Got my Gtech Competition - let the fun begin!
 

Hey everybody -

Just got in the mail yesterday a barely-used Gtech Competition Pro off Ebay. I've got a lot of mods in mind for my car that are primarily small refinements of the stock system, and a lot of the mods I'll be doing have never really been documented as far as how much power they make, where you pick up power, etc.

Enter the G-tech. I had an old G-tech back in the day - it was fun, but cumbersome to use and you couldn't save multiple runs, see horsepower, etc. A few years back they came out with the Competition Pro, which is the one I bought. It has a full screen on the unit, shift lights, and can read RPM's by picking up on the electrical pulses from the cigarette lighter. A few months ago, they came out with the Competition Pro SS and Competition Pro RR (whew! those are some names!). The RR is equivalent to the old Competition Pro, and the SS is a cost-reduced version without the PC serial port.

So, here's the trick for you guys. Hop on Ebay and buy an older Competition Pro. I got mine for about $140. Then, you can download the 4.0 RR firmware from Gtech's site and upgrade it - with that firmware, it is IDENTICAL in features to the new $290 Competition RR.

OK, so now you're ready for fun :). The G-tech can log torque and horsepower, as well as 0-60 times, quarter mile, etc., and also has road race features for logging lateral G's on the track.

My plan is to use it for logging horsepower. Every time I do a mod, I can go make some runs and see how much and where I picked up power. Then, I tell you guys and everyone's happy :).

I'm doing 2nd gear horsepower pulls. Stop the car, hit the "go" button, wait for the G-tech to tell you to go, get going in 1st gear, shift to 2nd quickly, then run 2nd gear from around 2000 RPM to redline. The software will show the whole 2nd gear pull as a horsepower/torque chart. I could do it in any gear, but 2nd is relatively sane for in-town purposes.

BTW, you also have to know the weight of the car with yourself in it. I headed to a local truck stop and weighed myself and the car on the CAT Certified Scales for $8. Me, car loaded as usual (spare tire, jack, etc. but no big speaker boxes or anything goofy), and a 20oz Sunkist were 3020 pounds. I'm just over 200, so 2800 pounds is a pretty safe bet for the car's weight. BTW, this is a '94 R2.

Attached are my 2 best runs from this evening. Mods are downpipe, OLD OLD OLD school Trust/Greddy cat-back, and Knightsports EBSIII boost controller holding boost steady at .7 bar (10 psi). I get 10 psi to redline with the EBSIII with no spike, but I'm choking up a bit at the top - I'm thinking the stock intake isn't helping there :).

Anyhow, the Gtech Competition is highly recommended if you'd like to have real proof about where your car is making power and where it isn't, not to mention finding out what mods help and which do little.

BTW, the only problem I had with the G-tech was getting the RPM's to read properly. Here's the trick - turn on your headlights and defroster, then calibrate the RPM's. The extra load makes the pulses easier to read for the G-tech, and the G-tech matched the tach dead-on. Doing testing tonight, it read fine with just the headlights on.

Dale

niiiiiiiiiice, ive been wanting to get one of those. . . thanks for the info on the "cheat" :D

paul

When mine was working well, it was really cool. But since, it has been going to hell, ive been getting some really messed up readings. I contacted the company and they told me what to do to fix it, I just havent gotten a chance. Have fun with it.
adam

Looks pretty fun. On the Hp front, I've always felt my FD made more power in 3rd gear than second. More boost time? Is there a way to measure power in conditions other than in 2nd gear?

i'm posting because i'm bored haha


those are fun but the inaccuracy comes from
-car uses different maps on different days according to intake temps, etc
-you don't always drive the same everytime you make a run
-weight is really picky, but you got yourself the exact weight so no prob there
-1/4 mile times are without reaction times

anyway it's a really fun toy, but if you wanna figure out horsepower numbers take it to a dyno =)

Dynos are the way to tune, but there is still wide varience with them (same issues with intake temps etc) nand yes even on the same dyno. Using a datalogit or PFC map trace indicate the maps. Theorizing the Gtech Pro is accurate it would not be able to give comparable wheel hp to a dytno because of drag,

Gtech = Junk in = Junk out..

take the readings with a grain of salt.

I had one of the original g-tech and now have the comp pro. On the old one, I was within about 5 rwhp compared to the dynojet....not to shabby. Also looking at Dale's map, I think it's knida neat that it picks up the 2nd turbo kicking vs rpms like it should.

Tim

what about 1\4 mile times.. do any tests.. how accurate can that be?

It's actually pretty accurate. I haven't paid much attention to the quarter mile stuff, as I'm primarily planning on using it for measuring horsepower in 2nd gear. But, I do believe you can set all kinds of other factors with drag racing - like rollout and such. There's also pitch factor, where you can set how much the car "tilts" every time you shift. If the car has a really soft or a really stiff suspension, you can alter it to get a better reading.

Nothing short of an engine on an engine dyno under controlled conditions is perfect. The good thing with the G-tech is it's a good way to see what mods make horsepower and where, which is exactly what I intend to do with it.

You can measure horsepower in 3rd, but I wasn't comfortable with redlining 3rd on city streets. The only downside is that each power run HAS to begin with a dead stop. This is partially due to the accelerometers in the G-tech - at the start, they say "the car is stopped, and this is level ground, so level out the reading". It's kind of good in a way, as the old Gtech was really fiddly with trying to level it for a good reading.

BTW, this is what originally sold me on the idea -
http://www.rx8club.com/showthread.php?s=&threadid=17055

Jeff Abrams used a G-tech to document and verify his results with tuning an RX-8 with an E-manage. Proof is in the pudding, as they say :).

Dale

Dale,

Thanks a lot for the info! I think using the G-Tech to test minor changes is a great idea. Of course, it's not perfect, but if you are careful to keep conditions similar, I'm sure it will be accurate enough.

Now that I know I can just do the firmware upgrade, I'll be picking up one of the Competition Pros this weekend.

-Alan

BTW, for those of you who love keeping the interior tidy, the newer Competition RR and SS use amber backlighting instead of blue, like the "old" Competition :).

Of course, you pay more for the privilege.

Dale

I bought an old school Gtech Pro for $34.99
 

http://www.softwareandstuff.com/CES10539.html

Gtech Pro Performance Meter

$34.99

Condition: New
Warranty: 90 Days

Product Description: G-TECH is designed to make a professional test driver out of anybody. All you have to do is plug it in a cigarette lighter, mount it to the windshield and start accelerating. G-TECH/Pro does the rest automatically and displays the results. It's a great way to get performance and safety information about you car.

All the measurements are performed automatically. All you have to do is push the button indicating to G-TECH/Pro that you are ready and then G-TECH/Pro will zero-out and display -GO-. Then simply start accelerating. G-TECH/Pro will know your speed and distance at any given moment and stop the measurement at 60 MPH or 1/4 mile point.

Measures:

- 0 to 60 MPH time
- 1/4 mile elapsed time (E.T.)
- 1/4 mile trap speed
- Instantaneous lateral acceleration (G s)
- Sustained lateral acceleration (G s)
- 60 MPH braking distance
- Instantaneous braking Gs
- Sustained braking Gs
- Horsepower

I still have to figure out how to get it to work...

The old school ones are a dime a dozen on Ebay, but they're nowhere near as powerful as the Competition. With the Competition you can save runs to your computer, compare them, have real horsepower and torque graphs, you name it. But, the old G-tech is a good way to do some basic testing for a budget price :).

Dale

Acceleration graphs
 

Here are a couple graphs from my car last weekend. Weight was 3120lbs since there were two of us in the car. The launch was slippery so don't dog on my times.

I noticed peak acceleration is at the top of 1st gear:).

I've had a Tazzo VPC (http://www.tazzo.com/tazzo/) for a long time now. It's definately fun to play with. IMO, the Tazzo was slightly better than the original G-Tech. It has a whole host of features, including a dual-axis accelerometer (doesn't require leveling). But obviously the newer G-Techs have taken everything one step further. The data loging ability is quite slick! I think I may need to upgrade just for that.

-Rob

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