DFI vs FAST ?
- Thread starter G McCall
- Start date
Gotcha,
And from another list they sent me a few screen shots and showed the F.A.S.T. unit they had allowed for individual timing and fuel comps per cylinder, but the would seem to be a Sequ unit only option.
Has anyone documented any HP gains with the in cyl trim on a GN?.
berrelauto
New Member
- Joined
- Feb 20, 2003
I don't have the paper documentation any more but when I dynoed my motor on John Meany's dyno we saw a 24hp increase with I/C fuel tuning. This was at a little over 1000hp (low Boost)
Why is anyone comparing anything with a Gen 6 system?
After that system's retirement years ago, there was Gen 7.
Now, there's Gen 7+.
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Seems comparing currently available systems might be more purposeful.
TIA!!
After that system's retirement years ago, there was Gen 7.
Now, there's Gen 7+.
______________________________________________
Seems comparing currently available systems might be more purposeful.
TIA!!
Because when Greg started this thread, he said he had DFI (which we all presumed to be VI, though he never came out and said so), and he wondered if the FAST would be an improvement over that. If he had asked if the gen VII would be an improvement, I'm sure this thread would have gone in a different direction
John
What specific question have you got bruce? You're "stream-of-consciousness" writing style usually isn't that clear to me, maybe I missed it or misunderstood it? I still think that a quick read through the FAST manual would answer a lot of questions.
John
John
- Joined
- May 28, 2001
OK I have used both so maybe I can help.
Had a DFI Gen 6 with a VIC on the same motor.
Here is what I have seen so far.
Gen 6
Number 1 It is at least 10 years old.
The DFI does datalog but the amount of info it gives you does not equate to a full run down the track. You cant really see shift points in gears, AF ratio across the run and so on. The DFI has a limited amount of sensors it can log. ( Limitation of an old system.)
There is no wide band function.
Job mentioned it and I will say it too. 4 drivers is not enough when you are running big (over 70 #) injectors. It does help a lot when there is one per injector.
There seems to be a 4 degree error built in to the DFI when it comes to timing. It was never on the money. You simply allowed for an additional 6 degrees on the crank using a DFI.
FAST
Its all Windows based and it does use a lot of Win keystrokes in the program.
You can have 4 or 5 ( more if you want ) separate windows open and running at the same time which is great in tuning a new car or an existing system when you are chasing problems.
The WB funtion allows the ECM to adjust fuel on the fly and keep the motor from killing itself. Very helpful.
Timing is dead nuts on and controlled.
The increased speed of the chip, from 8 to 32 is helpful in that the program loads much faster, and I do believe the datalogging capability is greatly increased because of the processor speed.
The is my own opinion but the system does what it used to take two or three items to accomplish. I dont care what anyone says, having a computer that you can adjust in between runs, analyze the previous run and make INFORMED changes instead of guesses as to what is going on is truly priceless.
Had a DFI Gen 6 with a VIC on the same motor.
Here is what I have seen so far.
Gen 6
Number 1 It is at least 10 years old.
The DFI does datalog but the amount of info it gives you does not equate to a full run down the track. You cant really see shift points in gears, AF ratio across the run and so on. The DFI has a limited amount of sensors it can log. ( Limitation of an old system.)
There is no wide band function.
Job mentioned it and I will say it too. 4 drivers is not enough when you are running big (over 70 #) injectors. It does help a lot when there is one per injector.
There seems to be a 4 degree error built in to the DFI when it comes to timing. It was never on the money. You simply allowed for an additional 6 degrees on the crank using a DFI.
FAST
Its all Windows based and it does use a lot of Win keystrokes in the program.
You can have 4 or 5 ( more if you want ) separate windows open and running at the same time which is great in tuning a new car or an existing system when you are chasing problems.
The WB funtion allows the ECM to adjust fuel on the fly and keep the motor from killing itself. Very helpful.
Timing is dead nuts on and controlled.
The increased speed of the chip, from 8 to 32 is helpful in that the program loads much faster, and I do believe the datalogging capability is greatly increased because of the processor speed.
The is my own opinion but the system does what it used to take two or three items to accomplish. I dont care what anyone says, having a computer that you can adjust in between runs, analyze the previous run and make INFORMED changes instead of guesses as to what is going on is truly priceless.
I was meaning in a very technical sense.
ie is the code running continuosly or on a series of interupts.
Are they actually doing PW corrections as the injector is firing.
Are any of the programs really turbo specific?.
If you read thur what GM has been doing for years, are they even trying to match them?.
GM has had a Power enrichment multiplier for time in PE since the GNs came out.
TCC stuff has been ignored just until lately by the aftermarkets.
I see from the last post the 8 to 32 bit advantage seems to be in datalogging. OK, how many frames a sec will the new aftermarkets record at?, and how many parameters?. Will they accept extra channels.
Why don't they release the Source Code, for people to look at?.
While it's just my opinion, if someone wants to claim some product as being best, OK, lets hear the details of way.
If you want to use a 1.5 Ghz processor, fine by me, but if you want to claim that it gives an edge, lets hear the real why it gives an edge. If it's just because the software for editing loads faster, OK, say that.
I just have to say that do you know how many millions of dollars GM and all OE manufactures spend developing their engine management systems? And after spending all of that money they still aren't perfect hence the calibration updates that are constantly being released. If there was a aftermarket company willing to spend a fraction of that kind of money, the system would cost many times more than you paid for your car. The systems that are available today do a damn good job and what they were designed to do. There will always be a compromise. How about you actually use and tune one of there systems before you pass judgement on them and compare them to something that is not even in the same league.
Yes, I have a very good clue about what the oems spend, I've been thur an oem's emission lab., engine, and powertrain dyno areas, and have spent a fair amount of time discussing various aspects of what they go through. And I've seen some of what they use for data logging and have been able to draw my own conclusions about what I need, since I've seen true state of the art equipment. I know what 1 msec data sampling rates really look like. Also, what 100 channel data logger looks like that can record 20 of those channels a 1 msec sampling. Ya, I have a clue about what the oems do.
Yep, after doing a few thousand cars/trucks problems do crop up, and yes they update the calibrations, but that has nothing to do with the subject at hand. The aftermarkets also don't have to worry about the EPA and 100K mile warranties either.
So your saying that they can't match the oem ecms?. If they have to make so many compromises, why not just design software to run in the oem ecms, then?.
I've taken then time to develope my own source code for the 1227148 ecm, by removing the ROM in the ecm and then rewrote the code. I then changed some of the routines, and finally have changed it over to a true 3 bar MAP system. I say I but I had alot of help. So I've used a given ecm in Batch Fire, SEFI, MAF and MAP. So I would claim to have a little knowledge about how an EFI system works. Oh and I have a scanner logger, where I can watch all 256 RAM locations, and add 6 channels of additon inputs.
And the aftermarket folks claim to be so good, yet to date I have yet to see them approach the oems. They offer a pretty editor, and simplistic tuning, but for me I just don't see where their claims justify the expense. There has been mention of a possible few reasons for things, but nothing that I'd call as concrete data.
So why are faster processors really an issue?. I have several possible answers, but it would be just kind of nice to hear from someone that really knows why. Like I mentioned earlier the hardware is just incredibly slow and not that accurate, so why is there an actual need for the signal processing?. It's not like their running OBDII and having to basically run two systems with one just as a sanity check.
- Joined
- May 28, 2001
. They offer a pretty editor, and simplistic tuning, but for me I just don't see where their claims justify the expense. [/B
Let me make this simple then. You cant use a stock ECM ( and I mean stock not modified) to tune motors to the HP levels we do.
Before you say it, yes there are others using modified ECMs to come close to doing the job. And there are those who are smart enough to do it themselves because they ARE an engineer or have taken the time to figure it out.
You start comparing apples to oranges with a stock ECM versus an aftermarket ECM. It comes down to money and units. GM can justify the millions they spend on a stock ECM because that ECM will go into thousands of cars. DFI does not have that kind of capital to invest nor will they sell the number of units that GM would.
Let me make this simple then. You cant use a stock ECM ( and I mean stock not modified) to tune motors to the HP levels we do.
Before you say it, yes there are others using modified ECMs to come close to doing the job. And there are those who are smart enough to do it themselves because they ARE an engineer or have taken the time to figure it out.
You start comparing apples to oranges with a stock ECM versus an aftermarket ECM. It comes down to money and units. GM can justify the millions they spend on a stock ECM because that ECM will go into thousands of cars. DFI does not have that kind of capital to invest nor will they sell the number of units that GM would.
THE BEAUTY OF GEN 7+
Running the Gen 7+ with the piggy-back harness allowing the retention of the OEM ECM for basic functions is an option chosen by many.
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One of the most astounding gifts provided by the Gen 7+ is the highly user-friendly graphic interface & control of all the pertinent engine parameters WITHOUT having to learn & master rather arcane ( in some cases antique ) "codes" and/or "languages".
Now the average "Joe Sparkplug" ( like me ) can enter & prevail in an arena that heretofore seemed a "darkly magical & mysterious realm" previously reserved for just a relative few.
The "genius" of the Gen 7+ is in its awesome simplicity of operation.
_________________________________________________
And that's a very wonderful thing!
Running the Gen 7+ with the piggy-back harness allowing the retention of the OEM ECM for basic functions is an option chosen by many.
_________________________________________________
One of the most astounding gifts provided by the Gen 7+ is the highly user-friendly graphic interface & control of all the pertinent engine parameters WITHOUT having to learn & master rather arcane ( in some cases antique ) "codes" and/or "languages".
Now the average "Joe Sparkplug" ( like me ) can enter & prevail in an arena that heretofore seemed a "darkly magical & mysterious realm" previously reserved for just a relative few.
The "genius" of the Gen 7+ is in its awesome simplicity of operation.
_________________________________________________
And that's a very wonderful thing!
Neat way of limiting the conversation, ie ruling out a $125 expense to justify a several thousand dollar replacement.
Again you're saying that the aftermarkets aren't as good. With you comment about they can't spend the money to do the R+D.
Your reply can be taken to mean, the for $125, and some elbow grease, then the oems are still a better ecm. Your logic, not mine.
And you still haven't mentioned one thing that the aftermarkets have an advantage with a faster processor.
Without being to crase, it just seems like so far the defenders of the aftermarkets are refusing to use any real elements of design to prove they are better.
Re: THE BEAUTY OF GEN 7+
I fail to see what's arcane about just using an editor, it takes care of the math, and high end calculations. Something as wasy as Tunercat and a Romulator, gives you editing and on the fly changes. And for that you're looking at less then $300.
15 years ago it was difficult to edit the stock stuff, but that was 15 years ago. ALOT has changed in the 2 years.
I guess I don't see the difficulty involved with using an emulator.
Again thou we've missed anything that touches on my guestion of what a faster processor gets you.
I fail to see what's arcane about just using an editor, it takes care of the math, and high end calculations. Something as wasy as Tunercat and a Romulator, gives you editing and on the fly changes. And for that you're looking at less then $300.
15 years ago it was difficult to edit the stock stuff, but that was 15 years ago. ALOT has changed in the 2 years.
I guess I don't see the difficulty involved with using an emulator.
Again thou we've missed anything that touches on my guestion of what a faster processor gets you.
- Joined
- May 28, 2001
Neat way of limiting the conversation, ie ruling out a $125 expense to justify a several thousand dollar replacement.
No Bruce you are mistaken. A stock ECM cannot drive bigger injectors and an aftermarket can. It is not about justifying the higher expense, it is about keeping a motor together that someone will spend thousands of dollars on.
Again you're saying that the aftermarkets aren't as good. With you comment about they can't spend the money to do the R+D.
You are saying the aftermarkets are not as good based on the R&D limitations they have versus GM. Its about a market and my point is that we Buick people do not constitute the mass market that GM sells to.
Your reply can be taken to mean, the for $125, and some elbow grease, then the oems are still a better ecm. Your logic, not mine
No your logic. My point is that there are those who are doing well with a stock ECM. I am acknowledging that because it is only fair. Your logic not mine.
In fact, you can tune a stock ECM to go just as fast but you will still not have the datalogging features, you will not have a WB function and you still cant take a chip burner to the track and adjust timing and fuel to compensate for elevation.
The market has a lot to do with this conversation. If you will recall FAST was given the opportunity to make a better product because DFI took 15 years to come out with a GEN 7.
More power to FAST.
So yes we who are not working with GM powertrain, an OEM emissions lab and a dyno are at a disadvantage.
You can use chips and you will get it right but I can use a FAST computer and get it right at the track and do it sooner than you can.
No Bruce you are mistaken. A stock ECM cannot drive bigger injectors and an aftermarket can. It is not about justifying the higher expense, it is about keeping a motor together that someone will spend thousands of dollars on.
Again you're saying that the aftermarkets aren't as good. With you comment about they can't spend the money to do the R+D.
You are saying the aftermarkets are not as good based on the R&D limitations they have versus GM. Its about a market and my point is that we Buick people do not constitute the mass market that GM sells to.
Your reply can be taken to mean, the for $125, and some elbow grease, then the oems are still a better ecm. Your logic, not mine
No your logic. My point is that there are those who are doing well with a stock ECM. I am acknowledging that because it is only fair. Your logic not mine.
In fact, you can tune a stock ECM to go just as fast but you will still not have the datalogging features, you will not have a WB function and you still cant take a chip burner to the track and adjust timing and fuel to compensate for elevation.
The market has a lot to do with this conversation. If you will recall FAST was given the opportunity to make a better product because DFI took 15 years to come out with a GEN 7.
More power to FAST.
So yes we who are not working with GM powertrain, an OEM emissions lab and a dyno are at a disadvantage.
You can use chips and you will get it right but I can use a FAST computer and get it right at the track and do it sooner than you can.
Here's my 10 cents on this thread, then i'll shut up.
We have people here defending either system, similar to the arguement between Ford and GM cars, who's better? Well, it depends on what you want, what they offer, and how much your willing to spend. Each design has it's own qualities. As each new system comes out, it BETTER be an improvement over what is currently available or don't bring it. When the DFI 6 came out it was IT, then the FAST came out and it was IT, now we are up to the 7+ and it is the ONE. When the new FAST comes out, it will be king. It's called progress.
The MSD 6 box was the one to have for the longest time. But it is an analog unit. People asked "why not a digital" MSD said it was too expensive. I thought the 6 was expensive for an analog box, but it didn't take MSD long to come out with their Digital once Crane did for less money. This is the same argument.
Will the aftermarket match the OEM's? I doubt it, it's not good money. So stop trying to compare them.
But what I am seeing most, is that someone wants DFI and/or FAST to ante up their software and hardware so he can decipher it, and decide which is better. Not going to happen. Ford has a program that does just that. Saleen currently takes advantage of this. Perhaps if you are currently on the same playing level as Saleen, Ford will give you this code. Of course, you will have to sign a non disclosure form and give something back to Ford.
But, this is all just my 10 cents.
We have people here defending either system, similar to the arguement between Ford and GM cars, who's better? Well, it depends on what you want, what they offer, and how much your willing to spend. Each design has it's own qualities. As each new system comes out, it BETTER be an improvement over what is currently available or don't bring it. When the DFI 6 came out it was IT, then the FAST came out and it was IT, now we are up to the 7+ and it is the ONE. When the new FAST comes out, it will be king. It's called progress.
The MSD 6 box was the one to have for the longest time. But it is an analog unit. People asked "why not a digital" MSD said it was too expensive. I thought the 6 was expensive for an analog box, but it didn't take MSD long to come out with their Digital once Crane did for less money. This is the same argument.
Will the aftermarket match the OEM's? I doubt it, it's not good money. So stop trying to compare them.
But what I am seeing most, is that someone wants DFI and/or FAST to ante up their software and hardware so he can decipher it, and decide which is better. Not going to happen. Ford has a program that does just that. Saleen currently takes advantage of this. Perhaps if you are currently on the same playing level as Saleen, Ford will give you this code. Of course, you will have to sign a non disclosure form and give something back to Ford.
But, this is all just my 10 cents.
Not at all, I have my own software, I could care less what they're doing.
The thread was about which was best.
So far, other then some user graphics, no one has mentioned anything really relavent to the subject.
It's sounding like they just run their code in one long string, and to get any really speed out of it, they are having to run a faster processor. Where as the oem code runs on a series of interupts, and small loops. So in effect the GM code just runs what's needed at any given time. And by doing that, they have very efficent code.
If you were buying a car wouldn't you open the hood, and at least have some interest in what you were getting?.
Juding an ecm by the *dash board* doesn't sound like best way to buy a car, er, ecm.
If THEY want to claim better, well, why not ask them to say why?.
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