Comparison of the GMS and C&L CAI's with detailed info...
10/30/06, 04:34 PM
#82
SUPERCHARGED RED ROCKET ------------------Master-Moderator
Because the MAF isn't setup for the amount of airflow through the housing and it pegs, the signal maxes out, so the jumper scales the signal and this will increase the amount of range it has so it doesn't do this. It also adjusts the signal to correct the a/f ratio.
One thing that still has me puzzled is why didn't he just setup the jumper for the stock MAF sensor?
One thing that still has me puzzled is why didn't he just setup the jumper for the stock MAF sensor?
Last edited by m05fastbackGT; 9/17/23 at 10:45 PM. Reason: Revised Text
10/30/06, 04:46 PM
#83
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The reason why Doug ? is I believe that GMS mentioned his calibrated MAF was calibrated to his larger intake tube and then scaled to read the additional amount of airflow or something like that, and yes it's all very confusing no question about it..
If I'm also not mistaken Doug ?? I think he also mentioned that his MAF sensor is electronically scaled similar to that of the Ford GT, so maybe that's what his factory sensor was originally calibrated for ??
If I'm also not mistaken Doug ?? I think he also mentioned that his MAF sensor is electronically scaled similar to that of the Ford GT, so maybe that's what his factory sensor was originally calibrated for ??If his meter was actually calibrated to the intake then it wouldn't require the jumper at all.
Thanks, Doug.
10/30/06, 04:46 PM
#84
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10/30/06, 04:48 PM
#85
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Last edited by m05fastbackGT; 9/17/23 at 10:47 PM. Reason: Revised Text
10/30/06, 04:49 PM
#86
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I've been on the fence watching what is going on with the GMS if you had done any yet. Several people in our car club have your tunes and love them but none of them have the GMS. So far I have not had any issues yet and it does feel like there was an improvement over stock.
There's a different way to make the a/f right without messing with the MAF signal or even tuning the car. I should have one with me at St. Louis so be sure to stop by and I'll show you.
Thanks, Doug.
10/30/06, 05:09 PM
#87
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Doug, by any chance did you get the e-mail I sent yesterday? just wanted to be sure that you received it...Thanks, Rocky!
Last edited by m05fastbackGT; 9/17/23 at 10:48 PM. Reason: Revised Text
10/30/06, 05:33 PM
#88
I believe Granatelli claimed his "MAF electronics" are calibrated.. not just his sensor. MAF electronics are both his supplied sensor AND the jumper (which appears to boost the signal... that being the case, his claim is true.
10/30/06, 05:35 PM
#89
Definatly, there should be a gain. The point of this thread isn't to show that the GMS unit doesn't work, its nearly the same as the C&L and it works great, just to show the way it works and how closely related it is to the C&L unit.
There's a different way to make the a/f right without messing with the MAF signal or even tuning the car. I should have one with me at St. Louis so be sure to stop by and I'll show you.
Thanks, Doug.
There's a different way to make the a/f right without messing with the MAF signal or even tuning the car. I should have one with me at St. Louis so be sure to stop by and I'll show you.
Thanks, Doug.
10/30/06, 06:36 PM
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10/30/06, 07:13 PM
#92
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just as his claim about his MAF electronics are calibrated for his intake tube is also true, right? yea well Doug just proved that claim as being inaccurate as well...
Last edited by m05fastbackGT; 9/17/23 at 10:49 PM. Reason: Revised Text
10/30/06, 07:39 PM
#93
Guys,
Having been around racing Mustangs in "stock" classes for years, I can tell you how we used to do it. Note that I'm not saying this is how others are doing it today, just how I've done it in the past when required. So, with that little disclaimer there...here's some tech for you.
The EEC system (in any of its variants or even on other builder's cars) is just a computer that responds to certain inputs with certain outputs, according to a table, much like an excel spreadsheet, of data. So, let's say *hypothetically* that you have a car that is running lean on the top end, but you aren't allowed by the rules to change to a bigger injector or re-flash (in the old days "chip") your car - what to do? Well, if your injector isn't at 100% pulsewidth (constant on) then you could modify any number of sensor inputs to push the injector pulsewidth up, and so long as you don't come back with a lean signal at 100% on-time, you're okay. Even then, you can increase rail pressure to compensate somewhat too (although this is normally not a direct relationship between pressure increase and fuel delivered - 5 additional psi on the rail does not equal 5% more fuel, more like 1-2%). So what to change? Easy one in the old days was ECT (Engine Coolant Temp) to make the computer think the car was cold - it would richen the mix. - Now mind you just pulling the sensor doesn't cut it, you normally would wire in a resistor or voltage adjuster to vary the output, because simply pulling the plug on it would trip a CEL, which then would disregard that sensor, which isn't what you wanted.
This would have the result that the computer would go to the look-up table, and see that at 68 degrees, it should add +2 (just an example) to the STFT to help the engine until it reached normal operating temperature. A colder reading might yield more trim, a warmer reading less. Here there is no "re-flashing" - just using the stock look-up table to accomplish the goal in mind reasonably well.
Same holds true for airflow sensors. MAF sensors are normally what they call "hot wire" setups. One wire is a reference wire, heated to a certain temp (normally around 200 degrees) and the other is the actual sensor wire, that measures the difference in voltage required to maintain the same temp. Since the sensor wire is cooled by the airflow past it, some math can be used to infer what the airflow past the wire is, if you know the size of the orifice, the pressure of the air (BAP sensor), and the temperature of the incoming air (ACT sensor). Now, knowing all this, if you want to modify the output signal of the MAF to the computer to "fool" it into thinking there is more or less airflow there, you just boost or reduce the signal from the MAF to the computer. On the EEC IV, this was a 5V signal, and 5V was WOT, while anything less was some part-throttle position. Again, by modifying the signal, you could show a curve from idle to WOT, but WOT would normally arrive sooner as far as the computer was concerned, because the MAF would peg 5V sooner if you were just adding voltage to the signal (conditioning the wire so to speak). This again would change where the computer goes in the lookup table, thereby richening or leaning the mixture based on which way you threw the signal.
Now, all that said, why not just go and wire up a bunch of inline resistors and conditioners to the harness? While in theory it does work to some extent, nothing, and I mean NOTHING will replace a good operator tuning a car on a dyno where most all aspects of the SPECIFIC vehicle can be measured. FWIW, when we were finally allowed in 2002 to start using aftermarket tuning aids on our fuel-injected race cars, we picked up almost 2 seconds a lap on the Sebring long course - I would have auctioned off my first born for that kind of gain a couple of years prior to it (come to think of it I might still today if I could get another two seconds...)
So while we did what we had to when we couldn't dyno-tune the EFI cars, the second we got the chance, you can bet we were on the dyno, as were our competitors that wanted to run EFI (carb guys already could, and there wasn't anything we could do about it...) Also, the stock lookup table is only good for a relatively narrow range of changes - once you go outside of that, especially on the newer cars, you run into trouble because there isn't the "fudge factor" built into the tables - anything over xx% outside of range and you get a CEL - hence why you need to re-flash to get a "new" set of ranges, ones that will be closer to the optimum for the modificatins done to the car, and then let the STFT and LTFT multipliers do their thing.
So can you run a car without a tune? Sure. But it's always going to be a "workaround" and not a "maximum effort" solution. That's just reality.
So, that's my contribution to this. You want some tech and some data, there it is. Let's see what everyone else brings to the table, and if it is as useful and helpful as that. I for one would rather keep the discussion on the level, and let the facts speak for themselves, while you, the end users, learn what it really is going on inside your car without having to say "I don't know how it works, it just does."(not picking on anyone, but I've heard that a lot on a lot of different subjects) That's not right, you should be able to describe at least the theory if someone asks, because you should have been educated by the person selling it to you. If not, why did you give them your money - they didn't earn it. The guys out there trying to earn your business will be able to describe exactly what is going on, so you can make an educated buying choice. If they do that, then they should earn your business. If then you buy into the hype, well... caveat emptor.
* On Edit *
People have been guessing why the players have not chimed in on this thread - my *guess* is that they are actually at SEMA, and will get involved upon their return. Us being the "little guys" I couldn't justify spending 20k to do the show this year, but we will be at PRI, so any discussions involving our products between Dec. 12-16 will be getting a somewhat shorter response than this one has been.
Having been around racing Mustangs in "stock" classes for years, I can tell you how we used to do it. Note that I'm not saying this is how others are doing it today, just how I've done it in the past when required. So, with that little disclaimer there...here's some tech for you.
The EEC system (in any of its variants or even on other builder's cars) is just a computer that responds to certain inputs with certain outputs, according to a table, much like an excel spreadsheet, of data. So, let's say *hypothetically* that you have a car that is running lean on the top end, but you aren't allowed by the rules to change to a bigger injector or re-flash (in the old days "chip") your car - what to do? Well, if your injector isn't at 100% pulsewidth (constant on) then you could modify any number of sensor inputs to push the injector pulsewidth up, and so long as you don't come back with a lean signal at 100% on-time, you're okay. Even then, you can increase rail pressure to compensate somewhat too (although this is normally not a direct relationship between pressure increase and fuel delivered - 5 additional psi on the rail does not equal 5% more fuel, more like 1-2%). So what to change? Easy one in the old days was ECT (Engine Coolant Temp) to make the computer think the car was cold - it would richen the mix. - Now mind you just pulling the sensor doesn't cut it, you normally would wire in a resistor or voltage adjuster to vary the output, because simply pulling the plug on it would trip a CEL, which then would disregard that sensor, which isn't what you wanted.
This would have the result that the computer would go to the look-up table, and see that at 68 degrees, it should add +2 (just an example) to the STFT to help the engine until it reached normal operating temperature. A colder reading might yield more trim, a warmer reading less. Here there is no "re-flashing" - just using the stock look-up table to accomplish the goal in mind reasonably well.
Same holds true for airflow sensors. MAF sensors are normally what they call "hot wire" setups. One wire is a reference wire, heated to a certain temp (normally around 200 degrees) and the other is the actual sensor wire, that measures the difference in voltage required to maintain the same temp. Since the sensor wire is cooled by the airflow past it, some math can be used to infer what the airflow past the wire is, if you know the size of the orifice, the pressure of the air (BAP sensor), and the temperature of the incoming air (ACT sensor). Now, knowing all this, if you want to modify the output signal of the MAF to the computer to "fool" it into thinking there is more or less airflow there, you just boost or reduce the signal from the MAF to the computer. On the EEC IV, this was a 5V signal, and 5V was WOT, while anything less was some part-throttle position. Again, by modifying the signal, you could show a curve from idle to WOT, but WOT would normally arrive sooner as far as the computer was concerned, because the MAF would peg 5V sooner if you were just adding voltage to the signal (conditioning the wire so to speak). This again would change where the computer goes in the lookup table, thereby richening or leaning the mixture based on which way you threw the signal.
Now, all that said, why not just go and wire up a bunch of inline resistors and conditioners to the harness? While in theory it does work to some extent, nothing, and I mean NOTHING will replace a good operator tuning a car on a dyno where most all aspects of the SPECIFIC vehicle can be measured. FWIW, when we were finally allowed in 2002 to start using aftermarket tuning aids on our fuel-injected race cars, we picked up almost 2 seconds a lap on the Sebring long course - I would have auctioned off my first born for that kind of gain a couple of years prior to it (come to think of it I might still today if I could get another two seconds...)
So while we did what we had to when we couldn't dyno-tune the EFI cars, the second we got the chance, you can bet we were on the dyno, as were our competitors that wanted to run EFI (carb guys already could, and there wasn't anything we could do about it...) Also, the stock lookup table is only good for a relatively narrow range of changes - once you go outside of that, especially on the newer cars, you run into trouble because there isn't the "fudge factor" built into the tables - anything over xx% outside of range and you get a CEL - hence why you need to re-flash to get a "new" set of ranges, ones that will be closer to the optimum for the modificatins done to the car, and then let the STFT and LTFT multipliers do their thing.So can you run a car without a tune? Sure. But it's always going to be a "workaround" and not a "maximum effort" solution. That's just reality.
So, that's my contribution to this. You want some tech and some data, there it is. Let's see what everyone else brings to the table, and if it is as useful and helpful as that. I for one would rather keep the discussion on the level, and let the facts speak for themselves, while you, the end users, learn what it really is going on inside your car without having to say "I don't know how it works, it just does."(not picking on anyone, but I've heard that a lot on a lot of different subjects) That's not right, you should be able to describe at least the theory if someone asks, because you should have been educated by the person selling it to you. If not, why did you give them your money - they didn't earn it. The guys out there trying to earn your business will be able to describe exactly what is going on, so you can make an educated buying choice. If they do that, then they should earn your business. If then you buy into the hype, well... caveat emptor.
* On Edit *
People have been guessing why the players have not chimed in on this thread - my *guess* is that they are actually at SEMA, and will get involved upon their return. Us being the "little guys" I couldn't justify spending 20k to do the show this year, but we will be at PRI, so any discussions involving our products between Dec. 12-16 will be getting a somewhat shorter response than this one has been.
10/30/06, 08:36 PM
#94
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I lied.
I was going to quote that whole thing but figured it would be too long. I do appreciate you explaining the intricacies of how GMS is probably "calibrating" their MAF. I also took apart my harness, and yes you're right, there were a series of resistors, but there was also an IC in the center. Looks like it may be processor controlled to an extent now, but I'm sure it's probably achieving what you described. And while I do understand your statement about how a tuner and a dyno is the best possible way to maximize your horsepower gains on a SPECIFIC vehicle, the "canned" tunes that come with a lot of CAI and tunes are toned down in a sense, so that they'll work with every vehicle, or should anyways. Right?
So then the horsepower gains should be comparable, and numerous people have posted their gains after dyno runs, and they look about the same as any other CAI I see advertised with a tune. Now at the time, the main selling point for me was not taking the chance on altering the factory settings with a tuner, and possibly jeopardizing the warranty, but apparently since then the consensus seems to be that you can reflash back to stock and they can't tell, so if I was looking for a CAI now who knows. This is my daily driver and what was important to me at the time, and to an extent still is, is being able to fully revert back to stock with minimal time or effort if I had to, and I can still do that.
I guess what I really meant to say was not so much that "I don't know how it works, it just does", if that was referring to me, but more so, I'm not getting any CEL's, so I'm assuming the a/f mixture is good, unless you're saying they change the values of the o2 sensors too, in which case I might worry. I can feel the horsepower gain, and not just a little bit, I mean a nice big difference in the pull midband. So, it works as far as I'm concerned. So it's not so much I don't know how, it's I don't really care how. And I don't mean that in a nasty way, I really do appreciate your synopsis, it was very informative.
I will continue to monitor what comes of this, just when you think it's finally died down, here it comes again. I have seen numerous people, on multiple forums, posting their before and dyno HP gains, but I haven't seen any with the a/f ratio too now that I think about it, so I guess it's possible it could be off.
I was going to quote that whole thing but figured it would be too long. I do appreciate you explaining the intricacies of how GMS is probably "calibrating" their MAF. I also took apart my harness, and yes you're right, there were a series of resistors, but there was also an IC in the center. Looks like it may be processor controlled to an extent now, but I'm sure it's probably achieving what you described. And while I do understand your statement about how a tuner and a dyno is the best possible way to maximize your horsepower gains on a SPECIFIC vehicle, the "canned" tunes that come with a lot of CAI and tunes are toned down in a sense, so that they'll work with every vehicle, or should anyways. Right?So then the horsepower gains should be comparable, and numerous people have posted their gains after dyno runs, and they look about the same as any other CAI I see advertised with a tune. Now at the time, the main selling point for me was not taking the chance on altering the factory settings with a tuner, and possibly jeopardizing the warranty, but apparently since then the consensus seems to be that you can reflash back to stock and they can't tell, so if I was looking for a CAI now who knows. This is my daily driver and what was important to me at the time, and to an extent still is, is being able to fully revert back to stock with minimal time or effort if I had to, and I can still do that.
I guess what I really meant to say was not so much that "I don't know how it works, it just does", if that was referring to me, but more so, I'm not getting any CEL's, so I'm assuming the a/f mixture is good, unless you're saying they change the values of the o2 sensors too, in which case I might worry. I can feel the horsepower gain, and not just a little bit, I mean a nice big difference in the pull midband. So, it works as far as I'm concerned. So it's not so much I don't know how, it's I don't really care how. And I don't mean that in a nasty way, I really do appreciate your synopsis, it was very informative.
I will continue to monitor what comes of this, just when you think it's finally died down, here it comes again. I have seen numerous people, on multiple forums, posting their before and dyno HP gains, but I haven't seen any with the a/f ratio too now that I think about it, so I guess it's possible it could be off.
10/30/06, 08:50 PM
#95
Mach 1 Member
A friend of mine has a GMS and had a dyno done after installing the intake and MAF. He got 281 HP at he rear wheels on his best pull, so I in no way doubt the claims made about the gains. I don’t think they recorded at A/F ratio on his dyno sheet, but I do remember that the guy doing the dyno made a comment that the ratio looked good. I wish I could be more scientific here, but if things were out of whack I am sure the shop would have not told him everything looked so good.
10/30/06, 08:51 PM
#96
Marcello, thanks for taking the time to share some knowledge.. great analogies and explanation. BTW, you earned my business 2 weeks ago... bought one of your honeycomb rear panels for my 2006GT... fit's like a glove and looks like a million bucks! (your billet fuel doors are top notch too.. just waiting for sale!) 
10/30/06, 09:27 PM
#97
And while I do understand your statement about how a tuner and a dyno is the best possible way to maximize your horsepower gains on a SPECIFIC vehicle, the "canned" tunes that come with a lot of CAI and tunes are toned down in a sense, so that they'll work with every vehicle, or should anyways. Right?
I guess what I really meant to say was not so much that "I don't know how it works, it just does", if that was referring to me,
So it's not so much I don't know how, it's I don't really care how. And I don't mean that in a nasty way, I really do appreciate your synopsis, it was very informative.
I'm not saying that products don't have room for improvement once released, but when you blatantly duplicate someone else's homework assignment and don't even cchange the title of the report, should you still get an A for your efforts? So if you're going to spend your hard-earned money on a product, I'd hope that if you wanted a concise and clear explanation of how and why it works you could get it, and not a bunch of marketing hype covering up what is really going on. Not saying that you care to understand the intricacies of it, just that if you want a clear explanation, one should be available for you.
Again, you confirmed what I said about the design of the wiring, I was just guessing based on how we did it "in the old days"
I will continue to monitor what comes of this, just when you think it's finally died down, here it comes again. I have seen numerous people, on multiple forums, posting their before and dyno HP gains, but I haven't seen any with the a/f ratio too now that I think about it, so I guess it's possible it could be off.
Marcello, thanks for taking the time to share some knowledge.. great analogies and explanation. BTW, you earned my business 2 weeks ago... bought one of your honeycomb rear panels for my 2006GT... fit's like a glove and looks like a million bucks! (your billet fuel doors are top notch too.. just waiting for sale!)
10/30/06, 10:28 PM
#98
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Here's mine. 283 HP after being flogged for 30 minutes. I do not have the A/F but was told they were fine. All of this with no tune and 87 octane gas. Does anyone have a dyno sheet with the C&L with an 87 tune to compare?
10/30/06, 10:52 PM
#99
SUPERCHARGED RED ROCKET ------------------Master-Moderator
on the other hand, I'd still be really curious about my A/F just for my own piece of mind...
Last edited by m05fastbackGT; 9/17/23 at 10:51 PM. Reason: Revised Text
10/30/06, 11:06 PM
#100
Man, checking out that graph really bugs me...
33Hp is a very respectable increase - but the way it comes in tends to make me wonder what's up. All the way from idle to 5300 RPM your two graphs are pretty much doing what I'd expect, then all of a sudden they diverge quite far from one another, one dropping quickly, the other spiking upward. What's even crazier is that the Hp charts are almost identical at around 5250, which is yet another little tidbit of weirdness, because while I'd expect the torque / Hp charts to cross there, I wouldn't expect the Hp to converge into the other Hp before splitting off...
Admittedly I do not do enough tuning on a dyno to offer an explanation, but I don't think everything there makes sense - the torque graphs look exactly as I'd expect...but... this looks more like an anomoly than a typical run. On a typical run, I wouldn't expect such a "hiccup" in the stock run and corresponding spike in the aftermarket run - look at the graph of our car (manual 91 octane - otherwise 100% stock at the time) to see what I'm talking about in the upper range of the graph. The smooth arch is much more typical of a modern engine - the days of the peaky performance motor are pretty much gone (well except in Hondas and RX-8's and even they are coming along). Even if the motor was "peaky" you'd expect to see the modification amplify it, not invert it as is seen on this graph.
Again, not saying this isn't showing what you've got - just saying it looks weird... Doug?? Jump in on this whenever you wake up...
* WAG here *
Maybe there is a transfer function that was happening there, and it transitioned from one mode to the other right there - possibly a lagging IMRC or something? I find it difficult to believe the stock curve would go so quickly after performing so well up to that point - a more gradual tapering off I might understand, but that is just weird.
33Hp is a very respectable increase - but the way it comes in tends to make me wonder what's up. All the way from idle to 5300 RPM your two graphs are pretty much doing what I'd expect, then all of a sudden they diverge quite far from one another, one dropping quickly, the other spiking upward. What's even crazier is that the Hp charts are almost identical at around 5250, which is yet another little tidbit of weirdness, because while I'd expect the torque / Hp charts to cross there, I wouldn't expect the Hp to converge into the other Hp before splitting off...
Admittedly I do not do enough tuning on a dyno to offer an explanation, but I don't think everything there makes sense - the torque graphs look exactly as I'd expect...but... this looks more like an anomoly than a typical run. On a typical run, I wouldn't expect such a "hiccup" in the stock run and corresponding spike in the aftermarket run - look at the graph of our car (manual 91 octane - otherwise 100% stock at the time) to see what I'm talking about in the upper range of the graph. The smooth arch is much more typical of a modern engine - the days of the peaky performance motor are pretty much gone (well except in Hondas and RX-8's and even they are coming along). Even if the motor was "peaky" you'd expect to see the modification amplify it, not invert it as is seen on this graph.
Again, not saying this isn't showing what you've got - just saying it looks weird... Doug?? Jump in on this whenever you wake up...
* WAG here *
Maybe there is a transfer function that was happening there, and it transitioned from one mode to the other right there - possibly a lagging IMRC or something? I find it difficult to believe the stock curve would go so quickly after performing so well up to that point - a more gradual tapering off I might understand, but that is just weird.