Olitho

I have been kicking around the Internet and this forum this afternoon trying to figure out what consensus is on 100 lbs effect on lap times on a 2:00 course in a 3200 lb car with 380 HP, aka roughly a T1 Corvette.

My car is about 50 lbs overweight now. I want to figure out what effect 100 lbs theoretically has on a "typical" 2:00 track to see how motivated I am to lose more weight myself as well find a few more pounds on the car.

BuckeyeZ06

Oli,

I've been told by several "in the know" people that 100lbs is equal to half a second at Mid Ohio.

MySR71

I wonder if the recent Road & Track Corvette article would be of any help.

http://www.roadandtrack.com/tests/car/corvette-fever

While I haven't read the entire article, I did see that the weight difference between the ZR1 and Z06 Ultimate Performance Package (3310 lb) was 95 lb with a similar suspension. The Z06 lapped 0.84 seconds faster at Spring Mountain (75 second lap times) depsite the engine differences between the Z06 and ZR1. Tommy Milner was driving.

I'm not sure of all the differences between the two cars though..... I thought they had the same tires but I'm not sure.

Of course, the real answer I'm sure is..... It depends..... (not very helpful of course)....

fatbillybob

I think T1 should give you penalty weight so after you guys gain 500lbs I'll be competative.

drivinhard

In my experience, 100 lbs is about 1 sec/lap on a 2-2.5 mile track.

Seat of the pants, I notice it the most in braking.

The trick is reprogramming your brain to push the car a touch harder in all areas. Take what it will give you. Ie, if you take 100 lbs out of the car and just go out and hit your normal marks, don't expect much of a gain.

sperkins

Also remember it's important to maintain the balance of the car as you remove weight from it (corner weights). For one weekend last year at Road Atlanta, I ran my car about 90lbs lighter than normal and actually ran slower. I lightened the car by grabbing the easiest stuff like ballast and other larger heavier items. I adjusted the cross weights afterwards, but the actual corner weights were horrible. I was very surprised with the results. I need to get more creative with my setup so I can remove weight and still maintain good balance with the car.

redtopz

That's interesting. I never check corner weights, only ride heights. But in our T1 cars it's difficult to make changes anyway, unless you have a C6 which required ballast. The problem I have with getting my car too close to the weight limit is that the scales are not consistent. One time I came in close to the limit and another time I came in 80 lbs over weight. Nothing changed in my car.

drivinhard

seems to be ever so common for track scales

J.R.

Oli,

I think you will find that David's comments are pretty close to what I have heard. .5 on a 1:30 course with an approx. 3200 lb car.

I think there was a recent post by Louis (LG Motorsports) that on a 2-3 min course that 100lbs in a 3000 lb car equals approx. 1 sec.

J.R.

Painrace

WOW! Corner weights are far more important than ride height!

My 2 cents is get the car as light as you can and then add weight as low as you can to reduce the center of gravity and set corner weights.

Jim

MJM

Apples and oranges but this week's F1 race said 10 kilos = 0.4 seconds per lap. That's 22 pounds in American.

Matt

redtopz

Really? I always thought corner weighting was overrated. I think having a proper ride height equal side to side with forward rake will get a stock-ish corvette 90% there. In T1 we can't really move things around to improve corner weights (at least that I'm aware of). I did corner balance my ST2 car and it's 50/50 front to back, side to side, and corner to corner with me in the car. The T1 car is nowhere near there, but handles well anyway. I've been driving mostly the T1 car for the past 6 months. I guess I'll see what difference the ST2 car makes later this year.

mcar00

This is what I've always used and it sounds reasonable to me.

Slalom4me

Generate results based your own circumstances.

Add 100 lbs, time several runs, then infer what will happen when weight
is removed, instead of added.

45lb bags of sand sell for $4.00 at HD. Two fit easily in the p-footwell.
Dead weight is less distracting than live weight.

Calculate your Body Mass Index. If it is approaching 30, set aside
the effect losing weight will have on lap times as a motivator
and focus on losing weight to enjoy everyday life more. Better
track outcomes will just be one of several spinoff benefits.

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