????'s on some #'s Mike
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From: CT.
????'s on some #'s Mike
I was out playing with my G-tech Comp i just got only did two (tests) ...do these #'s sound off?...weight at a C.A.T. scale...4400#'S stock wheels, without me..i have a heavy a$$ sub-box and tonneau cover...1/4 ..14.7 (some wheelspin) 191 r.w.h.p. ? does the h.p. sound low? i think i could do better i was just messing around.... the last 1/3 of the hp curve is a flat line....thought that was odd ...
Last edited by ROUSHFAN-1; Dec 23, 2002 at 08:38 PM.
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From: Virginia
Hi RF-1,
Ahhh, so you got the G-tech Pro Competition model for Christmas too, eh?
I have had a chance to read thru thoroughly on it's documentation, and the HP figures are absolutely dependent on a *number* of things, first of all vehicle weight of course.......but more importantly, the driving *technique,* which needs to be different that the driving technique used for making a 1/4 mile run, and they talk very specifically about that particular aspect, so you'll definitely want to review that.
What I suggest is to go back thru your G-Tech Pro Competition model manual and read the *entire* thing very carefully, especially where it talks about the digfferent driving techniques required for the most accurate HP readings. They do a nice explanation there that applies to your situation, assuming that all of your calibration data is correct, etc. (The basic calibration stuff of holding it in all the different positions is simple of course, and the rpm thing is easy too, though I completely disagree with revving any engine under no-load like that, what I'm talkign about are things like rollout distance, etc.).
Remember, even this "Competition" model is still a very inexpensive device having, apparently, a single 3-axis accelerometer, though they describe it in various areas as having "3 accelerometers" (on the outside of the box, nice marketing!!) and then in the actual manual as having "a 3-axis accelerometer," which to me clealry states that it still have only 1 single accelerometer, but a 3-axis unit instead of a single-axis unit they used previously. I haven't talked to them about that yet to ask them specifically.
Bottom line, it's only going to be as accurate as the quality of it's design and the actual components used combined with it's various data sources, and there is no free lunch. In it's manual, it describes replacing the functionality of "$10,000" equipment, but don't you believe it, not in terms of it's accuracy. This unit, like all G-Tech's, get's it's data from the cigarette lighter, including rpms & most other things, and that signal is not the best way to get that data, by far.
The best way to get the highest HP reading is during a full-throttle upshift on the 1-2 with an automatic, you can get a good "spike" there if you're into that, otherwise, just let it do a long hard pull in 2nd gear only. For manuals, let it do a long hard pull in 3rd gear. Getting a flat line for HP curve indicates it's not pulling hard enough to register much, or you may have a problem with the unit calibration/setup, or a problem with the technique used or the unit itself, there are plenty of variables. Review the manual is your first step in figuring out how to get the best HP data, and if all else fails, give the manufacturer a call directly.
As it's own manual says, if you do things like lower the vehicle, fold in the mirrors, etc. that too will affect the HP reading, even though HP hasn't actually changed one iota, the point being, take the HP results in particular with a grain of salt. They can be affected even just by the amount of rollout distance you plug in during calibtration. It's still a very inexpensive device, and for it's low cost works like a champ, it's just not going to be as accurate as a chassis dyno. Speaking of which, a lot of *them* aren't particularly accurate, either.
Pulling a 14.7 second ET was very nice, overall it just sounds to me like you need to work on your driving technique for best HP numbers really, so re-read that section of the manual & you'll get it dialed in!
Have fun,
Ahhh, so you got the G-tech Pro Competition model for Christmas too, eh?
I have had a chance to read thru thoroughly on it's documentation, and the HP figures are absolutely dependent on a *number* of things, first of all vehicle weight of course.......but more importantly, the driving *technique,* which needs to be different that the driving technique used for making a 1/4 mile run, and they talk very specifically about that particular aspect, so you'll definitely want to review that.
What I suggest is to go back thru your G-Tech Pro Competition model manual and read the *entire* thing very carefully, especially where it talks about the digfferent driving techniques required for the most accurate HP readings. They do a nice explanation there that applies to your situation, assuming that all of your calibration data is correct, etc. (The basic calibration stuff of holding it in all the different positions is simple of course, and the rpm thing is easy too, though I completely disagree with revving any engine under no-load like that, what I'm talkign about are things like rollout distance, etc.).
Remember, even this "Competition" model is still a very inexpensive device having, apparently, a single 3-axis accelerometer, though they describe it in various areas as having "3 accelerometers" (on the outside of the box, nice marketing!!) and then in the actual manual as having "a 3-axis accelerometer," which to me clealry states that it still have only 1 single accelerometer, but a 3-axis unit instead of a single-axis unit they used previously. I haven't talked to them about that yet to ask them specifically.
Bottom line, it's only going to be as accurate as the quality of it's design and the actual components used combined with it's various data sources, and there is no free lunch. In it's manual, it describes replacing the functionality of "$10,000" equipment, but don't you believe it, not in terms of it's accuracy. This unit, like all G-Tech's, get's it's data from the cigarette lighter, including rpms & most other things, and that signal is not the best way to get that data, by far.
The best way to get the highest HP reading is during a full-throttle upshift on the 1-2 with an automatic, you can get a good "spike" there if you're into that, otherwise, just let it do a long hard pull in 2nd gear only. For manuals, let it do a long hard pull in 3rd gear. Getting a flat line for HP curve indicates it's not pulling hard enough to register much, or you may have a problem with the unit calibration/setup, or a problem with the technique used or the unit itself, there are plenty of variables. Review the manual is your first step in figuring out how to get the best HP data, and if all else fails, give the manufacturer a call directly.
As it's own manual says, if you do things like lower the vehicle, fold in the mirrors, etc. that too will affect the HP reading, even though HP hasn't actually changed one iota, the point being, take the HP results in particular with a grain of salt. They can be affected even just by the amount of rollout distance you plug in during calibtration. It's still a very inexpensive device, and for it's low cost works like a champ, it's just not going to be as accurate as a chassis dyno. Speaking of which, a lot of *them* aren't particularly accurate, either.
Pulling a 14.7 second ET was very nice, overall it just sounds to me like you need to work on your driving technique for best HP numbers really, so re-read that section of the manual & you'll get it dialed in!
Have fun,
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From: CT.
Thanks...I will work on what you said ..I just got it so can't expect too much...yet !! hehh hehh.....I noticed how it said it was a 3-axis accelerometer instead of the 3 (seperate) accelerometers too ?!?!?...I also laughed when I read the $10,000 equipment replacement statement too!!! ha ha...Do you know anyone that has done a P.I. head swap on a 4.6L(mines an early 97) I think that's where I'm headed next,...BUT I need A-LOT more info do you know of any site with some good reading? Thanks!!! Hope your Holidays were good!! Must have been nice to get away from the phone and keyboard a bit!!
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From: Virginia
Hi RF-1,
Actually, most of my holiday time was spent getting caught up on emails. Sad, ain't it? However, over this next weekend I'm gonna be very lazy & try to stay off the keyboard & let me wife know I still exist.
Actually, this month's MM&FF is a must-read for you and anyone else contemplating the swap to the PI heads, as it contains a decent article on 4.6 modular motor parts cross-compatibility. It gives the specific chamber cc's on both PI & non-PI heads, and very interestly points out something we saw some time back, that the PI heads only flow better up to somewhere between about .450-.475 or so of valve lift; by the time you get to .500 valve lift or more, the *older* non-PI head flows better, and this is true both in stock and in ported trim for both heads!
You will get a compression bump from the PI heads on a 98 or earlier 4.6 mod motor, which will require using premium gas and/or tuning changes.
If I had a 97 or 98 mod motor & wanted better flowing cylinder heads, I wouldn't change out to the PI units, I'd have the non-PI heads ported, shaved, throw bigger valves & cams in & unshroud the intake valve for the ultimate cylinder head. This is of course shy of just picking up the FRPP 4.6 cylinder heads.
Grab this issue of MM&FF & read it thoroughly, and next month too, when I think they're doing a similar parts compatibility comparo article on the DOHC versions of the 4.6.
Good luck!
Actually, most of my holiday time was spent getting caught up on emails. Sad, ain't it?
However, over this next weekend I'm gonna be very lazy & try to stay off the keyboard & let me wife know I still exist.Actually, this month's MM&FF is a must-read for you and anyone else contemplating the swap to the PI heads, as it contains a decent article on 4.6 modular motor parts cross-compatibility. It gives the specific chamber cc's on both PI & non-PI heads, and very interestly points out something we saw some time back, that the PI heads only flow better up to somewhere between about .450-.475 or so of valve lift; by the time you get to .500 valve lift or more, the *older* non-PI head flows better, and this is true both in stock and in ported trim for both heads!
You will get a compression bump from the PI heads on a 98 or earlier 4.6 mod motor, which will require using premium gas and/or tuning changes.
If I had a 97 or 98 mod motor & wanted better flowing cylinder heads, I wouldn't change out to the PI units, I'd have the non-PI heads ported, shaved, throw bigger valves & cams in & unshroud the intake valve for the ultimate cylinder head. This is of course shy of just picking up the FRPP 4.6 cylinder heads.
Grab this issue of MM&FF & read it thoroughly, and next month too, when I think they're doing a similar parts compatibility comparo article on the DOHC versions of the 4.6.
Good luck!
Last edited by Superchips_Distributor; Dec 29, 2002 at 01:30 PM.
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From: CT.
..........................Muscle Mustangs & Fast Fords..........
Well,...gee uhhh ...that sounds easy
and $$ cheap too $$ ..thanks for the info though!! I can't take it more research
Have a great weekend with the wife!!
Well,...gee uhhh ...that sounds easy
and $$ cheap too $$ ..thanks for the info though!! I can't take it more researchHave a great weekend with the wife!!
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From: Nu Joizey
Hey ROUSHFAN-1, thanks for the speedy reply!
I know what you mean about research I've been following the PI head swap threads for a long while since they were introduced along with many others. Still alot of ?s and not many answers.
By coincidence I just happen to have a set of non-PI heads already on my truck! Encouraging news at last !!
BTW, you're showing some impressive numbers on the G-tech!
I know what you mean about research I've been following the PI head swap threads for a long while since they were introduced along with many others. Still alot of ?s and not many answers.
By coincidence I just happen to have a set of non-PI heads already on my truck! Encouraging news at last !!BTW, you're showing some impressive numbers on the G-tech!
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From: Virginia
Hi Le Pew,
Sorry about that, "MM&FF," better known as Muscle Mustangs & Fast Fords, is one of the performance "bibles" for EFI Fords, primarily V-8's, with heavy emphasis on the 5.0's, though we are starting to see more articles & parts about & for the modular 4.6 & 5.4 V8 motors over time.
In fact, this month's issue is *excellent* for modular motor owners, thanks to it's info in the SOHC versions (which is what all of these trucks & SUV's have as well as the Mustang GT & other FoMoCo's) various parts interchangeability/compatibility & production info, casting#'s, etc. This is what I was referring to in my previous post.
You & other non-PI motor owners will love it, since it goes over how the non-PI heads will actually flow better than the PI heads at higher valve lifts, starting about .500 & up. So this is true only if you swap the factory cams out for higher lift units of course, as the stock truck cams don't have enough lift to make that happen. The Mustang GT from 1999 & up uses cams with enough lift to show this, for example, with .505 lift on the intake & .534 on the exhaust. There are also some nice aftermarket cams like the ModMax units, etc.
Just FYI.....................
Sorry about that, "MM&FF," better known as Muscle Mustangs & Fast Fords, is one of the performance "bibles" for EFI Fords, primarily V-8's, with heavy emphasis on the 5.0's, though we are starting to see more articles & parts about & for the modular 4.6 & 5.4 V8 motors over time.
In fact, this month's issue is *excellent* for modular motor owners, thanks to it's info in the SOHC versions (which is what all of these trucks & SUV's have as well as the Mustang GT & other FoMoCo's) various parts interchangeability/compatibility & production info, casting#'s, etc. This is what I was referring to in my previous post.
You & other non-PI motor owners will love it, since it goes over how the non-PI heads will actually flow better than the PI heads at higher valve lifts, starting about .500 & up. So this is true only if you swap the factory cams out for higher lift units of course, as the stock truck cams don't have enough lift to make that happen. The Mustang GT from 1999 & up uses cams with enough lift to show this, for example, with .505 lift on the intake & .534 on the exhaust. There are also some nice aftermarket cams like the ModMax units, etc.
Just FYI.....................
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Joined: Mar 1998
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From: Virginia
Hi RF-1,
Yeah, "Hot Rod" used to be a decent rag, but it's really not up to date for EFI owners, and certainly not Fords.
For all late-model F-150 platform vehicle owners, we recommend 3 rags to subscribe to............
1.) MM&FF
2.) Truckin'
3.) Street Trucks
I wouln't pick 1 of the 3, you'll miss too much. If you're not into any show-type stuff in any way, shape or form *at all,* you could potentially skip Street Trucks, but I wouldn't be without all 3 of those titles, every month, always.
Yeah, "Hot Rod" used to be a decent rag, but it's really not up to date for EFI owners, and certainly not Fords.
For all late-model F-150 platform vehicle owners, we recommend 3 rags to subscribe to............
1.) MM&FF
2.) Truckin'
3.) Street Trucks
I wouln't pick 1 of the 3, you'll miss too much. If you're not into any show-type stuff in any way, shape or form *at all,* you could potentially skip Street Trucks, but I wouldn't be without all 3 of those titles, every month, always.
