13G vs. 13C Turbos

[bjmsam]

Originally Posted by lawdogg

does the gtech reads too slow? I got some gtech times for my car but I'm not sure because they don't seem believable.

No, since under acceleration, terminal speed is higher than trap speed.

Originally Posted by bjmsam

I have the first-gen G-Tech with the red L.E.D. display. It reports elapsed time extremely accurately (verified through comparison with my slips at TOTB, the one and only time I have ever been to the strip, where it was dead on) and terminal speed rather than trap speed.

Originally Posted by bjmsam

Again, the first-gen G-Tech reports terminal speed, not trap speed. Regardless of how the G-Tech computes those speeds, if they are compared to each other, fuel, turbos, exhaust and a bit more boost netted an increase of 12.8 mph in my case.

Originally Posted by bjmsam

Simply suction it to your windshield, select acceleration mode, level it out and drop the hammer! It will flash your 0-60 time briefly as you continue toward the 1/4 mile mark where it will display elapsed time and terminal speed.

Sadly, things have gotten worse in the last three months:

Originally Posted by bjmsam

The only way I might regret my decision is if I change my goals and want to raise boost on race gas (pump gas costs $9 per gallon over here, so not likely).

Here in Yorkshire, the June 2008 average price of super unleaded was 123.8 pence per liter (55.1% taken as tax), or about $11 per gallon. See page two for how prices in the USA compare to other countries.

[3Sfever]

Originally Posted by bjmsam

No, since under acceleration, terminal speed is higher than trap speed.

Terminal will be higher than trap, but probably not by much. . . I think the trap lights on most tracks are separated by 60-70 feet. Trap speed is the average between those two points. (ie. the speed at approx 30-35 ft before finish line). . . . I doubt we gain much mph in the last 30 ft. . . . even 1 mph might be a stretch.

The interesting thing about sending your gtech around, is that if it is consistent , then it will be a good comparison between setups, even if not totally accurate.

[lawdogg]

Reason I ask is because with the 13T's and boost at 15psi, with the 550cc injectors, I used a gtech and although I did pull a 1.702 60' time in the middle of the highway, it reported my 1/4 mile as 12.88 @ 108 ... this is right after I ran a 12.44 @ 111 at the same boost level (but with stock injectors) at a real track.

I am going to take it to the track with me next time I go, and see how close it is.

[3Sfever]

Originally Posted by lawdogg

I am going to take it to the track with me next time I go, and see how close it is.

That is the thing to do. . . . Once know how close it is, you can always "offset" later when not at track. (as long as it is consistent)

We were hoping to get BJMSAM's Gtech "calibrated" at NG, but Murphy's Law beat that plan to a pulp.