Rambling Thoughts on Land Speed Racing....

[Sumner]

It is the last week that the store will remain open before we close it for good and since I haven't seen too many customers   I've been spending some time writing what I've called.............

..........."Rambling Thoughts on Land Speed Racing"...........

The link to it is  ( HERE  ) .  I'll probably be surprised if anyone actually reads all of it.

I'm open to constructive criticism on it, but remember it is free and you can stop reading it any time you feel like it .

c ya,

Sum

[Seldom Seen Slim]

What a disappointment!  I thought it was going to be a nice, heavy, philosophical treatise that'd help me with my insomnia.

Sum, I finished the Bill Ward book you lent me, and I'll send it back.  Thanks -- I enjoyed it.

[Sumner]

What a disappointment!  I thought it was going to be a nice, heavy, philosophical treatise that'd help me with my insomnia.

Sum, I finished the Bill Ward book you lent me, and I'll send it back.  Thanks -- I enjoyed it.

I figured it might put someone to sleep .

I'll send you an address for the book as I'm going to have you send it on to Hooley and he can read it and then get it back to John.

Look at your PM's,


Sum

[jimmy six]

I found your transmission study to be most interesting. If you feel that the overdrive is the best way to go, consider Tex-Racing. Because of others on this site I purchased one made to my specs. Have them send you the gear sheets available and you will be surprised.

They of course do transmissions and rear ends for many Nascar teams. Many use their transmissions for one race or maybe less before rebuild with new parts.

I purchased one made of aluminum which is no longer used by the major teams. They look like your typical GM 4-speed but they are hell for stout. Thay are thicker everywhere and can be had with cooling and a pump if needed. They made mine with the gear combo I selected with the 3rd gear position being an overdrive. Since we push off anyway 1st is not that important so I started with 1.60, 2nd is 1.23, 3rd is 1.0 and new 4th is.96..
I could have picked many selections from .80 to .98 for that OD gear.

These were typically used at Pocano until outlawed by the France family.
Anyway the prices are very reasonable with the "used" gears with all new bearings and such. Extra "3rd" gear sets can be bought for $75 a set, and changed in the pits by anyone understanding a 4-speed. You shift them like you stole them with no clutch needed unless you want to. Ours came with a new shifter (Hurst or Long) at a price a few thousand less that what you have in the article......An OD does take a little more HP but the closer to 1to1 the less it is....Good luck J.D.

[terry russell]

Thanks( gave me a head ach trying to soak it all in)great info for us (me) behind on the learning curve.
Thanks again for the info
terry

[Sumner]

I found your transmission study to be most interesting. If you feel that the overdrive is the best way to go, consider Tex-Racing. Because of others on this site I purchased one made to my specs. Have them send you the gear sheets available and you will be surprised.

They of course do transmissions and rear ends for many Nascar teams. Many use their transmissions for one race or maybe less before rebuild with new parts.

I purchased one made of aluminum which is no longer used by the major teams. They look like your typical GM 4-speed but they are hell for stout. Thay are thicker everywhere and can be had with cooling and a pump if needed. They made mine with the gear combo I selected with the 3rd gear position being an overdrive. Since we push off anyway 1st is not that important so I started with 1.60, 2nd is 1.23, 3rd is 1.0 and new 4th is.96..
I could have picked many selections from .80 to .98 for that OD gear.

These were typically used at Pocano until outlawed by the France family.
Anyway the prices are very reasonable with the "used" gears with all new bearings and such. Extra "3rd" gear sets can be bought for $75 a set, and changed in the pits by anyone understanding a 4-speed. You shift them like you stole them with no clutch needed unless you want to. Ours came with a new shifter (Hurst or Long) at a price a few thousand less that what you have in the article......An OD does take a little more HP but the closer to 1to1 the less it is....Good luck J.D.

Thanks J.D., from what I could find and after some phone calls I was under the impression that Tex-Racing and G-Force were one and the same.  If I remember right I called Tex-Racing and asked some questions they couldn't answer and they gave me the number for G-Force.  

We would like to find a used one and have started to search.  I would still like to find a 5 speed if possible, but I think they are going to be way harder to find as NASCAR didn't/doesn't use them only the 4 speed.  I need to find a source for used road racing stuff as they seem to be the ones using them.

Jerico told me that they could set up a 5 speed with "square" sliders if I remember right that would keep the transmission in gear on the salt if the throttle is lifted, but would still work well at the drags.  Hooley is looking to maybe with gear changes in the transmission using it at the drags the rest of the year.  It would save him from having to find another transmission to use there.  If we went with a purpose built one then used is going to be hard to find probably.  I didn't get back to G-Force to see if they could make an equivalent transmission.  Both of them are very close in price for an equivalent transmission.

Last year when I looked the cheapest used transmission was about $2200 for a 4 speed.  I was interested in your used gear set prices as it looks like new ones go for about $350 a set.  If you have a source for used transmissions and/or gear sets could you PM me??

Are you using the V-gate or H pattern shifter??

BTW if anyone is interested here are the links to the gear sets for both G-Force and Jerico transmissions and for the 4 and 5 speed:

http://www.gforcetransmissions.com/techdata.asp

http://www.jericoperformance.com/2.html  (look at right side of page)

Thanks,

Sum

[bobadame]

Sum, thank you for doing this.

[jimmy six]

I looked on the net and didn't find what used to be there on Tex Racing. The person I talked to was Rick and he told me about using the aluminum case which was no longer used by Nascar and they had plenty of them. I use a H pattern and the price for the gears was from him.

The only problem I had was I purchased a yoke from them and it broke on the first pass in 2004. Lucky it didn't hurt anything. I called and sent it back but never heard anything from them.

KT is the one who put me on to them and the barely used stuff. It was a T-101. I could have had a new one with the extra center bearing but felt I didn't need it. Total price was near 3K and I thought that was "inexpensive" and would do it again. Crap my pistons and rods cost that much. Good Luck..J.D.

I'll try to find the # I called

[Elmo Rodge]

http://www.texracing.com/  And I have 910 428 9522 from the website. Wayno

[WZ JUNK]

I do not express myself well in type but I felt that I wanted to say something.  I have got to know several of the people who post here and I wanted to add some thoughts that are distantly related to Sumners post and are part of the Bonneville LSR experience.  It is my rambling.

When I read Sumners post on his rambling thoughts about LSR it got me to thinking about my thoughts and feelings about the same subject.  Mine are not technical thoughts but impressions and feelings I have about being a part of a team and running a car at Bonneville.  I have decided not to pursue and participate in landracing in the future.   I would like to go back to the salt when Sumner runs his lakester but I will not be involved with the #974 anymore.  This decision did not come about because of any personal problems with Hooley or anyone else but rather a life choice.  Many times the paths that we take in life are determined by events that we have no choice in the direction that we must go.  This time I had a choice.   I have several other areas of motorsports that I want to try and my time to do this is running out.  At anytime I may go back to LSR.   I check the LSR board a couple of times a day and I am very interested in what is going on.  Nuff said about that and now on to the important stuff.

Our first trip to Bonneville was a street rod trip through part of the west and on to Speedweek.  We were all overwhelmed with the whole atmosphere of Speedweek.  When we came back and Hooley said that he was going to build a car, I wanted to help.  I had read about Bonneville since I was a kid and although going there was really special, suddenly I was going to actually get the chance to help build and run a car.  It was something that I never thought would happen.  I will never forget the time that I spent working out the problems we had with the car, designing and building parts for the car, and trying to massage a rusted bunch of metal back into a car body.  The trips back and forth to the salt where an adventure in its self.  I met so many interesting people and I got to see projects that people have spent a good part of their life working on.  The quality of workmanship and the thought that went into these vehicles is mind boggling.  Being a crew chief the last couple of years was another very memorable experience.   I did things that in the past I took for granted and I realized that there were lots of decisions, planning, and work that I just never thought about before.  Everyday things like making sure we had food for lunch and that everyone drank enough water.  Simple stuff that you just do not think about ordinarily.   There is a long list of other jobs like making sure there is someone to do all the preparation that goes with getting the car to the line, then getting the car started and then pushed off.   I really enjoyed it all and I think about the experience nearly every day.  In the future when you are running on the lakebeds or at Bonneville, I will be there with you in my thoughts.  What an experience it has been and I thank all of you that I met, and all of you that helped us.

John

[John Burk]

Sum
I agree that a 4000 pound streamliner going from 330 to 350 in the last mile appears to be mainly fighting air drag but here are the numbers .

Gaining 29.4 ft/sec in 10.56 seconds (340 mph) is .089 g's
.089 g's x 4,000# = 356#
356# x 500 ft/sec divided by 550 = 324 hp

Based on the rolling drag numbers I've seen from the Ohio electric streamliner and the Goldenrod I'd say the power from the 4,000# streamliner is roughly equaly split between acceleration , aero drag and rolling drag .
John Burk

[Sumner]

Sum
I agree that a 4000 pound streamliner going from 330 to 350 in the last mile appears to be mainly fighting air drag but here are the numbers .

Gaining 29.4 ft/sec in 10.56 seconds (340 mph) is .089 g's
.089 g's x 4,000# = 356#
356# x 500 ft/sec divided by 550 = 324 hp

Based on the rolling drag numbers I've seen from the Ohio electric streamliner and the Goldenrod I'd say the power from the 4,000# streamliner is roughly equaly split between acceleration , aero drag and rolling drag .
John Burk

Hi John, I would agree with that as the cars in your example haven't reached their top speed and are using a lot of HP still accelerating and the rolling drag is going to go up at those high speeds also.

In the one formula I included, HP = [(W X R) + D] X V divided by 375, R is the rolling Rolling Resistance and whoever came up with that formula stated the 0.008 is a good value for highway speeds for R and over 150 mph maybe double R to 0.016.  I have a feeling that the over 150 value wasn't meant to represent really high speeds, like let me guess over 250 (my guess only), so it needs to go even higher for you guys running over 300.

In most of what I wrote I used Hooley's car as an example since I have data on it.  The point you are making would have been true in our case in the 3 to 4 mile section where we were still accelerating at a pretty good clip.  At any point in that mile the HP needed to over come the aero drag would have been represented by the HP needed formula for the speed at that point.  Also the weight on the drag wheels would have been shown by the other formula.  If there would have been excess HP and still traction available with the drive weight exceeding the weight needed for traction then the car would have been accelerating as per your example with the excess HP.

In our 5th mile where we hardly picked up any mph we could now see that the HP was all going into the aero drag and rolling resistance with I believe (at 240 mph) the majority of the HP going into the aero drag.

So you bring up a good point I was trying to show what happens when the car reaches max. speed with available HP and traction assuming it had enough time for acceleration to get there.

Your points need to be added to the discussion (more has to be written) so a person can figure the acceleration possible with their car and the track conditions.  This would also tie in with (what Tom e-mailed me)  about picking gear ratios for the transmission that would allow you to accelerate under ideal conditions.

Maybe you could help me with that section.  I think your math skills are better than mine .

c ya,

Sum

[PorkPie]

Sum....

I read your "rambling...."

a interesting reading......you picked also on the point "aerodynamic" as important.......but what is "aerodynamic"........

....may be you read my point of view to this issue.......

[hotrod]

Sum


The original source of that formula is probably the following;

Bosch Automotive Handbook
pg 418
Motor-Vehicle dynamics

Rolling resistance

The rolling resistance FRO is the product of the deformation processes which occur at the contact patch between tire and road surface.
FRO = f[/b] * G * COS a = f[/b] * m * g[/b] * COS a

=======================
f[/b] = coefficient of rolling resistance
G = weight (mass * g)
Cos a = cosine of road surface slope angle
m = mass
g[/b] = acceleration due to gravity 9.81 m/s or 32.2 ft/sec
=======================

An approximate calculation of the rolling resistance can be made using the coefficients provided n the following table and the diagram on P 379.

The increase in the coefficient of rolling resistance f[/b] is directly proportional to the level of deformation, and inversely proportional to the radius of the tire. The Coefficient will thus increase in response to greater loads, higher speeds and lower tire pressures.

Road Surface      Coefficient of rolling resistance f[/b]
______________________________________________
Pneumatic tires on:
Large sett pavement         0.013
Small sett pavement         0.013
Concrete, asphalt            0.011
rolled gravel            0.02
Tarmacadam            0.025
unpaved road            0.05
field               0.01 --- 0.35

...

Steel wheel on rail         0.001 -- 0.002

-----------------------------------------------------------------------------------

Here is another authoritative source that explicitly cites a speed factor for rolling resistance:
This is where the rolling resistance value that I use in my calcs comes from. This source uses the approximate calculation for air drag
(.00249) (ACd) V^2  which gives values about 8% low because it uses improper units (mph^2), so in my calculations I use the proper calculation which includes air density and ft^2 for the velocity.

Pg 151
Near-Term Hybrid Vehicle Program
Final Report - Phase I

Contract No. 955190

Written by General Electric Company
submitted to JET Propulsion Laboratory
Oct 8, 1979

================
D Total Vehicle Drag

Summing the effects outlined above, the expressions for the drag of the hybrid vehicle in the equilibrium condition (warm tires) can be written:

F = .011 W + .00003 WV + (.00249) (ACd) V^2

= .011 W + .00003 WV + .02 V2

Where

W = vehicle wt. (pounds)
V = vehicle speed (mph)

========================

Larry

[Greyboy]

My two cents...

Sumner, I really enjoyed your miscellaneous ramblings on lsr, particularly the section on aero. I am the furthest thing away from a mathematician, but have always wondered about a couple of concepts I have not seen developed in lsr.

1) Supercavitation ~ I quote from Wikipedia for a definition better than I could write:

"Supercavitation is the use of cavitation effects to create a large bubble of gas inside a liquid, allowing an object to travel at great speed through the liquid by being wholly enveloped by the bubble. The cavity (i.e., the bubble) reduces the drag on the object and this makes supercavitation an attractive technology; drag is normally about 1,000 times greater in water than in air."

Does that mean that using a perforated body skin on a streamliner with the right amount of air being pumped out of the car in the right places could have a big enough role in reducing drag? Having not probed the depths of the rulebook (my bad) I don't know if there's a stipulation about on-board engines/motors needing to be involved in vehicle propulsion only (maybe to prevent a Chaparral 2J fiasco) but if so, maybe a wheel-driven pulley could spin an air pumper that...

2) Vortex Generators ~ again I quote from Wiki:

"The purpose of the generators is to stick out of the stagnant air near the surface of the wing, and into the freely moving air outside the boundary layer. This layer is typically quite thin, but dramatically reduces speed of the airflow towards the rear of the wing. The generators mix the free stream with the stagnant air to get it moving again, providing considerably more airflow at the rear of the wing and thereby providing the control surfaces with more power. This process is typically referred to as re-energizing the boundary layer."

(Me again) In lsr I would think that having a tidy airflow at the back of the car would be as important as the front. I've seen vortex generators on only a few race cars, an old Indy Eagle, and on the back deck of one John Force's floppers.

Maybe these two concepts provide not enough gain for the trouble, or wind tunnel $ is best spent on other bigger issues. For interest, I found a picture of a shark's skin; it's vortex generating surface results in a more slippery body that I would guess needs less energy to go through the water...

www.filmstream.com.au/ extraordinary.html

Thanks for enduring my own ramblings ...