Rx-8 Big Brake Kit Bias
 

Hi all,


I know that it is best to have the front brake kit a little bigger than the rear, so we should have a 6 port big brake kit front and a 4 port rear...

However, im just wondering to what devastating effects or HOPEFULLY little minor effects would one have if he were to place a 4 port big brake kit front and also a 4 port rear brake kit ?




Tried searching in the net but didnt cater specifically to the rx-8...


Much explanation is greatly appreciated..

Do the math. 4 pistons have less braking force than a 6 piston caliper. The front brakes stops your car. The rear brake helps to slow you down and give you control.

you also have to consider the factory abs settings?

Life is not that simple, Simon ...

and I'd like to personally thank the OP for starting another pointless generic thread on an RX8-specific forum without bothering to google, research the topic, and educate yourself properly first

look... as stated... i did bro...


BUT, it was not up to what id say a satisfied answer...



So far this is what i have gathered...



Most probably, it would not affect so much as under hard braking, you would have sufficient stopping power to hold yourself...

but after using some common logic, it would have to be... braking hard on a straight line that would be safe..

what about hard brake during a corner??


- would it be a severe badass of ass swinging / veering off the track?


maybe, or not... so was wondering if anyone ever had any experience and may share...

why u ask?

as we all know... most brake kits for rx-8 are usually 4 port front... and the big brake kits selling by branded companies are also 4 port for the rear (deletes parking brake)...

As i have a 4 port front bought, im hoping that under severe braking it would not be so bad so that i need not buy a 6 port front to REALLY balance out the 4 port rear (even though logic would say otherwise.. but hey, wasnt this forum suppose to assist with those strapped with cash and earning and saving every dollar they can)...

OD bro... would it still be active with the semi DSC function activated during tracking?

The braking force has more to do with pad material and surface area, than the number of pistons.
DSC/TSC counts the number of rotations of the wheels. Changing brakes would have minimal effect if any.

Stop Tech has a good article concerning BBK's and ABS. Go to their site and read about it.
BBK's can affect the ABS in a negative way, but if they are designed correctly they usually dont. Heck even running a different diameter tire/wheel than oem could possibily affect the abs.
It doesnt mean that there will be negative affects in all cases. But before the big money is spent make sure you are getting what you want.
BBK's sure look good but I dont see where they really increase the braking performance. Mazda did a pretty decent job with the braking system. It is ugly though.

oh wellz...


Guess no one really knows for sure what will happen...

@alnielsen... Thanks for the reminder... sometimes u just want to be sure, u knw...

@charles... Thanks boss... depends on skill at the end of the da..

@olddragger... still thinking of a way to repay for the SUPERBLY helpful hints all this while..

Maybe this music video... wish the rotary was long lasting like this...

Hi-jacker, stay on topic:squint:

:D:

just and update...

Had my 4 port rear BBK (with no e-brake delete)...

No severe brake bias during hard cornering! In fact it is sweet!!!

The basic force on the pads (ignoring ABS or proportioning valves) varies with the ratio of the area of the brake cylinder(s) to the area of the master cylinder. 4 or 6 little "pots" may or may not have the same area as 2 bigger ones.

Calculate the cylinder area of OEM front and rear. Calculate the area of the proposed BBKs. If they are the same as OEM, no problem. If the percentage difference from OEM to BBK is the same front and rear, it's likely to be ok. If not, I'd fret that the proportioning valve would have to be re-calibrated to achieve basic F/R balance. At the limit, the ABS would take care of an imbalance, but braking would be squirrelly up to that point.

I'm not including effects of changes in pad area or disk radius, but think a similar analysis of BBK/OEM ratios would give a similar guide.

YMMV, I'm a non-expert on the subject.

sounds expert enough to me...

If it helps, the bbk's maximum rotors accommodation for front and rear are both 330mmx30mm..

pads are street/ track pads from AP Racing at the time of test..

nothing funnier than a mathlete failing his own "calculate the math" reply.

What rear brake kit are you using that uses 4-piston (or 4-pot, not 4-port) calipers without deleting the e-brake?


.

^ hydraulics. feel free to do it right.

DK Brake Kits... Module/ brake caliper is attached to the e-brake so it does not delete it..

no double handbrake or hydraulics... i posted a thread on this asking if anybody is interested but so many sarcasm... so... thatz that...

I bought this one from a bin sale

It scared me away from changing to a big brake system.
It's the only thing I've read on brakes so I can't even say if the book accurate.

I did switch pads and installed braided brake lines

Here is a bit about bias -- a the thread is titled

Not sure if it's readable .. but I'm trying
Attachment 228198

Team you must have some books on brakes.
Any recommendations?

bottom line--unless you are doing some hard tracking on big r compound tires--it is going to be hard to improve on the oem brakes + the right pads and fluid.

the key would be to maintain the same front vs rear total piston area balance (hence the mathlete sarcasm towards the person stating 6-piston is greater than 4-piston, that depends on the piston diameters and their total area because hydraulic pressure x piston area = applied force), once you get too far away from this then some type of compensation is usually required

however, with an independent ABS system it will still release the rear caliper hydraulic pressure if it sense the rear hubs locking up, which is likely all that is occurring here

what the end effect can be will vary by the sophistication of the system, there are a number of know issues on certain vehicles getting into an ABS condition known as "ice mode" with just a brake pad change, typically earlier less sophisticated model years

any way, I can only find one reference to this particular brand/kit so far (DK / Density Kinetic) to a company in Singapore, not even on their website just promoted on a forum.