[enkeivette]

"...we took it to two dragstrips: the eighth-mile at Irwindale, California, and the quarter-mile at California Speedway in Fontana, California. ...At Irwindale, the car cut a 2.05-second 60 foot (on stock tires) and ran 9.14 at 76.81 mph in the eighth. Using the standard eight-to-quarter conversion factor of 1.57, that gives a quarter-mile time of 14.34. At Fontana, the track was not as well prepped, and the car spun to a best 60-foot of 2.34 and ran 14.56 at 96.77 mph, losing almost exactly the same amount of e.t. as it did 60 foot, meaning with a good launch, it would have run right 14.34."

Hot Rod Magazine June 2008, yes June 2008 (I guess they put them out in advance)

[Vettezuki]

Originally Posted by enkeivette

"...we took it to two dragstrips: the eighth-mile at Irwindale, California, and the quarter-mile at California Speedway in Fontana, California. ...At Irwindale, the car cut a 2.05-second 60 foot (on stock tires) and ran 9.14 at 76.81 mph in the eighth. Using the standard eight-to-quarter conversion factor of 1.57, that gives a quarter-mile time of 14.34. At Fontana, the track was not as well prepped, and the car spun to a best 60-foot of 2.34 and ran 14.56 at 96.77 mph, losing almost exactly the same amount of e.t. as it did 60 foot, meaning with a good launch, it would have run right 14.34."

Hot Rod Magazine June 2008, yes June 2008 (I guess they put them out in advance)

I think there are at least two potential problems with this analysis, hopefully SoCal Racer or other expert can chime in.

1 - the conversion factor is probably quite gross. Different cars accelerate very differently. I think there are plenty of car comparos where the outcome would be completely opposite at the 1/8th and 1/4, which by definition means the conversion is not wholly accurate.

2 - I've always heard that time saved on on 60' equals a total savings of around 1 - 2x in the ET. In other words 0.3 in the 60' would reduce overall ET by 0.6-0.9.

To support my assertion, let's compare Sonic's 03' Cobra at Irwindale and Seans's 04' Cobra at Fontana. Note the 60' times and 1/8 ET. The difference would would continue to grow out to the 1/4.

If I can, I'll go to Irwindale this Thursday. My Vette has had no mods made to it since my Fontana Times and I'm a pretty consistent driver, so we can do some averaging.

Also, as I mentioned, C6Zs routinely run low 11s on the East Coast. They routinely run mid 12s at Fontana.

[Sonic03SVT]

just to give you an idea, i let the clutch out pretty rapidly off a 3k launch on Sumitomo HTRZ3's at 25psi, and dead hooked, even bogged, where it looks like Sean slipped it out at 2500 and spun. Irwindale's track prep is worlds better than Fontucky...place is terrible.

[SeanPlunk]

Originally Posted by Sonic03SVT

just to give you an idea, i let the clutch out pretty rapidly off a 3k launch on Sumitomo HTRZ3's at 25psi, and dead hooked, even bogged, where it looks like Sean slipped it out at 2500 and spun. Irwindale's track prep is worlds better than Fontucky...place is terrible.

It's horrible, but my driving isn't helping. I'm interested in your 3mph advantage at the 8th. The horrible 60ft and weak launch alone shouldn't make that much difference. I guess since it was 90 degrees out, that could have affected thing, but it still seems down on power.

[Vettezuki]

Originally Posted by SeanPlunk

It's horrible, but my driving isn't helping. I'm interested in your 3mph advantage at the 8th. The horrible 60ft and weak launch alone shouldn't make that much difference. I guess since it was 90 degrees out, that could have affected thing, but it still seems down on power.

We're going to have to get a weather station to get really serious about this. However, FWIW, my NA motor is noticably different on a hot humid day (like today) vs. a nice cool dry winter night. . . very noticable.

[Sonic03SVT]

right, look at the time of day for my run. These cobras love cold weather like few cars ive ever driven.

[Vettezuki]

Originally Posted by Sonic03SVT

right, look at the time of day for my run. These cobras love cold weather like few cars ive ever driven.

Yeah, interesting. I can feel the difference between hot and cold days, but to be honest, my times from the fall (a fairly hot day with a lot of ash in the air from the fires) were basically identical to the winter, which was a nice cool day. If it stays warm, this Thursday night should be a fair analogue to my winter runs and give reasonable data to compare. I would like to get a weather station and get all sciency about it some day though.

[enkeivette]

Originally Posted by SeanPlunk

It's horrible, but my driving isn't helping. I'm interested in your 3mph advantage at the 8th. The horrible 60ft and weak launch alone shouldn't make that much difference. I guess since it was 90 degrees out, that could have affected thing, but it still seems down on power.

You should keep your hood propped up till you're ready to run. Maybe even poor ice on the motor before you get in line.

I notice a difference with the heat. Especially after a long drive on a hot day, the motor gets heat soaked. And the air intake (mine especially is forced to breathe that air).

[Vettezuki]

Ok, check out the numbers.