That makes absolutely no sense IMO. Run B will not be accellerating harder since time and power was wasted spinning tires.

Regarding the timeslip showing the faster mph, although the car wasnt faster, The traps dont selectively lie. it measures how much time it takes your front wheels to break the first beam to the second beam. 66 ft i think, which =

20.1168 meters

If it takes you .41 seconds to travel that 66 ft. you are going 49m/s which is 110 mph

 

the time lost spinning the tires means nothing to the time at the end of the track, the lost time spinning the tires is why the ET's are slower...all i know is my timeslips back it up

 

Generally, in my experience, if I spin, my mph is a little higher (as well as the et). However, if I get tracation, I run a little slower mph but run a faster et.

 

will,

how does it make sense? I doubt the car is accelerating harder in the traps, but lets assume run b is accellerating greater in the traps, it doesnt have the acquired velocity that run a has established from hooking and using that power instead of wasting part of the track spinning. The traps are measuring the velocity, not acceleration.

*shrug* hopefully I can get enough money to test this out myself

 

hmm...now im confused...i know someone explained it to me and it made sense...

 

okay how bout this...these are times before and after my 4.10 install...everything else the same...

Before:
60' -- 2.2
ET @ 594 -- 8.8
1/8 ET -- 9.4
1/8 MPH-- 68.9

After:
60' -- 2.1
ET @ 594 -- 8.6
1/8 ET -- 9.2
1/8 MPH -- 76.6

this on identical tires...One tenth was cut off by 60', two tenths were cut off by the 594 ft. mark, the same two tenths through the traps, but almost 10mph more through the traps...just with gears...this confused me alot...

 

your mph increased because your car was able to accelerate harder, the gear swap multiplys the torque the engine produces to the ground if you dont spin your mph increases. some of what you may be experiancing regarding your mph drop on a higher et may be the result of engine bog it takes the engine longer to recover from a bog than wheel spin. My T/a has absolutly no bog off the line, with the converter flashing to 3500 on the brake at launch with the et streets it hops off the line,If I dont heat the et streets and launch it spins,my 60ft goes down and my et and mph drop evenly how do you explain that?

 

i dont think you understood my point, the time gap at the end of the track, from 594ft. to the 1/8th mark remained the same, while the car was going almost 10mph faster...so this tells me that the run before the gears must have been accelerating more in the end of the run that after the gears to keep that constant .2 sec gap ...i dunno, its late, and im tired of thinking about this

 

All else being equal, if you have a great launch with no tire spin, and no bogging, you will have the fastest trap speed.

Spinning looses distance with very little acceleration happening, so you don't have as much distance left to get to the speed you could have.

Bogging slows you down at the start and covers unwanted distance at a slow speed. You then have less distance to get up to speed.

Dan

 

no, the traps are measuring acceleration. if you were maintaining a constant speed across the finish line versus accelerating i bet your mph would be real low. thats why when you see someone let off right before the line their mph is way off.

for example: a car runs 10.60 @ 130mph, which would be roughly a 6.8-6.9 @ 101-102 in the 1/8.

if something goes wrong or he just lets out to not show everyone what he can run, say 100-150ft from the line, his time will be like 10.80-10.90 at 100-105. if he doesnt touch the brakes and just coasts through you know he would have been going at least 125-127 100 ft from the line, but yet the trap speed is 100-105 and hell he was doing that at the 1/8 mile mark. so if someone is coasting through or decelerating then their mph will be way off.

 

Traps are not measuring acceleration. They are measuring velocity. If it was measuring accceleration it would be in ft/s^2. Well we all know it's not that. If it was measuring acceleration, that would mean that if you set the cruise control right before the traps, so you maintaind a constant speed, your trap speed would be 0, because there is no acceleration. To measure acceleration, you need two different speeds, which would have to be taken by 4 different points along the track. 2 pts for the 1st speed, and 2 pts for the second speed, then use the time between those two speeds to find acceleration. All velocity is is how far you go in a certain amount of time (hence miles per hour). All the tracks are doing is measuring how long it takes to get from point a to point b at the end of your run.

 

I think I agree that the more traction you get the better your mph and et. It just doesn't make sense in my mind that spinning could make your car faster, UNLESS it is because the engine is winding higher than usual when the tires grab, causing the car to finish the 1/4 mile at a little higher rpm. Then again if this is true, why don't we all put on our line locks when we stage and keep smokin' em till the 3rd amber comes down....then let er rip!!

 

Exactly,anyone who knows anything about racing will tell you to look at your mph as an indication of the cars potential not the et ,its the one thing that usually remains fairly constant.Therefore why would that indication of the cars potential slow with traction? Its not to say it doesnt happen but A variable in the equasion is the only thing that would slow a cars mph with a higher et with traction. All else being equal traction should result in a higher trap speed and a quicker et.

 

Not possible. Math equations state the rpm the motor will be at with certain gears at a certain speed. The motor will drop the rpms to whatever actual speed the car is travelling at.


Marshall, your logic makes no sense. If someone coasted along the track, stopped before the traps, and launched their car again for the remaining 66ft, you are saying they would have a tremendous mph which is plain untrue.

Velocity = m/s or mi/hr
Accelleration = m/s^2 or mi/hr^2

 

ok, maybe thats not what im saying...what im trying to say is that its not a very good indicator of speed if your are coasting or slowing down.