Karmann

I am considering a Gtech Pro SS for my brother as a gift. I was wondering how people feel about these units. Are they worth buying? Any information or opinions would be appreciated. Thanks.

Karmann

I should have noted that he has a 16V VW that he has done considerable work to. Does the unit work equally well with all vehicles?

Scott M.

Jim;

I don't thing they work so well on VW cars, mainly because they don't have V-8's.

Seriously, depends on how technical he is. If he is a true gadget type check out the MR Dyno unit. Way more functionality, but no pretty display that the GT pro has. But at 75 bones compared to the GT at ~300 large, maybe a no brainer.

Personally, I have the standard GTech, the Pro and the MR Dyno. I find the MR Dyno to be the weapon of choice.

Scott

Karmann

Good point about the price. Are these units sensitive enough to pick up slight changes in performance associated with minor mods? , i.e aftermarket air filters.

WallyP

I doubt that ANY meter will be sensitive enough to pick up the power increase due to an aftermarket air filter on a 928...

Scott M.

Gtech claims a +/- 1% accuracy rate for HP and torque and a +/- 2% for RPM's.

So, statistically and analytically speaking, a 300rwhp car may see a 3 rwhp variance, and if someone like K&N claims at least a 5 hp gain, you may see just enough gain to make you wonder if you saw any gain. But then again, they also claim... "Absolute accuracy of all measuring equipment, including G-TECH, depends on proper use and minimization of variables along with proper averaging of results."
I'm sure I can average out (or into) a fair amount,

All I can say is it sure beats plunking down 60-75 greenbacks each time you visit the Dyno.

Scott

Tony

If he is a "tech head" be sure to get the one with the PASS software. Its the GTECH RR.

Not cheap but its a great tool and toy.
It not only seems to be very accurate but also consistant, which is what you want when making modifications from one run to the other. A true dyno is the way to go for the "graph" of the motor, but if you want perforamnce figures as well, i think the Gtech works great. I havent really tried the "dyno" function on it yet.

this is a screen shot of one of my runs.

SLOW RUN: selector in 2 and leaving it there, letting it shift automatically. I had wheel spin for the first 3 secs until it shifted 2nd.

the other, a MUCH better launch, run in" 2" with the kickdown switch on and a manual 1-2 shift near redline . Made a big difference in my times.

The bulges on the slopes are wheel spin.

Karmann

Sounds like a pretty good item. He's always trying to improve on the car. (It's definately easier on the wallet than our 928's)

Karmann

Another question. For those of you that have the gtech pro, do the rpm functions work on your cars. GTech states that the rpm functions ,i.e rpm graph, shiftlights, redline alerts etc, do not work on all cars. He has an 86 VW. Any info as to whether these functions will work on his ride?

SharkSkin

I picked up a Gtech RR from another Rennlister that decided it wasn't giving him results that he could use given his altitude above sea level. I bought it not with the expectation of getting dead-accurate 0-60 or 1/4 mile times, but with the expectation that I could get repeatable data that could be used to evaluate changes to see whether performance is gained or lost with the change. It seems to give very repeatable results, with all of my runs to date showing identical results within the margin of error.

Initially I had some issues with the RPM calibration, but I calibrated RPM again, doing it at cruise instead of at a stop with the trans in neutral. Since doing this the RPM indication is dead nuts on.

Tony

Seem to work fine on mine as far as i can tell. You just have to calibrate the device to the specific car. You can also store 4 cars(i think 4) in the device. Each car will have a different RPM signal. During the setup you calibrate the device to the RPM signature of your engine as fed back through the alternator....i think thats how it works. The shift light is actually a handy litlle thing. Flash out of the corner of the eye and i hit the 1-2 shift.


I will remember that if i have probelms. Mine seems ok after doing it the garage...perhaps the Altenator signal is a bit differnt under the load of "driving"

so far so good though.

SharkSkin

Tony, I think that the real difference was due to my ability to hold the RPM more steady while driving than while running the engine no-load, especially at 4K.

Karmann

Thanks for all the info. It will prove helpfull. I'm pretty much sold on it. Did it come with decent instructions on how to program it?