Big Brake Upgrades

[Slow and Slightly Angry]

I am looking into upgrading the brakes on my IRS coupe build. A majority of the upgrade is for aesthetics but the RSC coyote is heavy-ish and a good bit of HP so I want them to work. Has anyone done any big brake upgrade beside wilwood (i.e. brembo, baer, drag, street etc)? If so, any extra complications because of the choice? Have the upgrades been worth it? Use of the car will be mostly cruising, no autox etc.
I have a bit of non-wrench time on my hands right now so I have been running through a bunch of different options.
I do have the mustang performance brembo brakes from my donor but they will require at a min of 19" rim and an adapter.

[Gordon Levy]

You would be happy doing the upgrade. In my 30 years as a Wilwood dealer and 25 of putting them on these cars I have never had one person regret the upgrade.

[daxtojeiro]

Hi, I am considering something like this for the fronts, but until my coupe arrives in the UK I am keeping my mind open. Apparently the FFR standard setup works well anyway, until I see what comes in the kit I will decide then.

https://www.svtperformance.com/threa...cobra.1175014/

thanks
Phil

[NAZ]

Brakes are a safety critical item that you will want to get right the first time. The front and rears need to be engineered to work in concert or you can be surprised with a poor handling car when the brakes are applied hard. If you are going away from an OEM engineered design, I would urge you to seek assistance from folks experienced in setting up braking systems, either someone like Gordon or the brake manufacturers. The math is not difficult when selecting parts for a balanced system but an understanding of the physics involved is important.



Most OEM systems have several times more stopping torque than the car’s engine and drivetrain can produce. In my experience, the most common brake system problems come from using the wrong pad compound. There are a couple thousand brake lining compounds out there, all formulated to meet some specific needs. The OEMs place a DOT code on the pads (edge codes) to help guide service techs to replace the pads with the proper compound for the application. Most DIY folks and even parts counter sales staff at the corner parts house are not aware of these.



Pad compound coefficient of friction is critical in achieving good braking performance and most don’t know how to choose the correct compound. A street car needs good cold braking torque and if you purchase one of those “race” pads that need lots of heat to increase the coefficient of friction you may not be happy with your brakes. Same with selecting pads based on low dust qualities alone. But the experts can guide you.

[lance corsi]

Naz, I always learn from your posts. Thank you for educating me.
I have a question to ask of you; How does gun drilling an axle improve its strength, or is it merely to reduce weight? Tia

[NAZ]

Lance, good question. Weight saved on a race car is important and where the weight comes from is also important to how the car performs.

When it comes to simply lightening a bar (axle) it doesn't matter where that material is removed from. A cubic inch worth of steel cut from the end or the O.D., or the center will weigh the same. However, where you remove the material can have a significant effect on strength. The strength of a bar is more dependent on the outer diameter than the inner core. So gun drilling the axles can remove pounds and not significantly reduce the strength. I saved a whopping 7lbs with gun drilled axles. Doesn't seem like much but on a race car pounds saved = better performance. And the axles will handle more than the 14,757 pound feet of torque my car is capable of exerting on them.

[J R Jones]

A professional like Levy with knowledge of your car is valuable. I recently saw Frankc5r help out an 818 guy understand his braking weight transfer to pick appropriately matched calipers.
Tuning the system is the last step to make both ends cooperate and not have one axle lock in emergency braking. A balance bar on the pedal or proportioning valve makes the system tunable. Staggered tire sizes complicates the predictions.