mark kibort

I just did the same thing this week at a Karting event. We ran 3 different races, changed cars at each race, and this one guy was about .5 to 1 second quicker than me, no matter what I did. He was smoother around the track, but you could tell that even on solid laps, the acceleration, even when he was off line was better. I had about 30lbs on him and thats like 25hp with the normal race sedans we run. (not to mention braking and cornering advantages). I think when they run the Kart racing, they need to run a ballast box with a pole to slip weights on to equal out the Karts. Conversly, there was a pretty decent driver that had some good experience at this track, that I could just mop up no matter what the difference was in the Kart. He was about 20lbs heavier than me. Hp to weight, absolute weight. .....Both very important in racing.

Anyone do the Karting in South Sanfrancisco? .It was my first time My times were 30.1 and 27.95 for the monza and yokohama tracks. The guy I took 2nd behind was running 29.90 and 27.10. He had 35 days on the track and ranked in the 99% of all time. They track 10s of thousands of times too. pretty well organized karting establishiment.

mk

Cory M

That's the same number I've heard thrown around. I wish the extra 20 pounds was the only thing slowing me down

Veloce Raptor

Spot-on, Bob.







Professional Racing and Driving Coach

multi21

What kind of car do you have? If we're a 250# guy in a go kart vs a 150# guy there's a couple seconds to be had. If we're talking about 3000# GT3s then your 100# disadvantage is barely a factor. You can either spend your money on lighter parts or spend you money on more horse power......... (Torque? )

mark kibort

I read it. He said that driver weight is not a major factor, yet SpeedGT and Touring seem to think so to the point they weigh cars with driver. Sure, its more of an issue with smaller cars, like open wheelers.
BUT, 100lbs different of driver weight in a sedan is still substantial.
So, maybe we need a special weight rule for those not pear shapped fatties, as you say.
I think by most folks account, 100lbs is worth about .5 to 1 second depending on the track, driver, car, etc. But still substantial. Is 10hp substantial, and even more for braking and cornering effects?

Veloce Raptor

No, actually, that is NOT what I said.

Read it again.







Professional Racing and Driving Coach

BC

I weigh 260 (6'3") When I work out it usually only goes up from there unless I starve myself. I was racing against a bunch of 20 year olds last time that were all 5'8, 5'10" and probably 175-200, tops. I got down to 30.5 on a certain track over the weekend, which was still a half second off the main pace of these little weasles. It was fun.

BC

Well, if its .2, then I can multiply .2 x 6 for 60 pounds. 1.2 seconds.

On a different track I have more work to do. Two long straights kill my average speed compared to others.

Veloce Raptor

Consider salads...







Professional Racing and Driving Coach

mark kibort

Oh for the love of Toyo, can you be any more of a pain?
You said:
"In an SRF or open wheel/formula-type car, driver weight is a major factor. In a sedan-type car, not so much, unless the driver is 500 lbs, IMO."

If you read what YOU said,it sure sounds like to me, that Its "not so much" of a major factor with sedan type cars, unless the driver is 500lbs.

Anyway, driver weight is important. sure, more important for lighter cars where driver weight is more of a proportion.

Any one with a calculator and an ounce of common sense would LOVE to race in speedGT or Touring against a guy that weighed 100lbs heavier than you if it weights were cars only. Chip Herr would be drooling to be able to race a car weight vs driver with car, considering the guy weighs 100lbs dripping wet vs you or me at 200lbs

mk


https://rennlist.com/forums/6538631-post10.html
and the post before it.

Veloce Raptor

And I stand by my words. It ISN'T as much of a factor in 2,800 pound 300hp sedans as it is on 1,000 pound formula cars 0r 100hp Spec Miatas.

Also, James Clay is 270+ pounds. He ain't any faster or slower than Chip Herr, genius.







Professional Racing and Driving Coach

mark kibort

Einstein, You have got to be kidding me!

Chip is not any faster, because the cars in WC are weighed WITH DRIVER! BOTH cars weight the same with driver, no matter what the driver weight is. Now, if Clay is still as fast, and is heavier, what does it say about Chip's driving? . The reason they have the REWARDS system is because the weight does hurt the performance. Go out and put a girl (100lbs) in the passenger seat next time you are catching times. I've done it a few times. 200lbs (guy) cost me about 1-1.5 seconds.

I have already said that its more important in a smaller car, but still is very important in sedans. If we disagree there, fine.

EDIT; If we are talking same weight cars AND this is with their drivers, then yes, i would imagine that the heavier driver might be more of a handling disadvantage in a SRF or formula car because of optimal center of mass trade offs. I dont know, I would have to go through the calculations. As it is now, most formula cars have their drivers pretty low in the car. I would think that the handling effects might even be a trade off on both styles. I couldnt say definitively one way or the other. But if you have the data, lets see it!

Anyway, if that was where you were going with all of this, then my example would be Paul Tracy doesnt get hurt that much vs the sticks he races against in the open wheelers!

see the original post: https://rennlist.com/forums/6538631-post10.html

mk

mark kibort

VR,

Sedan: 2800/300hp 9.3 hp/weight ratio add 100lbs 9.6 4% worse HP /weight

Miata: 2200/100hp 22 hp/weight ratio add 100lbs 23 4.5% worse HP /weight

formula: 1200/300hp 4 hp/weight ratio add 100lbs 4.3 4.3% worse HP/weight

100lbs is bad for everyone as far as acceleration, but also braking and cornering.

Cory M

30.5 second laps- which track in SoCal is that? an indoor place?

multi21

It's got to be? F1 in Carlsbad perhaps?

I think Perris is around 50 sec. Depending on configuration, Fontana is 1 min.