This thread is in response to all the “if it’s not Stop-Tech, then it’s crap” posts. It seems the only requirements to be a brake expert are reading the Stop-Tech White Papers, browsing the Zeckhausen Racing website, and hating any non-Stop-Tech BBK.

Stop-Tech’s front BBK reduces stopping distance by utilizing a smaller piston area than stock. Yes, the Stop-Tech front caliper has less stopping torque than the stock caliper. Stop-Tech BBK's are the best available. But "brake balance" can be achieved by lessor brake companies.

The proper question to ask is the size of the pistons and the rotor. I’ll explain.

First, all brake kits operate on the same principals. Hydraulic fluid is pushed through a line that compresses a piston which pushes the pads on the rotor.

Second, total piston area determines the torque of any given caliper. For example, the stock caliper on a 2005 6MT has two 1.75 inch pistons. Do some math and the total area is 4.8 inches. This calculation uses the pistons on only one side of the caliper. So, a six piston caliper’s piston area would be based on 3 pistons. Strangely, the stock sliding calipers brake as if they had identical opposed pistons (why? Ask a physicist).

Third, the number of pistons does not affect torque. I doesn’t matter if you get 4 inches of piston area with one big piston or 9 tiny pistons.

Fourth, rotor diameter effects brake torque. For example, if the only modification you did to your stock brakes was increase the front rotors to 14 inches then front brake bias would increase 2%. A 13 inch rear rotor would reduce front bias 2%. That rear rotor upgrade is starting to look pretty good now...

Fifth, our cars come from the factory overly front brake biased (74% front/26% rear). Although this increases stopping distance, a front biased vehicle is easier to control.

Therefore, reducing front brake bias will balance the car and decrease stopping times. However, shift the bias too far and the rears may lock up before the front. VERY DANGEROUS!

Stop-Tech has determined that magic amount of brake bias to magically balance a 350z/G35. I would love to know the piston area of the Stop-Tech front BBK.

So you want to know the effectiveness of your specific BBK. Get a ruler and measure the piston areas and rotor diameter.

Then use a brake bias calculator like the one at http://dsr.racer.net/brake_bias.htm. If the ratio is the same as stock, then your brake distance will be unchanged. If the ratio is more front biased you will take longer to stop and unnecessarily burden your front brakes.

If you are going front only, make sure the total piston area (and front brake bias) is slightly less than stock. A general rule of thumb is no more than 5%. Also, search the forums and call the distributor to determine if there are any problems with that specific BBK locking the rears.

For example, I have Wilwood 6 piston calipers on 13 inch rotors. The total piston area is 4.06 or .74 inches less than stock resulting in 72%/28% bias or 2% more rear bias.

A Wilwood 6 piston superlight BBK with a 13 inch rotor will stop in a shorter distance than stock.DOMO

Of course different BBK's will have better heat dissipating characteristics, pedal modulation, etc... but that is for another post.

 

thanks for the good read.

 

So all you've proven is what we've said all along, and thats that the reason to choose stoptech is because they keep the brake bias similar to stock. No other kits provide piston sizing information or explain how they go about setting bias. Many offer the same kit for the front whether you purchase a rear kit or not. They offer the same kit for all 03-06 models regardless of rear brake setup. You just happened to luck out with your kit because infiniti decided to increase the rear brakes on the 05+ g35's. The arizonazcar kit was designed around the smaller 03-04 brakes and actually INCREASES the front brake bias. So much for great engineering right? BTW, using your calculator you provided, your brake bias calculations appear to be incorrect, I get a stock bias of 66/34. and the 05+ front piston size is only 1.69".

 

I measured the piston diameter at 1.75 inches. But if they are 1.69 inches rear bias increases 2%.

I assume your calculation is different because of master cylinder diameter. The default setting should be 1 front and 1 rear. I would be interested in knowing the actual numbers. But it does not make a difference. As long as you establish a base line to work off of.

I think your missing the point of my post. It's not a rant against Stop-Tech. The point is to provide a methodology for determining if a BBK is actually effective and MORE IMPORTANT how to set up brake system that actually works.

If we (meaning lessor BBK owners) could get a hold of the piston area of the Stop-Tech front BBK we could have a bench mark to balance our brakes. Honestly, I could save a ton of cash if all I had to do was buy a Racing Brake larger diameter rotor kit.

 

Yes, this is a perfectly valid way of determining brake bias if you have the information beforehand. The problem is that every time someone who has a kit other than stoptech is asked if their kit addresses brake bias or if they knew how it affected it, we never get an answer. Stoptech is the only company that has addressed this to the Z/G community publically. This is the reason why many of us recommend stoptech. How many other kits do you know the piston sizing for without having the kit in front of you? Are you going to just guess and check by purchasing multiple kits until you get one that has better brake bias? That is the the big picture you have to look at.

 

Why wouldn't the Racing Brake OEM caliper bbk wouldn't work?

 

I recommend Stop-Tech as well and applaud them for their dedication to our cars. But cost is a very real issue.

I wish I had a M3, but for know I will settle on a G35 that handles and brakes like an M3.

The Wilwood website contains detailed information on every caliper it makes. This includes the piston diameter.

 

If you installed only the rear kit you would reduce front brake bias 2%. The result would be shorter stops.

The 13 inch front kit would not improve your stopping distance (probably increase stopping distance). It would give you better heat dissipation however.

 

So install both sides.

 

Good info

 

wait until Q45tech to come in

can i ask a question?
let just say that i ate lotta foods and haven't poo-poo for days...therefore i must have few extra pounds of **** in me,would it make the car stops a little longer in distance because of the extra weights ???











j/k

 

Better/additional info.

https://g35driver.com/forums/showthr...=217148&page=3

 

That's one way to get to 6,000 posts...

 

Installing both would be less effective. Remember, it's about reducing front bias.

 

Perhaps but I think the RB front/rear was designed around the 03-04s.

They list the fronts for 03-04s but make the rears available for 03-07s.

Little odd per your information.