brake pedal ratio Chase Bays

A properly set up Manual Brake Conversion Kit improves lap times and makes for a more controllable drift / rally / road race car. There is a lot of incorrect information out there about Manual Brakes, from forums to other videos. We have sold over 15,000 Manual Brake setups in the last 10 years…everything from winning Road Race chassis to winning Drift chassis.

So forget everything you've heard about manual brakes, forget everything you know about master cylinders and boosters all together. We've seen it all and know exactly how Manual Brakes give consistent and controllable brakes.

Every single day numerous times a day, we get asked “what are manual brakes like?” and sometimes followed up with “my buddy said they suck!” or "just unplug your vacuum hose!". The FACT is, the fastest road race cars in the world have manual brakes. From F1 to GT4. The difference in those setups from just slapping a big master cylinder on a plate and calling it a day, is they use pedal boxes with a 6:1 or 7:1 ratio.

Like anything else on Motorsport chassis, with Manual Brakes, setup is everything. We make a Single Piston and Dual Piston Brake Booster Delete. Where our Single Booster Delete differs; it's a single piston design and its working with the stock 3.5:1 to 4.5:1 pedal ratio (depending on the chassis). The pedal ratio is basically just a way to measure leverage you're giving the master cylinder, it's the distance from the top swinging axis to the brake foot pad divided by the distance from the top swinging axis to the master cylinder clevis mounting point. Our Dual Piston is a 6:1 Pedal Ratio which is what you see on high end motorsport pedal boxes.

Changing the pedal ratio to 6:1 is a major function and feel upgrade to allow the use of a larger master cylinder. The OE pedal ratio can only leverage so much, so we’re limited to a 3/4 or smaller master cylinder. The improved Motorsport pedal ratio gives you a better mechanical advantage with additional leverage. This means we can use a larger 1 inch master cylinder with more fluid being pushed per mm of piston travel inside. It allows you to have a better braking feel and more force to the calipers with equal or lesser force at the pedal. That translates to less leg effort and more braking power while keeping a similar throw distance.

WHY ARE MANUAL BRAKES GOOD?
A proper manual brake setup (matched ratio with MC bore size, good pad compound, and Front / Rear Bias Adjustment) is the exact same braking every time. The modulation of max braking just before lockup is where manual brakes really thrive. We call it the 90-99% zone. Finding the exact level of leg pressure to get that exact threshold is just not possible with power brakes, they’re too inconsistent...especially with boost. Maybe your buddy did X and Y on the track with it but thats anecdotal info. Acquired Motorsport Data isn’t wrong. YES the 90-99% zone is a little more leg effort than power brakes but that’s what makes it so great. This is massively to our benefit in finding the right leg force every time. IF your manual brakes don't feel great, your set up is lacking something. But don't worry we can help figure it out.

Manual brakes are also great in Drift and Rally environments where nearly every turn has a different entry angle and speed. We’re always making tiny on-the-fly driver adjustments. If we take the same turn 10 times, we may only hit the foot brake half the time. As well, left foot braking is more common…your left foot isn’t used to braking and is often done on the fly as a correction. With the stiffer slightly more leg pressure 90-99% braking, this allows us some forgiveness in not locking up the front brakes and easier modulation with the opposite foot used to controlled modulation. Touchy power brakes are terrible for left foot braking.

WHATS WRONG WITH POWER BRAKES?
Power brakes are inconsistent, they're too touchy or too soft (especially under boost). When you’re going 100+mph into your braking zone lap after lap…the braking experience MUST be the same for better lap times. With vacuum assisted brakes we’ve all experienced it…one push is one level of braking and the next is entirely different. This works fine on everyday drivers around town barely paying attention and wanting to put the least amount of effort in. This just simply doesn’t work for Road Race, Rally, or Drift chassis…which is why under dash manual pedal boxes from companies like Tilton exist.

OKAY I WANT MANUAL BRAKES AND A 6:1 PEDAL RATIO!
How can we achieve pedal box function seen in F1, Indy, IMSA, & GT4 without $3,000+ in parts? Without days of prep, relocation of under-dash components, and fabrication? How can we have a DUAL Piston / Isolated Front and Rear Circuits setup thats approved for nearly every sanctioning body from FIA to Formula Drift plus SAE and DOT approved? How can we achieve this without removing and drilling the stock pedal or without massive modifications to the firewall or interior? After years of hard work, testing, and procurement...Chase Bays has it figured out.

The Chase Bays Dual Piston Brake Booster Delete with Bolt-On 6:1 Pedal Ratio is the ALL inclusive package to get you HIGH END motorsport brakes on your car with ease. It includes:
• 1 inch Bore Ultra Compact Master Cylinder

• Isolated F/R Circuit High Heat Polypropylene Fluid Reservoir

• Billet Chase Bays Reservoir Cap with High Heat Vented Diaphragm

• Billet MC / Firewall Adapter Plate with Raised Mounting Point (inside is hollowed for weight reduction)

• L-Banjo Front Outlet Fitting for easy front line mounting w/ SS Banjo Bolt

• SS Rear Outlet Hardline to Adj. Bias Valve

• Adjustable Bias Valve w/ -3AN 90º Outlet

• Carbon 4140 Steel Push Rod and Clevis

• Stainless Steel Bolt-On 6:1 Ratio Pedal Adapter

There are about 5% of motorsport builds that require a pedal box. They need to decrease front AND rear pressures simultaneously…if you’re one of them you probably know it! One day soon we’ll make a pedal box for ya.

Beyond this, you will need our Brake Line Kit to make it all work. We make them for the following chassis (click them to be linked to the kit). If we don't make it you will need to make your own lines or have them made. All 3 outlets are -3AN Male.

Click here for Chassis Specific Brake Line Kits for Dual Piston Brake Booster Delete

 If you have a BMW, FD RX-7, or Mitsubishi Evo chassis (or just want a cool matching clutch reservoir for this product) those get the clutch fluid from the Brake Reservoir. You will need this part to share the reservoir on our Booster Delete Chase Bays Clutch Reservoir for Dual Piston Brake Booster Delete

TL;DR
• Consistent and Controllable Brakes for the EXACT same braking every time, unlike inconsistent Power Brakes made for non-Motorsport use. This results in better lap times and/or a more controllable drift/rally car.
• Pedal Ratio change of 4:1 to 6:1 via supplied Bolt-On Bracket for increased leverage on Master Cylinder. This allows you to unlock the amazing powerful braking of a Manual Setup.
• True Dual Piston Master Cylinder and Isolated Front and Rear Circuits within Reservoir. If you lose front brakes you still have rear brakes to get to safety and vise versa. Which makes this suitable and approved in FIA, FD, SCCA, WRC, and dozens of other sanctioning bodies.
• The FACT is, the fastest road race cars in the world have manual brakes. From F1 to GT4. This product allows you to unleash that same potential without all the under dash pedal box fab or complication.

APPLICATION GUIDE

• Honda | Nissan | Mazda | Mitsubishi | AE86 [CB-DBBE-U]
(Requires 10 minutes of firewall, click here for guide)

Honda Acura (Civic,Integra, RSX, TSX)
Nissan (240sx/Silvia, Skyline, 350Z/G35, 510)
Mazda (Miata, RX-7)
Older Toyota (AE86, TE72)
Mitsubishi (Evolution, Eclipse, 3000gt)

• BMW E30 | E24 | E34 | Porsche | VW [CB-DBBE-EURO]
(Requires 10 minutes of firewall, click here for guide)

BMW E24, E30, E34 (Does NOT fit LS Swapped E30's!)
Porsche 944, 928 (only applicable to 4 bolt OE booster mounting pattern)
1990-1999 Volkswagen VW (only applicable to 4 bolt OE booster mounting pattern)

• BMW E36 | E46 [CB-DBBE-E346]

BMW E36 | Z3 (incl. 318ti)
BMW E46 (must use E36 Pedal ... only $35 ... part # 35211158386)
BMW Z4

• Toyota Supra | SC300 | Soarer | IS300 | Nissan 280z [CB-DBBE-MK]

Toyota Supra MK3/MK4, Soarer
Lexus IS300
Lexus SC300 / SC400
Toyota Cressida MX73
1970-1977 Celica TA23, RA23, RA24, RA25, RA28, TA28 & RA29
Datsun / Nissan S30 chassis 240z / 260z / 280z

• Toyota GS300 | MX83 | JZX90 | JZX100 [CB-DBBE-MX]
(Requires 10 minutes of firewall, click here for guide)

Toyota GS300 | Aristo
Toyota Cressida MX83
Toyota Cresta / Chaser / Mark II JZX90, JZX100, JZX110

• Toyota 86 / FR-S / Subaru BRZ | 02-07 Subaru WRX [CB-DBBE-SUB]
(Requires 10 minutes of firewall, click here for guide)

02-07 Subaru WRX including FR-S / 86 / BRZ