mountainbiker2

This last weekend in my C5Z06 I went faster with passengers. Were talking #220-250. This is not always the case, but this time without a doubt. This was an Autocross on a slippery lot. My car is corner balance for a half tank of gas, and my weight of #150. I probably only had a 1/4 tank of gas or less when I turned my best times with these passengers. I don't get it. The track was going clockwise. Any guesses?

Steve

SunnydayDILYSI

My guess is that you had a bit more adrenaline and pushed the car closer to the limit with an audience. I generally run 1 to 1.5 seconds slower with a passenger on road courses.

froggy47

I have found the same when I give rides, I attribute it to better rear grip/traction mostly. I always run a full tank on low grip lots.

I get really excited when I get a 150-175 # passenger to ride.



200+ not so much.

SouthernSon

Even though my car is corner weighted with only me I find the same with a passenger and I do some fast lap times. The car does have a different feel that I like. Beats me, but it does happen.

brkntrxn

Right side weight in a clockwise direction is always a good thing. Same as left side bias in counter clockwise, basic physics.

Something the others did not mention, you may have been driving smoother with the passenger than when you are alone. Smooth = speed

96CollectorSport

Typically you get to take passengers at the end of the day - the more you run a track the better you get at it. I've done the same thing with a passenger - and it kinda pisses you off - where was that 1 - 1.5 seconds an hour ago!

Charley Hoyt

did you see the corner and cross weights when you had the corner weighing done? When I had mine done I was surprised by the variation. You may have better balance with a passenger?? Also the strange way GM manages fuel my not be helping. The right tank empties first then the left tank.

Charley

theseal

Well, if you can fit two 300 pound guys in the car, it could handle like a c6z!

romandian

are we talking about c5? my tanks equalise when engine is not running. just some food for thought.

fatbillybob

Steve,

I have thought that too on occasion. Have you thought about taking your car as is race weight and scale it and measure the alignment/ride height. Then add the 200lb guy in the right seat scale and measure again and look for changes? RH is definitely effected.

With cornerweights 99% of people go for 50/50 cross which is supposed to equalize left and right turns. I have heard others sacrifice 50/50 for more equal LF and RF weights for better threshold braking. I presume there are other theories as well. Perhaps the added weight altered the corners was the ticket.

Your impressions could be very track specific too like more left turns than right turns. That's why I think I notice a change only on occasion like your report.

Soloontario

Considering that no matter what track you run on, there are a net 360 degrees more of Left or Right turns depending on the direction of the track, i.e More left turns on counterclockwise and more right turns on clockwise tracks. In that case is it reasonable to want a 50/50 weight distribution? Do the round y round guys just set their corner weights at 50/50 Left to Right or do they put more weight on the inside?

Considering that all the tracks I run are clockwise, I would think the added traction of a passenger might be worthwhile and that I should set the car up to have more weight on the right side of the car (considering that I don't compete with a passenger). OTOH, I have no idea of how much more weight should be on the right side.

sperkins

I learned years ago that my car was much faster and easier to drive when it was heavier with ballast than it was when it was lighter (better pw/wt ratio).

Kevova

It might be worth while if the opportunity presents itself to weigh car with passenger to see what changes. Then maybe trying to adjust car (if possible) to same percentages to see how car handle with passenger out of car. It can be surprising what a 1-2% change will do.

mountainbiker2

It depends on who whats a ride, but the audience usually gets me slower times. I'm to worried about what there thinking.

I might have to try that. I'm usually around half a tank.

I posted the video earlier and it didn't look that smooth to me. I was sideways a lot. Sometimes my smooth equals slow.

This was in the morning session.

I did it myself. So yes.

Good idea, but that sounds like a lot of work.

My conclusion: Drive the car to your best ability. Setup the car up to your best ability. Let it go at that.

Thanks for all the comments.

Steve

Rookieracer

It really depends on the track configuration. Most circle car classes have a maximum left side weight rule for just that reason.

Mountainbiker2,

I've got some scales left over from my NASCAR days. I'm in Valencia. Bring your car and lets take a look at your corner weights with and without a passenger.

My 2002 Z06 with 315-30-18 Hossier A7s on Z06 wheels looked like this with about 5/8 tank fuel.

Driver only:

906 841

765 758


Driver and passenger:

921 901

804 839

Soloontario

Any idea of what the max L side weight would be for a circle track car? Is it expressed as a percentage?

Rookieracer

2900 - 3000 lb cars would be 57 - 58% maximum left side weight depending on the class.

blackozvet

When I was Kart racing we had to carry weight to make up the minimum class weight, being new at the game I made up my lead weight and bolted it to the rear of the kart seat.
The track I ran at was anti-clockwise. One day I noticed that all the regular racers had their weights on the left side of their seat.
So next meeting I put mine on the left side of the seat, and guess what, my lap times were faster. It was a bit of a dog on the only 2 right hand corners but that didnt matter !

Soloontario

Wow, that is a lot more than I would have thought !

Really makes you think that 50/50 side to side may not be the right way to go and may explain why some folks find having a passenger helps lap times despite the higher weight.

Maybe for clockwise track we need cars with right hand drive like the Brits.

Kevova

looking at Rookieracer's weight chart the passenger changes front weight from 55 to 53%, left side from 53 to 50% and cross weight from 51.5 to 50% which makes a big difference how car will handle. IMO the car should handle better because of better weight distribution, If possible I would try to adjust to get these percentages without adding weight if possible.