Just finished ground up rebuild and Gen 3 conversion.
Sand blasted frame and paint, all new rod ends and AN bolts, new style UCAs, Penske shocks, new body sections, butler seat, CDS dash , new wiring harness. New style wheels and new Goodyears.
Car has about 5 gal. of gas . But no battery in car.
Total car weight 1,330 lbs.
My question is " After the new Goodyear tires came out this year weighing less than last year Goodyears, shouldn't the Min. Weight be reduced further. I have not weighed the new tire vs the old tire but the new ones are lighter by I think 6 lbs ea.

no

-10 lbs. Yes.

I thought it was 10 lbs total (for all four tires).

DaveP

Bob K - did you weigh your bare chassis to see where it weighs on the approximately 25-30# spread for different chassis weights? That would be a fairer starting point in the weight debate. Gen 3 car - now starting Gen 6 weight war.,

claysylvester wrote:Bob K - did you weigh your bare chassis to see where it weighs on the approximately 25-30# spread for different chassis weights? That would be a fairer starting point in the weight debate. Gen 3 car - now starting Gen 6 weight war.,

But rotating mass is the square of the speed heavier than static mass, right?

I did not weigh the bare frame. I did add the steel plate under the fuel cell and I have the stainless steel foot pan.
I will weigh an old tire and wheel and compare that to a new tire and wheel, but it will take till tomorrow- on the way to the golf course now.

No, it should be raised

Ohhhh the great weight debate...

I think MBI is on their 10th or so Gen3 conversion. On multiple cars, after the conversion, the total car and driver weight was down about 20 pounds. For example Driver XYZ (not me, but I will get to my example in a minute) weighed approximately 1710 in a Gen2 after the race so about 40 lbs over minimum. This year, after the race in a Gen2 he weighed 1580, about 20 lbs over min. On another driver's car, we had to add 20 extra pounds of ballast so that he wouldn't be light.

Now for my fat ass... A few weeks ago at Laguna, they told me I was light after the race Ok for those that know me, you can stop laughing now. When they reweighed me I was 11 pounds to the good. I have a newer chassis (871) and it is a fact that they are lighter than say a 200 series chassis. However, I had a heavier tail on my car, the huge Laguna muffler kit, I have a CDS system, 2 archaic Chase cameras plus the CDS converter thingy for data and video overlay and I probably ended the race with 2 gallons more fuel than necessary. Point is, if I bought a go pro, measured my fuel, and didn't have to run the Laguna only muffler, I bet a guy that weighs 240+ would be close to minimum.

This is racing and as fierce competitors we want as few disadvantages as possible, but I PROMISE you, being 20 pounds extra over minimum is not going to make someone lose a race.

I say keep the weight where it is, but as they say, YMMV

20lbs is nothing. I was 100lbs over in the Gen2, and that translated to an equal 100lbs over in the Gen3. Only the new tires made a 10lb difference, and little self weight loss helped - but being 85 over still sucks.