0-60 Time

In the absence of a rolling road it is nice to see if the performance of the car is dwindling in horses in any way.

There is an excellent on line 0-60 mph calculator http://www.060calculator.com/

For the Megabusa this gave 3.9s for 621.5kg and 176.4bhp. The weight was taken from the recent corner weight measurement and the bhp was taken at Sitech racing last year http://westfieldbusa.blogspot.co.uk/2014/06/dynamometer-test.html

I set up a track on Race Chrono, using a safe bit of road where the terminal speed was less important and 60mph was obtainable in relative safety. You can see that the example gave a result of 3.7s which is about 0.2s optimistic (or the Sitech results are pessimistic). However if you take into account that the test track was up a gradient and the starting speed is not 0 then the level of correlation is not bad.

I have measured my wife's Mondaeo, Sylva J15 and a Westfield Zetec and all gave results that were within about 0.5s of prediction.

Corner weights

I have been pondering for some time the issue of corner weights and how far the setup on the Westfield was from optimal. There is a very good on line spread sheet and explanation of how to set up your car at: https://robrobinette.com/corner_weight_calc.htm

There is also a very good Excel spread sheet by Nick Warinner of ntw@360racing.com that I copied and modified to add the cross weight calculation information recommended in the above advisory site.

Cross weight = (Right Front + Left Rear)/Total weight.

I also purchased a set of Proform Bluetooth corner weight measuring pads from ebay tegiwaimports these are a budget product but works well and is easy to use.

Here are the results, you will have to open the image by double clicking it.

In summary I did the following.
1) Ensure the tyres are all the same pressure
2) The suspension height front and back are correct. In my case the lower front wishbones are horizontal and the front to back was 20mm
3) Adjust all the spring lengths FL = FR and RL = RR as a good starting point.

Starting point no driver

Adjusted no driver

Adjusted + driver

In summary I cannot see the advantage in my car of biasing it to handle with the driver only as it only makes a 0.3% difference. It means the handling is optimal with a passenger also depending on weight.