Hey everyone, i was wondering what everyones thoughts were on this kit, i was thinking on getting it sometime in the future. https://www.chasebays.com/products/chase-bays-brake-line-relocation-mazda-rx-7-fc-for-bbe

 

Hey, something I have direct experience with! With my ITB's and peripheral port engine, I wasn't getting consistent enough vacuum to the brake booster and had to find a solution. I bought the Chasebays dual piston master cylinder/delete kit with the proportioning valve. You'll want the dual piston as there are two circuits in the master cylinder versus one. If you have a failure with a single circuit, you're SOL and have no brakes.

Overall, the part quality is good. There are no instructions and the FC is a LOT harder to install this into than the FD or Miata shown in their install videos. In the FC, the clevis that attaches to the brake pedal hits the pedal support frame. You either need to cut the support frame or find a way to bend it to get enough clearance. I used a vice-grip and was able to bend it.

There's also no instructions on how far out the piston rod needs to be adjusted to, so be prepared to take the new master in and out several times. If I had known about the fiddly stuff above, my 5 hour install would've been 2 hours. Other than that, pedal feel is firm and consistent.

 

Sweet! Thank you for the info, definitely makes more sense to get the dual cylinder as id hate to total my ride like that.

 

Hope I'm not thread hi-jacking here but with the availability of brake boosters these days I too have thought of one day switching to a manual setup. IIRC your car is still a streetcar or at least is driven on the street sometimes. If so, how well does it work in a street application compared to the stock setup? Like their description says the internet is rife with comments on how manual brakes suck. Is it truly just bad setup and/or wrong pedal ratio?

 

my 1958 Tr3 had manual brakes, and they were great.
i found that not many people have driven a car without power brakes, and they get really weird about it, if you tell them the car doesn't have it.

i have found that without power brakes, pedal feel is better. the pedal is more linear too, although effort goes up with the travel, so normal braking isn't that different, but you need more leg to stop harder

 

@Dak

It's a hard comparison for me, as with the new engine my power brakes were basically non-existent. So, this change was derived from necessity. That being said, the pedal feel is firm but not overly firm. it's consistent, and the ability to adjust the bias is an added bonus. I street drive my car, and have no issues.

For reference, with the brake booster capped off, I couldn't lock the brakes even if I stood on them. I could barely slow the car down if I encountered a situation that required emergency braking. With the new set-up, I was able to dial in the brakes to what I feel like is the correct amount of pedal force required to lock (or not to lock, for that matter) the brakes up. It's a good piece of kit, albeit a PITA to install in the FC.

 

I've also tried driving with the booster vacuum capped off to test something and it was really hard to stop as well, no idea why if a booster delete isn't like that. The booster return spring isn't that strong.
That informed my opinion on deleting booster and probably others as well.

 

I think I had a car without power brakes and didn't realize it. Back in the mid '90's I had a 1973 VW Bug. Brakes worked fine and beyond noticing they were drums all around I didn't give them a second thought. From a little internet searching I think they were manual.

 

It's likely tied to the master cylinder ratio. With the booster capped off, the stock master isn't sized correctly as it's expecting vacuum assistance. With the delete, it's specifically designed to work without vacuum, so the master cylinder is larger and the pedal ratio is adjusted.

 

Yep, that's key. I see Chase Bays's kit adds the 3/4" master cylinder (stock is 7/8") and bracket to change the pedal ratio. Other booster deletes I've seen is just the firewall bracket.