Well I finally got my new exhaust on the car and it seems to have opened her up a good bit. I also haven't ran the car at the track sine I did some fuel tuning with my new cams. That said I wanted to go out and see what I could pull with the ole GTECH. Laugh all you want but if properly leveled I have found the GTECH to be VERY accurate in terms of ET's in relation to my track times. However the trap speeds have generally been a few mph high. I trusted the GTECH fairly well as a general estimate until today.

First run:

0-60mph....5.54sec. Had a good launch and that seemed about right.
1/4mi......13.5 Heck yeah! Ran a 13.7 with 173whp and now had 180+ so I figured that could be pretty close.
Trap speed..... a snail like 118mph!!! Seems like the GTECH is just a tad bit off.

Second run:
0-60mph....5.58
1/4mi....13.5
Trap speed.....117mph

The ET's seem like they could be close, but unless that new exhaust found another 90whp or so I think the GTECH might be off.

 

yeah, ive noticed the same thing to, its usually off by quite a bit on the mph
but usually accurate on the times

im pretty sure u could run at least a 13.5
get to the track dammit

 

'Bama roads make you faster. I should have kept my GTECH to play with when I'm bored.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AK94GSR &raquo;</TD></TR><TR><TD CLASS="quote">yeah, ive noticed the same thing to, its usually off by quite a bit on the mph
but usually accurate on the times</TD></TR></TABLE>
Isn't this due to the fact that at the track they take the avg. speed over a short portion(im not sure how long) at the end of the 1/4 mile and with the GTECH it just uses your speed at the end of the 1/4 mile. Or am I just making this **** up as I go?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ReBornGSR &raquo;</TD></TR><TR><TD CLASS="quote">
Isn't this due to the fact that at the track they take the avg. speed over a short portion(im not sure how long) at the end of the 1/4 mile and with the GTECH it just uses your speed at the end of the 1/4 mile. Or am I just making this **** up as I go?</TD></TR></TABLE>

i heard of that before too

 

I thought the trap speed was the average speed in the last 66 feet of the track.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris N &raquo;</TD></TR><TR><TD CLASS="quote">I thought the trap speed was the average speed in the last 66 feet of the track.</TD></TR></TABLE>
Yeah that's what I was trying to get at. And the gtech measures the speed right at the end so it will be a little higher

 

what do we expect his trap speed to be at 13.5?

I thought it was a bit high, but I'm having trouble seeing how averaging the final 66ft would lower his speed that much...

either way, gtech is a bit high.

 

i used gtech before in one of my civics i too noticed that it s was really close on teh ET but way off on the trap speed

 

is this the old gtech or the newer version that you guys have used.. i have thought about purchasing one

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ReBornGSR &raquo;</TD></TR><TR><TD CLASS="quote">
Yeah that's what I was trying to get at. And the gtech measures the speed right at the end so it will be a little higher </TD></TR></TABLE>

Yes that is the case it is explained on the GTECH website and the leaflet that comes with the unit.

 

i tried a newer gtech.. it said i ran a 12.6 @ 155 mph LOL. i think we set it wrong

 

With gtech, do you need to enter the veichle weight to do the 1/4 mile times or just for it to calculate horsepower?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jond &raquo;</TD></TR><TR><TD CLASS="quote">With gtech, do you need to enter the veichle weight to do the 1/4 mile times or just for it to calculate horsepower?

</TD></TR></TABLE>

You only enter vehicle weight for hp. I've played around with the GTECH many times before and it has never been this far off. It's usually only 2-3mph off on the traps. I expect my traps to be close to 102mph meaning I was expecting GTECH to read 104-106mph.

If you calibrate the GTECH correctly (get it dead level) and run on a level road it has no choice but to be close. Acceleration (measured in G's)x time= distance. However there is no substitute for a real drag strip.