Big50

So, i went to infineon raceway last night. The best i could do was a 12.43 at 112.04. I pulled a 12.30 at Sacramento raceway at 118.32 two weeks prior. What i am confused about is why my trap was so low. There was a head wind blowing at 16 mph against the track. This is the only variable i can think of between the two tracks. The da was within 100 ft of each other. I was easily trapping 118 even with a poor 60' when i went to Sacramento, and i was getting 111-113 at infineon.
When i compared my slips two best slips from the 2 tracks i noticed i run simmiler times until i get to the 1/8 mi mark. By then i lost 2 mph and finish with a 112 compared to a 118, both 60' were almost identicle 1.809 to a 1.84.
I did notice one run when the wind died a little i trapped 113.5 at infineon. Either that or one of the tracks radar guns is off.

Projectquick

The wind is going to affect your trap and E.T. without a doubt.

Stkjock

timing lights could be off, the wind hurt, did the car feel as if it ran as strong? thinking your plugs maybe an issue

JD1969

That head will hurt you. Generally if a car spins a little bit the trap will go up, when it hooks the trap will down. Also tracks do not use a radar gun to determine trap speed, they use two sets of optical beams (similar to the starting line beams). The time it takes for the car to travel the distance between the beams is how the system figures MPH. Of course they could still be off, but I doubt it in this case. When they are wrong is usually pretty obvious.

Big50

Car felt good. I had the plugs changed when they put the blower in 2 months ago, so i don't think it was that. And it's only been two weeks and i barely drove it in between visits.

JD1969,
I hooked great on 2 runs in Sacramento and still trapped 118, so i don't think that is it either.

Projectquick

I say check the plugs again just to be sure, I saw a buudy foul 6 of them in two weeks after he put his blower on. But I'm positive the head wind would definatly hurt your trap, but how much I'm not sure of. After checking the plugs there is only one way to find out, and thats to run it again without the wind.

67mustang302

What were the exact weather conditions? Just cuz the DA is the same doesn't mean the engine will react the same. You could have low temps with low baro pressure and high humidity, and high temps with high baro pressure and low humidity...the DA is the same, but the hotter air may be enough to cause the knock sensor to activate and pull some timing, due to minor detonation. Excessive heat is the single biggest cause of knock.

And yeah, check your plugs.

Big50

I just checked the da and amazingly they are almost identical, check it out:

http://www.dragtimes.com/da-density-...time=5:54%20PM

http://www.dragtimes.com/da-density-...time=8:53%20PM

Thinking back to when i went to these tracks before i put in the blower i trapped higher at Sacramento too. There is always a headwind at infineon. I'll check the plugs, but the car feels like it is running fine. I think i might take it to Sacramento this week to see if the wind makes that much of a difference. It just sucks because Sacramento is an hour away compared to 20 min.

AmericanSpeed

67mustang has some good points.

Lots of variables. Time in between runs. Shift points. Shifting all together. Sometimes my car is a bitch to shift, other times it slides in each gear like a hot knife through butter.

I've had days where my car was trapping significantly lower. You really can't make the best judgment after one trip to the track.

S8ER01Z

10mph headwind and ~500da difference took me from 13.1 @ 108mph to 13.2 @ 106mph on similar 60fts..

It's always a raffle trying to beat your old record passes and trying to stay positive when the weather is hurting you.