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A Novice's Question
Posted: Mon Jan 28, 08 8:09 am
by Anonymous
Last night I was flicking through the old pictures in Dave McBride's 2007 Calendar. I noticed something which to me, seemed odd.
When launching off the start line, Bob Brown's Daytona lifts its RHS (as you look out through the screen) front wheel. When Kev launches, he lifts the LHS front wheel. Why dont both cars try and lift the wheel on the same side?
Posted: Mon Jan 28, 08 9:03 am
by TyreFryer
Is it the weight of the driver? Kev's car is righthand drive.
Posted: Mon Jan 28, 08 9:10 am
by Blue
The short answer is chassis set up. Direction of engine rotation means the car will naturally want to roll anticlockwise and lift the NSF wheel first. To counter act that roll, you have more spring leaves on the OSR, and you could also stiffen up that side shock. Front to rear weight distribution, corner weight and the cars ability to transfer that weight all contribute to what exactly happens when you launch the car. An ideal launch would be both front wheels up a few inches and the car remaining level.
Posted: Mon Jan 28, 08 9:11 am
by Anonymous
Can't be, surely?????
I thought the wheel that lifted was dependent on rotational torque of engine. Engine pulling body up on one corner. Sitting on that side would only dampen the effect, not assist the opposite side cos thats being dug down I would have thought?
Posted: Mon Jan 28, 08 9:25 am
by Dave-R
Blue. You should know by now that using offside and nearside terms throws 50% of the users here into confusion.

Posted: Mon Jan 28, 08 9:30 am
by Dave-R
Clivey wrote:Can't be, surely?????
I thought the wheel that lifted was dependent on rotational torque of engine. Engine pulling body up on one corner. Sitting on that side would only dampen the effect, not assist the opposite side cos thats being dug down I would have thought?
Quite right Clivey. The car body tries to rotate clockwise (from in the car) so the left (nearside) front wheel lifts and the rear left (offside) drops lower (in effect the same as the left rear tyre rising up so you loose traction on that side).
Posted: Mon Jan 28, 08 9:34 am
by Anonymous
That being the case, why is it that Bob Brown's Daytona lifts the OSF wheel??
Posted: Mon Jan 28, 08 9:37 am
by Dave-R
Maybe his engine runs backwards.

Posted: Mon Jan 28, 08 9:50 am
by Kev
What's yer explanation here, Dave?

Posted: Mon Jan 28, 08 9:52 am
by Blue
If Bob has compensated to eliminate torque roll, and the OSF is lighter and/or higher, that wheel will come up first.
Posted: Mon Jan 28, 08 10:01 am
by Anonymous
Blue wrote:If Bob has compensated to eliminate torque roll, and the OSF is lighter and/or higher, that wheel will come up first.
Cheers fella.
I was standing by the back door last night quaffing some tea, and for some reason the question sprang to mind
Posted: Mon Jan 28, 08 10:02 am
by Blue
Kev, I think you could call that excessive weight transfer!
Posted: Wed Jan 30, 08 7:16 am
by SteveCase
How do they get THAT much power thru those little wheelie bar wheels then?!

Posted: Wed Jan 30, 08 9:01 am
by andyrob
clivey maybe the photos been reveresed just to confuse you

Posted: Wed Jan 30, 08 9:05 am
by Anonymous