m05fastbackGT

Justin, perhaps both you and Doug can answer this for me? let's say if I were to use Granatelli's jumper box and so called calibrated MAF sensor along with my X-Cal II strategy flash preloaded tuner and Steeda intake by selecting the stock airbox as Granatelli recommends, would his recalibrated MAF function correctly or would there be problem issues? Thanks, and speaking of Pro-M, doesn't Anderson Ford Motorsport use PMAS Pro-M meters in his power-pipes?

Doug@C&L

Being that you plan on installing a tune with it I wouldn't use the GMS maf sensor at all but rather the stock sensor and have it custom tuned or purchase a tune from someone who has dynotested one. With a SCT tune it will most of the time lean out the mixture a bit because the a/f from the factory usually ends up around 12.0-12.2. With the canned SCT stock tune it ends up around 12.6-12.8(both of these figures are with the stock airbox installed). I dont know what the GMS does as of yet with the a/f ratio on the stock tune so without that information I cannot tell you that you would be 100% safe doing it that way. If the GMS leans it out too then it would probably lean it out too much if you used the stock intake tune from SCT.

I know its a bit confusing but that's my take on it for now, I'll have more on it after I get on the dyno with one.

Thanks, Doug.

DoctorQ

Doug, based on what I'm reading (or believe I'm reading, as I'm no expert here at all), are you saying the GMS MAF sensor is truely not a "calibrated" sensor for this increased airflow, but the jumper harness is actually increasing the voltage to tell the ECM "don't throw a CEL". Or can you tell me that the GMS MAF is actually working the S197 ECM to modify fuel tables to keep a/f mix ratios within spec (and not lean-out a/f).

05GTRedfire

Well after reading all of this info, I have to say I'm really surprised. I had been waiting on Doug's results after seeing that he was working on some data with regards to the GMS CAI. What I fully expected and truly believed was that we were going to see comparisons between a GMS CAI with his MAF and other CAI's, like the C&L and some tunes. What I expected to see was Doug saying, ok, with a stock GT, the numbers were this. With the GMS CAI the numbers were this. With a C&L and an 87 tune, the numbers were this, with a 93 tune the numbers were this. As you can see, my 87 tune was a bit lower than the GMS, but my 93 was a bit higher, or whatever. I was able to get out an additional <blank> horsepower on the GMS by custom tuning on the dyno. I was able to get <blank> horsepower on the GMS by using the stock MAS instead of their MAS. I was really looking forward to getting some independent tuner info, because now that I have the GMS CAI, I want more.

Instead, what we got was another witch hunt. We could have just added this thread to the "Granatelli Intake w/New MAF" thread, along with all the other haters. Doug, I am really surprised that you went this route, I wouldn't have expected this. I am not trying to defend Granatelli in any way, any fool can see the similarities between the two intakes, but if you were earnestly only trying to point out the similarities, or differences, then why didn't you include the BBK CAI too? http://us.st11.yimg.com/us.st.yimg.c...15_1921_554634 Looks pretty similar too if you ask me.

I spoke with you once on the phone a couple of months ago, back when I was researching which CAI to buy, and you told me then about how you felt that GMS just copied other peoples products, and then you did mention the BBK, and you went on to say well there's only so many ways you're going to be able to make a new intake, so why single out the GMS? It doesn't bother me that you gathered data, it bothers me that you gathered this data and then say that you're not trying to implicate something, when you clearly are. Right now, it's like, "I'm not one to gossip, but..."

As has been posted by numerous people, the GMS CAI with their MAF works. Period. You say that their MAF isn't actually calibrated because it didn't work with a stock MAF, and you also say that it's dangerously close, and would cause those error codes. I have yet to see a single GMS CAI customer post that they've gotten a CEL after everything was installed and working, and after all the crap that's been posted, I'm sure if it happened someone would, then all the naysayers could go, "See!? GMS sucks!" Only it hasn't happened.

I don't claim to know exactly how the GMS CAI works, I only know that it does. Just like everyone else who has purchased and installed one knows it too. Again, I was really looking forward to seeing some tuning results, but instead all we got was a new thread full of the same ol ****

neil07gt

Ok. Here you go. I was among the first who purchased the GMS CAI in August for my 07 GT and I returned it a few days later after only about 50 miles. I congratulate Granetelli for being prompt in issuing my refund. I don't have my own dyno, nor the time and money put my car on a dyno after every mod. I can only tell you that it doesn't work for everyone.

shatter

05GTRedfire,

Have you read the recent two part article on tuning in Muscle Mustangs and Fast Fords magazine? If not, then I definitely recommend you give it a look. It will explain a lot regarding fooling the EEC vs. proper tuning of the computer to operate the engine systems. I think Doug's speaking along those lines regarding the MAF jumper. By using the GMS jumper you are fooling the computer into operating the engine within spec to keep the CEL from coming on. A tune on the other hand will reprogram the computer to properly control the engine based on what is actually going on. I can't say that one is more dangerous than the other since I am not a tuner but I can understand why folks would be wary of fooling the computer, it's like a lazy tune instead of doing things right.

BTW, I don't run a CAI or custom tune on my mustang so I have no vested interest in any of this. I am waiting for the fallout before I make any move.

Galaxie

Doug,

Thanks for doing all this reasearch and the explanation.

05GTRedfire

Ok, think about it. If it were only "fooling" the ECM, that all it would do is prevent a CEL, and you would only get slight horsepower gains because you wouldn't actually compensate for the additional air coming in, but the horsepower gains are huge when compared to other CAI's with a tune, therefore proving that it is actually adding more fuel to compensate for the additional air. So no, it is not just fooling the computer.

DoctorQ

Shatter,
This post (among a few others recently) is the reason I cancelled my GMS 410040-P order this morning... my primary concern is the arguement regarding the GMS 'calibrated' MAF sensor and it's sidekick 'jumper'. I can't seem to get an answer if in fact the GMS MAF (and infamous jumper) actually works with the S197 ECM to change fuel tables...to accomodate for the higher airflow, thus maintaining a safe, constant A/F ratio.... or is it just 'tricking' (as some elude to) the ECM to not throw a CEL? If this was the case, wouldn't the a/f mix ratio be leaned out? My 2006GT only has 1100 miles, so I, like many others, have this Dealer warranty concern... so the GMS w/ it's MAF and no tune looks very appealing. But is my concern warranted? Does this calibrated MAF truly work WITH the ECM (to adjust a/f mix) or just blowing a smoke screen it's way? Anyone?

Sendero

The EEC Processor is easily "fooled" by restricting/amplifying the electronic signal from it's various sensors. Remember that unless something actually writes to flash RAM, it is operating on stock parameters. Whether or not it is reading the actual conditions is determined by how much you modify the signal.

05GTRedfire

Yes, it would have been nice to see an actual dyno run with a/f mixtures, instead of multiple photos showing "similarities". I don't think I'm going to be posting in this thread anymore, it was hell in the other thread, and ultimately it is not my name that is being dragged through the mud. I just can't believe that we are still having a debate about how it is possible the GMS CAI works some 6 months later. Again, I don't know how either, but I know it does, and I for one am very happy with my choice.

Doug@C&L

Well, the GMS sensor is factory calibrated but it isn't the proper calibration for use with the air intake and the Mustang PCM. This is why the jumper harness is included to adjust the output signal of the MAF to the PCM to correct it for both the increased airflow of the CAI and the lower voltage output of the included MAF sensor. It corrects the signal going to the PCM from the MAF sensor. It doesn't show the true signal coming from the MAF because then it would require tuning to be right.

In short, it works with the provided sensor but if you were to get a custom tune then I would recommend going back to the stock sensor.

Thanks, Doug

neil07gt

Lets step through the logic...let me know what i'm missing...An MAF sensor delivers a voltage to the ECU. The GMS jumper seems to alter that voltage and return a different voltage. A stock meter in a larger intake would be pegged out at full voltage most of the time right?--because it is seeing an increased airflow that it wasn't designed to see. It seems that a jumper would change that pegged out full voltage to be something less than pegged out. Then your ECU would see via the O2 sensor that things are lean and still be able to add more fuel.

Remember from the movie "Spinal Tap", the amps that go to eleven? Well maybe the stock MAF doesn't go to eleven, and the GMS jumper makes 10 be a little lower so that there's still room to go higher with more fuel.

DoctorQ

Here's the thing: the GMS CAI comes with a 'calibrated' MAF sensor AND it's matched wire harness... so why the need for the harness if the MAF sensor is 'calibrated' with the CAI increased airflow? Why the additional electronics (harness?)

neil07gt

I know. The harness changes the voltage. I was attempting to reason why a voltage change is necessary.

Doug@C&L

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?

mtchstng

Has anyone dyno'ed a GMS w/MAF to see what a/f ratio it has?

mtchstng

Doug, when you are in St. Louis are you going to dyno the GMS with out your tune first? That would answer a lot of questions it seems. I'm in St. Louis too and am running a GMS intake now so I am very curious.

Doug@C&L

I'll do it anyway you want if you'll be there. Just let me know, are you going to run your car too?

mtchstng

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.