Probing for ideas for a FWD lakester

[Jack Gifford]

... No engine-breaking is a must...

Engine braking is probably also a no-no...

[Sumner]

Scrub radius is a big deal.

Scrub radius is a big deal!!

Scrub radius is a big deal!!!     .

Did you just say Scrub radius is a Big Deal?  Did you just say Scrub radius is a Big Deal??  Did you just say Scrub radius is a Big Deal???

I just ordered 2 new front wheels today to cut about 1 1/4 inches of scrub radius out of my front non-driven wheels.  Just a note to those concerned with scrub radius, Marsh Wheels has some other centers vs. the dished ones they normally use that will increase the backspacing about another 1 1/4 inches.  If you can use the additional backspacing talk to them about those centers,

Sum

[Boostedballs]

I haven't overlooked scrub radius but I am under the impression that it should be fairly easy to solve with the right wheel and tire combo. Now, CASTER is something that I figure would take some work to get right. Right?
The QC allows me to easily set the caster to whatever I want since the tubes can rotate in the housing and are locked down with the set screws. The question is, what effect does the caster have on scrub radius?

Run the suspension with no springs or shocks?  Is this safe? I am building this for B'ville but it would be nice to also run it at other venues. Engineering it as a rigid would be much easier but how would it do on some of the other courses?

[Boostedballs]

Boosted,
I'm going to order the QC setup I described when I get back.  (In Nicaragua now.). You can check it out if want before you order yours.  My shop is in Hayward.

Count me in! I have work sites that I visit in your area fairly often and I would love to stop by!

[Sumner]

I haven't overlooked scrub radius but I am under the impression that it should be fairly easy to solve with the right wheel and tire combo. Now, CASTER is something that I figure would take some work to get right. Right?
The QC allows me to easily set the caster to whatever I want since the tubes can rotate in the housing and are locked down with the set screws. The question is, what effect does the caster have on scrub radius?

The problem with getting the scrub radius right is made harder by the narrow wheels and the limited offset you can have with them.  With a conventional rear drive car in the front four or five things can effect the scrub radius.  The king pin angle if you have one (or the A-arms), the tire height (distance from the tire center to the ground), the caster can effect it as the more caster the further out the contact point is in front of the tire patch and the wheel offset.  Also you can modify the spindle and/or bearing surfaces to move it in some cases.

With frontwheel drive I'm not sure how the Winters is setup on the axle ends and how it drives the hubs.  I didn't even know they had a frontwheel drive version until this thread,

Sum

[Richard 2]

Here's a thought.
Would you need to run narrow front tires in a front wheel drive set up?
Not sure about the availability of wide tires for 300mph or 400mph.
Richard 2

[entropy]

I haven't overlooked scrub radius but I am under the impression that it should be fairly easy to solve with the right wheel and tire combo....

I hope you are right, but we sure did NOT find it "easy to solve"...   Also be aware that vavle stem placement ain't a slam-dunk.
As Sumner says:
"The problem with getting the scrub radius right is made harder by the narrow wheels and the limited offset you can have with them"

From our "tweak" diary: http://www.landracing.com/forum/index.php/topic,13291.0.html
Another major issue has been getting wheels with 1 5/16" offset (gives zero scrub).  That seems to have been accomplished through the help of Allied Wheels in LA.  Greg Mulkey took interest in our project and suggested aluminum with steel lug inserts.  He recently turned out a beautiful pilot wheel, stout as heck, which measures up just fine.  He is now making 5 more.



Karl

[kiwi belly tank]

Nice, is that a one piece billet or a spun rim with an added center??
 Sid.

spell check

[entropy]

Nice, is that a one piece billet or a spun rim with an added center??
 Sid.

spell check

Sid,
The wheel has a very stout billet center with 60 degree tapered steel inserts welded onto a spun rim (Greg calls them shells)
The center is 360 degree welded to the shell outside, stitch welded inside.

One "fly in the ointment" is that SCTA requires 1" hex lug nuts, and they are apparently only available off the shelf with 45 degree taper. 
Thanks to this forum, we were lucky enough to find a source for 1" 60 degree lug nuts.
karl

[kiwi belly tank]

I might need to talk to these guys. How's the runout & how fast do they think they'll go??
  Sid.

[entropy]

I might need to talk to these guys. How's the runout & how fast do they think they'll go??
 Sid.

runout:  .012" +/- .002-3 radially, and a bit less axially.

how fast will they go?  the company made no claims.
But judging by the sturdy construction, 360 degree welding and low runout (seems low to me), we feel the risk is low at whatever our 500hp Lakester will go.

Even though you didn't ask...  The clearance of the center over the hub is .004" total; we are told the wheel is both "hub-centric" and "lug-centric".

Our pilot wheel is the 1st "Bonneville wheel" Allied Wheel Components (AWC) have made.  BTW, Raceline is the aluminum wheel product line of AWC.  We worked with their development guy, Greg Mulkey, to spec our specific needs, and i gotta say he is a Prince to deal with.

And i might as well address the other question you didn't ask,
Q: how much did they cost?
A: call Greg Mulkey  , our development deal is likely not the production deal

karl

[kiwi belly tank]

PM'd you.
  Sid.