Just got GTech Pro
08-25-2005, 10:31 PM
#1
RX8INCH
Thread Starter
Join Date: Aug 2005
Location: Los Angeles, Ca
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
Just got GTech Pro... Best way to launch???
I just got an 8 last week. I ordered the Gtech Pro RR and got it today. Nifty little thing. I need to go weigh my car to get acurate HP. any ways i was using it to test 0-60 times. I launched a few times and i was getting 6.8-6.9sec.. I was pissed. So I launched at about 5K and i got 6.1 something.. it was 97 out side with 2 ppl in my car and lil under 1/2 tank of fuel... Do I really need to launch at like 5K... what RPM have you guys gotten you best times at? I have 6spd with the Dunlop SP's. My car is stock 
not for long
not for long
Last edited by RX8INCH; 08-25-2005 at 10:40 PM. Reason: revision
08-25-2005, 10:41 PM
#2
Registered User
Join Date: Sep 2004
Location: Louisiana
Posts: 127
Likes: 0
Received 0 Likes
on
0 Posts
5k seems right. Im amaized you pulled a 6.1 with two people in the car. Did you adjust for their weight when you made you pull. I think 6.1 pretty damn good concidering that 5.9 is the best I've seen and that was with the 250 HP ecu before they had to change it! Two ticks off aint bad at all.
08-25-2005, 10:48 PM
#3
Registered
Join Date: Mar 2005
Posts: 691
Likes: 0
Received 0 Likes
on
0 Posts
1> Without a proper weight in the system the times can be off greatly even if you're wrong by only 100lbs or so. And you were probably off by more than that.
2> Yes, a 5000RPM launch is normal. In fact it's probably a bit low for "best" times. 7000+ is about the only way to break into the 5s. That's a byproduct of a car that's generating less torque than my buddies 1.8L Honda Civic on the low end of the tach.
2> Yes, a 5000RPM launch is normal. In fact it's probably a bit low for "best" times. 7000+ is about the only way to break into the 5s. That's a byproduct of a car that's generating less torque than my buddies 1.8L Honda Civic on the low end of the tach.
08-25-2005, 11:01 PM
#4
RX8INCH
Thread Starter
Join Date: Aug 2005
Location: Los Angeles, Ca
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
1> Without a proper weight in the system the times can be off greatly even if you're wrong by only 100lbs or so. And you were probably off by more than that.
0-60 6.192
60ft 2.263
if it makes a diferance that run i set weight @ 3400.
08-25-2005, 11:24 PM
#6
RX8INCH
Thread Starter
Join Date: Aug 2005
Location: Los Angeles, Ca
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
2> Yes, a 5000RPM launch is normal. In fact it's probably a bit low for "best" times. 7000+ is about the only way to break into the 5s. That's a byproduct of a car that's generating less torque than my buddies 1.8L Honda Civic on the low end of the tach.
08-25-2005, 11:29 PM
#7
Registered
Join Date: Mar 2005
Posts: 691
Likes: 0
Received 0 Likes
on
0 Posts
Yes, it is really bad to launch at 7000; it wouldn't matter if the RX-8 had a great clutch. You should save that for rare occassions at the track. And if you're going to do it with any sort of regularity you definitely need to upgrade the clutch, but you'll never be able to make a habit out of those kind of clutch-drops.
08-25-2005, 11:46 PM
#8
i dont know how gtech's work, but i doubt it has some kind of sensor wire hooked up to your speedo to tell you how fast you're going right?
If that's the case then the way it calculates speed (in this case 0-60) would be based on weight, how many g-forces are pulled etc. So if your weight is off, then it would throw the 0-60 off because the g-force would think 60 is sooner then it is since it has no connection to your speedo.
If that's the case then the way it calculates speed (in this case 0-60) would be based on weight, how many g-forces are pulled etc. So if your weight is off, then it would throw the 0-60 off because the g-force would think 60 is sooner then it is since it has no connection to your speedo.
08-26-2005, 04:59 AM
#9
Registered User
Join Date: Jul 2003
Location: Ottawa, Ontario, Canada
Posts: 356
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by cleoent
i dont know how gtech's work, but i doubt it has some kind of sensor wire hooked up to your speedo to tell you how fast you're going right?
If that's the case then the way it calculates speed (in this case 0-60) would be based on weight, how many g-forces are pulled etc. So if your weight is off, then it would throw the 0-60 off because the g-force would think 60 is sooner then it is since it has no connection to your speedo.
If that's the case then the way it calculates speed (in this case 0-60) would be based on weight, how many g-forces are pulled etc. So if your weight is off, then it would throw the 0-60 off because the g-force would think 60 is sooner then it is since it has no connection to your speedo.
08-26-2005, 06:40 AM
#10
RX8 ADDICTED!!!
Join Date: Aug 2003
Posts: 1,108
Likes: 0
Received 0 Likes
on
0 Posts
I hope your 8 that is a week old was used and you are not launching a brand new one without being broken in. Also what Car and Driver found was thier rx8 long term car got faster with miles. They were getting 5.9 0-60 after 40,000 miles. So depending on how many miles are on your car may cause a few tenths too.
08-26-2005, 06:45 AM
#11
RX8INCH
Thread Starter
Join Date: Aug 2005
Location: Los Angeles, Ca
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
I have 700 miles on it. Just wanted to see what it would do. It is a 2 yr lease(not that im going to trash it). Thanks for your imput guys.. The Gtech just plugs into my lighter. I have to calabrate RPMS and enter weight thats it. It goes off the electo pulses in the elec. system i think.
08-26-2005, 09:21 AM
#12
Registered
Join Date: Aug 2004
Location: Virginia/Maryland
Posts: 1,294
Likes: 0
Received 0 Likes
on
0 Posts
It processes the noise in the electrical system and looks for the pulses from the ignition system to get the engine rpm's. For 0-60 it integrates the acceleration over time. From this you can compute velocity and position at any instant of time.
The fundamental kinematic equations you get from integrating are these.
v(t)=v0+a*t
x(t)=v0*t+1/2a*t^2
Airplanes and Nasa both use this same technology to provide telemetry data to propogate their position.
For torque/hp runs the weight is needed.
The fundamental kinematic equations you get from integrating are these.
v(t)=v0+a*t
x(t)=v0*t+1/2a*t^2
Airplanes and Nasa both use this same technology to provide telemetry data to propogate their position.
For torque/hp runs the weight is needed.
Last edited by rkostolni; 08-27-2005 at 11:51 AM.
08-26-2005, 12:33 PM
#13
Originally Posted by rkostolni
It processes the noise in the electrical system and looks for the pulses from the ignition system to get the engine rpm's. For 0-60 it integrates the acceleration force over time. From this you can computer velocity and position at any instant of time.
The fundamental kinematic equations you get from integrating are these.
v(t)=v0+a*t
x(t)=v0*t+1/2a*t^2
Airplanes and Nasa both use this same technology to provide telemetry data to propogate their position.
For torque/hp runs the weight is needed.
The fundamental kinematic equations you get from integrating are these.
v(t)=v0+a*t
x(t)=v0*t+1/2a*t^2
Airplanes and Nasa both use this same technology to provide telemetry data to propogate their position.
For torque/hp runs the weight is needed.
08-27-2005, 11:55 AM
#15
Registered
Join Date: Aug 2004
Location: Virginia/Maryland
Posts: 1,294
Likes: 0
Received 0 Likes
on
0 Posts
The older gtech's don't use rpm, but the newer gtechs do. I have the gtech pro rr, it gives a nice full screen rpm gauge that synch's extremely well with the factory rpm gauge. It is pretty accurate except at idle it gets a little confused, but only on our car, I've tried it on four or five other cars and it works perfectly. I suspect its the negative timing split that confuses it. It uses the rpms to generate dyno plots and provides info on what rpm you launched at, where you shifted at, all kinds of good to know info.
08-29-2005, 07:11 AM
#18
New Member
Originally Posted by cleoent
i dont know how gtech's work, but i doubt it has some kind of sensor wire hooked up to your speedo to tell you how fast you're going right?
If that's the case then the way it calculates speed (in this case 0-60) would be based on weight, how many g-forces are pulled etc. So if your weight is off, then it would throw the 0-60 off because the g-force would think 60 is sooner then it is since it has no connection to your speedo.
If that's the case then the way it calculates speed (in this case 0-60) would be based on weight, how many g-forces are pulled etc. So if your weight is off, then it would throw the 0-60 off because the g-force would think 60 is sooner then it is since it has no connection to your speedo.
G is gyroscope... it measure the acceleration and speed of the car without any attachment and will be independent of what car you are travelling in.
If to measure the hp or torque.. it will be an estimated equation which need an input of mass... most people have said it.
It is a nice thing, but for $300 I would have the REVi or something like that :p
08-29-2005, 04:03 PM
#19
RX8INCH
Thread Starter
Join Date: Aug 2005
Location: Los Angeles, Ca
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
G is gyroscope... it measure the acceleration and speed of the car without any attachment and will be independent of what car you are travelling in.
If to measure the hp or torque.. it will be an estimated equation which need an input of mass... most people have said it.
If to measure the hp or torque.. it will be an estimated equation which need an input of mass... most people have said it.
08-29-2005, 04:46 PM
#20
just checked my unit and the correct #s are. 6.1 to 60 and 14.45 for the 1/4 @94.5.
beers
beers
Originally Posted by swoope
not bs,
and it does not use rpm. 6.1 is damn good. best i have done is 6.45 to 60 but have got a 13.9 @ 94.5mph 1/4.
have fun be careful.
beers
and it does not use rpm. 6.1 is damn good. best i have done is 6.45 to 60 but have got a 13.9 @ 94.5mph 1/4.
have fun be careful.
beers
Thread
Thread Starter
Forum
Replies
Last Post
{FS/WTT} 04 Black Rx-8 TRACK AUTOX TIMEATTACK
Billy Marcial
RX-8's For Sale/Wanted
5
03-01-2018 06:50 AM
Lock & Load
Australia/New Zealand Forum
26
01-06-2004 02:21 AM
