that Merlin had? It was an Autronic. It was a killer system on his car. :D
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Jul 10, 2003 | 08:38 AM
  #3  
Re: Accel DFI VS. FAST EFI (542C2)
The sequential option only becomes an issue when you get into tuning individual cylinders. I've been running a FAST B to B on a Buick for the past 4? years. I had the system firing 96 lb injectors on a car that ran 117 in the 1/4 to begin with. They idled the same as a set of 36 lb injectors they replaced. The same 96 lb injectors are now in a car running in the 140's.

The FAST B2B total pulse width is the same as with the sequential. It's not a batch fire setup. The nice thing about the FAST is that it's really fairly simple. The controls are there to get the car dialed in but you don't have too much to really overwhelm you. The Accel system looks nice with some pretty interesting features, but if you're just starting out programing fuel injection there's some stuff in there that could get a little confusing. There is also a good knowledge base on the FAST where I'm haven't seen much on the Accel. Experienced guys are switching over to the Accel, but I've also seen guys switch to the Accel and then switch back to the FAST.

It's a tough call. Personally, if you don't have programming experience, I'd lean towards the FAST. Good knowledge base, and the wideband can do wonders for you. I've seen it save many peoples bacon.
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Jul 10, 2003 | 12:41 PM
  #4  
Re: Accel DFI VS. FAST EFI (542C2)
I was thinking of just bank to bank, but at the same time, I was figuring, best potential ability to get the maximum tunability from my car. as far as dialing everything in, your right, I don't have any experience in actually setting these systems up. However I am 100% confident that I could tackle it fairly quickly. But so far it seems that both systems are capiable to control a certain engine just as well, so I guess the deciding point would be just cost. which ever one pops up first I guess.

Steve, I have never heard of Autronic, but at the same time, It seemed that they had one heck of a time trying to get that thing setup right.
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Jul 10, 2003 | 12:55 PM
  #5  
Re: Accel DFI VS. FAST EFI (WashingtonRacer)
I think Merlin had/has a Motec system in it.

(edit) Isn't Autronic's the parent name of MSD.


[Modified by SloRvette, 5:57 PM 7/10/2003]
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Jul 10, 2003 | 02:29 PM
  #6  
Re: Accel DFI VS. FAST EFI (SloRvette)
Autronic is made in Australlia, I think MSD is Autotronic, but I could be wrong. Good thinking though. I looked into it. It seems much like the Haltech system, almost down to the t. They clame about the same which is just as good as Fast or accel if not better. They really seem intrested in getting their product over here, though I think their main use over here has only been in race boats so far.
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Jul 10, 2003 | 03:01 PM
  #7  
Re: Accel DFI VS. FAST EFI (WashingtonRacer)
Not to throw another name out there, but have you looked into the Electromotive TEC-3 system? About 5 years ago I was looking into stand alone systems for an RX-7 Turbo I had. It seemed then Electromotive was the way to go. They've updated the system twice now, but there are also new competitors on the market.
http://www.electromotive-inc.com/products/tec3.html
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Jul 10, 2003 | 09:09 PM
  #8  
Re: Accel DFI VS. FAST EFI (WashingtonRacer)
You are correct, Autronic is made in Australia and MSD is owned by Autotronic. I was just joking about the Autronic system that Merlin had. It seemed to have a lot of capabilities but it was never programmed properly. The car ran terribly with the way it was set up.
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Jul 10, 2003 | 10:05 PM
  #9  
Re: Accel DFI VS. FAST EFI (SloRvette)
Quote:
The Accel system looks nice with some pretty interesting features, but if you're just starting out programing fuel injection there's some stuff in there that could get a little confusing.
Yea right like the feature that allows you to click on autocalibrate and it sets the af ratio to whatever you have typed in for a target af. Thats really difficult. If you know how to click a mouse you can tune it.


[Modified by black bart, 10:06 PM 7/10/2003]
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Jul 10, 2003 | 11:41 PM
  #10  
Re: Accel DFI VS. FAST EFI (black bart)
?
Quote:
Yea right like the feature that allows you to click on autocalibrate and it sets the af ratio to whatever you have typed in for a target af. Thats really difficult. If you know how to click a mouse you can tune it.


[Modified by black bart, 10:06 PM 7/10/2003]
If you've already typed in your A/F ratio why would it need to change it ? Are you trying to say that the autocal will adjust the VE table so that the actual A/F ratio matches the commanded A/F ratio ?
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Jul 11, 2003 | 09:54 AM
  #11  
Re: Accel DFI VS. FAST EFI (SloRvette)
Quote:
?

If you've already typed in your A/F ratio why would it need to change it ? Are you trying to say that the autocal will adjust the VE table so that the actual A/F ratio matches the commanded A/F ratio ?
With a Gen. 7 wideband you answer several questions and it builds a V/E map no big deal they all do that but you type the A/F ratio that you want to run at in what is called Target A/F Ratio the wide band will force it to run at the A/F that you typed in the target A/F map but if it has to make a 15% correction it will show you that and you can chage the V/E map by typing new numbers like most do or you can click on the autocalibrate button and it will change the V/E so that the A/F will be at the target A/F ratio and O2 don't need to make corrections. The Gen.7 can be switched from B-B toSFI with a click of the mouse. The FAST you have to remove it and send it to the factory for a board change. I don't know how long that would take but it sure is not as handy as just a mouse click. Gen. 7 will operate three stages of NOS FAST don't come with that feature either. The idle compensator is a nice feature with a high duration cam that has a lope you can build this map that changes the timing so when the engine drops below target idle speed it will advance the timing and when it is above target speed it will retard the timing this results in a much smoother idle. If you like to hear what some think is bad sound just don't use this feature I like it my car idles much better with it.
Speaking of idle with a really big injector the pulse width is too narrow at idle when the pulse is less than about 1.5 ms the idle becomes erratic if you increase the pulse you are rich. The Gen.7 not only can control mutiple throttle bodys but it will operate mutiple injectors per cylinder not only will this improve the idle it improves throttle response. You could install a 70lb injector and a 30 lb. injector it will run on the 30lb untill you reach 30% throttle then it will run on both. It will keep them linear so that they both reach 100% duty cycle at the same time.
As was pointed out you don't have to spend money for a data logger it has one built in. When Fast came out with their current system Accel had the old Gen.6 and the Fast was much better then Accel came with the 7 it had some software problems at first but those issues have been taken care of. The Gen.7 is far advanced over the Fast system. I'm sure fast is working on a new one and whenever it comes out it will be more advanced than the Gen.7 technology just keeps getting better. I had a Gen.6 sold it and bought the Gen. 7 wideband big difference the wideband is the only way to go. I have no regrets about the extra money for the wideband it is worth every dime.



[Modified by black bart, 10:49 AM 7/11/2003]
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Jul 11, 2003 | 12:25 PM
  #12  
Re: Accel DFI VS. FAST EFI (black bart)
Thanks for your thoughts on it, I am now offically leaning towards the Accel system. Now just thinking about it. the Haltech system, with it's claimed abilities, seem to be leaps and bounds infront of Fast or Accel. Their software is very clean and friendly, sweet 3d maps and all that jazz, but I think the kicker that I like about it is it's ability to control the wastegates. and the pressure can be set at each RPM level for complete control. I think John's Big Stuff III is supposed to incorporate the same feature, but take it a step further and use it as a traction control device. Monty has more knowlege on that. Well hopefully I will have my self a ECU soon. Then I can finallly start the car and get it out into the driveway and clean it all up, Paint it, then I will feel it's worthy to show pics :).
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Jul 11, 2003 | 02:56 PM
  #13  
Re: Accel DFI VS. FAST EFI (black bart)
How accurate is the Autocal ? On the FAST when you're live you can hit the "L" key with the VE window open and it will correct that cell for the wideband's correction. The problem is that if you're in a transitional period and you have acceleration enrichment, the correction that the wideband is applying is to the total pulse width. So if you have too much acceleration enrichment it will lower the VE cell too low. Or if you don't have enough acceleration enrichment the VE table will end up too high.

It sounds like the FAST system has the same stall saver spark function that the Accel has.

I personally know that the FAST's circuitry is stable enough to give a repeatable pulse width of 1.3 ms for a stable idle. That's where my car idles with the 96 lb injectors.

I wonder about how well the staged injector setup with the Accel system works ? I know I used to run a second fuel pump that would spike the system and mess up the O2 correction. FAST lists a staged injector system but I don't think they've got the system to work to their liking.

Does the Accel system only allow you to log 6 sensors ? On the demo version I've got that's what it looks like.

Also, Does the Accel wideband correct at WOT ? I keep hearing different stories.
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Jul 11, 2003 | 04:43 PM
  #14  
Re: Accel DFI VS. FAST EFI (SloRvette)
Hmmm.. I have never heard of that problem witht eh Wideband with accel. Very important question though. If it didn't work, I would be demanding that they take their POS back and buy me a fast system. cause isn't that THE most important feature that Wideband gives you?
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Jul 13, 2003 | 09:21 AM
  #15  
Re: Accel DFI VS. FAST EFI (SloRvette)
Quote:
The problem is that if you're in a transitional period and you have acceleration enrichment, the correction that the wideband is applying is to the total pulse width. So if you have too much acceleration enrichment it will lower the VE cell too low. Or if you don't have enough acceleration enrichment the VE table will end up too high.

I personally know that the FAST's circuitry is stable enough to give a repeatable pulse width of 1.3 ms for a stable idle. That's where my car idles with the 96 lb injectors.

I wonder about how well the staged injector setup with the Accel system works ? I know I used to run a second fuel pump that would spike the system and mess up the O2 correction. FAST lists a staged injector system but I don't think they've got the system to work to their liking.


Also, Does the Accel wideband correct at WOT ?
YES

The way a dfi works all of them must be running at a steady state to adjust the base fuel. Once the base fuel map is right the AE map is easy. If you flat line the AE on zero for about the first 30% of throttle opening then while cruising you can adjust the base map without any AE being added. It is hard to accelerate but if you go beyond the 30% you pick up the AE and when you get to the speed you want back off hold it steady and adjust it. I think it is easy enough but it takes time to get it right but the wide band makes it a lot easier. My biggest complaint is that the ecm requires a serial port I have a new laptop and like most it has usb instead of serial ports so I had to but a device that converts the usb to a serial don't know why they didn't make it to work with a usb :mad
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