lightweight wheels

[Marcus Miller]

In addition to prepping for the 25 hour in 05, I got my clock cleaned in the double regional @ Buttonwilllow last weekend. Norcal Pro7 rules only allow 185's on 5.5 inch wide rims, Socal allows 205's on 7 inch wide rims. (Amongst other things- I brought a spoon to a gun fight)

Exhibit A: Circle aluminum, 9.10 pounds $240 each
Exhibit B: Real racing wheels, 10 pounds $175 each
Ehibit C: Diamond Racing wheels, 13 pounds ~70 each
Exhibit D: Panasports - ?? weight, ??? each.

Questions:
A) I can't find Panasports online to comapre price and weight - any leads?
B) Lighter is better, but is 3 pounds worth $100 a wheel? Is 4 pounds worth $170? Is one pound (going from 10 per to 9 per) worth $70 a wheel? Anyone have data? Assuming I can use the gain, is 9 pounds per verse 13 pounds per going to make me *that* much faster a lap?
C)Anyone know where I can get them cheaper? http://Forum.ImprovedTouring.com/it/smile.gif
D)How much would you estimate I was giving up running full tread 185's on a 5.5 inch rim verse a shaved 205 on a 7 inch rim. 2.65 mile course. (Bwillow #14 CCW)

thanks!
Marcus

[ddewhurst]

***(Amongst other things- I brought a spoon to a gun fight)***

Question:

Do you have everything else in place to be FAST ?

13 X 7 (seven) Panasports weigh 9 pounds $18? something 4 years past.

Have Fun http://Forum.ImprovedTouring.com/it/wink.gif
David

[Tom Donnelly]

Marcus,

Paul Spruell Motorcars in Atlanta used to have the Panasport Ultralites for $176.00.
There was a discount for SCCA members.

The website is http://www.paulspruell.com/

I don't know if they still sell them.

Tom

[wlfpkrcn]

Marcus,

" full tread 185's on a 5.5 inch rim verse a shaved 205 on a 7 inch "

Talk about bringing a spoon to a gun fight. You probably lost equal to more time with the full treads compared to the tire size difference. Take a pencil with a full eraser and scrub it sideways across the table. Note the deflection. Cut down the eraser just prior to the metal sheath, and do the same thing. Now think about those full treads. The smaller tires should acclerate quicker all things being equal (think gear ratio), and the 205 carrying more speed through the corner. When Pro7 changed to the 185 times dropped dramatically, but they were running 205's on the 5.5" wheels.

As far as weight of a wheel. Think of the amount of energy it take to accelerate and decelerate that additional 4 lbs. It is unsprung weight. I once read a article on rotating weight (Circle Track). Basically givin the same weight and diameter, you would want the weight in the hub of the wheel. They dyno tested driveshafts. Steel small diameter vs a lighter aluminum larger diameter. The heavier steel accelerated faster and more HP to the wheels. So... 2 different 9lb wheels may not perform the same on the track. I know this doesn't directly answer your question, but some info you might like to know and help with your decision

Eric

[This message has been edited by wlfpkrcn (edited November 01, 2004).]

[Marcus Miller]

Originally posted by ddewhurst:
Question:

Do you have everything else in place to be FAST ?

The car is missing four key pieces to be socal prepped:
rims/tires
proportioning valve <-- input on this one? Some say its key, some say not.
cold air/ram air inlet (now done)
relaocated battery
The last two are not ITA legal which was why I had been holding off on them.



13 X 7 (seven) Panasports weigh 9 pounds $18? something 4 years past.
Thanks!



Have Fun http://Forum.ImprovedTouring.com/it/wink.gif
David

Oh we are, it would be nice to be with the main pack instead chasing them though... The in car video is hilarious, showing how little front grip I really had.

Marcus

[Marcus Miller]

Originally posted by Tom Donnelly:
Marcus,

Paul Spruell Motorcars in Atlanta used to have the Panasport Ultralites for $176.00.
There was a discount for SCCA members.
Tom

Thanks! I'll check in with them.

[Marcus Miller]

Originally posted by wlfpkrcn:
Marcus,

" full tread 185's on a 5.5 inch rim verse a shaved 205 on a 7 inch "

Talk about bringing a spoon to a gun fight. You probably lost equal to more time with the full treads compared to the tire size difference. Take a pencil with a full eraser and scrub it sideways across the table. Note the deflection. Cut down the eraser just prior to the metal sheath, and do the same thing. Now think about those full treads. The smaller tires should acclerate quicker all things being equal (think gear ratio), and the 205 carrying more speed through the corner. When Pro7 changed to the 185 times dropped dramatically, but they were running 205's on the 5.5" wheels.


Yep! I'm aware of the disavantage I was at http://Forum.ImprovedTouring.com/it/smile.gif I had a set of shaved 185's I usually run, but went out the first session and had a real bad chatter. (I'll post video later) We put on the back up tires (my full tread rains I was planning on using at Western states) and went out for qualifying. I got three laps and the both front wheels were falling off.

Going into the race, I had 7 laps total on the track (never having been to buttonwillow before)... I got my times down near respectable levels, but would love to know if shaved tires would put me close... sigh.



As far as weight of a wheel. Think of the amount of energy it take to accelerate and decelerate that additional 4 lbs. It is unsprung weight. I once read a article on rotating weight (Circle Track). Basically givin the same weight and diameter, you would want the weight in the hub of the wheel. They dyno tested driveshafts. Steel small diameter vs a lighter aluminum larger diameter. The heavier steel accelerated faster and more HP to the wheels. So... 2 different 9lb wheels may not perform the same on the track. I know this doesn't directly answer your question, but some info you might like to know and help with your decision

Eric


Thanks! At this point I'm leaning toward the steel wheels for next year for cost savings. It's a judgement I've got to make regarding how many Norcal verse Socal events I'm going to run... I liked the 23 cars grid down south. Western state has two cars listed, and I'm one of them... work may preclude me from going but I'll be at the NASA days the 13-14th, not sure if I'm racing or HPDE`ing....

Marcus

[This message has been edited by Marcus Miller (edited November 01, 2004).]

[Marcus Miller]

Following up on this, my spoon became a spork. I negotiated a set of lightly used, shaved 205's...

We are getting there...