VINCE

iTrader: (1)

I want to know the rationale behind people claiming high traps speeds are attributed to spinning off the line. Are you actually going 130mph at the 1/4th mark or is there some kind of funky math that calculates this and while also taking spinning off the line as a factor. My ignorance needs to be educated.

SPANKY LS1

iTrader: (24)

I've think that MPH is more of a "true" indicator of power and torque because it is affected less by track "variables" than ET is. I know I have spun wildly off the line and not lost alot of trap speed, for example I ran 12.0s stock internal, at ~109-110. When I spun badly (2.0+ 60fts), my ET would suffer greatly, but my MPH was never less than 108.xx.

Shawn

383ss

iTrader: (14)

i don't know about that... it wasn't that way with my car. I was trapping 112 with street tires and putting out 400rwhp. then trapped 115 with 440 rwhp. put on slicks and trapped 120-122 with no other changes...

VINCE

iTrader: (1)

So basically spinning has nothing to do with it right? You are either going 130mph at the traps or you are not.

The Juggernaut

iTrader: (7)

You will usually trap higher spinning as opposed to bogging.(but not blowing the tires off,though)It applies more so to an under geared car.
I'm not J-ROD so I don't do 3,000 word posts.LOL

1BADAIR

iTrader: (1)

I always trap higher when I spin. In a M6 car its like having a stall convertor. The car gets to peak rpm quicker if you spin.

VINCE

iTrader: (1)

If you are correct why did 383ss run a higher mph with slicks?

gator's 99TA

iTrader: (2)

i along with nearly everyone i have ever seen has trapped higher consistently on slicks. 1) tire growth - though it is minimal 2) if you spin for lets say 60 feet, you have just taken away 60 feet of the track to accelerate. thus you will trap less with less track 3) if you can come out of the hole and be grabbing second gear by the 100 foot mark we ALL know you will be going faster (by simple math) than if you are spinning in 1st still.

we see this ALL the time when people are dissapointed with their new big cam big dyno setups, go to the track on radials, and think well they wont get a great ET but they will trap well....and they never trap big mph do they? ever run on ice?

SMOKIN01TA

iTrader: (10)

i traped high 118's with a sliping cluch running 11.9, with a new clutch ill be going like 11.0 @120. not much change in mph, much better traction. just think of the clutch as spinning tires.

CHRISPY

Me too
121 on street tires, 124 on slicks. I find how well you hook in second plays a huge factor in mph.

SilverGhost

iTrader: (53)

what 01z is saying is true. put a set of et streets on a car for example and make two back to back runs.

1st pass launch the car at an rpm that will bog the car, like 2 grand in a six speed or something. the car won't be in the powerband and will have to take the time to get back into it before actually getting down the track.

2nd pass luanch it at an rpm that will give some spin through the sixty foot and the MPH will be a few MPH more compared to when the car bogged. Like he said, not blowing the tires off, there is a fine line between a bit of spin and too much.

the question wasn't asking to compare street tires to slicks as several people have turned this into, it was about how mph is affected by spinning or not spinning. Of course a car that 2.3 sixty foots on a radial and then 1.6's on slicks is going to mph better on the slicks, that's not rocket science.

gator's 99TA

iTrader: (2)

i still dont buy this. the question relates to spinning out of the hole = higher trap speeds versus hooking. this isnt true. even if we eliminate the radial tire comment and talk straight et streets or slicks. launch at 6K rpms and get out of the hole and as you accelerate throughout the ENTIRE quarter mile, you WILL have a higher trap speed versus spining, bogging, or whatever. remember this is about acceleration.

SilverGhost

iTrader: (53)

i agree, of course a deadhook is the best option.

once again all i'm saying is that 01z is correct, we are saying that spinning vs bogging you will have more MPH with a slight spin. you bog it its not going anywhere.

i never said a deadhook and solid acceleration isn't the best option.

Roger White

Mph is a good sign of how much horsepower you are making if you are hooking. If you are wearing a good tire, the spin will not be that much of a problem.

So if some runs a 11.75 @ 127 on street tires you can bet a few mph of that will disappear with ET streets.

Likewise a 10.75 at 125 is most likely a real mph.

CHRISPY

I dont agree with that. I would think the car with hook would run a 10.3@130mph with a setup like you described. If you have significant wheelspin and are running radials...

gator's 99TA

iTrader: (2)

again why doesnt anyone talk about the "shortening" of the track when you spin for lets say 60 feet out there. you KNOW you are not acclerating to the combos full potential.

also we are still not addressing WHY so many cars mine included run better mph, usually 2+ mph on a low hp car like mine with slicks every time.

Roger White

Spin = greater mph
bog = less mph

Dead hook, no bog, no spin, = best ET

I guess I should have posted that. Or maybe not

CHRISPY

again that is incorrect (at least in my case)

slicks mph higher every time without fail. I find it is because the car on street tires breaks loose for all of second till third and scrubs off mph.

With the slicks there is no spinning on the shift (except for a chirp) and it rockets the car forward.

This is regardless of a 6000rpm dump or a off idle launch

Unusual T/A

I don't agree with this either, as when you are spinning you are taking away area to get down the track. Hence the shortening of the track to get to a certain speed. Think about what happens when your done spinning, your mph is going to go back down to a certain point and you have to start from there. I agree with Chris ARE 360 and gator's 99TA.

Joe Overton

low torque car or to low gearing spin = more mph
good torque car or to high gearing spin=less mph