Fast Efi

big_G

big_G

Blown Member
Joined
Mar 23, 2008
Messages
618
Location
Austin, Texas
I bit the bullet and ordered my Christmas present for this year. I will be pulling the carb. off the beast and installing a FAST EFI system this winter. It will have sequential fuel injection via an EFI ready Vic. Jr. intake and a 1200 cfm throttle body. I have some driveability issues with the carb., like stalling on heavy braking and uneven fuel distribution (full boost at at full throttle). I think the EFI will cure these problems. I will post progress pics. as I go along, if anyone cares...:p
http://www.fuelairspark.com/
 
Hope that works out for you.....I LOVE DPFI, best thing since sliced bread...

:trumpet::D
 
mrvette said:
Hope that works out for you.....I LOVE DPFI, best thing since sliced bread...

:trumpet::D
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It will. In '89 I put an '87 'Vette engine in my short bed S-10. Been working on Corvette EFI since I started my business in '87, so I'm no stranger to it. Nothing like the pure reliability and consistency of EFI.
 
Bullshark said:
Glad to hear it! Another crossover to the dark side.:bounce: You won't be sorry. BTW, Why did you opt for FAST? Just curious.

Bullshark
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Not the dark side...this is the 21'st century, isn't it? I looked at all my options/features with each vendor's product. One was a Chevy, another a Buick and the FAST system was the Caddy. I like Caddy's. FAST (it seems to me) really had their act together as far as options, ease of use and tech. support. The only other players, IMO, were Edelbrock and Accell. I managed to get such a good deal on the FAST set-up, I couldn't turn it down. In the end, I probably paid $400 more for the name...but it is a Caddy, after all!
 
Don't they use the kit computer?? the one from Megasquirt...Bowling/Grippo? in a blue box instead of silver???

:fishing:
 
Dunno about the guts. Comp. Cams owns FAST. It's a red case. I've seen the Megasquirt unit and there is no similarity in the hardware/manuals. The FAST unit supports individual tuned runners, something called Intelligent Traction Control, boost control, transmission control etc. It has data logging capability and multiple base fuel/spark map tables to choose from. Maybe MS has changed in the past year, but I was not impressed with the hardware or software.
FAST
150_xfiecu.jpg


Megasquirt
frontal.jpg
 
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Hey man, I don't want to be a wet blanket here, but if you didn't already purchase the FAST you may want to consider some of the other manufacturers such as Bosch for example.

If you look at what European road race cars use, those systems are far more elaborate and tuneable for street driving.

The FAST due to it's limited configurability is more like a carb in the respect that you only have one tune, and it does not read the O2 sensor to adjust on the fly.

It is a fairly raw system, and although an improvment over a carb, not the best all around solution for all around driving. It is typically good for a single purpose vechicle. Basically it is like tuning a stock car to open loop, it's not very effective. Many tuners would argue that the stock ECU from a C4 is a better street system than the fast in terms of ability to control the fuel delivery. The FAST is easy to tune, and works, but is very raw.

Just my .02 before you spend the money.
 
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Jsup said:
Hey man, I don't want to be a wet blanket here, but if you didn't already purchase the FAST you may want to consider some of the other manufacturers such as Bosch for example.

If you look at what European road race cars use, those systems are far more elaborate and tuneable for street driving.

The FAST due to it's limited configurability is more like a carb in the respect that you only have one tune, and it does not read the O2 sensor to adjust on the fly.

It is a fairly raw system, and although an improvment over a carb, not the best all around solution for all around driving. It is typically good for a single purpose vechicle. Basically it is like tuning a stock car to open loop, it's not very effective. Many tuners would argue that the stock ECU from a C4 is a better street system than the fast in terms of ability to control the fuel delivery. The FAST is easy to tune, and works, but is very raw.

Just my .02 before you spend the money.
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Where did you hear all that?... I did my homework on this. The FAST ECU is about the most advanced system out there, right up there with the "Big-Stuff" ECU. Much more advanced than the Edelbrock and Accell set-ups. It is completely self-adjusting, using a wide-band O2 sensor and speed-density technology. It can be set up for batch-fire or sequential fire, coil on plug, DIS, etc. Go to the FAST website and read the install doc. and set-up details. You will be impressed with it's capabilities. http://www.fuelairspark.com/
http://www.fuelairspark.com/Instructions/XFI_ECU_OperationManual.pdf
 
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What GM ECM do you mean? The 1st generation or the 2nd gen weatherpack ECMs?
Comparing the XFI system to a 10.000+ dollar Bosch motorsports ECU is kind of silly. Usually you see the Zytec and DTA systems here. The top of the line Bosch system costs around 27.000$ (yes no typo) and the cheapest able to control an 8 cyl is right around 3000 and you need optional components to be able to have knock control.
 
Twin_Turbo said:
What GM ECM do you mean? The 1st generation or the 2nd gen weatherpack ECMs?
Comparing the XFI system to a 10.000+ dollar Bosch motorsports ECU is kind of silly. Usually you see the Zytec and DTA systems here. The top of the line Bosch system costs around 27.000$ (yes no typo) and the cheapest able to control an 8 cyl is right around 3000 and you need optional components to be able to have knock control.
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Marck, no offense buddy, but anyone spending that type money on a simple engine control computer, is NUTZ, simply WAY in hell over priced.....

IMO, a simple induction setup and throttle body is a grand, and after that another 500 for the electronics, the injectors maybe 50 bux each, if that...

so for 2 grand, it's done....including wide band O2 sensor in that 500 figger for electronics above...

the programs are all ready in the can, common internet knowledge mainly thanks to Megasquirt...

I mean my project to convert to the MS system 2 winters ago did not go well, but that was ME and the computers I don't get along well, but really the hardware was fine....

:tomato:
 
that's not 27.000 for an injection system, it's 27.000 for an ECU!! no cables, no injectors, no nothing. Just a little black box.
 
I will add that the later C-4 ECM's like from '95 and '96 (OBDII) can work pretty well. They are flash programmable and employ sequential injector control. Other than that, don't think the earlier ones are all that good.
 
big_G said:
Jsup said:
Hey man, I don't want to be a wet blanket here, but if you didn't already purchase the FAST you may want to consider some of the other manufacturers such as Bosch for example.

If you look at what European road race cars use, those systems are far more elaborate and tuneable for street driving.

The FAST due to it's limited configurability is more like a carb in the respect that you only have one tune, and it does not read the O2 sensor to adjust on the fly.

It is a fairly raw system, and although an improvment over a carb, not the best all around solution for all around driving. It is typically good for a single purpose vechicle. Basically it is like tuning a stock car to open loop, it's not very effective. Many tuners would argue that the stock ECU from a C4 is a better street system than the fast in terms of ability to control the fuel delivery. The FAST is easy to tune, and works, but is very raw.

Just my .02 before you spend the money.
Click to expand...

Where did you hear all that?... I did my homework on this. The FAST ECU is about the most advanced system out there, right up there with the "Big-Stuff" ECU. Much more advanced than the Edelbrock and Accell set-ups. It is completely self-adjusting, using a wide-band O2 sensor and speed-density technology. It can be set up for batch-fire or sequential fire, coil on plug, DIS, etc. Go to the FAST website and read the install doc. and set-up details. You will be impressed with it's capabilities. http://www.fuelairspark.com/
http://www.fuelairspark.com/Instructions/XFI_ECU_OperationManual.pdf
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It started with my tuner, who is a FAST dealer and installs them regularly. He said that the stock ECU in my '90 was superior to the FAST in that it can better manage the engine.

As my wife says, I "shop for shoe laces". So I started making calls to tuners, and people I know and ran the theory past them.

I could not find a tuner who disagreed with the original assessment that the OEM ECU with the Pulse Width Limitation taken off, is more refined and more accurate than any after market system available.

Now, I am not presenting myself to be an expert here, let's be clear. I am just saying, the brochures say one thing, and tuners seem to be saying another.

Does this mean there is anything WRONG with FAST? No, absolutely not. Perhaps you can pick up a stock ECU and harness for a lot less and end up with a better tune, if done right. Just sayin'...

I am simply speaking to the research I had done and what I was told by people who are experts.

Can you do batch or sequential but big deal. The only advantage to sequential is at idle, as far as I can tell.
 
No, the earlier ones are crap. They are PROM based and you either need to burn EEproms or convert it to a flash rom setup to be able to do some meaningful tuning and this means investing in a whole slew of programs and ahrdware. You're already a good way towards a decent aftermarket ECU then. Then there's the fact that it doesn't readily handle map values over 1 bar (later weatherpack ECM being speed density) and you need a workaround for that also.

Then there's the fact that those ECMs are narrow band sensor based. Fine for controlling around lambda=1 with a proper calibration (something GM invested heavily in) but once it's off the troubles are starting.

The old style non weatherpack ECMs are also 160 or 8192 baud (earliest ones are 160)

I only see drawbacks. Those ECMs are nice for controlling a stock engine, if you get away from those stock parameters it's not going to be worth it IMO.

I too have been looking at the XFI unit for future use on a IR EFI system and from all the systems I've seen it's the most user friendly and capable system out there. If I had to choose, that one would be it also.
 
big_G said:
I will add that the later C-4 ECM's like from '95 and '96 (OBDII) can work pretty well. They are flash programmable and employ sequential injector control. Other than that, don't think the earlier ones are all that good.
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Mine is a 90 OBD1, I asked the questions from that frame of reference. Again, just posting what I learned, don't shoot the messenger. I am hoping to have responses which validate or not what I have been told.

Does the FAST support knock sensors? Will it throw a "check engine light"? I don't think so.

Now, older ones, I think 88 back, had slower chips that were pretty poor.
 
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What pulsewidth limitation are you talking about? If you mean the 80-85% max,. that's because above that the injector pintle starts floating and won't close, whenever that happens the actual flowrate drops down to 90% of it's max. That's the maximum pulsewidth limitation that I know of. Is there something else in those ECMs that limits it even more?
 
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