mikew968

I notice a lot of racers use the 1st level of curbing (and beyond but before the 2nd level of curbing) as a regular part of the racing surface. My experience there is it feels like it is going to beat the car apart! Do you think using the curbing adds a material risk of increased wear or breakage to the car.

stujelly

yup, but it is the fastest way around the track.

The nascar curb at turn 5 and 8 really pitches the car and I can feel the left front taking a beating but with the right shock package it can take it.

Van

I once heard David Murry say about curbing, "I'm paid to make the car fast - if I don't use the curbing, I get fired. It is hard on the car, but you have to figure out how to treat your own car."

Meaning there's no shame in not using the curbing - we're amateurs who own our own equipment, and some of us on a budget!

Veloce Raptor

+1

ProCoach

My experience and data indicates that the INSIDE curbing is useful as an additional, inside apex point, opening the radius of the car's path through the corner.

The STEPPED, secondary section inside the flatter, level section, is designed to keep folks off of the grass, but if the car is NOT upset by the use of that second level, by all means use it. The inside wheels are often (or should be) "light" as the weight rolls to the outside of the car and the corner, so not so much inside wheel weight on the inside curbing. Much of Mid-Ohio and Road America's inside curbs are fully usable. The "turtles" that comprise the secondary, higher curbs inside at Laguna Seca and COTA are not...

The OUTSIDE curbing, OTOH, is NOT conducive to an orderly exit from the corner and is there as a safety net if you MAKE A MISTAKE and run wide. It's also MUCH more injurious to car components because the weight transfer IS to the outside of the loaded wheels and lateral loading is NOT YET DONE when most folks hit the outside, exit curbing.

Matt Romanowski

IMHO, David Murray has the right answer.

ProCoach

THIS is why they have track walks before every pro race. It's a mistake to lump all curbing together, even at the same point on the circuit. When pointing out to drivers HOW to do what David Murry so eloquently points out, I share intimate knowledge of joints, seams, surface consistency, bevels and whether the plane of the curb is equal (or more likely NOT equal) to the plane of the adjoining pavement. You HAVE to do your homework...

I was at the Tudor race at VIR for the track walk with a few clients and we walked by the Porsche engineers with the CORE team. They were using inclinometers and surface friction gauges to catalog every joint that the drivers were likely to hit. It was fascinating to observe and confirmed how important this is. Did the drivers "kiss" or "crash" the curbs? More often they "kissed" them...

OTOH, too often club and many pro drivers use curbs as an excuse to be less precise. Upsetting the car, doing damage and losing time to competitors are all downsides to that approach. You could see this comparing the Tudor (and a few of the GT3 Cup) drivers at COTA this past weekend to the WEC (which requires respecting "track limits") drivers and Jeff Mosing, the WINNER of the Gold class in the GT3 Cup. Jeff was picture perfect and VERY accurate and measured in his use of the curbs. He won, too.

David, Seth Thomas, Tom Long, Patrick Long and many others place the joint between the sidewall and the tread surface of the tire over half-dollar size spots on each curbing EVERY time around. THAT is awesome to watch...

Keith Verges - Dallas

An important note is to tap up brakes in every brake zone if you do use curbing. I learned that lesson the hard way into Canada and into the tire wall under the grandstands. I was fortunate to be upright.

Veloce Raptor

True. Pad knockback is a big issue at RA, as it is at COTA and to a lesser degree the Glen. Anywhere where you use a lot of rumble strips and/or there are bumpy brake zones...

Veloce Raptor

This is a very good point. Precision in use of curbs and rumbles is key... Precision everywhere.

I am a huge advocate of track walks, and lead them whenever possible (COTA, Watkins Glen, Sebring, TWS, MSR, etc). Huge amounts of relevant info available on one's feet that is often invisible in the car at speed.

stujelly

AMEN to that

knock back at road america is nasty in the cayman

morsini

Racing surface, what racing surface?