[Topic Split] Does spinning = higher mph in the 1/4

[QWKSNKE]

i didn't know my KB was that loud lol. i love that sound to. i only ran ray to what my 1/4 speed usualy is & that's around 130 then i let off, did that every race.

When have you ever run 130 in the 1/4

[ChipR4cam]

When have you ever run 130 in the 1/4

:rofl:I guess he means what it would trap in theory.

[TheJeanyus]

When have you ever run 130 in the 1/4
It's kinda like Back to the Future - brake stand until the speedo reads 88 mph and let off the brake. :jester:

[Greg03Cobra]

funny i like that shit lol. lee i have trapped 127 before so i'm just going by the trap speed that others have with my mods as a reference of where i should be if this pos would run right for once.maybe one day my car will run right, when i put a ls7 in it.

[QWKSNKE]

What was your e.t. on the 127mph run?

[SphyNxXx]

.maybe one day my car will run right, when i put a ls7 in it.



:D

LS7 + FI = :burnout: x 1000000


Hehe....great engine, but that puppy will set you back about $12K

[Greg03Cobra]

What was your e.t. on the 127mph run?

it was 12.1 with wheelhop in 1st & sideways in 2nd on my drag radials. & i think a 2.0 60' brad & some other friends were there when i ran that. once my car hooks it pulls really hard but it don't hook to good with these drag radials.

[QWKSNKE]

Once you hook, you are probably going to see that 127 mph you have trapped drop.

[coupe]

Once you hook, you are probably going to see that 127 mph you have trapped drop.

:think:

Well, I uhhh...

:think:

Can someone explain this??? I have heard it before (higher mph theory due to tire-spin) but it just physically does not add up.
I think it is a misconception due to other factors myself. My car trapped more mph with the better 60' time. :shrug:

Maybe this discussion would need another thread.

[Blown 5.0]

:think:

Well, I uhhh...

:think:

Can someone explain this??? I have heard it before (higher mph theory due to tire-spin) but it just physically does not add up.
I think it is a misconception due to other factors myself. My car trapped more mph with the better 60' time. :shrug:

Maybe this discussion would need another thread.

Mine will usually trap about the same, maybe 1-2 mph off, but never higher?

[QWKSNKE]

:think:

Well, I uhhh...

:think:

Can someone explain this??? I have heard it before (higher mph theory due to tire-spin) but it just physically does not add up.
I think it is a misconception due to other factors myself. My car trapped more mph with the better 60' time. :shrug:

Maybe this discussion would need another thread.

tire spin will result in a higher e.t.

I have trapped over a 100 on a 15 sec pass in my 93 due to spinning so badly in 1st and 2nd gear. Came back around and ran high 13@99.x mph
That was when my car was stock.

With the blower my mph was all over the place depending on how bad I would spin but I NEVER made a pass where I hooked to tell you what the car would mph on a clean pass.

[QWKSNKE]

I would like to also add...

in my experience it seems the most difference in mph was when my car would spin a lot in 2nd gear. The more I spun in 2nd the higher the mph would be. 1st gear spins would effect it some but not if you are on and off the throttle repeatedly trying to get it to hook

[rtusnake]

It seems my car would do the same, the more it would spin the higher the trap would be. Strange thing is my best 60ft I ever had resulted in my best trap speed :huh:

[Greg03Cobra]

well i guess i'll just have to install a clutch & put some slicks on it & find out won't i. lee i need you to install a clutch.

[TheJeanyus]

Did you put the solid axle under it yet?

[ChipR4cam]

Did you put the solid axle under it yet?

Nope he's just gonna cross his fingers.:D



:huh:

[Greg03Cobra]

yep fingers crossed lol. i'm not doing a solid axle now, gonna show them how to do it with a irs. goin to install level 5's around summer.

[TheJeanyus]

It takes a lot more than level 5 shafts to make an IRS work right with a 600 hp car on slicks. If you're going to do a solid axle swap anyway, I wouldn't waste the cash on level 5 shafts either. For what those half shafts cost alone you could probably build a really nice live axle. I plan on doing all of the other "red pill" mods, then if a half shaft breaks I'll upgrade to level 5s.

I'm not saying an IRS won't stand up to your power level - everyone here knows I'm the biggest IRS fanboi around. I'm just saying without a few mods there is no way it's going to withstand that much torque on slicks. It might work a few times, but it's a grenade just waiting to go off.

[QWKSNKE]

Broke doesn't seem to have a problem with his IRS



and its stock!

[qkjuicedpony]

ive seen a few irs cars running deep into the 10's on slicks.just make sure it has good bushings and a brace.

[coupe]

Strange thing is my best 60ft I ever had resulted in my best trap speed

It's not strange michael...it's physics. Newton's Laws of Motion. If you're hooking, you're accelerating. Period. If you're spinning, you're wasting valuable ground that could be used to accelerate you. The more ground you can use to accelerate, the more mph you will have at the end of that distance.

All other differences must be attributed to other things.
:popcorn:

[Italian LX]

It's not strange michael...it's physics. Newton's Laws of Motion. If you're hooking, you're accelerating. Period. If you're spinning, you're wasting valuable ground that could be used to accelerate you.
:bs:

You're still accelerating when you spin, you're just taking longer to cover the same ground. If this wasn't true, than nobody would need to use their brakes when doing a burnout, right? :shrug:


The fact is, whether you spin or hook, you will always trap the same. (This is assuming that you never lift off the gas when you wheel spin and you don't hit the rev limiter.)

The reason why most people trap lower when they spin is becuase they lift to some extent during part of the run.

The reason some people trap lower when they hook (like Lee said) is because they are comparing a street tire run vs. a slick run. The slicks are normally a taller tire and will change your ratio which can affect trap speed.

[coupe]

You're still accelerating when you spin, you're just taking longer to cover the same ground. If this wasn't true, than nobody would need to use their brakes when doing a burnout, right? The fact is, whether you spin or hook, you will always trap the same.<--BS (This is assuming that you never lift off the gas when you wheel spin and you don't hit the rev limiter.)The reason why most people trap lower when they spin is becuase they lift to some extent during part of the run.The reason some people trap lower when they hook (like Lee said) is because they are comparing a street tire run vs. a slick run. The slicks are normally a taller tire and will change your ratio which can affect trap speed.

:nono: ...but the rate of acceleration is greater when you hook. The more acceleration you can have during that 1320', the higher your actual speed at the end will be.

But, one thing that can throw off numbers is how far apart the last two trap-timers are from each other. They are used to calculate trap mph...which is just short of the actual miles-per-hour your car is running at the exact time you cross the stripe.

So a vehicle that has a greater rate of acceleration during it's 101-105 period than it has during it's 103-107 period may show more trap mph if it passes through the stripe at an actual 104 than it would if it went through at and actual 105! :yup:

Figure that one out.

[QWKSNKE]

wished I could figure out how to explain this through typing. Hopefully Edgar can come on here and explain it.

All I can say is, it happens. But it (mph) is more prone to be affected if you are running street tires (and drag radials) Like I said in my original post, if you spin a good bit (including while in 2nd gear, your trap speed will be way off compared to a run where you have minimal tire spin

[Sendero]

I'm with Matt on this one; let me set this up so no one can "literalize" it.

Said car with consistant HP, shift points, and driving should trap higher with no tire spin than if a run has tire spin.

[rtusnake]

Broke doesn't seem to have a problem with his IRS



and its stock!

I'm going to put my halfshafts to the test as well. Lots of stock rears doing well with slicks, not to well on street tires and drag radials

[Skillet]

I ran the same MPH on a 2.1 60 as I did on a 1.70 60 with a 15" street tire the first time and a 28" slick the 2nd. 13.2@104 and 12.8@104.

[QWKSNKE]

I'm with Matt on this one; let me set this up so no one can "literalize" it.

Said car with consistant HP, shift points, and driving should trap higher with no tire spin than if a run has tire spin.

You can't. Tire spin throws all of your shift points out the window. That's why the issue with mph changing. You will shift sooner with tire spin than without and thats why you will see the difference in mph. You will actually be going through the traps at a different rpm (and maybe even a different gear) then you would if you were using all of the rpms in every gear.

[TheJeanyus]

Broke doesn't seem to have a problem with his IRS



and its stock!
Actually he has a Billetflow IRS brace and adjustable shocks. Without the BF brace, I'm sure he'd have blown the differential cover up the way he launches, and the adjustable shocks do a LOT against wheel hop.

[coupe]

As we've seen, shift points, throttle variations, spinning tires, tire compound, and probably several other factors can and will vary your trap speeds at the track.

But, there is no "magic" mph gain associated with tire-spin.
Once again, physics is shown to be a law, not a theory.
The perpetual motion machine has been foiled again. :D

[rtusnake]

Actually he has a Billetflow IRS brace and adjustable shocks. Without the BF brace, I'm sure he'd have blown the differential cover up the way he launches, and the adjustable shocks do a LOT against wheel hop.

I have the stock shocks on mine and mine doesn't hop at all with the slicks on. Believe it has to do more with the tires

[Italian LX]

But, there is no "magic" mph gain associated with tire-spin.
No, that's not what I'm saying.

I'll prove my point by throwing your statement back at you: There is no "magic" mph gained when you hook.

Looks like your the one trying to invent the perpetual motion machine. :D

[Italian LX]

I ran the same MPH on a 2.1 60 as I did on a 1.70 60 with a 15" street tire the first time and a 28" slick the 2nd. 13.2@104 and 12.8@104.
That right there supports my theory. :nice:

[coupe]

There are other factors causing it...That's all I'm trying to say.

Wheelspin does not cause your mph to be higher in a run. Nope. :shake:

Mph is gained when you hook because you are accelerating at a greater rate than when your spinning. It's not magic.

It's physics. :shrug:

[Wickd GT]

When you spin from you 60' to 330' mark, which are the most critical phase on a run, if it spins and the car stays straight, the tires have a motion on them, then when it hooks, you final et is going to be slow, but it would show a slight bit of mph, not in the effect on the hp, it shows that the car recover and put at the other half of the track its hp. Example: my 60ft time will be in a hooking track 1.55 blowing the tires(At FFW) and spinning through the 330' mark, my 1/8 mile shows a 6.40 at 112 mph and then run faster at the other end with a 9.95 at 137.90 mph at the other end the mph stays in between 138-139mph, but in the 1/8 it says that the et should of been slower, but the mph says the car was spinning. I don't mean that car gains mph in the 1/4 mile, but it would show a mph that makes raise your eye brows.


Edgar

Sorry I have not been around, but have been sick as a dog. Have not been ar work for a week, been in bed.

[TheJeanyus]

My car traps higher the harder it hooks. 2.1 or worse 60' is usually 115 mph, 2.0 is about 116 mph, Matt's 1.9 60' was 118 mph.

[Italian LX]

My car traps higher the harder it hooks. 2.1 or worse 60' is usually 115 mph, 2.0 is about 116 mph, Matt's 1.9 60' was 118 mph.
Not a very good comparison because none of those were all-out pedal-to-the-floor runs.

[TheJeanyus]

Not a very good comparison because none of those were all-out pedal-to-the-floor runs.
Are you saying that I lifted on all of those passes? At Steele my car spun all the way through 2nd without me letting off on multiple passes. I've run in the neighboorhood of 12.5 without lifting, 60' around 2.0, and trapped 116.

Or are you just trying to find a nice way to say I'm a shitty driver? :think:

[Greg03Cobra]

Joseph i'm not doing the solid axle now. I'm building the shit out of the irs. After talkin with broke a few times & my mechanic i realized that the irs is the way to go. My question for everyone is back in november i saw a 03 cobra at steele that has the same mods at me. His 1st run was a 10.4 at 132 sideways with the backend almost on the wall the entire 1/4/ then he hooked real hard & didn't spin at all & ran a 10.3 at 132. He was on slicks & skinnies. I'm just tryign to learn as much as i can here so lets keep this goin.

[TheJeanyus]

I'm a firm believer in keeping the IRS - I just thought you'd mentioned a solid axle before. I didn't know you were planning to build the IRS up. My long-term goal (if I keep my car) is to have it in the 10's on IRS with full weight and all the creature comforts still in place.

[Greg03Cobra]

I was going to do the solid but chose to keep the IRS around Thanksgiving. Really seeing Broke run at track day is what made my mind up. I beleive when i get all the bugs worked out on my car & learn to drive it right i will be in the 10's no prob. How hard was it to install the bushings & brace on your car?

[TheJeanyus]

Both were sort of a PITA honestly. IIRC, the IRS bushings took about 9 hours - no joke. Lee and Brian can vouch for how much it sucked. The brace wasn't nearly as bad except that it's nearly impossible to get to a couple of the bolts.

ETA: I think we're going to need another thread split. :D :lol:

[rtusnake]

Both were sort of a PITA honestly. IIRC, the IRS bushings took about 9 hours - no joke. Lee and Brian can vouch for how much it sucked. The brace wasn't nearly as bad except that it's nearly impossible to get to a couple of the bolts.

ETA: I think we're going to need another thread split. :D :lol:

I'm going to install the slp line lock next week so I will let you know how much more a pain you will be looking forward to:yup:

[TheJeanyus]

I'm going to install the slp line lock next week so I will let you know how much more a pain you will be looking forward to:yup:
I really need to get mine installed. :banghead:

I'll be installing a JLT and MAF Xtender tomorrow. :banana: And hopefully the new tunes that Ed wrote for me will take care of my detonation problem in cold air. :banana2:

[coupe]

Not a very good comparison because none of those were all-out pedal-to-the-floor runs.

No, it was an excellent comparison.

Better hook, higher mph out the back door.
Physics.
Not magic.
:dance:

And more proof (my car):

Slicks:
1.9 60' - 12.95 @ 107
1.8 60' - 12.74 @ 109

Earlier that year on radials:
2.3 60' - 13.65 @ 105
2.1 60' - 13.55 @ 106

[Italian LX]

No, it was an excellent comparison.

Better hook, higher mph out the back door.
Physics.
Not magic.
:dance:
If you don't use full throttle during the entire run, then you're not using the same amount of power and the comparison is no good.

If we went by that, then I could do a complete half-throttle run and be hooking the whole way and I can guarentee that my mph would a lot lower than the full-throttle run spinning through 1st and 2nd. :P


And more proof (my car):

Slicks:
1.9 60' - 12.95 @ 107
1.8 60' - 12.74 @ 109

Earlier that year on radials:
2.3 60' - 13.65 @ 105
2.1 60' - 13.55 @ 106
Proof? :lol:

I've had difference like that at different time os the year with the exact same combos!

. . . it's called weather changes. Comparisons need to be on the same day for them to mean anything to me.

[slvrbullit]

No, it was an excellent comparison.

Better hook, higher mph out the back door.
Physics.
Not magic.
:dance:

And more proof (my car):

Slicks:
1.9 60' - 12.95 @ 107
1.8 60' - 12.74 @ 109

Earlier that year on radials:
2.3 60' - 13.65 @ 105
2.1 60' - 13.55 @ 106


Here is some proof that tire spin in my car equals higher MPH.


3yrs ago ran a nitrous pass on street tires:

12.8 at 119 with 2.3ISH 60'

Then an hour later after bolting on the slicks,

12.43 at 108 with a 1.6ish 60'

Both runs I crossed the line in the same gear just as my shift lite was coming on at 5800.

[QWKSNKE]

Here is some proof that tire spin in my car equals higher MPH.


3yrs ago ran a nitrous pass on street tires:

12.8 at 119 with 2.3ISH 60'

Then an hour later after bolting on the slicks,

12.43 at 108 with a 1.6ish 60'

Both runs I crossed the line in the same gear just as my shift lite was coming on at 5800.


Thank you Tommy, that is the same type of runs I have experienced but I didn't have the timeslips to give exact examples.

[Sendero]

So I guess loss of traction equals higher MPH trap, right?

[QWKSNKE]

So I guess loss of traction equals higher MPH trap, right?

In a lot of cases, yes

[coupe]

You guys actually have yourselves convinced. :huh:

I've had difference like that at different time os the year with the exact same combos!
. . . it's called weather changes.

:slap: But these were back to back runs.


3yrs ago ran a nitrous pass on street tires:
12.8 at 119 with 2.3ISH 60'
Then an hour later after bolting on the slicks,
12.43 at 108 with a 1.6ish 60'

But turning off the Nitrous ruins the credibility of that one. :nono2:

If conditions could really be controlled and tested with precision, you guys would see the truth...

See, what we have here is an old myth...a wives tale that I've heard for years. Some of these things are just drilled into us at the track and we believe them...often times to try to explain our mis-shifts, poor driving, or just plain crappy tunes. Not pointing fingers obviously, I would be the last one to say I'm a good racer...I have way less track time than most of you.

But if conditions are the same and wheelspin is controlled (which is unlikely), the passes with more traction will always have more mph at the big end. If not, something's wrong with the timers or the car, or some other parameter.

Think about it:
Trying to get from A to B in as little time as possible requires the greatest acceleration possible. Right?
Getting the greatest acceleration possible from your car requires traction. Right?
Achieving this greatest amount of acceleration (with traction) from A to B will yield the maximum speed during the trip at point B. Right?

:smartass:

Actually, it is Rocket Science.

[QWKSNKE]

You guys actually have yourselves convinced. :huh:




But turning off the Nitrous ruins the credibility of that one. :nono2:

.

:lol: You can tell by looking at his 60' the nitrous was not turned off.

Its easy to convince ourselves when we have done it. Please spare me your theories and laws you have read in a book somewhere, they are not credible to me as real world experience.

[coupe]

Please spare me your theories and laws you have read in a book somewhere...
:slap: No, I googled it.

Its easy to convince ourselves when we have done it.
Well, some of us have done the opposite. :shrug: Does either one validate our stance? No. What I'm trying to say is the track runs aren't offering any proof. Too many other variables.

And I don't believe a car can go 119, then 108 on the next run (with the same amount of nitrous) unless the second run is all tire-spin...or there is a malfunction in the nitrous. Slvrbullit has a ton of track experience, but I think there was something else amiss on that example.

[Sendero]

I can accept that good traction results in a lower ET and average MPH because if a car truly "hooks" and has consistant shift points, then it will be at the same RPM and gear selection at the timers which in turn equals MPH (save for rolling and aerodynamic resistance). Because their isn't a loss of traction, the car can cover the set distance in the quickest amount of time.

What I cannot accept is that a spinning tire equals higher velocity. Since F=m(a) and a=delta v/t; if you can't apply force to the ground then what is causing the higher mass acceleration, time? I'm sure some equations and variables are missing, but it should cover the main point.

Damn, I should of paid more attention in applied physics.

[Italian LX]

What I cannot accept is that a spinning tire equals higher velocity.
Just to clear things up, I'm not saying it yeilds a higher velocity -- I say that the traps speed will be the same.

[QWKSNKE]

:slap: No, I googled it.


Well, some of us have done the opposite. :shrug: Does either one validate our stance? No. What I'm trying to say is the track runs aren't offering any proof. Too many other variables.

And I don't believe a car can go 119, then 108 on the next run (with the same amount of nitrous) unless the second run is all tire-spin...or there is a malfunction in the nitrous. Slvrbullit has a ton of track experience, but I think there was something else amiss on that example.

Have you ever owned a car that would spin 1st-3rd gear on street tires at the track? I am not talking about 'chirping' the tires between gear changes either.

I have a little bit of track experience as well between the 3 mustangs I have owned that saw a quite a bit of track time (the 93 alone has over 300 passes on it). I guess there was something amiss on my runs as well.

That's ok though. You and I will have to agree to disagree. :nice:

[slvrbullit]

You guys actually have yourselves convinced. :huh:



:slap: But these were back to back runs.



But turning off the Nitrous ruins the credibility of that one. :nono2:




The nitrous was not off and there were no missed gears or anything, there were even a couple other people that witnessed it at Steele. It has also happened at Lassiter, Holiday, and Chilton County.


I guess I need to take it to the track and prove it.

[rtusnake]

I really need to get mine installed. :banghead:

I'll be installing a JLT and MAF Xtender tomorrow. :banana: And hopefully the new tunes that Ed wrote for me will take care of my detonation problem in cold air. :banana2:

Did you get your car redynoed? If so did it make more power? Btw it took alittle over 3.5 hours tonight to install the line lock

[TheJeanyus]

Did you get your car redynoed? If so did it make more power? Btw it took alittle over 3.5 hours tonight to install the line lock
The intake still is not installed. So far the tube is in place, the mass air meter is half way installed (plugged in, but not attached to the tube), and the air filter is in the trunk in the box. :banghead:

[Ramsiec5]

Send this one to the MYTH BUSTERS! lol

[rtusnake]

Send this one to the MYTH BUSTERS! lol

I was thinking the samething the other night :chug:

[SvoBrown]

Keep in mind this is a brain that has been down the track maybe 10 times.
A while back there was a video of slow motion drag cars starting at the line. The hole way the tire would slip little by little. I know the clutch slips off the line also. This lets the engine rev and make power without the bogg.
If the tires did not slip any then the engine would lose power because of the loss of motion in the tires.
With the tires spinning the engine operates at the most power. Tires not spinning the engine has more load on it and will lower power until the rpms catch back up.
I would think the spin also makes more torque like a lower gear would.


No spin gets you out of the hole very quick but may bogg the motor some after the 60 ft.

My head hurts more now than before I had to get up for drugs.

[Blown 5.0]

I just have to add this, How much tire slippage does it take to acheive maxium accelateration, traction???

[SvoBrown]

Slipping the clutch you can make more power and faster times starting out of the hole. I do anyway. I would think the same would be for tires getting power to the ground.
If everything hooked up, something would break or bogg.

Now I am going back to my autocross that I'm not much better at.

[QWKSNKE]

Keep in mind this is a brain that has been down the track maybe 10 times.
A while back there was a video of slow motion drag cars starting at the line. The hole way the tire would slip little by little. I know the clutch slips off the line also. This lets the engine rev and make power without the bogg.
If the tires did not slip any then the engine would lose power because of the loss of motion in the tires.
With the tires spinning the engine operates at the most power. Tires not spinning the engine has more load on it and will lower power until the rpms catch back up.
I would think the spin also makes more torque like a lower gear would.


No spin gets you out of the hole very quick but may bogg the motor some after the 60 ft.

My head hurts more now than before I had to get up for drugs.

interesting post

[slvrbullit]

Another example, from 5.0 of MM&FF, was earlier last year on a shakedown run Tim Lynch at E-town ran a 6.6ish at 215mph, then on another pass went a 6.8ish 223mph and the article said it was due to tire spin off the line.

[qkjuicedpony]

Joseph i'm not doing the solid axle now. I'm building the shit out of the irs. After talkin with broke a few times & my mechanic i realized that the irs is the way to go. My question for everyone is back in november i saw a 03 cobra at steele that has the same mods at me. His 1st run was a 10.4 at 132 sideways with the backend almost on the wall the entire 1/4/ then he hooked real hard & didn't spin at all & ran a 10.3 at 132. He was on slicks & skinnies. I'm just tryign to learn as much as i can here so lets keep this goin.



was that car burgandy?