Mivec beater

twistea · Post by **twistea** » Thu Apr 01, 2004 11:46 am

how good are these times for a manual GR.

0-100kph: 6.83secs
0-400m: 14.99secs @ 154.9kph

i recorded these times with a G-Tech Pro and was consistently achieving similar times (within 0.1secs). my modifications include airfilter and exhaust.

ruchi · Post by **ruchi** » Thu Apr 01, 2004 11:59 am

please don't take any offence, but I think the reading could be wrong. Even with a tailwind and a downhill slope I'd be surprised to see those figures from a GR.

Not many NA GPX's could do that 0-100 time, and if they could they'd need some decent modifications.

What % error do the G-Tech's have?

twistea · Post by **twistea** » Thu Apr 01, 2004 12:09 pm

no offence taken ruchi, thats exactly the response i was expecting from someone with a GPX

well anyway, i plan to record the next run i do on video to confirm my measurements.

Adriano · Post by **Adriano** » Thu Apr 01, 2004 12:16 pm

hey twistea, how do you launch??

who knows, urs could be one of those manual GR freaks out there

i have a manual GR too, but no times as good as those... i could only manage high 8s 0-100....

GPXXX · Post by **GPXXX** » Thu Apr 01, 2004 12:22 pm

Wow, nice effort!

bear in mind though' that G-Tech's are widely known to be inaccurate, and no that's not a biased comment from a GPX owner (such as myself)... I have friends who drive Skylines/WRXs/Supras who can't wait to get rid of their GTech because their readings are way off the official timing on the same race track...

Best way to get your times is to head to the tracks...

I'm not saying I don't believe you... afterall we do have freak GRs out there (yours could be one of them) that can serve a good can of whoop-ass, but all i'm saying is don't take those figures as bible, cool?

ruchi · Post by **ruchi** » Thu Apr 01, 2004 12:56 pm

LOL!

Nice comeback Twistea!

There's no need to video it, I believe that the G-Tech provided that reading, what I doubt is the accuracy of the G-Tech unit. I did a very quick search at the G-Tech website and found two points of interest:
1) While they list the accuracy of the G-Tech Pro Competition model, they do not list the accuracy of the plain G-Tech Pro unit. Rather they simply provide a spiel trying to make it sound impressive, but not backing it up with figures. (reminds me of some politicians

) However, when you read the information about the Competition model, it compares it to the standard model and the way they emphasise so many times how much better the competition model is, it brings into doubt the accuracy of the standard model:

"There are several significant improvements over the original G-TECH/Pro Performance Meter that have been implemented in the new COMPETITION model. First of all, there are 3 accelerometers and they are fully temperature compensated. This in itself is a huge improvement in accuracy. Secondly there is a very sophisticated new calibration algorithm that allows much higher precision. Also the system now has 32 times higher resolution which speaks for itself. New Noise-Correction algorithms have improved overall accuracy as well."

2) The units need to be recalibrated periodically as they go out of whack. The instructions on how to do this are at their forums.

Two questions:
1) Did you recalibrate yours before you took those measurements?
2) Have you tried this same G-Tech pro unit in a manual GPX, and if so what time did it get?

Not trying to sh*t stir here, but realise anyone who posts any sort of performance figures that appear out of the normal will get questioned, either how they did it or for their accuracy.

As I've stated many times now, figures mean nothing unless we're comparing apples-to-apples or there is some sort of baseline to judge it by.

Please understand we are not bagging you, rather we are saying that these figures don't mean much by themselves as it would appear that the unit is not as accurate as other measuring devices and that there is no benchmark or other test to compare the result with.

Post by **smorison** » Thu Apr 01, 2004 1:50 pm

Ruchi:

I know of two GR's who regularly smash GPX's when running. One is GAV the other well i don't know where ricks old Black GR is these days but i'm sure its still out there somewhere.

on the G Tech, i would be a little cautious of the readings as already stated they are a little un-reliable.

I'm thinking about getting a GShock (or whatever they are) for my RSM and testing that way, but will need to throw it down the track to double check its readings.

have you dyno'd your car?

FTO338 · Post by **FTO338** » Thu Apr 01, 2004 2:32 pm

Great effort twistea, u should make a video so we can mix & match it with other's owner video clip, & turn it into FTO Australia Club mix.

d_stroy_r · Post by **d_stroy_r** » Thu Apr 01, 2004 3:01 pm

The wierd thing is that if you have a 155kph top speed at the end, you'll probably get mid 14's.

twistea · Post by **twistea** » Thu Apr 01, 2004 3:34 pm

the g-tech was calibrated by the owner of it before the measurements. FYI, in the g-tech pro manual they quote an error of +/- 0.1 sec for 0-100kph and 0-400m. these claims can definately be put under scrutiny though. also bear in mind that the g-tech works from the moment you start moving. so there are no lights to wait for and no reaction times included in the times i posted.

as for the competition model with the 3 accelerometers, they are all used on three different axis (horizontal, vertical, sideways). the pro model only has one on the horizontal. this combined with the different measurement algorithms definately makes the comp model a better product. no disputes there.

i do not take the g-tech measurements so seriously that they should be taken as quotes from the bible. good one though. but i am keen to go down the strip sometime this year as it is the best real world measurement standard.

as an aside, i knew calling the topic mivec beater was sure to stir up some controversy. but theres nothing wrong with that hehehe.

i wont go into who i have outdragged because more often than not it comes down to beating the driver, not the car. so if anyone with a GPX wants to compare their performace with me im more than happy to have a go, any takers (preferably from SA)???

twistea · Post by **twistea** » Thu Apr 01, 2004 3:35 pm

Adriano wrote:hey twistea, how do you launch??

who knows, urs could be one of those manual GR freaks out there
i have a manual GR too, but no times as good as those... i could only manage high 8s 0-100....

to get those times i practised launching at different revs between 3300rpm and 3700rpm. my best results came from launching at 3400rpm.

scracy · Post by **scracy** » Thu Apr 01, 2004 4:53 pm

1/4 Mile times at a track dont add reaction time.

HostileSmoker · Post by **HostileSmoker** » Thu Apr 01, 2004 7:56 pm

I have a mate who I go drag racing with on a regular basis, he has a versionR and his best time at the strip is 15.09 - but he consistantly gets better times on his G-Tech so there's clearly some inaccuracy there.

At the end of the day, it's not so much that the G-Tech might be wrong, it's that the majority of people simply wont believe you unless you've had your times recorded using proper timing gear at a drag strip - then they can't argue!

Leigh · Post by **Leigh** » Fri Apr 02, 2004 1:39 am

I got a Gtech for my brother and I tested it for about 5 or so runs, best I could get was 15.3 and 97 Mph (155kph). but at the strip my best is 14.6 and 95mph (152kph). which is kinda backwards... snicker.
maybe your really doing 14.2's! wooot!

ruchi · Post by **ruchi** » Fri Apr 02, 2004 1:43 am

Did you calibrate it first?

d_stroy_r · Post by **d_stroy_r** » Fri Apr 02, 2004 2:20 am

As i said the the top speed is different to what it should be on the gtech.

Eg 15.3 and 97 Mph (155kph) on the gtech vs;
14.6 and 95mph (152kph) on the strip.

15.3@97 and 14.6@95

G_A_V · Post by **G_A_V** » Fri Apr 02, 2004 2:45 pm

Nice one, good to see another mivec beater

(also glad your not in nsw id have some hefty competition). Although the gtechs are not the most accurate way of recording yourtimes, theyare still great times, and i am sure it wouldnt be hard to time how long it takes you to get to 100km/h or 400m, so it cant be toofar off. Its funny to see some people critisise the accuracy but not offer to line their car up with yours.
Im not sure what modification has been done to these "freak" gr's but i have a feeling it has to do with the cams (I have spent ages looking for computers, and other modifications). The reason why i think its the cams, is after installing a new airfilter the car gets very loud under wide open throttle, and when it hits 5 1/2k rpms, similar to the mivecs, but i have found no other grs which do get this loud, and also have a distinct change in power/sound (it also increases in power at around 5 1/2 rpms). Now while my understanding of overhead cams is very limited (i still try to get my head around how they increase power, even though my mechanic trys to explain it to me every time i see him). Though when i replaced the timming belt my mechanic said he didnt seeany aftermarket cam gears, though he doesnt remember too well as it was 12 months ago.
Ifanyone other gr owners have dyno charts I can compare maybe we can look at where the power lines differ.
The other difference i notice with my car and mivecs is the low down torque, when racing otherm mivec cars, I find i gain most when the revs are lower, and I also have compared dyno charts with other mivecs and can seewhy, my gr seems increase power a lot quicker down low, though i havent compared to other gr dyno charts. I realise that the gr's are supposed to peak quicker (with a redline of 7.5k instead of 8k)
Anyways this is my 2 cents

Adriano · Post by **Adriano** » Fri Apr 02, 2004 2:54 pm

im thinking of going to the dyno day on the 17th... i have a manual GR too... but i dont think i have a freak... so maybe u can compare it to mine....
mine does get loud with a kn filter, but at 3.5 rpms....
would be good to see what was done in yours though, for other GR owner's benefits

Post by **smorison** » Fri Apr 02, 2004 3:35 pm

everyone should bring their cars down for the dyno day its only $45.00

twistea · Post by **twistea** » Fri Apr 02, 2004 3:50 pm

G_A_V wrote:Im not sure what modification has been done to these "freak" gr's but i have a feeling it has to do with the cams (I have spent ages looking for computers, and other modifications). The reason why i think its the cams, is after installing a new airfilter the car gets very loud under wide open throttle, and when it hits 5 1/2k rpms, similar to the mivecs, but i have found no other grs which do get this loud, and also have a distinct change in power/sound (it also increases in power at around 5 1/2 rpms).

gav, my freakin car has the same freakin response when i get to about 5500rpm, the intake starts to freakin roar really freakin load.

man, i think im starting to freak out here!