K-PAX Racing's attempting to turn an off-the-line Volvo C30 into a world-beating race car in 60 days. Driver Robb Holland's going to give us weekly project updates. Part Seven: them's the brakes. —Ed.
14 DAYS! 14 DAYS! ARE YOU FRICKIN' KIDDING ME! Um, sorry did I say that out loud? Yeah it's that time. The guys at K-PAX Racing are on it literally 24/7 these days. They've even called in the reinforcements in the form of Kiwi, Keith Andrews, my head wrench from last season.
Kiwi usually works full time for 3Zero3 Motorsports, but this year he's getting traded over to K-PAX Racing to fill out their roster and run my car for them. Usually Kiwi's job doesn't really kick in until the season gets underway but this year he's been called in a bit early, as the shop has been operating at full capacity between this C30 project and updating the S60 GT cars to the current spec of the new street car that was just launched by Volvo late last year.
We spent the early part of the week getting the car ready to head to the dyno. Although "getting ready" was a bit of an overstatement as with no hood, doors, or windows, the car rolled onto the trailer looking like something that had been left on the street a bit too long in South Central LA.
Turns out, we didn't need to have it fully finished and prepped, as the guys informed me that this dyno session was mainly a shake down run to make sure that all of the bits and pieces we pulled out of the car didn't wreak havoc with the CAN-bus system and prevent our engine from running at all, let alone reach max boost. Leaving all that stuff off of the car meant that the crew had access to all of the important bits if something broke or needed to be changed out, without having to pull half the car apart to get to it. Smart guys.
As it was, our test was a mixed bag. On one hand the car ran flawlessly and pulled strongly from idle all the way to redline in every gear (except 6th which is an overdrive gear on almost all manual streetcars these days and is unusable by us as we rarely max out 5th). On the other hand we were way down on horsepower, by at least 20%, from what we were expecting.
That's a pretty major deal. We're not super concerned right now as we have several options to get the power up to the level we need it at, but with so little time left until the season opener in St. Pete any setback is a big deal.
As I mentioned last week, go fast stuff has been showing up on our doorstep non-stop but the last bunch of boxes to show up actually contained a bunch of go-slow stuff. Go-slow as in stopping. Boxes containing our Stop Tech brake system, Prospeed brake fluid, and Raybestos brake pads all showed up on the same day. Braking is one of the most overlooked performance enhancements in racing.
If I can brake 20 feet later then my competition and still get down to the same corner entry speed as they do, then that is a huge advantage. Think about it. While they are hard on the brakes, I will still be full throttle for that additional 20 feet. Yup, big deal.
To get the skinny on how these braking systems work in both race and street environments I asked the smart guys from StopTech, Prospeed, and Raybestos to give me their insights on how their high performance products function in such diverse environments.
Ryan Kim is the Motorsports Sales Engineer for StopTech. As such he will be our go to tech guy at all the World Challenge races this year. I told him that if I got him a mention in my post that he would have to buy me drinks all season. So I got that going for me now.
Well known in the Street Performance world for their Big Brake upgrades, StopTech is also the official brake supplier to the World Challenge Touring Car field and as such has created a unique braking package for every make of car in the field. As our racecars are very similar to their street counterparts I was curious as to how the StopTech engineers adapted their system for our cars.
On creating an upgraded braking system for a production car:
We begin with an evaluation of the vehicle characteristics and typical use of the vehicle. Technical considerations include power, weight, stock wheel size and typical use of the vehicle. An assessment of customer expectations includes rotor diameter (compared to stock and competitive offerings, if any), caliper piston count and finish level. In most cases, our brake systems are designed to integrate with a vehicle's stock brake pedal, booster, master cylinder, ABS and other vehicle dynamic controls.
Engineering usually starts by driving the stock car and evaluating the stock brake system response and balance. The stock brake and suspension components are measured so that the hats and brackets can be designed. Geometry issues, such as the position of the stock caliper mounting lugs or the parking brake drum diameter, may lead to a change in rotor size or caliper selection. Caliper piston sizes are calculated. Once the components are prototyped, the vehicle is fitted with the brake upgrade and testing performed to ensure the performance meets all requirements.
On the differences between StopTech's off-the-shelf caliper and the World Challenge versions:
The StopTech brake systems used in World Challenge Touring Car racing differ only in small detail from the street version available to the public. The minor differences include fully floating rotor mounting hardware and a natural-anodized AeroHat on the racing version.
The full-float rotor mounting helps eliminate pad knockback under the higher cornering forces possible with race tires, but would exhibit unwanted noise for a street car. Natural hard-anodized AeroHats are completely resistant to color change at the high temperatures experienced in racing. Standard street systems with painted calipers are supplied to all World Challenge Touring Car teams, with black anodized hats and anti-rattle rotor hardware, but will otherwise perform identically to the systems used on our street version.
On what StopTech gets out of racing:
Our involvement in World Challenge, Grand-Am and ALMS allows us to constantly review our current technology and find ways to improve. Racers find ways to exceed the limits of almost any engineered component. Working with them to develop their braking systems for success helps us not only build better products, but also provide better service to the track-day enthusiast and club-level racer.
Technology and product development transfer in both directions. Our Trophy Brake System calipers were conceived for racing, but have proven popular with street customers. Conversely, the natural anodizing process applied to the rotor hats for Trophy Brake Systems and the World Challenge Touring Car systems was first developed for a customer building high-horsepower street cars.
Next, Josh Russell is the Marketing and Sales Director for Raybestos Brake Pads. He spends a huge amount of his time on the racing circuit following us around and tailoring brake pads for each team. He also does side work on some series called NASCAR. Supposedly his pads do kinda well there winning 90% of the short track and road course races last year.
On various brake compounds:
The different racing brake compounds are prepared individually for the type of vehicle, its setup, the type of track it's being raced on, and even the driver's style. Each provides a different friction level, and different characteristics (in both initial bite and release) — so the driver or crew chief can "tune" with the pad compound to deliver the intended performance. A change in pad compound can help target the ideal bite, fade resistance, release and wear characteristics the racer is looking for at a given event, or sometimes, for a different approach between qualifying and raceday setups.
On racing pads vs. street pads:
Racing pads are engineered to thrive in sustained high-heat operation, delivering a tremendous amount of friction and torque, for improved stopping power. Our ST-range of race pads operate at 1,100-1,400°F, while typical street pads rarely see temperatures above 600°F. Competition friction material in racing pads is also 6 to 7 times more dense, and heavier, than a comparable street pad. They are far more aggressive, wear more rapidly, tend to make some noise, and create a lot of dust. All fine in a racing application, but definitely not the kind of attributes you want in a street pad.
Finally, one of the most overlooked (at least in my opinion) components of a braking system is the brake fluid itself. Michael Wachholz, President and CEO of Prospeed Inc. supplier of brake fluid to teams like Andretti Autosport (IndyCar) Panther Racing (IndyCar) AFS Racing (Indy Lights) and ExtremeSpeed Motorsports (ALMS GT) gave me a quick look at what characteristics make a good racing brake fluid.
On the differences in brake fluids:
The first things most people look for when they are looking for a high performance brake fluid are the dry and wet boiling points. Higher boiling temperatures are definitely important however there are several other critical characteristics to look for, such as a high resistance to compression and high temperature stability. These characteristics mean a better and much more consistent pedal feel for better braking control throughout the wide range of extreme temperatures racing brakes experience.
On using a racing brake fluid in a street application:
As long as the brake fluid complies with all the DOT requirements (not all do), there is no reason a high performance racing brake fluid cannot be used in a street application. Using a racing brake fluid will provide the street driver with all the benefits the race car driver experiences and in addition will increase the margin of safety by reducing the probability of boiling the brake fluid.
On frequency of changing brake fluid:
For the professional (IndyCar, NASCAR, ALMS, World Challenge, etc.) team, the brake system should be flushed and refilled prior to every event with, as time allows, bleeding in between sessions. This practice will assure that the driver will always get the absolute best performance from the brake fluid. For the track day/weekend warrior type of driver using a high performance brake fluid, the driver should be able to do a full season on a flush/fill without experiencing a noticeable degradation of performance.
Next week is the big one. Our C30 gets polished up and we head to High Plains Raceway to do a prelim shakedown and get a feel for what we've got. Cross your fingers and whatever other random body parts you can manage, we're gonna need it…..
- How To Turn A Grocery Getter Into A World Beater In 60 Days: Part One
- How To Turn A Grocery Getter Into A World Beater In 60 Days: Part Two
- How To Turn A Grocery Getter Into A World Beater In 60 Days: Part Three
- How To Turn A Grocery Getter Into A World Beater In 60 Days: Part Four
- How To Turn A Grocery Getter Into A World Beater In 60 Days: Part Five
- How To Turn A Grocery Getter Into A World Beater In 60 Days: Part Six
Robb Holland is a professional racecar driver with K-PAX Racing and 3Zero3 Motorsports. When he is not racing in World Challenge, Holland works as a performance driving instructor and owns a travel company that takes US clients over to Europe to drive the Nurburgring. You can follow him on his Facebook page.