I have a hard time understanding why my trap speed has not changed even though I am running faster. Help me understand.
no mods to the car between runs just a month time.
Same temp out side also.
I am 470

 

Your 60' time improved, hence the decreased time.

 

so just because I got faster out of the whole that means I would not get down the track at a higher MPH?

 

You launched better in the second run, but you most likely shifted slower.

 

Appears so. CW guesstimates for every tenth faster on the 60' translates to about 2 tenths less on the 1/4.

Hopefully Davidv & cohorts will chime in for a better analysis.

 

Every 1/10th you take off of the 60' does equal about 2/10ths in the 1/4 mile.

The 60' wasn't posted on the first slip, but I did notice your 330 was quicker, likely due to a better 60'.

 

Lots of potential factors. Remember that trap speed is the average speed during the last 60 feet. Your car may not acceleration during the last 60 feet.


Also look at the difference between 1/4 mile and 1/8 mile MPH: 20.44 MPH. I would like to see 21 or 22 MPH.

 

Yea, it just seems that your second run had a better launch, hence the difference in ET's.

Also coming out of the hole better, will get you a better ET most of the time, but will not necessarily give you the best trap speed. Generally you will achive your PB trap speed on a run that was not your best ET, if that makes any sense to you!

 

Another thing to consider is that it takes you less time from the starting light to the finish line, so all things being equal between runs, the car has less time to accelerate.

 

Thanks guys

 

That is not always true. Last weekend i had a 2.09 60' and ran a 13.98
then later got a 2.13 60' and ran 13.89.

I think the reason could be that I might have hit the shift points better in the second run or the car had slightly more power as the engine temps might have been down, but you see the point.

But then again on the best 60' time I launched at 2600rpms or so and the clutch slipped and the car bogged.

On the other run I launched at 3100rpms, had a lot more wheelspin, no bog but a little wheelhop.

Looking back what my butt dyno felt, I would have guessed the second launch was better. But to my surprise it wasn't.

 

+1 That's what I've always figured.

Also, as davidv has already mentioned, it is the average mph, so it's best to keep your foot on the accelerator until after you pass where the green light comes on (if you win). You should know what I'm talking about, Travis.

 

kleefton, understandable with what I said earlier, its not perhaps always true, only if your shift points and techniques were exactly the same.

I do like the way Z-Gad put it though!

 

I dont let off until the first turn off The shifts were the same. I guess I will go with what Z-gad said.