GTECH/Comtech SC Before & After Tests
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The G-tech is not very flexible. You can only run it's preprogrammed tests. Unfortunately, they all require shifts and driver skill which fudges things up. That makes it tough to say how much the sc really helped. By all means run 0-60 and 1/4 mile but if you can consider other similar devices you can get much more reliable info.
I do speed to speed tests using my Vericom or Race Technology AP-22 or a datalogger. If you run from one speed (and RPM of course) to another in a given gear on the same stretch of road with similar weather conditions you can repeat to tiny fractions of a second. So you can examine the benefits of air filters, plugs, oil, in addition to big things like a SC. Speed to speed tests are very easy on a car since there are no hard launches or lighning shifts required. They are also perhaps the best way to compare CAI options since the intakes see real air flow.
Some folks have run faster 1/4 miles stock than with the SC yet the SC is clearly the faster car in-gear. The launch and gear shifts make a big difference.
Stan
I do speed to speed tests using my Vericom or Race Technology AP-22 or a datalogger. If you run from one speed (and RPM of course) to another in a given gear on the same stretch of road with similar weather conditions you can repeat to tiny fractions of a second. So you can examine the benefits of air filters, plugs, oil, in addition to big things like a SC. Speed to speed tests are very easy on a car since there are no hard launches or lighning shifts required. They are also perhaps the best way to compare CAI options since the intakes see real air flow.
Some folks have run faster 1/4 miles stock than with the SC yet the SC is clearly the faster car in-gear. The launch and gear shifts make a big difference.
Stan
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From: Houston
I did the same tests before I got my SC. My fastest 0-60 stock was 5.4, and 5.1 with SC. I tried very very hard to get the 5.4, and I didn't have to try too hard to get the 5.1 w/ the SC. I noticed it was much easier to get consistent mid 5's with the SC, while it was not that easy with stock. Once I got the 5.1 I haven't Gtech'd since then. As for quarter mile, I hardly ever ran it, not many places to go 0-100+ MPH around here. I did run a 13.78 1/4 mile on the street with the GTech. My best time stock was in the high 14s, once again, on the street - not the track.
Wesmaster
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>>I like your suggestion of speed tests in a specific gear. I will do that.<<
I've been doing those for many years...it separates fact from fiction pretty quickly. You can't do that sort of test with the g-tech though..
I think that SCC magazine did an in gear test of an SC s2K among other measurements..or at least a from a roll test to avoid launch variables.
Also, I wouldn't be surprised if an SC car is even more temp senstive than a stock s2k. Since the install takes more than 15 minutes, you need to try to test with comparable weather conditions too.
Stan
I've been doing those for many years...it separates fact from fiction pretty quickly. You can't do that sort of test with the g-tech though..
I think that SCC magazine did an in gear test of an SC s2K among other measurements..or at least a from a roll test to avoid launch variables.
Also, I wouldn't be surprised if an SC car is even more temp senstive than a stock s2k. Since the install takes more than 15 minutes, you need to try to test with comparable weather conditions too.
Stan
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From: Houston
Originally posted by E30M3
I do speed to speed tests using my Vericom or Race Technology AP-22 or a datalogger.
I do speed to speed tests using my Vericom or Race Technology AP-22 or a datalogger.
Wesmaster
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>>>Can you tell us more about these, how they work, how much they cost, where to plug them in? I'd be very interested, I've just never met anyone that has such a thing. <<<
If you are a detail oriented sort of person, you can use devices such as these as your own private dyno, just about.
I have 5-6 such devices. Some measure acceleration using a sensor that measures g-force. This is the push in the back that you feel when you hit the gas. From that you can calculate speed, distance etc etc. and come up with things like 0-60, HP curves and so forth. Another kind measures speed related pulses such as those from an abs sensor or vehicle speed sensor or the actual ignition sparks. There are also radar and GPS approaches, but these are super pricey.
The two that I mentioned are popular and use accelerometers to measure g-force. The Vericom is pricey and well established and is used by many police accident investigators. Check out www.vericom.org. The Vericom mounts to your windshield with four suction cups and then plugs into your lighter outlet. There are also various verions of the device but they are all pricey. I bought mine used for 100 bux.
Another is the AP-22 from Race Technology. www.race-technology.com The AP-22 is the one to get from that company as you can record runs and then upload to your pc for processing. It has a serial port on the back of the unit. You can store a few minutes of activity or longer if you change the sampling rate. Or indefinitely if you connect it to your notebook and use the dcat softare. They have an analysis program out (dcat) but it is limited at this point. I find it easier to use a spreadsheet.. I think I paid around 230 - 240 for it. It is smaller than the vericom but larger than the g-tech. It runs on batteries. No backlight. I use blu-tack to hold it above my steering column. It has two accelerometers in it, lateral and longitudintal. So you can do mapping of your location at an autocross for example. The mapping software is not as well developed as Geez though the hardware seems better and there is the ptential for better information IF the softare gets developed. . If you're interested I can post some of my runs so you can see what the data looks like. One of the neat things it does is give you position, gs, HP, speed etc every 1/100 th of a second. You can change something and see not only what happened to the HP / torque curves and so forth but you can see how much ahead you would be if you ran your car next to itself with and without the mods. For example on my car the controversial Nology plug wires are better than Magnecores to the tune of about 4-5 feet by the time you reach 60 mph from 15 MPH staying in 2nd gear, no shifting, no driver skill needed, very repeatable.. You can also do number crunching via spreadsheet to find the area under the torque curve which is far more important than peak gains. You can do 60 foot launch times to find the best technique. You can see bogs and wheels spin. You can also apply correction factors and allow for air drag. The main thing is to keep things constant and change one item at a time. If your're ahead, the exact HP doesn't matter - relative diffs are more important. Braking and cornering and driving technique and many other things can also be explored.
At the moment I am fine tuning my fuel injection using the AP-22 to find the last pony or two. This is easy if you have programmable injection and are already close. I simply vary the entire curve up or down a few % and then see specifically where the accel was hurt or helped. You have to also monitor things like EGT and O2 sensor activity to be safe.
Stan
If you are a detail oriented sort of person, you can use devices such as these as your own private dyno, just about.
I have 5-6 such devices. Some measure acceleration using a sensor that measures g-force. This is the push in the back that you feel when you hit the gas. From that you can calculate speed, distance etc etc. and come up with things like 0-60, HP curves and so forth. Another kind measures speed related pulses such as those from an abs sensor or vehicle speed sensor or the actual ignition sparks. There are also radar and GPS approaches, but these are super pricey.
The two that I mentioned are popular and use accelerometers to measure g-force. The Vericom is pricey and well established and is used by many police accident investigators. Check out www.vericom.org. The Vericom mounts to your windshield with four suction cups and then plugs into your lighter outlet. There are also various verions of the device but they are all pricey. I bought mine used for 100 bux.
Another is the AP-22 from Race Technology. www.race-technology.com The AP-22 is the one to get from that company as you can record runs and then upload to your pc for processing. It has a serial port on the back of the unit. You can store a few minutes of activity or longer if you change the sampling rate. Or indefinitely if you connect it to your notebook and use the dcat softare. They have an analysis program out (dcat) but it is limited at this point. I find it easier to use a spreadsheet.. I think I paid around 230 - 240 for it. It is smaller than the vericom but larger than the g-tech. It runs on batteries. No backlight. I use blu-tack to hold it above my steering column. It has two accelerometers in it, lateral and longitudintal. So you can do mapping of your location at an autocross for example. The mapping software is not as well developed as Geez though the hardware seems better and there is the ptential for better information IF the softare gets developed. . If you're interested I can post some of my runs so you can see what the data looks like. One of the neat things it does is give you position, gs, HP, speed etc every 1/100 th of a second. You can change something and see not only what happened to the HP / torque curves and so forth but you can see how much ahead you would be if you ran your car next to itself with and without the mods. For example on my car the controversial Nology plug wires are better than Magnecores to the tune of about 4-5 feet by the time you reach 60 mph from 15 MPH staying in 2nd gear, no shifting, no driver skill needed, very repeatable.. You can also do number crunching via spreadsheet to find the area under the torque curve which is far more important than peak gains. You can do 60 foot launch times to find the best technique. You can see bogs and wheels spin. You can also apply correction factors and allow for air drag. The main thing is to keep things constant and change one item at a time. If your're ahead, the exact HP doesn't matter - relative diffs are more important. Braking and cornering and driving technique and many other things can also be explored.
At the moment I am fine tuning my fuel injection using the AP-22 to find the last pony or two. This is easy if you have programmable injection and are already close. I simply vary the entire curve up or down a few % and then see specifically where the accel was hurt or helped. You have to also monitor things like EGT and O2 sensor activity to be safe.
Stan
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>>Stan thank you for that information. I found it very helpfull. Where did you find your vericom used? <<
I found an ad for it in the local "Bargain News" under car parts for sale. It used to belong to a guy who drag raced Buick Grand Nationals.
Stan
I found an ad for it in the local "Bargain News" under car parts for sale. It used to belong to a guy who drag raced Buick Grand Nationals.
Stan
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From: Atlanta, GA
garyj.....you should have let me know you were looking for a gtech pro...i've got one...would have let you borrow it.....anyways....the best i have run 0-60 stock with a jr filter was 5.5 secs.....launched at 6.5k...spun a little...good run though....desperately tried to get in the low 5's, but just couldn't....had consistent 5.7's to 5.9's....haven't tested the 1/4 yet though....let us know what your times are...maybe you got a bone stocker like SEV's and can run high 13's stock....