Track Racing

[Tesla 940]

Been doing some track racing - up to now only at Willow Springs "Streets" and "Big Willow", and have been thinking of trying some really soft tires for extra grip. Since I like to drive the car periodically on the streets I was thinking of purchasing another set of wheels. Any comments regarding this would be appreciated. Specifically regarding the wheels - yes or no, and then which wheels? Specifically regarding the tires - what sizes and makes.

I'm rather conservative since I would like to avoid going off-track. My best time on Big Willow is 1:52.4 and on Streets is 1:43.7.

Thanks

 

[hcsharp]

Do you already have the Tesla forged rims? They are stronger and lighter than the stock alloy rims. I also recommend the brake rotor upgrade with aluminum hats if you haven't already done it.

 

[wiztecy]

Tesla 940 is currently running the CRF rotors & AX6 pads, so he's good there

I'd try to experiment a little, I've been reading many who race the Elise/Exiges who went to the 15" front / 16" rear combo and it proved to yield great results. Some of the benefits as described in the link below are: "There are some advantages to making this change including lighter weight, more sidewall which can help keep more tread on the ground during cornering, and a smaller outside diameter. The latter can provide an acceleration advantage."

Tires should be somewhat cheaper, I also suspect you might be able to brake later and dive later into the turn where you can pick up some time due to the smaller size, steering wheel would have more response. If the track has many quick snappy turns, I'm sure you'd do pretty good running this. If more straights, not so much. But the Roadster is really fun and good in turns if the handling is tuned right, your brakes are upgraded as we described (and going to bigger brakes / rotors on the front/rear would be another added benefit) Here's one link I read going down 1" from stock. Since you have a 2.x you have the tire learning unlike myself in my 1.5 where I'm locked into it:

Lotus Elise Experience, New Wheels and Tires for Thunderhill

Lastly carry an infared temp reader or tire temp reader, shows where your tire is heating up. If dropping down an inch on the tire/rim size, I suspect the tire would build heat up a little faster as well.

 

[simonog]

From my racing experience, a larger tyre sidewall will flex more and need to be inflated several psi over road pressures to stop it rolling off the rim under cornering.

You want to be driving on the bottom of the tyre, not the sidewall!

I haven't raced my Roadster though its road handling is very similar to my Morgan; I think the Roadster might be a bit front light though in which case expect some understeer so a very very gentle application of brakes into a corner can help keep the nose down and make a clean turn in.

It should be fun!

 

[wiztecy]

The goal of the smaller wheels is for less rotational mass which gives you benefits in many areas, braking, suspension, acceleration which help yield in faster lap times. Also the tires are cheaper, so if you go out often that adds up.

As for the Roadster being light up front, Tesla/Lotus dialed that in stock with lots of understeer so those who are not experienced with performance driving won't wrap the car around a tree due to the rear favored weight. All that can be setup the way you want it, and you can actually set it to have too much grip up front which will dig/grip more than what you want by over-adjusting your camber and suspension settings. I have none of that light feeling on my Roadster since I dialed in myself.

Lastly have you corner balanced your Roadster? The Elise and Roadster are both sensitive to it. Its something I need to do with mine.... Looking for a used set myself but you can take it into a pro-racing Lotus shop and they'll dial it in for you for a fee.