Guys,

I have a question for you! Does trap speed go up or down with traction? Physics and common sense tells me up, other people say down. I believe up, however I can't test this theory myself for awhile!

Wasting energy (spinning tires)does not make you go faster. That defies the laws of physics, and the car cant travel farther whether you spin or not. 1320 ft is 1320 ft.

Those are two rebuttals against arguements I have heard for it going down.

 

Well, generally, great traction will lower your trap speed, and a lot of spinning will also lower your trap speed (due to excessive time wasted not accelerating). To get the best trap speed you need a happy medium of traction and slipping. But if your spinning, then you're not getting your best ET, and ET is what it's all about my man.

 

I'd prefer if when you posted, if you could give an explanation on why you think it is how youve seen it.

It makes no sense to me if it goes down with traction.

 

ditto what FastWhiteTA said.

If you bog, you will lose trap. if you spin like crazy, you will lose trap speed. However, usually bogging hurts trap speed the most.

 

I agree, but with what fastwhiteta said, "time wasted not accellerating"

thats my arguement that great traction will increase speed

 

thats not true,trap speed always goes up with traction because when you stick you are giving yourself a longer run way to get up to speed not wasting you first 15 ft by spinning.this has always proved true on all the cars I have owned and tuned at the track.on my ta without traction on the motor my mph was 107 with traction I have gone as high as 113.

 

i guess if youre talking massive tire spin... yeah - that's going to be slower ....

i would have to agree with fastwhiteTA on that ... finding a happy medium between barking and traction....

but there have to be sooooooo many factors affecting it ... if your car has a flatter torque curve, if your power starts lower, if you have to rev to the moon to make power (i.e. many 4 bangers) ....

it all comes down to skill and luck in the end....

your own motor skills and hand-eye coordination for M6 guys....

......or your ability to stamp a pedal for autos......

 

I concur.

 

LOTS of variables could cause either one but to clear up the "distance traveled" thing, the car will get from 0 to 115 MPH just as fast (in E.T) but if the car is traveling down the track as opposed to spinning, the car will reach the end of the track sooner and have a quicker E.T with a lower MPH.

----------------60 ft---ET---MPH----zero to-115 MPH
street tires-2.1-----12.5--115-----------12.5
slicks------- 1.8------12.2--112-----------12.5

Way too many variables for EVERYONEs car to have the same outcome but the above scenario is what I have found on MY cars to be true. This is assuming the car has enough gear, same size slick/street tire, small stall, etc. and there is no excessive "lugging" with slicks or "blowin the tires away" on street tires.

Lloyd

NightTrain66

 

I have never seen a mph slow down with traction,and I have been racing for 10 years.Even my 9 second buick has responded with a lower e/t and higher trap speed with traction.Explain why your mph would drop with a lower et! Im sure your experiance did have variables to contend with but with all else remaining the same with traction mph WILL increase

 

You also have to remember that if you are running slicks compared to street tires your mph might drop with a higher et due to increased rolling resistance because of a wider footprint and stickey rubber, sticking a launch with the same tire you spun with has always resulted in a higher mph for me.This could be accomplished with a chasis mod that allows for traction ,if you base line a slick car spinning and then sticking we have seen an increase in my buddys tubbed 7 sec nova running 33/14 inch wide slicks of 10 mph with traction.

 

Guys...they measure trap speed over a 60' (i think its 60') distance at the end of the track, and they time it. The two marks are 60' before the finish line, and the finish line...so think about it, if the same car on two different runs gets traction once, run A, and spins a little on the other, run B ...then run A will of course be a faster ET, but on run B, the car is accelerating harder through that last 60' than run A was, therefore taking a shorter time to get through that last part of the track, so your timeslip shows a faster trap MPH even though it probably was not actually a faster mph at the end of the 1/4 mile

...how many times have you looked at two timeslips from the same night and said, "I know there is more in the car, cause this ET is better, but This MPH is faster, so I know it can go faster" ...well, this is not true

someone like shoebox needs to chime in here and explain this a little better

 

You will find people that will have had this do either one but the above was my last "hand on" experience from going to slick from street tires and it was from the late 80's. The car might not have had enough HP to be a true test but these are the results that I had.

26" street tire and 26" slick. It was a 440 with a small cam, headers, 3.23 gears and stock converter in a 73 Cuda. The street tires might have allowed just enough "slippage" to keep the engine in a sweet spot or something ????? Can't explain why, I can only tell you MY results with MY set up. As mentioned, I can see it going either way.

If you are using slicks and not comparing to stret tires and the 60 ft is getting better due to more gear, better tuning, making more HP, etc., than OBVIOUSLY the MPH will be more.

Lloyd

NightTrain66

 

Ive had it go both ways. On slicks, the harder i 60' the faster i trap.

On street tires, the more i spin the higher the traps. If you hook on streets you generally arent leaving as hard though, which would account for some of it.

I remember reading something from lingenfelter. He said 10% tire spin off launch is ideal for best ET/trap.

 

I know on our drag cars when we have a little tire spin right off the line (slower 60') we have more mph. I dunno if that tells you anything or not, but if you wanna get a good idea of how it works research a little into the NHRA prostock setups. They set their car up for a little tire spin off the line.