Brake guys - Manual brakes and Alum 7/8" bore MC qun

Hey guys,

Im interested in your thoughts on this one...

My setup has Wilwood Dynapros front calipers and rears are Nissan Skyline single piston alum calipers (a common swap over here)

My setup is manual brakes with an underdash / cantilever arrangement - pedal ratio is around 6.4 and the current setup does'nt give me enough bite on the rotors, so I'm thinking a 7/8" bore MC will up the ante in the line pressure dept.

The pedal is great without excessive travel and there is no air in the system as far as I can tell. MC was bench bled as well.

In the front line I have a line lock and in the rear, and adjustable proportioning valve which is backed right off for full pressure to the rears at present, but I'm not getting enough grab/bite.

I will be checking pressure at the calipers as soon as the gauge kit turns up, but in the meantime, I'm wondering which 7/8" bore MC Pt # is used. This is a 2 bolt MC deal (std Mopar 2 bolt MC spacing.

Would love some input on my setup and suggestions of a source for the MC.

Thanks !

http://www.3gduster.com/brakes.html

Yep I used that s/sheet (great info btw) and ended up with a 15/16 MC for the manual 4W discs but Im not getting enough stopping power with it which is why I'm asking about the 7/8" bore MC.

Any thoughts and suggestions as to which 7/8" MC I should be trying?

Dr Diff can fix you up with a 15/16" master. Not sure about a 7/8".

It sounds like a nice light weight brake setup. Also, per my understanding, those front calipers have smaller piston area vs stock and need quite a bit of brake line pressure. On a Cobra based setup in an E I needed a dual diaphragm 8" booster + 15/16" master to get full braking.

http://www.doctordiff.com/

I don't think his setup is anywhere near stock and I am thinking not Mopar either, but brakes are brakes.

The sheet will show you what pressure changes might occur with a larger bore M/C.

Yep Cass fixed me up with the 15/16" MC originally, great guy !

FWIW - Piston area on the Dynapro is 2.76" on one side (1.38x2)

The Wilwood calipers tend to have tiny pistons which kills the brake force. That is one reason why I stopped using them back in the day when I was doing brake kits. If your calipers have four 1.38 pistons then the brake force is roughly 50% lower than what the stock Mopar cast iron caliper has.

Andy -- I was/am planning to make the swap to the 11.75: Cordoba discs, and had planned to use the lightweight Wilwood calipers WITH your caliper adapter brackets.. but I've been disappointed that those brackets were discontinued by you at least over the past year (or a little while longer than the past year). So, what you're saying is, in other words, to forget the Wilwood calipers (as well as the adapters.. if I could still find any out there)... and be better off with the stock cast iron calipers?... either sliders or pin types? I have 10.75 discs with pin-type calipers now.

I want to avoid any larger rims such as 17-18s -- at this time for the next few years likely -- and keep using 15" rims (street/hwy crusing) and also to continue with my 16s for some HSAX/lapping sessions ans Hoosier AX SCCA Solo II events.

Send me a PM if you want... T/Anks ahead... winter brake project in the works.

The kit I was selling was using the largest piston size available from Wilwood. Those calipers had 1.75 inch pistons which worked out okay as long as the MC size and the rear piston size was reduced. It is a system so if you reduce the front piston size you also have to reduce the MC piston and the rear caliper (or drum) piston size.

I eventually gave up on the Wilwood stuff for a variety of reasons. A person can make it work but it isn't super high quality stuff so it is a lot of work and then in the end you don't have the best thing to show for it. The Brembo based kits are a better solution but most people don't want to pay that much money.

I'm so happy I was able to get one of your brembo kits before they were discontinued, still one of my favorite upgrades!