Datsun Roadster Forum-311s.org

Another member PM's me and asked me to comment on how the 300ZX fronts work with the 8" Ford/ Explorer rear disks. Here's my setup:

Nissan 26mm 300ZX Calipers up front - Spriso serial number 1 for the 26mm setup
Ford Explorer rear disks
7/8 bore 240Z Master cylinder
Stock pedal ratio
Wildwood proportioning valve

Comments:

The front and rears play well with each other, however you definitely need the proportioning valve to tune the system. Pedal is nice and firm. I would say the pedal effort is still a bit high for my tastes. With that, I would consider dropping down to a 3/4 bore Master cylinder- That should multiply line pressure up to 134%. I wouldn't say the overall stopping power is "Stunning", but waaaaayyyyy better than stock Datsun system.

The other side benefit is you're not reinventing the wheel. It's a proven system on a number of roadsters

Regards,
Steve

I would NOT recommend using the 3/4" brake master.
I have the similar brake setup ( 68 SR Conversion using the RX7 rear end ) with the 3/4" master from the stock roadster brakes.
Brakes work good but the pedal feel is not firm or reassuring.
I am upgrading to a 7/8" master as Spriso recommends.

Ted.

"Brakes work good but the pedal feel is not firm or reassuring"

Not sure (from a technical standpoint) why higher line pressures would make the system feel soft?? Thanks for the info

Regards,
Steve

Yes, wish I was a hydraulics engineer!
Something more related to the volume of fluid needing to be delivered to the pistons.
I hope one of the more technical knowledgeable members will give us the answer.

Ted.

Yes, the volume goes way down. So I suppose it takes XX many CC's to move the pistons tight to the disks. So as a result you could see more pedal travel until it gets stiff. I'll buy that "from a technical standpoint" Oh, I used to be a hydraulics engineer (35 years ago) , plus I recently stayed in a Holiday Inn. Does that qualify me?

Regards,
Steve

Like Ted mentioned, I am a huge fan of the 7/8" master cylinder when using our 300ZX brake conversion-- but many people find that the stock 3/4" master suits their needs.

We have both the 26mm (non-turbo) and the 30mm (twin turbo) 300ZX brake kits in stock, ready to ship-- our website is not working correctly right now, but if you send me a PM (or email to sprisomotorsports@gmail.com) I can shoot you more info.

Michael