Author Topic: TFA Racing Lakester "tweak" diary  (Read 98015 times)

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Offline Sumner

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Re: TFA Racing Lakester "tweak" diary
« Reply #150 on: September 24, 2014, 10:12:05 AM »
... so long as the higher traction side can handle the higher percentage of applied torque, no relative wheelspin will occur. ...

The Torsen can't fix all traction problems.  As long as you don't overpower it I would think the car would go straight since neither wheel is spinning faster than the other even though more power is being transmitted to the ground through one vs. the other. 

Overpower it and you can get out of shape just like you can with an open rear or locked one or other type of posi. 

The open rear is the most forgiving in that it won't step sideways as fast as you still have 3 tires that have traction, but it is also the first to break a tire loose and just spin that tire and the car stops or slows acceleration.

Locked or posi rears are going to stay hooked up longer than an open rear but once they break loose then the back is going to want to take off in one direction or the other only to be stopped by lifting, the chute or hopefully the CG is ahead of the CP  :-).

Another link for you...

http://www.maximummotorsports.com/Torsen-Limited-Slip-Differential-C157.aspx

...and this should be the company but it wasn't coming up this morning...

http://www.torsen.com/

Sum

Offline Interested Observer

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Re: TFA Racing Lakester "tweak" diary
« Reply #151 on: September 24, 2014, 12:01:12 PM »
Quote
I would think the car would go straight since neither wheel is spinning faster than the other even though more power is being transmitted to the ground through one vs. the other. 

Sumner--relative wheelspeed is not the determinant of whether the car will “go straight”.  The tractive effort supplied by either wheel would be the pertinent quantity.  If one side has 3 times the tractive effort, i.e. a 3:1 torque ratio, that will induce a yaw moment which will be seen as a tendency towards a direction change.  As the torque ratio changes due to surface condition (traction) changes, directional “hunting” will be the observed effect.  Any diff that biases the torque will, for this reason, produce this effect.

Clearly an open diff (a torque divider) would be preferred up until overall traction limits become a problem.  Then it is a matter of adding weight or trading off stability for velocity.


Offline SPARKY

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Re: TFA Racing Lakester "tweak" diary
« Reply #152 on: September 24, 2014, 12:02:32 PM »
After reading this this morning---something occurred to me---in the last 30 years how much has changed with fwd cars they used to be horrible to drive in rain---some were down right dangerous-- I have seen many that had spun off the road during rain storms.

 GM had a problem and then they programed the "system" to drop cruise control at the first sign of wheel spin.  They were also working on no reverse steering inputs---ie wheel spin jerking the steering wheel---Karl  you most likely do not want to have to put a late model steering system in your car.  I would recommend a 40 to 1 ratio and pick as much of it as you can with mechanical advantage with the steering arm lengths.. YMMV

PS  the reason so many FWD car manufactures choose the Torsen  may be to keep the wheel speed the same is to minimize steering wheel jerk in hydroplaning situations
« Last Edit: September 24, 2014, 12:06:06 PM by SPARKY »
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline jdincau

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Re: TFA Racing Lakester "tweak" diary
« Reply #153 on: September 24, 2014, 03:49:19 PM »
After reading this this morning---something occurred to me---in the last 30 years how much has changed with fwd cars they used to be horrible to drive in rain---some were down right dangerous-- I have seen many that had spun off the road during rain storms.

 GM had a problem and then they programed the "system" to drop cruise control at the first sign of wheel spin.  They were also working on no reverse steering inputs---ie wheel spin jerking the steering wheel---Karl  you most likely do not want to have to put a late model steering system in your car.  I would recommend a 40 to 1 ratio and pick as much of it as you can with mechanical advantage with the steering arm lengths.. YMMV

PS  the reason so many FWD car manufactures choose the Torsen  may be to keep the wheel speed the same is to minimize steering wheel jerk in hydroplaning situations
Isn't this the reason to keep the scrub radius zero on front wheel drive?
Unless it's crazy, ambitious and delusional, it's not worth our time!

Offline SPARKY

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Re: TFA Racing Lakester "tweak" diary
« Reply #154 on: September 25, 2014, 01:02:44 AM »
that is one of them  but I think all cars will handle better with 0 scrub radius
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline entropy

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Re: TFA Racing Lakester "tweak" diary
« Reply #155 on: September 27, 2014, 10:22:49 AM »
Man o' man, TFA received a ton of good discussion on our Lakester's handling issue.
Thanks to everybody! :cheers:

And that reminds me...
It's also time to thank SSS for maintaining landracing.com & encouraging the kind of participation we just experienced. :cheers:
I'm guessing i can find the "Thank You" button somewhere here

Next topic i want to get educated on is very high performance 260cid, V8 NA engines... 
I am sure lr.com already has a great thread on that topic.

karl

Offline Rex Schimmer

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Re: TFA Racing Lakester "tweak" diary
« Reply #156 on: September 28, 2014, 09:08:27 PM »
Easy answer, Keith Dorton, Automotive Specialist,  www.automotivespecialists.com, 4357 Triple Crown Dr SW, Concord, NC 28027
(704) 782-0420.

Great guy, great motors.

Rex
Rex

Not much matters and the rest doesn't matter at all.

Offline entropy

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Re: TFA Racing Lakester "tweak" diary
« Reply #157 on: September 29, 2014, 04:40:55 AM »
Easy answer, Keith Dorton, Automotive Specialist,  www.automotivespecialists.com, 4357 Triple Crown Dr SW, Concord, NC 28027,  (704) 782-0420.  Great guy, great motors.
Rex

Rex, thanks!
their web site seems to be down but i poked around their facebook page.  
Seems like they have been building motors for a LONG time!

What i am looking for is an education in D & E sized motors.
I am a complete novice about car motors and want to cure that ignorance.  I know plenty much about the 1630 Busa motor, every facet of building.  I am a one trick pony, but that detailed Busa knowledge should (might) allow me to at least ask a few 1/2 intelligent questions. 

Max hp and build cost are obviously important, but max hp at the lowest build cost may NOT lead us to the BEST motor for us.  It all starts with definition of our objectives, and those objectives may evolve as we see what the options are.

Basically, i want to build a big spreadsheet which captures all significant factors (w/pros & cons) which would play into selecting a much higher hp motor for our lakester.
My partner has some good experience & knowledge in this area and quickly starts talking about a D motor and even where he would source it.  He is lucky to have this info.

On the other hand, his knowledge may be excluding a better solution.  Probably not, but maybe...
I will just feel better about our new motor selection if i know exactly its pros & cons vs other options.
« Last Edit: September 29, 2014, 04:49:58 AM by entropy »

Offline entropy

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Re: TFA Racing Lakester "tweak" diary
« Reply #158 on: October 11, 2014, 09:31:04 AM »
TFA Racing had a great WOS event and my Partner & I are great buds, but last week he offered to sell me his 50% in TFA Racing.
Dang sure i bought it, but with Don leaving TFA, we have lost our fabrication guru :-(

Upshot is I need to quickly identify and engage a very safe, competant, available, innovative, cheerful, energetic, etc, fabricator (Boy Scout?).
A guy who says "4-6 weeks" and kinda means it. 
Although i'd prefer he be located in Sugar Land, Texas, i will bring the car almost anywhere to the "right" person. 
Any thoughts?
Karl

Offline Tman

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Re: TFA Racing Lakester "tweak" diary
« Reply #159 on: October 12, 2014, 02:11:44 PM »
Brian Bass, Bass custom is in the Big D. He has worked on Lee Sicilios Superbird and helps with a roadster as well as building his own roadster for the salt.  http://www.basskustom.com/

Offline entropy

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Re: TFA Racing Lakester "tweak" diary
« Reply #160 on: October 12, 2014, 02:36:13 PM »
Brian Bass, Bass custom is in the Big D. He has worked on Lee Sicilios Superbird and helps with a roadster as well as building his own roadster for the salt.  http://www.basskustom.com/
Thanks for the info Tman!
Karl

Offline Kiwi Paul

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Re: TFA Racing Lakester "tweak" diary
« Reply #161 on: October 12, 2014, 09:32:24 PM »
Yep, Karl -  :mrgreen:Brian would be a good choice. I`d love to do it, but shipping the car to Washington State probably isn`t going to work.....

Offline Freud

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Re: TFA Racing Lakester "tweak" diary
« Reply #162 on: October 12, 2014, 11:23:22 PM »
Paul........Don't pre-judge. Shipping it may be minor when

he gets good service and quality work.

I would hope he choses You.

FREUD
Since '63

Offline Sumner

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Re: TFA Racing Lakester "tweak" diary
« Reply #163 on: October 13, 2014, 10:02:36 AM »
I think maybe clear up one thing that at least I'm confused about. 

Are you looking for someone who has a business that you can take the car to and pay for the service or are you looking for another crew member that has the capability to perform some or most of this work for no pay but possibly driving the car or if they have no desire to to that but only want to be part of a team effort and would like that opportunity?

Sumner

Offline Kiwi Paul

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Re: TFA Racing Lakester "tweak" diary
« Reply #164 on: October 13, 2014, 09:46:57 PM »
True, Sumner. Since I make my living doing Metal Body Repair and General Antique/Classic Automotive Fabrication, I should have made it clear to Karl that there would be money coming from his wallet to my grimy hand...not that I would turn down a chance to be a partner/drive the car and work for free, but my mortgage wouldn`t get paid that way, and I can`t afford the divorce that would result from all those free hours...sigh...