WiseAssJester

Does anybody have one of those nifty Gtech things that would appear to be wastes of money?

I have an 01 WS6, bone stock.

I haven't been to a track in order to get an actual quartermile time since my car has been running right. The last time I went I had to skip second(couldn't get it in) and ran a 15.200. Not the greatest of times.

So making some gtech pulls, with the car set to 4000 lbs I hit a peak horsepower of 220 something. TOrque read the same. But my quarter mile time hit a 14.0 flat and trapped approx 90 MPH. I'm at an altitude of 5500 feet, so a 14 might seem about right. I'm unsure.

The horsepower and torque, though, is WAY off.

As I sit, without spray, I run neck and neck with(normally faster, actually) other LS1s with intake and cat-back systems(don't normally count these as performance upgrades, but... haha).

Anyone see similiar problems with the gtech? Or better luck?

Also, at 5500 feet what would be a decent stock 1/4 time?

Black99TransAm

iTrader: (16)

i ran a 14.5 @101 with a 2.5 60ft... so i needed new tires(tires were bald)... also car is a auto. i had a friend with a 02 ws6 pull a 13.8 at the same track. which is 5000 ft elevation in co. low 14s are most common here. rare with the high 13s stock.

six_string_wiz

Do you think 4000lbs is a bit heavy?Not 37ish with you in it?

WiseAssJester

Well, the car was what, 36** stock?

And there are two of us in it, at 150 lbs a peice.


And I've got some misc. crap in it. Not the least of which was a full ten lb nitrous bottle.


Aside from that, if I were to have dropped the weight the HP and torque numbers would have dropped, too.

So I'll just assume the Gtech is highly inaccurate?

Thanks for the info, Black99TransAm

Black99TransAm

iTrader: (16)

which g tech are you using... the one i used measured your hp off of acceleration and car weight

also what state are you in

marcus769

I have the G-tech pro-RR and I have found it to be accurate, but it needs exact weights, and setup correctly... There is a setting for suspension. (for how stiff it is) I dont remember what else.. I havent used it in forever... It was kind of a pain setting it up all the time.. Each time it is removed from it's spot on the windshield i'm pretty sure it says to re-calibrate it, or re-set it up... Most people dont have a clue how to set it, and their readings are WAY off...

Ex. My buddy has a 14.5 sec Nova and his G-tech was saying it was an 11 sec car... The track proved him wrong..

WiseAssJester

Haha! 11 seconds to 14.5 his a harsh wake up.


I'm in Nevada, Reno specifically.

And we're using the gtech that measures HP and torque based on gforce.

In all honesty, we probably don't have it set up correctly. We didn't touch suspension.

Frankly, we didn't care too much for specifics. We were more concerned with gains.

orangeapeel

iTrader: (18)

Those things can be hit or miss. I worked at a parts store for about 9 months, and we sold 2 of them and 1 came back.

180ls1

iTrader: (4)

I would say they are accurate with MPH just like any gps is but the times are a gamble.

GregAbell60143

If you have it set up right, they are pretty accurate with the ET, but the MPH will be higher. The GTech will give you the exact MPH at the 1/4 mile stripe, while the drag strip will give you the MPH calculated from the last 60 feet or so (I don't remember the exact distance off hand) - the 1st stripe is where the speed starts being measured, and the 2nd stripe is the finish line. I bought one to play with, and took it to the track with me - the ET was within .01 but the MPH was a bit higher. I made sure that it was perfectly level on the windshield while I was in the pits with one of those small (6" or so) levels. I was surprised how close it actually was.

Martin HD-28

iTrader: (16)

The HP is figured using a formula, I figured it to be about 65 more than the gtech reading. Everything else is real close to actual. I took my car to a truck stop and had it weighed, input parameters need to be damn near exact. I lost my last gtech and liked it so much, I just bought another one from this website. My 1/8th time was within .02 of my track slip!!

RW99

The GTech is a nice tool, but you have to know its limitations. Most importantly, it's really only useful to use in comparing your own car to itself... so trying to make claims on how fast your car is or how much power it makes based on GTech numbers won't gain you much respect.

First off, you must weigh the car on a certified scale with a full tank of gas. Get an actual weight, and know how much that weight will decrease as you empty the tank. I know it sounds like overkill but if you really want to track your car accurately you've got to be able to tell the device EXACTLY what weight the entire car is at (with you in it) every time you make measurements.

Secondly, you must find a FLAT STRAIGHT stretch of test track. You gotta use the same chunk of road every time you make a measurement. And if you really want numbers that you can have confidence in, you should make four measurements each time you go out: two in each direction.

Lastly, I'd recommend doing "dyno pulls" instead of quarter (or 1/8th) mile timed runs. Dyno runs take traction out of the equation (as long as you're not spinning while in gear). To do these runs, you just accelerate mildly in first gear and shift at about 3000 rpm. Then roll into the WOT in second gear and wind it all the way through the shift into third gear. Decelerate with braking and store the run. As long as you have one of the units that will download to your PC, you can analyze your data with the PASS software that they supply.

Results generated by GTech measurements will always be significantly lower than what you see on a dyno, because aerodynamic drag and rolling resistance reduce the acceleration that your car can achieve. These numbers will also suffer from greater losses at higher speeds because drag increases with velocity. But again, you should be making apples-to-apples comparisons on your own car, not trying to generate a number that you can use for bragging rights or to compare to xyz dyno setup. Here are some runs over the years with my TA. Red was intake/exhaust form, blue traces are heads/cam/headers, and green traces are turbo setup:

WiseAssJester

Exactly what we were deciding to do with the Gtech, RW99.

Haha. Thanks for the input, man.

How much boost was that turbo run?

RW99

At that time, I was running my old valvesprings and usually had about 11 psi, 595 rwhp and 618 rwtq on a Dynojet.

pugads650

iTrader: (1)

maybe be its stuck on v6.