Autostream

I bought the new GTechPro when I got my AMG E55 last spring to keep track of my mods.

I can tell you that this new GTechPro kicks the crap out of the old one.
For one, you put it on the dash in ANY position you want. It has 3 accelerometers so it works in any position. It monitors more stuff now, including rpm's so it can now figure HP too!!
You just need to get your car weighed. Which isnt a bad idea anyway, you should be corner balancing your car once in a while anyhow.



Some of the cool features are:

• An easy to adjust, never comes off suction mounts
• Shift lights - Super bright LEDS illuminate
• Cornering light - Lights come on at preset point during cornering
• Reaction time measurement - [reaction time AT THE TRACK is the amount of time between the last amber light and the time when the front tire crosses the starting line. This time increases when the car is staged farther behind the starting line. This so-called rollout distance must also be set for the reaction time to be accurate]A perfect reaction time is 0.500 seconds. Any less is a foul and disqualification. Pro racers use a pro 'tree' where all 3 amber lights come on at once. 0.400 seconds later the green light comes on. The gtechpro allows a choice between 4 type of trees. It has 4 Lights built into it which simulate a 'tree'
• Staging and rollout settings - Staging means your front wheel is blocking the second 'stage' beam. Rollout is the distance the car moves before it unblock the stage beam and start the E.T. timer. A long rollout is called a shallow stage and leads to a higher quarter mile speeds, shorter E.T., and longer reaction times. A short rollout is called a deep stage, and leads to lower quarter mile speeds, longer E.t>, and shorter reaction times.
  Consider a shallow-stage, where the leading edge of the front wheel is barely blocking the stage beam. When the gas is pressed, the car rolls 14 inches before the beam is unblocked. This is considered a 14 inch running start and the car is already going 4 mph before the stage beam is unblocked. This will lead to a faster 1/4 mile time than deep-staging everytime.
  The GTechPro start the ET time in exactly the same way as the track.
  First you enter your rollout distance into it. During any run made from then on, the gtechpro will not start the ET timer until the car has rolled exactly the number of selected inches. During launch, its capable of keeping track of movements of less than an inch and is very accurate at measuring rollout.
  The GTechPro's rollout distance is limited to a max of 16 inches because at NHRA tracks the ET timer is always started by a 3rd beam, the guard beam, placed 16 inches behind the staging beam. This beam prevents cars with very low chassis parts from cheating and getting an unreasonably long rollout and head start.
  
  Regardless I never use the rollout option because I care mostly about street racing AND want accurate 0-60 times. Though if you are a track junkie, use the very shortest rollout, since this is the truest measure of a car's performance, regardless of staging.
• Speedmarks - I have it to signal when I hit 60mph. Also usefull during braking tests
• Distance marks - I have it set for the 1/4 miles so it fires a single LED, then I know the run is over
• Firmware updated through internet

But the best part in my opinion is the dyno chart that you print out on your computer.
The GTechPro hp figures may be LOWER than a traditional Dyno because it shows the MOST accurate HP, ACTUAL NET HORSEPOWER, which is more accurate than Rear Wheel Horsepower. This is because the gtechrpo takes into effect aerodynamic drag AND friction losses of the tires on a real road surface as opposed to a smooth dyno drum.
In any case, the power measured by GTechPro is truly the amount of power left to propel your car forward
which is really what matters when tuning a winning vehicle.


You can select between many different graphs including hp/time, rpm's, speed, etc.

Notice the very flat torque curve of AMG's 5.5l V8. After 1st gear during a drag race, I am averaging no less than 350rwhp. As oppose to say a large turbo charged car with a peaky torque curve. It could have a peak hp rating of 600hp, yet the curve is soo peaky, that they may only average 300hp during a drag race.
So it is very real that you may out drag a car with a much high HP rating easily. (of course as soon as you hit 1400 feet slam the brakes!!)

ps. the green chart is when my car was stock and I know I added a bunch of stuff while the weight stayed the same. I removed the spare tire, jack, 3 headrests, some insulation, and some heavy plastic **** mercedes puts in the engine bay that doesnt do ANYTHING! It all turned out to be the same weight again when I was done.

The GTechPro in my opinion is very accurate. And by the way it is made, it should be. It even includs internal temperature sensors to calibrate itself continuously as the unit heats up. I compared my real time slip from the track and taking into consideration the above, it was dead on everytime to the tenth. - Scotty V 11/13/03 usastreetracing.com

Sleestack

Nice writeup. I have the old G-tech and I think it sucks big monkey butt. The new design seems to take care of many of the older model's deficiencies... I'll have to pick one up.

CHB

What do you guys think of the, Gtimer?

sajecw

So how bad did you blow your car up?

Autostream

you'll find out soon enough!

mb-mopar nut

When checking horse power, will it work on 0-60 suns or do you need to do the full 1/4 mile?

BoughtaBenz

Very nice write up! Now I know what I want for Christmas. Your car is pretty quick if it's running 12.47's. That's great for a car that weighs 3700+ lbs. You'd be running low 12's if you got that short time down (60 ft. time. )

pocholin

Nice write up, thanks

N.M.M.

I have two questions , Are you really running Flowmaster mufflers? And you claim to have no cats how did you fool the ecu into thinking they are there? Thanks

Autostream

cuz the O2 sensors are still in the exhaust flow, just spaced 4 feet apart. sets the checkengine light once in a while, but i reset it with my palm pilot

N.M.M.

Thats what I was trying to figure out, I was seeing if you found a way to trick the car into not triggering the code for the engine light.

hellcat

But I thought your car wasn't modded as per all you claims in your blown engine thread... Then why would you need to specify a STOCK on your time slips there?