[Thorney]

Originally Posted by _Nathan_

John - Do you come in each lap and corner weight based upon the fuel used so far? No.

No, but we know we use between 22-28litres of fuel per race with some leeway for extra time etc so worse case we're out by about 20kg. Minimal.

Originally Posted by _Nathan_

Now take that compromise and expand it a bit, I'm not saying the car will be perfect but then no car is once it has used some fuel etc. The fuel load in my car (and indeed your M3) could vary by 85-90KG if it started with a full tank and ran to the reserve collector then add some driver weight varience on driver change, still worth doing though IMO

THats what I dont get, 85-90kg variance is so big that it makes corner weighting near enough moot (uness there has been a problem with the car) in other regards.

Originally Posted by _Nathan_

and I assume you'll still corner weight your e92 for British GT?

Yes, we test and corner weight it full, empty and midway, look at the laptimes and the data, however with endurance races the compromise is so large (different drivers) we only do it to check the data and see how weight affects lap times, the car isn't corner weighted in the same way as we would a sprint car, theres no point.

Originally Posted by _Nathan_

You found 0.7 seconds a lap through corner weighting your vx220, if you could find half of that by being half way towards perfect from your starting point then it is worth doing no?

The VX220 weighed 785kg's wet and only had 160bhp, its a momentum car so things like corner weighting (which we did actually to change some tyre wear patterns we were getting can make a much larger difference)

Originally Posted by _Nathan_

Of course it isn't going to be perfect at all points during the day but then geo won't be either after you've banged it off a load of curbs and people still set that.

Completely agree

Originally Posted by _Nathan_

Anyway, my opinion is just that, not trying to change your mind just putting another opinion there for people to read, I've not run a race team so that puts me on the back foot anyway. No point in arguing

Not arguing. My only point was that someone wanted to spend money on their track day and I was simply suggesting that money would be better spent elsewhere, thats my opinion, its not shared no problem.

Put it this way, if this thread was "I've got £300 in my pocket, I want to be quicker on track, corner weight the car or get some instruction?" we wouldnt have this discussion.