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Inside front wheel lift?
nstrug - 18/4/09 at 01:31 PM

Just looked at photographs from the trackday at Woodbridge the other day and it seems that we are managing to lift the front inside wheel on idl1975's Indy on fast cornering.

Is this a handling fault or normal? I noticed that the Red Bulls were doing it during Q3 at Shanghai today so I suppose we're in good company

Nick

brianthemagical - 18/4/09 at 03:04 PM

F1 cars do it due to zero droop. Most road cars that do it are due to a skewed roll axis, i.e, the front and rear roll centres are at differnt heights and thus, when the car rolls, one end has a higher roll moment, unloading the inside wheel at that end more than the other.
The solution is to try and match the roll moments, which will then give a more even weight transfer during cornering.

[Edited on 18/4/09 by brianthemagical]

britishtrident - 18/4/09 at 03:50 PM

The car has reach 100% weight transfer --- the point where the roll stiffness at the front has been stiffened to the point where no more stiffening will alter the handling balance.

Dosen't mean the car will handle badly but that to alter the handling balance to give more understeer something else has to changed rather than just stiffening the front or softening the rear..

Back in the days of the classic years of the special saloon class it was quite ammusing to watch all the Imp racers lift the inside front while all the Mini racers lifted the inside rear.

Canada EH! - 18/4/09 at 05:22 PM

And my Ford Anglia would hike the front wheel 6" at Moss Corner, Mosport, due to body flex, photographs revealed a large dent over the inside rear wheel when the front wheel was off the ground. The next car had a full roll cage, no more problems.

Antnicuk - 18/4/09 at 07:20 PM

i have pictures from woodbridge a couple of weeks ago and several cars were lifting the front wheel, including me and a touring car 1 series BMW. The point where the pictures is taken is the entry corner to the gate which has a fairly big bump, which is more to do with causing the front to lift. I actually had both inside wheels in the air. have a look at the woodbridge thread i started.

britishtrident - 18/4/09 at 08:23 PM

quote:
Originally posted by Canada EH!
And my Ford Anglia would hike the front wheel 6" at Moss Corner, Mosport, due to body flex, photographs revealed a large dent over the inside rear wheel when the front wheel was off the ground. The next car had a full roll cage, no more problems.


Told this story many times but the late Gerry Marshall was racing Vauxhalls for Dealler Team Vauxhall they had set up first the HB Viva then the HC Viva to handle pretty well, then the HC Firenza coupe was introduced they built a car based on the coupe shell The new car was built by simply changing over all the oily bits from the old 2 door saloon HC Viva racer.

The new car simply didn't handle and was unresponsive to any changes made it took them months to figure out what was wrong ;;; the coupe shell because of it thicker rear pillars was much stiffer than the saloon, they changed to much softer springs and roll bars and suddenly it handled like a dream.

[Edited on 18/4/09 by britishtrident]

britishtrident - 18/4/09 at 08:25 PM

Gerry Marshall and the "Old Nail" Firzenza. Rescued attachment Oldnail.jpg
Rescued attachment Oldnail.jpg