Is this for real!!!

[Supervette]

http://www.mass-floefi.com/reviews.html#chevy_hi_perf
I fuel injection system that tunes itself. Can I run this with my procharger D1sc 383 stroker motor. Can they handle 800 hp? Can it really compensate that fast for the air coming in? My jaw dropped when I saw this.

[Supervette]

Sorry I got all excited and mistyped some stuff. What I meant was is this fuel injection system real?

[camcojb]

Sorry I got all excited and mistyped some stuff. What I meant was is this fuel injection system real?

yes and no. Don't believe everything you read. No, it will require custom tuning to be correct on your setup, and since you can't tune it yourself expect a LOT of mailing back and forth to get anything close to running as good as it could.

Save yourself a lot of aggravation and get a system that either you can tune yourself, or that a local tuner can tune with your car in front of him.

Jody

[dannyho]

I do like the way they attach their fuel rails, pretty trick, and gives me some ideas https://static1.pt-content.com/images/noimg.gif

[andrewb70]

The Edelbrock EFI manifolds mount the rails in a very similar way.

Andrew

[Z-man]

http://www.mass-floefi.com/reviews.html#chevy_hi_perf
I fuel injection system that tunes itself. Can I run this with my procharger D1sc 383 stroker motor. Can they handle 800 hp? Can it really compensate that fast for the air coming in? My jaw dropped when I saw this.

It might be pretty good, but don't believe everything you read. That page claims that speed-density systems require a professional tuner which is a bunch of hogwash! With the new wide-band O2 sensors, you can set the desired air/fuel ratio at any speed and engine load and the computer automatically adjusts the injectors (thousands of times a second). With my system, once the engine is tuned, you don't need a laptop - that article is really slanted. If you accept one of their tune jobs, that's what you will get whether it runs the way you want it to or not. If you get a system you can tune yourself, you can do things like set the A/F ratio that you want during acceleration to be different from the A/F ratio at idle and different from the A/F at cruising, etc.

They do say that their systems can be used on engines up to 1000hp. With boost I'd really recommend a wide band O2 sensor.

[Hammered]

I second what everyone above says. I converted a Pontiac to EFI using an Accel Gen 7 system and have not found a need for a professional tuner even though I had no experience with aftermarket EFI. Even though there are no kits for the Pontiac or base tuning maps, I got it to start the first time within a few seconds of hitting the starter. I did study the hell out of EFI and the Gen7 manual before starting though. There are now several newer systems that purport to be easier than the Gen7.

John

[Fuelie Fan]

It might be pretty good, but don't believe everything you read. That page claims that speed-density systems require a professional tuner which is a bunch of hogwash! With the new wide-band O2 sensors, you can set the desired air/fuel ratio at any speed and engine load and the computer automatically adjusts the injectors (thousands of times a second). With my system, once the engine is tuned, you don't need a laptop - that article is really slanted. If you accept one of their tune jobs, that's what you will get whether it runs the way you want it to or not. If you get a system you can tune yourself, you can do things like set the A/F ratio that you want during acceleration to be different from the A/F ratio at idle and different from the A/F at cruising, etc.

They do say that their systems can be used on engines up to 1000hp. With boost I'd really recommend a wide band O2 sensor.

Hate to nit-pick, but at best I would say most aftermarket efi systems are updating the fuel calculation 100 times a second. More typical would be around 25. However, that doesn't matter, because at BEST you can hope for a response time of 100 ms from an EGO. Plus, you need more than one sample in order to make a fueling adjustment. On top of that, you have transport delays on the order of 0.1 to 0.5 seconds depending on a number of factors. So, you can expect your system to make somewhere between 1 and 5 adjustments (which are different from the base fuel calculation) per second. Unfortunately, this is not fast enough to cover up a lean misfire from inadequate transient enrichment or a "hole" in the VE table. This is why I know anybody who says a wideband can tune any engine hasn't worked with a lot of engines. If you're close, it'll finish the job, but if you're way off, a wideband can't work magic. You still need to perform some calibration. Now, you are correct in saying that because a wideband gives you so much info, it's a lot easier to tune now than it was 5 years ago. But, figure that if you can't tune a carb, you probably won't be able to tune efi, because you still need an underlying understanding of how an engine operates. This is especially true when something goes wrong, because 95% of the time the problem is not actually the fuel injection yet the unknowledgable customer blames it on efi because he doesn't have the fundamentals down.

Sorry, rant over.

[Z-man]

You're partially right. There isn't a need to make millisecond adjustments to fuel injector rates based on exhaust gas O2 content because of the transport delay. However, not all changes to the FI rates are based on O2 levels. The computer is firing the injectors at rates in milliseconds (thousandths of a second). In my system for instance (not even the latest and greatest) I set the rate of change of the pulse width in response to changes in the throttle position anywhere from 2 to 3.5 milliseconds. If the throttle goes from idle to 3/4 open in a quarter of a second, the computer will check the injector speed and adjust it by adding 2 milliseconds (or whatever the setting is) and recheck it until the preset injector duty cycle is reached. This process is repeated thousands of times a second until the predetermined setting is reached. During these events, there isn't any waiting for feedback from the O2 sensor. The same thing happens with changes to the manifold air pressure, decay rates, spark rates, knock sensor, etc.

I can record all sensor parameters 20 times / second. I wanted to point out that checking the intake and exhaust at engine speeds is no big deal for a computerized setup. Also, when you get your system dialed in, you don't need to carry a lap top like that article suggests... :)

Hopefully, you didn't think I wasn't the one suggesting that a WB can tune itself. But I do think you won't get anywhere near close enough without a WB sensor setup.

[pdq67]

OK!!

What's wrong w/ say having a laptop hooked up to the O2 deal and then having up to six (6) hand turned "pots" to tune the engine while I drive as I look at the engine eff. graphs?????

Is this possible or is this so "stone age", I'm outta date............

pdq67

[camcojb]

OK!!

What's wrong w/ say having a laptop hooked up to the O2 deal and then having up to six (6) hand turned "pots" to tune the engine while I drive as I look at the engine eff. graphs?????

Is this possible or is this so "stone age", I'm outta date............

pdq67

Paul,

the more you play with tuning on efi you'll appreciate the better resolution the good systems give. By that I mean being able to tune virtually any rpm/load area you can run across. The Edelbrock system works, but is simply not as tuneable as most others. In some cases that's fine, but most could be better with a better system and more tuning resolution.

Jody

[Gaslight]

Another one worth looking at with a "self tuning" system. I have been over to there shop. Although I am not up on modern electronics they have a neat system.

http://retrotekspeed.com/

Jake

[Z-man]

OK!!

What's wrong w/ say having a laptop hooked up to the O2 deal and then having up to six (6) hand turned "pots" to tune the engine while I drive as I look at the engine eff. graphs?????

Is this possible or is this so "stone age", I'm outta date............

pdq67

That might work, but I've tried it and it's dangerous to take your eyes off the road. You get so fascinated with whats happening!! :) Better to have the laptop record what happens when you are tweaking the "pots" and then review the O2 results when you get back home.

Just curious - What would the pots be tweaking?

[Fuelie Fan]

You're partially right. There isn't a need to make millisecond adjustments to fuel injector rates based on exhaust gas O2 content because of the transport delay. However, not all changes to the FI rates are based on O2 levels. The computer is firing the injectors at rates in milliseconds (thousandths of a second). In my system for instance (not even the latest and greatest) I set the rate of change of the pulse width in response to changes in the throttle position anywhere from 2 to 3.5 milliseconds. If the throttle goes from idle to 3/4 open in a quarter of a second, the computer will check the injector speed and adjust it by adding 2 milliseconds (or whatever the setting is) and recheck it until the preset injector duty cycle is reached. This process is repeated thousands of times a second until the predetermined setting is reached. During these events, there isn't any waiting for feedback from the O2 sensor. The same thing happens with changes to the manifold air pressure, decay rates, spark rates, knock sensor, etc.

I can record all sensor parameters 20 times / second. I wanted to point out that checking the intake and exhaust at engine speeds is no big deal for a computerized setup. Also, when you get your system dialed in, you don't need to carry a lap top like that article suggests... :)

Hopefully, you didn't think I wasn't the one suggesting that a WB can tune itself. But I do think you won't get anywhere near close enough without a WB sensor setup.

Ooh i did word that pretty poorly, you're correct that transient enrichments are open loop. Even more reason that you need to have some ability to tune. The wideband absolutely helps, not trying to deny that. But it doesn't do the work for you.

There's no feedback on injector speed. Once a transient interrupt has been flagged, the appropriate fueling profile is applied. Different ecus handle it differently. Some provide a single asynchronous pulse and then add the rest to the synchronous injections, while others overlay a series of asynchronous pulses over top of the synchronous. I can't remember how quickly an interrupt bit can be set, but the synchronous fuel is calculated much slower, like i said no faster than 50 times per second.

[viper11]

ok my turn hehe
when i first fired my 440 i was using a cutler fuel injection system (which later became the holley commander system)
it is not tuneable it learns itself, this was great i thought till it started to tune richer and richer to the point where i was pouring out black smoke constantly,
heres the deal
i could set the idle speed and the fast idle speed with pots, i could add acceleration enrichment if it was leaning out, or vice versa
everything else was controlled by the black box of doom
this box has no provisions for wideband or laptop and no default reset, so i was on my own
i set it up and it it started instantly, it idled smooth and i started the initial tuning by stepping up the rpm till the led would go off
i went through the whole process and it seemed to be going good
then i switched it to the tuning/running mode where it was supposed to go unnoticed, always tuning for best torque while i drive. thats when things turned ugly!
i drove it to work which is a 30 mile treck, as i was driving it started to get sluggish and started spitting puffs of black smoke at every light, then black smoke at idle then smoke while cruising, to the point where i had to take the back roads for other drivers safety due to the black thick smoke constantly pouring out (i went through $50 gas on that trip lol).
the reason?
there was no way to tell the computer what size injectors i had, there was a large camshaft with a low vaccum signal at idle and cruise which fooled the efi into thinking i was always accelerating,
there was no wb hookup to tell the efi that i was running so rich that it was bogging the motor, which seemed to inject more fuel in,
in the end i bypassed the brain and used my megasquirt to control everything and i have been having fun since
evertime i go out i run a datalog and try to perfect the tune a little more
so yes they can self tune, but without some kind of control (or a big cam and injectors) i can take on a life of its own
be warned
jason

[nitrovette]

We just put a massflow efi system on a members 72 pantera 392 windsor.Were working out a few small issues this week and then will let you know how it works out.

[pmazza]

I have been running the MassFlo conversion on a 468 BBC in a 72 Corvette most of the summer. Mild motor with @575HP at the crank. No complaints, good quality kit, runs very well. Car is 80% street, 20% weekend warrior.

I went with this system because I was interested in the mass air meter approach and I am familiar with the EEC-IV. I figured worst case I could tune with Tweecer. No problems so far however. It looks like some of the MassFlo marketing might be over the top, but I wasn't really looking at that when I bought the system.

Phil

[MonzaRacer]

Strange but I can buy a Megasquirt for a lot less, purchase a new lap top and do a lot of tuning for $3k plus.
I figured on having around $1k in my fuel system and this is if I cant used the racepumps fuel pump.
We picked one up off ebay and it wasnt operating quite right so friend is going over the problem but while it ran the FACTORY 350 TPI on a 305 Chevy (read this as a 4 in bore x 3 in stroke plus an 030 over bore) using the race pump and Megasquirt and this is a mild 8.8 to one and we made 430 hp and it ran strong til we ran out of fuel (ie no flow) so we went back to the dyno pump and finished tuning, (the autotune feature from megasquirt is pretty good) and the wide bad o2 isnt any better or faster its just a bigger picture that allows you to fine tune the response to a smaller change in A/F range.
With the custome having a MegaView in his dash he can keep tabs without the lap top, oh yeah he picked up a cheap laptop without looking and its a Via C7 powered unit with 1.5 GHZ and it was loaded up on memory and such and it has wireless and such and he only paid $399 and I can go to Newegg and get a laptop for less than $500 (why buy a $2k laptop to possibly get sstolen from car, had that happen to another buddy, luckily his insurance paid for it, a $3500 alienware unit, he bought 5 computers when he replaced it, including 3 lap tops)my only issue is with all new lap tops still having to come with Vista which still doesnt play well with others nor its self.
I set one Megasquirt up with a 7 pin HEI and an old 4bbl EFI setup from ebay and no WB and it ran great and will run the car into the high 5s in the 1/8th. That one only cost the money to update the fuel pump(as his old pump wasstill underwarranty and burnt up, it didnt cost as much).
It was harder to get someone to weld bungs into his stainless headers than tune.