BTCC shifting

[Radisichrox]

In the older days of the BTCC, when a driver shifts gear (this is with a sequential gearbox) , you can often see them lift their foot off the gas quickly, then put it back on. Then, when they downshift, they have to put their foot that they use on the gas, and balance it on both the gas and the brake, while the other foot uses the clutch. Does anyone know why they have to do that, or do they still do it?:confused: :confused: :confused: :confused: :confused: :confused:

[nem]

I give this a whack.

On the up shift they have to lift off the throttle so the engine torque is not pushing on the face of the gear teeth, so they can move the shift lever. Don't need to use the clutch on the upshift. So the quick lift is exactly the time they change the gear.

On the downshift they can't unload torque from the gear teeth because that would mean a slight press of the throttle, so they have to use the clutch, as opposed to the lift on an upshift. The downshift is necessary as they are braking for a corner so their right foot is on the brake. They need to match engine rpm's to the new lower gear so the right foot has to also operate the throttle by giving it a blip to raise the rpm's, or the driven wheels could momentarily lock up, or they could over rev the engine. This known as a heel/toe downshift though that doesn't accurately describe how the right foot is used. The heel stays on the floor. Half the right foot is on the brake and the other half on the throttle. The ankle is rotated slightly to the right to blip the throttle. With only a little practise it becomes quite simple and becomes second nature.

Some racecars having sequential gearboxes have a shift without lift feature (SWOL). There is a sensor on the shift lever that electronically accomplishes the throttle lift so the driver just keeps the right foot planted on the floor and pulls the lever to the next gear.

Of course F1 has the ultimate, fully auto gearbox shift. Only 2 pedals on the floor, brake and throttle. The clutch is on the back of the steering wheel and is hand operated.

[Radisichrox]

Originally posted by nem

Some racecars having sequential gearboxes have a shift without lift feature (SWOL). There is a sensor on the shift lever that electronically accomplishes the throttle lift so the driver just keeps the right foot planted on the floor and pulls the lever to the next gear.

Of course F1 has the ultimate, fully auto gearbox shift. Only 2 pedals on the floor, brake and throttle. The clutch is on the back of the steering wheel and is hand operated.

Wow, thanks for all the info! I think the Audi A4 from 1997 had that SWOL system on it. That's really facinating. Thanks!

[THR]

This year they had lovely xtrac gearboxes tho. so they could shift up with out lifting i guess? sounded like it to me.

down shift, yea they still had to toe and heal, but thats easy like you said. and makes the box last longer.
youre dead right tho, i agree with all you said.

oh i got an interview with xtrac on fri

[Radisichrox]

That's cool, I really like watching the driver's feet on the in-car cameras to see what they are doing. If in fact they did end up not having to lift this year on the upshift, I'll be happy! Remember the 1997 Audi? It had that system in it, so on every upshift it sounded awesome, it makes me want to run!