Mixing up brake pads on a race automobile can appear counterintuitive at first look however NASCAR Cup groups usually do it on function with a view to work across the guidelines and anybody eager to be aggressive at Phoenix this weekend shall be attempting it.
The NASCAR Subsequent Gen automobile is usually assembled with single supply components so groups can’t construct customized suspension or brake elements however brake pad compounds will not be restricted so groups have found out the best way to alter the dealing with of the automobile by mixing friction compounds and putting in several types of brake pads on every nook of the automobile.
This follow is named splitting brake pads and it may be very efficient at making a race automobile sooner or extra steady right into a flip however may also be harmful because the imbalance of friction backward and forward can overheat the brakes and trigger a rotor to shatter as we noticed with the No. 20 of Christopher Bell on the 2023 NASCAR championship race at Phoenix.
How brake pad splitting works
Crew working inside wheel wells of Austin Cindric’s Crew Penske Ford
Photograph by: David Buono – Icon Sportswire – Getty Photos
Within the easiest phrases, brake pad splitting means that you’ve a cut up compound both aspect to aspect or entrance to rear the place the brake pads throughout any angle will not be matched however as an alternative have completely different friction compounds. In an surroundings the place groups can’t construct customized suspension or brake elements with a view to enhance the dealing with of the automobile they chase no matter half is open and having greater friction pads on the fitting aspect of the automobile can assist a automobile be extra steady getting into a nook.
We checked in with Joey Cohen who’s presently president of GMS Race Automobiles and has labored in a variety of technical positions in NASCAR and different collection starting from engineer to government to study extra about brake splitting and why Cup groups cut up brake pads.“That is accomplished in an effort to tune for steadiness based mostly on how braking torques are utilized,” Cohen defined. “This can assist how a automobile hundreds a sure nook beneath braking together with weight transition and in addition the temperature vary the brake can function at. Some frequent configurations could possibly be entrance v. rear, left v. proper, and even remoted to 1 nook of the automobile to forestall lock-ups when a wheel turns into mild on load.”
Why brake pad splitting is necessary at Phoenix
As Cohen shares, the brake pads find yourself getting used to power the automobile to show a sure manner with particularly chosen corners of the automobile being grabbier than others and it turns into considerably necessary at a observe like Phoenix Raceway due to its distinctive structure. Phoenix is an uneven observe so braking and dealing with of each nook is exclusive and organising the automobile is all the time a compromise however splitting the pads can mitigate a few of that. Entry into flip 1 at Phoenix in comparison with flip 3 is kind of completely different because of the structure of the observe and Cohen shares that “Into flip 1, your entry is coming off the dogleg entrance straightaway whereas the entry into flip 3 is extra accomplished in a straight line off the again stretch.”
The cut up brake pads act virtually like a custom-made suspension with a view to enable dealing with to be equalized throughout distinctive corners together with the brake bias adjustment that the drivers have within the automobile which permits them to shift brake stress from entrance to rear on the fly.
One other one of many distinctive points of Phoenix that isn’t current at different quick tracks is the truth that it has fairly lengthy straightaways which implies that the brakes can see giant temperature swings if the brake ducts are extensive open. In sure instances, groups will modify the friction compound of a sure nook of the automobile with a view to decrease these temperature swings in the event that they count on the nook to be overcooled on the straights.
Aero additionally performs a a lot bigger function at Phoenix than at different quick tracks and Cohen mentions that splitting brake pads also can mitigate sure aero results: “Braking can create giant variations in platform of the automobile (pitch motion ahead). This may have an effect on the general and entrance/rear downforce profile of the race automobile transitioning from entry to heart of the nook. A brake pad of various friction configuration can remove or easy out the platform variations.”
Why groups use brake pad splitting
An in depth view of the NASCAR Subsequent Gen wheel
Photograph by: James Gilbert / Getty Photos
In previous generations of the NASCAR Cup automobile, groups might construct customized suspension elements and choose very particular brake elements for the automobile based mostly on observe and even combine and match issues like brake calipers or suspension arms from nook to nook. The Subsequent Gen mannequin eradicated all of these selections so groups now should use spec components from particular suppliers when constructing automobiles and the identical brake calipers and suspension arms should be used throughout quite a lot of completely different tracks.
Along with being able to construct customized brake and suspension elements in previous generations, groups might additionally set up shut off or delay valves or route brake strains in particular configurations with a view to have an effect on the bias to any particular nook of the brakes. Cooling was additionally as much as the groups so they might match particular corners with customized cooling for the friction profile of the brakes or for particular aero that they is perhaps chasing. With all of those choices off the desk, groups now attempt to do all of these modifications solely by customizing the friction compounds of the brake pads.
How brake pad Splitting could be harmful
Christopher Bell, Joe Gibbs Racing Toyota
Photograph by: Jared C. Tilton/Getty Photos
We noticed the championship hopes for Bell finish shortly throughout that 2023 finale at Phoenix as his proper entrance rotor shattered and took the fitting entrance wheel and tire. That is the place the hazards of brake pad splitting are available and why it’s all the time a fragile steadiness when groups chase efficiency in unorthodox methods. The possible situation in that scenario is that they have been chasing stability whereas getting into a nook by having greater friction pads on the fitting aspect of the automobile versus the left. It labored for some time however they went too far as the warmth generated by the friction on the fitting entrance was an excessive amount of for the out there cooling.
As soon as the rotor will get too sizzling it may possibly develop to such an extent that it may possibly contact the brake caliper after which as soon as the automobile will get on a straightaway will probably be all of the sudden cooled off which may trigger it to shatter from the big temperature distinction. Cohen notes that there are a selection of different disadvantages of splitting pads particularly over a long term in a race.
“Excessive temperature pad compounds can maintain residual warmth that would trigger rotor cracking, glazing of the rotor floor (much less out there friction), and failure in caliper seals and elements which might result in complete nook failures of the braking system,” mentioned Cohen. “Uneven rotor put on and tapering of a person nook can create vibrations and wheel shake for the driving force beneath braking, and inconsistency within the response of the brake pedal.”
Groups could have some powerful selections to make as soon as follow wraps up at Phoenix as they determine which brake pads they wish to take into the race and the way massive of a danger they wish to take with championship hopes on the strains.
We wish your opinion!
What would you wish to see on Motorsport.com?
Take our 5 minute survey.
– The Motorsport.com Crew
