atlsupdawg#2

Alright bro, you've got me brainstorming here. What do you think of this??

I've still got my old set of Supra TT rotors which are roughly 13.3" dia. front and 12" (something) dia. rear, which I won't even bother with. Bolt pattern is the same 5x114.5. So here's my idea:

Front: Use my OEM TT rotors to set-up the front measurements. I could possibly go with the Billet Superlite 6 pistons and fabricate a bracket template from 1/4" - 3/8" acrylic sheet. I have a router so it'll be easier to cut and shave the template where needed. Once all the clearances look good I can have the bracket machined from stainless. Next, I can get a set of the TT Brembo rotors and run those.

Rear: I'm sure that the Z's e-brake won't match up to the TT rears so I won't even bother with those. I can grab a set of the Brembo rear rotors for the Z and again fabricate a bracket for (maybe) the Superlite 4 pistons. It won't necessarily be an increase in size in the rear, but I think anything bigger than what's on there now wouldn't make too much of a difference.

Think it'll work???

gringott

iTrader: (17)

You are the man. I think you are 100% on target with this project. Basically, we buy all the parts individually, and make only the custom mounting brackets. The R&D is really already done. If we can get several people together and buy in bulk we can do even better. For example, I am sure a vendor would give a break (no pun) on selling 10 SS brake line kits vs. 1. Same thing with Wilwood. So if this is a going project I am more than willing to do my share, although what I can do is basically non-technical.

1.) We need a complete parts list with stock numbers etc.
2.) How many people do we need in this to make it economical?
3.) Arizona Z car sells a Wilwood kit for $1395 front and $795 rear, 13" rotors front 6 piston, 12.2 rotor rear, 4 piston. Parking drum is eliminated. He offers free shipping if you buy both (at least he did to me). So we have to beat $2190, and I want to keep the ebrake.

So I am in if this can be done.

J Ritt

iTrader: (4)

Take my 2 cents for what it's worth to you...

We constantly have customers call us to discuss setups / plans like this. Here's how it typically goes:

1. Customer calls and tells us about his plan to make an inexpensive brake kit. Most times, it goes like this, "I got a great deal on some Porsche calipers...or, I got a great deal on some Wilwood calipers..." They are typically convinced that they will be able to produce an excellent brake system for a cheap price.

2. We tell the customer that there is a huge number of issues to consider when selecting a brake kit. Material choice, production method, testing and analysis, overall balance calculations including piston size evaluation, non-abs testing, durability on racetrack, etc

3. The customer either trusts us and realizes what they face, or they go off and pursue their brake kit. When they do the latter, we usually get a call six months later from the same guy...

4. He says, "Hi, I talked to you guys 6 months ago. I tried to build my own kit and ran into problems. I'm having trouble with the studs backing out of the brackets I made...my rear brakes are locking up before my fronts...I took the kit no the track, and now I have a rattling noise coming from the bracket...the bracket cost way more to produce than I expected..."

The list of what we hear from customers goes on and on! In the end, a lot of these guys trash what they were working on and then buy one of our kits...so they've lost all of the money they invested on trying to do it themselves + the cost of their new BBK.

Some other pitfalls:
Will spare parts be available if you need them?
Will you have lots of pad and rotor choices?
Will you have tech support and service if you run into a problem?
Will you have piece-of-mind knowing that the product has been tested under all scenarios?

I'm not trying to be a jerk or be discouraging. I just want you to realize that cobbling a brake kit together is not as easy as it appears on the surface. It takes a lot of knowledge and testing to do it right. Also, we're not talking about windshield washer LED's here...brakes are a critical safety item on your car. This is exactly why other country's like Germany have TUV standards. I'm not talking out of my you-know-what like a lot of people do on these forums either. This is from years of experience talking to people that have been down this path and run into roadblocks.

My advice, buy our 332mm front kit at $1995. A rear kit is not necessary. Get some good rear pads and SS lines, beat the whole setup within an inch of its life on the street and track, and just enjoy them. You'll have someone there for product support and service if you run into problems, you'll have spare parts when you need them, you'll know the full cost up front, and you'll have a lot less headaches in general.

That's my advice, take it or leave it.

atlsupdawg#2

Alright fellas, took the liberty of pulling off a rotor and getting some "ROUGH" hat measurements. Here they are as if Wilwood would measure them:

Wheel Lug Pattern - 5x4.50
Hat Offset - .68"
Stud Hole Dia. - .50"
Center Hole Dia. - 3.656"
Face Thickness - .375"
Clearance ID - 5.625"
Rotor Thickness - .945"

Total rotor thickness from the front face of the hat to the backside of the disc is about 2"..

Looking at Wilwoods catalog if we were to go with their SRP Drilled Performance Rotors (any dia.) with a thickness of 1.10", the closest hat I could find to match the OEM's would be their GT Series Fixed Mount Rotor Hat p/n: 170-9128. The measurements are:

Wheel Lug Pattern - 5x4.50
Hat Offset - .72"
Stud Hole Dia. - .52"
Center Hole Dia. - 2.80"
Face Thickness - .31"
Clearance ID - 6.30

Total rotor thickness would be about 2.13"..Also, the center hole would have to bored out a bit to fit the hub. Not to shabby seeing as how the center line of the disc would only sit .130" further back than the OEM unit. Of course you can compensate for this when the bracket is manufactured.

kbiz

You know what...?? I totally agree with you. Brakes are probably more important to not F-up than even the engine... If you blow a rod, the odds of getting shrapnel through the dash is probably a lot less than the odds of getting hurt if your calipers all brake off their mounts

The only thought I was having is that IF I were able to buy individually for a significant savings (Just as an example):
-Stoptech 4 Piston ST-40 Calipers
-2 Piece Floating Directional 332x32mm AeroRotors (for the Z)
-Street Performance Pads
-Stainless Steel Brake Lines
and I happened to have a set of caliper brackets that go with this kit to duplicate and I did so with accuracy... the only issues I would run into would be installation related and, of course, no tech support.

The same can be said for an engine swap… If I want to have the buck stop with someone else, I have a shop fabricate my engine mounts, etc. If I want to save money and deal with any problems I run into, I do it myself. But I have to agree that no one should delude themselves into thinking that taking a pair of Porsche calipers and going through the process of jigging and shimming in order to “Design” a custom bracket that fits means you’ll be happy… you might be… I don’t know. But I do know that that type of thing has been done many times before with accuracy and good results... but only the right design information before hand.

And just a quick question since I've got a true expert on the line... does Stoptech sell the Caliper brackets to their kits seperately? If so are they in the $300+ range? I'm curious since many kit builders refuse to sell them seperately... in particular the companies selling Wilwood kits (duh...). If Stoptech doesn't sell them seperately, what would a customer do that wanted to put the calipers on a different vehicle, provided they were appropriate?

kbiz

You're right on track with what I was thinking could "Potentially" come from this exercise. The really interesting thing I've found so far is that even without a group buy I can reproduce several Wilwood Front BBKs for less money... and that would be using all brand name parts... not counting my time machining a bracket. The rears are funky because of the e-brake of course but there are a few kits for the Z that utilize a drum incorporated in the rotor hat. These may be custom fabricated parts but maybe not. I'd rather have a drum than put in one of those mechanical calipers... seems a little funky having two calipers on the back. The line lock seems a bit funky too... but I have zero experience with them.

So a group buy I'd bet would only bring the prices down further and, most importantly, make the bracket fabrication cheap.

kbiz

Very cool… Thanks for going to the trouble of yanking your wheel!!

This makes it much easier to shop for rotor hats!!!!

What I also wish I had was the measurements from the Precision Brakes Company front kit. The bracket I’ll have in the mail soon is from that kit. If I had those measurements, accurate measurements, then I could simply add any delta between rotor hats to the bracket’s dimensions. Or maybe get lucky and find a hat with the same dimensions. We can look into some other companies too…

I noticed you were looking at the 1.10 thick rotors in the SRPs… you might be limited to their narrow body line on the Billet Super Lites… I think it’s only a matter of the spacers that come with the caliper but if there ends up being a noticeable price difference than it might be easier to just go with the 1.25” which would be a little more standard anyway. Plus the kit that this bracket comes from is 1.25.

The more I think about this the more I think that there may be no way around having to change the caliper bracket a bit. That’s ok but it does open the door for more work… I suspect that Precision Brakes is making their own hats which means the odds of finding an exact match is unlikely. If we go with the closest hat and rotor, the bracket could be modified pretty easily…

I wonder how much essex parts charges to make custom rotor hats??? That could be an advantage to a group buy idea.

kbiz

Here's another Wilwood Rotor Hat that could work:
wilwood pt# 170-6947
5 x 4.50"
0.72" hat offset
.50" stud hole diam (matches oem)
2.53" center hole ID would need to be bored
.25" face thickness
5.90" Clearence ID
5/16-18 Mounting Holes for rotor ring
8 x 7.00" # of rotor ring mounting holes

So this hat uses 8 mounting tabs for rotor ring and has the same wheel stud diameter. Cener hole would need to be bored but other than that it should work. Bracket will need to reflect offset, of course. 8 tabs for rotor ring may widen the choices of rotors that can be used.

zillinois

iTrader: (6)

For those worried about brake bias, Wilwood sells a in-line bias adjuster for $43 bucks.

http://www.magnumforceracing.com/wil...g_residual.asp

Vamos_Rafael

iTrader: (18)

i think just buying stoptechs is much better choice..
race bred tuning...
might cost a bit more than annoymous brands...
but i think brakes are quite important to me (life/death issues here) so in my opinion... im not even going to upgrade brakes until bbk (not even pads)

zillinois

iTrader: (6)

People build off the rack Wilwood brakes for all manner of race car. Not just pros, but weekend warriors as well. Wilwood is a respected name in the racing community. I recently bought a D sport racer car and it has off the rack Wilwoods with custom mounts and a brake bias purportioning valve built in. This is a well traveled route. If the price is right for the bracket and all the parts numbers are all there, I would be very interested in this option as well. Its not for fainthearted or noobs though. Not because it can not be made safe, but because you have to test it to make sure it is.

atlsupdawg#2

Ran a few more numbers that MAY help with keeping the same brake bias as stock.

Front caliper piston dia. is 2.252"....Rear is 1.6874" (AllDataPro)

Based on these numbers the front calipers offer 25% more surface area than the rears. Fundamentally a brake system is just a simple hydraulic system. The more surface area a piston has the more clamping force it'll provide at a given pressure input. So in essence here, the front brake calipers clamping pressure 25% greater than the rear. If the front and rear calipers provided the same clamping pressure we would have to physically reduce the input pressure of the brake fluid going into the rear caliper, hence the need for a brake bias valve. BUT, if we can keep this same margin by playing around with different caliper piston diameters we'd be able maintain the stock bias.

Just a thought!!

EDIT: Looking at Wilwoods catalog we could possibly go with the Superlite 6's which have a total piston surface area of 7.72. For the rears we could go with the Forged Billet Superlites w/ 1.38" pistons which have a total surface area of 5.52. Based on these numbers the front calipers would give us 28.5% more clamping pressure than the rears. That's 3.5% over in the front than the OEM set-up.

kbiz

Also keep in mind that braking force, torque, is a factor in the biasing of a brake system. So if you increase the rotor diameter in the fronts, the torque will obviously increase. This is the fundamental question I've had all along as to how a BBK could maintain factory bias but increase just the front rotors to 14"??? The only answer would be in the amount of clamping force is reduced as the rotor size increases... This combination of rotor size variables and piston area variables is the reason why I was interested in duplicating the front brake kit that companies have already tested. In particular the 13" and 14" kits...

But, 3.5% sounds well within reason.

Also, I measured some EBC rotors that I had, and the Center hole diameter measures 2.684" It's been raining pretty hard so I haven't had a chance to pull a front wheel off to double check... but the measurements earlier of 3.656" seems off.

nissansource

iTrader: (10)

I am very interested in this guys keep up the good work.....

J Ritt

iTrader: (4)

This may help you out...

http://stoptech.com/tech_info/The%20...%20Systems.pdf

Good luck. May the (brake) force be with you...what a terrible pun.

zillinois

iTrader: (6)

This may help as well. Someone already did it.

www.350zbrakes.com

nissansource

iTrader: (10)

it still can be done cheaper...

C Ray Z

iTrader: (2)

I have been tracking this setup for two years and love it.

nissansource

iTrader: (10)

and it has an adapter right?

C Ray Z

iTrader: (2)

Yes very Tall. 13.6" rotors front and rear