Think of a rear wheel drive car. The front wheels are rotating at the same speed as the rears but are transmitting no torque to the road… In other words, it’s how hard the tyre is pushing backwards on the road.

@@JulianEdgar Ok, I get that. To my understanding, different «torque splits» - like 40/60 or 65/35, are possible only with some slipping in transmission. Can you explain it a bit better?

Yes, front MacPherson struts with revolving uprights (knuckles).

I cover two HPV suspensions in the book.

That's quite interesting isn't it.

If it's like my aero books, quite a few manufacturers will in fact buy it. However, they need to make cars for everyone: you need to modify a car only for (largely) yourself.

Yes it's always wise to start off by assuming that professional car company engineers usually have a pretty good idea of what they're doing. That said, when you read pages 271-272, you'll see that sometimes they're not directed very well!

Wait until you see the graphs in the book. Just amazing. We're talking multiple degrees, not fractions of a degree. And in most modern cars, it's meant to be like that!

@@JulianEdgar i'll love to get myself a copy for christmas. i have a project car home at the moment, a JDM Nissan Sunny B12

Hope you like it!

Scrub radius is in the book. That includes diagrams that show it and also a discussion of its implications and the fact that it actually varies with tyre centre of pressure (and so dynamically varies). The book does not cover how to measure it.

@@JulianEdgar Thanks for your reply. Would you then say that we can disregard that parameter when setting up our road/trackday car and rather focus on other aspects of the suspension/geometry? I’ll be open, the only reason I found myself hung up on scrub radius is since I found out that negative amount of scrub radius should produce an effect of car pulling inwards the corner if we’re applying the brake while cornering, and as I personally love to rotate my car on the brake (be it by trail braking or just transfering the load forward), I found that idea rather interesting. Currently I am making big changes on my project car and a lot of things has to be fabricated and custom made from zero so I thought if I can maybe incorporate a bit of negative scrub I’d be happy to test it out. Thank you again for finding the time to answer to our often ignorant questions.

To be honest, I think people often get hung up on what I'd consider to be peripheral issues. I don't think scrub radius is a major determiner of rotating a car under brakes: far more important is front weight transfer unloading the rear, and rear lateral weight transfer reducing rear lateral grip. Scrub radius is important in terms of steering feel and kickback, and (and I don't cover this in the book) self-aligning stability when braking on surfaces with different left/right frictional coefficients. Springs, dampers and sway bars (and at higher speeds, aero) comprise 90 percent of handling, with tyres adding the 'grip' element. I'll leave the book to answer the rest of your questions!

@@JulianEdgar Much appreciated, will follow your suggested guidlines. Looking forward to the book.

Sounds like a crock to me.

@JulianEdgar fill up a large clear plastic bottle with pump fuel.....the problem will be easy to see. What else would cause Fuel Injector Cavitation?

What fuel injection cavitation? I have never even heard of it.

Thank you!

Yep, works so well for so little money.

You'd have to ask a specialist in that car.