Stop Tech Level 2 front brake kit

[VFR750]

My stop tech L2 front brake kit just arrived.

Amazingly good packaging and the parts look fantastic. Confirmed 32mm leading and 36mm trailing pistons. 100% compatible without the need to change the master cylinder.

Rotors are beefy and have a hat design that really isolates the hot rotor from the hub.

Here is the difference in size between the STR-43 caliper and the stock ATE caliper. Pad volume difference is 2x.



Comes in two boxes. All packed to prevent damage and keep the box weight to ~25
Lbs. left and right rotors and calipers. Nice aluminum adapters. 309 pad compound included


You can see the swept cooling fins (44 total). And the minimal contact between the hat and the rotors.

[Hi_Fi_Guy]

Is there an unsprung weight penalty?

[VFR750]

Aluminum Calipers are much lighter. Rotor is heavier but the hats are aluminum. Probably a wash; my scale is not accurate enough to tell.

[VFR750]

Stop tech kit is 5 lbs lighter

Had to double-up the parts and level the scale to get repeatable measurements
I’d treat these numbers as relative and not dead-accurate.

SC system 39lbs
21 lbs - 20mm rotors
17 lbs- ATE M steel calipers
1 lb - pads

Stop tech level 2: 34 lbs
21 lbs - 28 mm rotors and hats
11 lbs - aluminum calipers and adapter brackets
2 lbs - pads

The assembled rotor uses both steel and aluminum efficiently verse the all steel 20mm rotors

Note the Carrera front brakes are even heavier with the wide-M calipers and 24mm rotors.

All aluminum calipers are significantly lighter than stock steel calipers.

[VFR750]

It should be noted the stoptech pads are longer but narrower.

This means the rotor wear surface is narrower. And lighter. The od are identical at 282mm


The added radial height in the stock rotors is pretty useless because the squarish pad only makes partial contact with the rotor. Losing this contact area will have minimal to no impact. I am not concerned.

[Bill Verburg]

Mike, If you can measure the distance from the axle center to the installed pad midline, that would be great

[VFR750]

First pass measurement

Stoptech 235mm mid contact

Stock 226, (231mm accounting for the lack of inner surface contact area.)

235/226 = 4% larger torque arm
235/231 = 2% larger torque arm

[VFR750]

Front left installed. Easy!

And the 6” wide Fuchs fit. That inner surface of the wheel is the fundamental problem with 15” and 16” Fuchs. That is why a spacer is needed to get enough room for the caliper to fit. This is what hurts bigger brake kits as the wheel has to be pushed outward to clear the ends of the caliper.




Mount bracket is pretty


Supplied brake line comes with integral mount that is compatible with the stock bilstein strut. Nice touch.

[gsxrken]

That is a NICE looking bit of kit. Track day ready...
I would consider de-badging them if possible. They’re quite proud of their logo.

[VFR750]

Logo isn’t too bad, and hardly visible through the Fuchs windows. I’m ok with it.

I went with the anodized finish to be more in line with the stock dull metal look of the ATE calipers.

Anodized is also cheaper than the black, red, or yellow options. Marginal utility of painted calipers is $0.00 to me.

[Locker537]

So no additional changes needed and you don't need to run a wheel spacer? It's nice to see more options available for us.

[VFR750]

Correct

Bias is a little bit more on the front.
Master cylinder stays the same
6” wide Fuchs fit without spacers

Caveat: I am using the non-dust seal version of the STR-43 caliper. This is fine for me because this is a track car with dry weather street driving.

You will need a shallow spacer to fit the dust-seal version of the STR-43 caliper.

[Locker537]

Originally Posted by VFR750

Correct

Bias is a little bit more on the front.
Master cylinder stays the same
6” wide Fuchs fit without spacers

Caveat: I am using the non-dust seal version of the STR-43 caliper. This is fine for me because this is a track car with dry weather street driving.

You will need a shallow spacer to fit the dust-seal version of the STR-43 caliper.

I'll be curious to hear your review after some track driving.

[VFR750]

Lime rock on 6/25
Thompson on 6/27

Should be a valid test.

[Locker537]

Originally Posted by VFR750

Lime rock on 6/25
Thompson on 6/27

Should be a valid test.

What organizations are you running with?

[VFR750]

PCA Connecticut valley 6/25
SCDA on 6/27

[GaryR]

What car are those mounted on? If an SC you may be able to add the Carrera restrictor to even out the F/R Bias, but Bill V. will know exactly what to do..

[gomezoneill]

Would it be inappropriate to ask $? That's a very nice kit.

[VFR750]

Yes an SC. I’m not worried about the small bias change. Tires, air pressure, camber, temperature all affect braking. 4% difference is not something I think is significant.

$1749. Some places have it for about the same.

[gomezoneill]

I wanted to go see that event at limerock but it's closed to spectators.