Galo, I need to talk to you anyway so check your pms in a min.

Technically you might be able to affect the bias via pads. Slightly. But I have never seen/heard/read any pad maker suggest that pads might aversly affect the ft/rear bias.

Using multipiston calipers AND using a bigger rotor for a larger torque arm, has A MUCH greater affect on the amount of force applied onto the rotors than a pad ever would.

IMHO. Let's say you used the highest co of friction pad that chews though your front rotors and only works when they are extremely hot. Then used the crappiest rear pads you could find. I doubt that situation (however extreme that might sound) would come close to affecting the frt/rear bias enough to warrant a design change.

Think about it. If you really had that much power with just pads, BBKs would never be offered, car makers would never even offer them and you would see many tests that show a pad only change can make great differences in braking distances.

On that note though. If you are wearing out your rears every 26k, maybe Nissan tried to up the rear bias in an attempt to increase braking performance of the later maximas. But I haven't read to much data to back that much too much. I saw a 2000 maxima 60-00 time of about 126-13x ft. I don't know what a 3-gen does but I'll look it up. I don't "think" it's that much better or worse. But FYI, I have gone over 100k and my rear pads are barely worn. So I definately needed more ooph in the rears after putting on my own bbk.

 

Jeff, of course I agree with you...the difference would be slight, definitely the mechanical/physical aspects you describe will have much more effect than pad compound -but intuitively, one could see where pad compound would indeed make a difference by looking at the graphs here. Granted, not a big difference but.....you can see here where one pad's CoF (the T compound) begins to drop at the same time the Q compound's CoF begins a rather marked rise.

http://www.wilwood.com/BrakePads/003-DESC/index.asp

BTW, I originally installed the Q compound pads with my brakes and then switched to the T compound -which actually drops in CoF after 500 degrees- and found my brakes to work better and quieter...maybe that 'better' was that these pads maintained a better front/rear effective bias.

On my rear pads, they were about 60% gone so..I figure they would have lasted about 40k miles. The reason I replaced them was a warped rear rotor -potantially another piece of evidence that my front/rear bias is not too bad...

Another PS edit: if you peruse the Wilwood site, you can see that both the T and Q compound are very easy on rotors, meaning one can find pads with various CoFs that dont necesarily eat rotors up...

 

Galo. You need to stop listening to Icy. He's a tard.

Anyway, I think if you can get a pad that needs to be somewhat friendly to rotors, then I think you can only expect so much performance from them. You can get them to perform when cold(which is a necessity) and then give up some when really hot. Or peform well when hot and give up when cold (bad idea) etc...

Do you have a factory fsm? It should list the oem bias in the brake section. I'd be curiuos to know what it is.

 

Galo,

I agree on the rear pads...

These white papers by StopTech really opened my eyes on variables that can be optimized to shoot for factory front/rear bias:

http://www.stoptech.com/whitepapers/...erformance.htm

Also, here is one on just REAR brake upgrades:
http://www.stoptech.com/whitepapers/...tter120601.htm

 

Ahh.....I'm not touching that one even with an 11-foot pole....LOL!!!!!!!!

Yes, indeed -very bad for street driving...

nope....dont have one

 

I see...

Control Valve
Applied pressure(front) = 1,067psi
Output pressure(rear) = 739-796psi

 

Mnnnn....interesting!! These numbers imply about a 70/30 bias in stock form for a car whose static weight distribution is 63 front 37 rear.....that does not seem to be enough front bias for any reasonably hard stop...

Of course, then all the other mchanical variables come into play and Lord knows what this equates to in terms of actual retardation force.

I give up. Those facts plus reading the Stoptech article about the elusive perfection means the're no way we are gonna get to the bottom of this without a Cray computer....I'm gonna go back to work....that's easier

 

hehe. Galo. Cracks me up. 70/30 is about right. And if you remember, Matt93se's long post on brake bias (which Driven clearly ignores) talks about what a bbk changes the frt/rear to. And why he made the the rear bbk. I think the post also mentions a 70/30 split.

 

You bring up a good point. A well designed brake system will take into account the weight distribution of the car.

 

IMHO...I'm feeling the 2K4 caliper/rotor setup, grippy tires, lowering the CG of the car, and maybe better pads in the rear is best for those that don't want to upgrade the rears, ie the majority here.

However, for the Z32 front calipers or most of the BBK calipers out there that dramatically increase FRONT rotor/piston size, you MUST run Matts' REAR BBK to end up near factory bias.

Looking at all of this now, I'd rather have gone the 2K4 route and not messed with the PITA rears, however for ~$1K for Matts' REAR kit+Z32 calipers/rotors/pads, it should put me back in the "safe" factory bias range.

 

um....is this using Matt's "formula?"

because if not:

1067 FRONT 60%
----------- = ----
739 REAR 40%

or 1067 FRONT 57%
----------- = ----
796 REAR 43%

 

That's just brake pressure proportioning front/rear and NOT the bias.

 

ight...just making sure....my math skills are a litte rusty and couldn't figure out how to mesh the proportioning with the caliper/rotor size bias....

 

hey Josh.. i jus mocked up the 6th gen calipers with the stock 17".. they clear the calipers.. byabout 1.5mm.. checked it wit feeler gauges.. for those who feel thats too close for comfort..get spacers.. if not.. itll work.. i torqued the wheels on as well.

 

Still working on that irish, but *IF* I get it figured out, I'll let you know.

What I do know is that messing with increasing rear bias is like messing with fire and not something to be taken lightly. Also per StopTech, proportioning valves are NOT an answer to fixing an improper biased setup, so choosing your rear bias increase is crucial.

 

Yes.

And, after 330-odd posts, I have a solution for a cheap, low-tech rear bias increasing device. Indeed, its the mother of all rear brake bias increasing devices.


e-brake

 

The 17's on the 02-03 are a bit different from the 00-01 17's...I can tell you that the 6th gen setup did NOT clear my 17's.....needed at least a few mm....they must have changed the back design, since mine would rub on the outside of the hub....

 

i got pics yall.. here









maybe the 02-03 model wheels are slightly different..

i used those 2 feelr gauges together..it cleared.. about 1.5mm.. i jus put them on..man..feels nice.. more confident braking..

 

Damn that IS close. Some OEM applications are extremely close too. Maybe not THAT close hehe.

 

Well that sucks...I thought 2K-2K1s would be the same as 2K2-2K3s, since the offset is the same just the center cap is different.

That means I'll need AT LEAST a 5mm spacer, since supposedly 2K2-2K3 only needed a 3mm spacer.

 

I was gonna do that...but I just sold my SE rims instead and will buy (for about the same price) some G35 SEDAN 17's, which have a 30-35mm offset and will clear without spacers.....

 

yeah.. 3-5mm spacers should work..

 

Ohh Noble Fishy One: I too have about 1.5 mms between my SSRs and the Wilwood caliper.....it was scary for the first coupla weeks, now it's like, who cares? Not a problem yet....

knock on wood now...

 

boo-ya! damn I wish it would stop snowing!

 

ahh yes.. the guiness.. haha nice.. front end feels heavy.. i dono if its jus me or wat..





sorrie.. had to post these..

 

Well, what the hell!



http://www.digitalbeta.net/jeff92se/photos/IMG_5495.jpg

 

ONLY thing too worry about being that close is when you press on the brakes, the caliper could flex/twist and contact/rub, maybe?

 

Yeah, you can definitely feel the extra weight of the rotors. combine those with my G35 rims and I'd probably run 16's in the 1/4 (if I ever wanted to run the 1/4, that is...)

 

I was thinking of doing the same, ie cheap 42mm offset wheels BEFORE you guys posted this, but it's too close to call/PITA because the spokes could still be a problem.

 

Muhaha. I have clearance for days mang. See the pic. Mega clearance. No spacers. But I do run a hubcentric ring.

 

I know it's so cliche' to say, but......

"Holy Wheel Gap Batman!"

sorry, couldn't resist. Especially since I'm jealous that your 6th gen brakes are on before mine (you must have a garage, because your weather looks like ours...)

on a side note....for your safety's sake, I really hope you're not planning on driving in the snow/slush with those RE92's....

 

Maybe he's not a WUSS! hehe. Or has a wife that yells out for the neighbors to hear "WTF are you doing out there! You are COMPLETELY nuts?!"

 

Hey....I like to DRIVE in the snow, not work on the car in it!

 

i did mine at work today.. wasnt anything to do.. so i pulled it in the shop.. boss left at like noon.. so i had a good 5 hours or so to mess wit it.. hehe. if it was nicer outside.. i woulda busted out my compressor.. need to use that thing..

 

I just used my digital "bathroom" 1/2lb increment scale and I got...

15.0lbs +/-0.5 for the Stillen OEM stock size replacement rotor.
and
22.0lbs +/-0.5 for the 13" Stillen BBK single piece rotor.

*CRUDELY* borrowing from the old 8:1, 1-lb of unsprung weight is equivalent to 8-lbs of sprung weight FOR WHEELS/TIRES(not brakes!!), and rounding to 22lbs. means that Jons' BBK or Stillens' 13" 1-piece BBK would be approximately equivalent to ADDing 112lbs. to the cars' curb weight. So, the increased front bias/braking force outweighed the increased moment of inertia created by the larger rotors AND decreased rear brake force.

I'd really like to see what Matts' rear BBK will do on Jons' car.

 

interesting....although this doesn't necessarily account for the extra rotational mass of the larger rotor (similar to a larger rim), which would have a (minor) adverse affect on braking because of increased wheel/rotor momentum.....or does it?

 

ding ding.

most OEM calipers are sturdy enough to prevent flex.

however, Wilwood's billet calipers aren't. they are prone to flex...

 

That's EXACTLY what it's accounting for, however the 8:1 ratio "rule of thumb" is typically used for wheel/tire(longer moment arm) so it's probably less then 8:1.

 

sorry for the newb question, but what exactly do spacers do?

 

of course it is....I am outthinking myself apparently.....