Q: “A little debate going on regarding a rule on when to accelerate. I’m of the belief that you accelerate when at the apex and you can start to unwind the wheel. Am I being too simplistic? I’ve studied a number of pro driver’s videos and they all seem to be consistent in acceleration when they start to unwind.”
A: Your guideline (not a rule, because there are exceptions!) of starting to accelerate when you begin to unwind the steering is good. You can also turn that around and say that you unwind the steering when you begin to accelerate. The reason for this, of course, is because of what we know from the Traction Circle or “100% Tire Rule” – you can only get 100% of traction out of a tire (see the YouTube video I did at https://youtu.be/QgVmMv9bmkI). If you want to use some tire traction for acceleration, you have to unwind the steering and give up some cornering traction.
But where you begin accelerating or unwinding the steering wheel and how that relates to the apex is not consistent enough to even make a guideline out of it. The acceleration/unwind point may be before the apex, at the apex, or after the apex. It depends on the radius and length of the corner, as well as banking/camber and surface grip. Oh, and how your car handles. And your speed. And… well, lots of things!
In some cars you need to wait for a fraction of a second to let the car finish rotating so it’s pointing out of the corner before you begin applying the throttle. This could be before, at, or after the apex. And in some cases (relatively rare), you begin unwinding the wheel before you begin accelerating. The reason for this is that you need to let the car rotate further around the corner so that when you go back to throttle, you’re able to commit all the way and go to full throttle sooner.
The fun challenge of driving fast on race tracks is there are no real rules! There are guidelines, and I think we’ve outlined at least one here – but there are always exceptions.
Ross you always provide great information and you touch on the key point in this “guideline”. However I think the idea of when you go back to throttle you have to go back to Full or at least “roll on to full” is the critical item. I am still trying to learn this esp in longer corners where I tend to carry a decent amount of maintenance throttle or “throttle steer” by moving weight around. As I improve and learn to understand the data and physics being able to roll right to full throttle is faster 90+% of the time from what I can see? It will produce a better speed trace on the squiggly lines and help to eliminate a U shape speed trace on the graph. You want to see either a V or at L looking trace where your speed slows to your VMin then immediately starts climbing again.
Ross, The upcoming car handling webinar is to good to pass up. There is a lot of info on the mechanical aspects of car handling, Springs, shocks, susp. settings. I look forward to Jeff’s comments on these. but, Will Jeff get into aero balance for sportsracers/formula cars? Since we don’t have access to the info and experience of wind tunnel testing, are there “rules of thumb” for the balance between splitters, wings, tunnels, diffusers? Is it possible (or useful) to do hand calculation to set a baseline to work from? Most of my aero setup is By guess/ By golly!! Just finished reading the autobiography of Adrian Newey. I didn’t know how much I don’t know!
Kurt – Jeff will definitely address aero. How in depth he gets is hard to say, as it’s kinda dependent on the level of the people online. However, we’ll be taking questions, so you can ask whatever question you want and Jeff will try his best to answer it.