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stoptech race 350z caliper bracket
stoptech race 350z caliper bracket
 The billet aluminum Stoptech race caliper brackets relocate the caliper from the top of the rotor to the front.  This reduces the effects of piston knockback on the brake pedal.  The higher bleed position also improves caliper bleeding. The bracket also comes with a longer brake line.

To improve our kit especially for race use, we asked Stoptech to use their Trophy kit race bracket.  The race bracket relocates the caliper lower to where it is perpendicular to the ground.  The reason for doing this is that the brake system will be less sensitive to piston knockback.  The 350Z has weak hubs and the bearings quickly develop play, especially when being driven hard on the track.  The play is not perceptible when trying to wiggle the wheel by hand but under load, the wheel and rotor wobble, knocking the caliper pistons back inside the caliper.  This makes the brake pedal long and mushy.

 loctite caliper bolts
 GTI's Costa Gialamis applies locktite to the caliper bracket bolts.  This is always a good idea for these parts.

When using a big brake upgrade, the big rotors exaggerate the problem making it worse to the point where you have to pump the brake pedal many times per lap.  The weak hub bearings are the Achilles heel of the 350Z.  Most of the play is oriented from top to bottom because of the tire's side loading.  By lowering the caliper, it does not see the large movements it would see if it was mounted on top of the rotor.  By being perpendicular, the caliper is also easier to bleed completely as well.  There is also a self centering moment created by the caliper's lower position that improves stability as well.

stoptech st22 caliper brackit
grinding 350z spindel for caliper bracket clearance
 The rear caliper brackets are a tight fit to the spindles.  Sometimes forging flash interferes with the bracket seating properly.  Here Costa Gialamis grinds the flash down so the brackets will fit.  This is pretty easy to do and could even be done with a hand file.

The most important reason why we selected Stoptech brakes is that they carefully engineer the proportioning of their systems to exactly match a car's stock hydraulic system.  On stock brake systems with a single master cylinder, the brake's hydraulic proportioning is largely controlled by the caliper piston size.  The larger the piston the greater the hydraulic force applied to the brake pad, the smaller, the less.  Stoptech duplicates this OEM like match with 19 different possible combinations of piston size to make precise proportioning possible without having to resort to a racecar like dual master cylinder system with a balance bar. Stoptech pioneered this ability to fine tune the piston size in the aftermarket. Many things are considered when choosing piston sizes; stock master cylinder bore diameter, car size and weight, weight distribution, brake pad size, rotor size, tire size and wheel size.

 st60 caliper stoptech
 The main reason why we like Stoptech so much is their correct proportioning ensured by a wide range of properly sized pistons.  By getting the hydraulic force proportioning right, you don't need a balance bar and twin master cylinders like other racing brake systems.  Also notice the dust seals.  Many racing brake calipers don't use them.  This shortens their service life when used on the street.

 

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Comments

Jasonrg77
# Jasonrg77
Thursday, June 24, 2010 7:38 PM
So the Stoptech brakes are 18 lbs. with the dust cover vs. the stock brakes are 21 lbs. with the dust cover? I'm not sure I understood clearly.
So is there a plan to strengthen the knuckles?
speedball3
# speedball3
Thursday, June 24, 2010 11:13 PM
I was a little confused in the first few pages, as I wasn't aware of how the stock 350Z brake calipers are aligned. A quick Google search solved that though, but still, a reference shot would be nice. And earlier than pg 5... which I'm assuming is the rear caliper anyway ;-)

Quick question on the caliper alignment of the 350Z... anyone know why Nissan chose to mount it at such an odd angle? Are they cleverly packaging the steering rods or front sway or ??? Why didn't/couldn't they choose the rearmost part of the rotor (which I always thought was "better" than the front, if it was possible)?
Mike Kojima
# Mike Kojima
Friday, June 25, 2010 1:52 AM
For the weight read carefully and add, its 1/2 lb total difference. Nissan has no plan to strengthen the knuckles on an out of production car. If you read the text the problem is the wheel bearings.

As far has how the stock caliper is mounted, who knows. For mounting the caliper at the rear of the rotor, self aligning torque is slightly better but cooling is worse.
karay240
# karay240
Friday, June 25, 2010 9:23 AM
Front Caliper location is mainly dictated by steering rack placement. Most Nissans have the steering rack behind the X-member, so the calipers end up in the front.

From a strictly performance stand point, having the caliper in the rear and rack in the front is better in just about every way (Self Aligning, Bump Steer, and Cooling... more on the cooling later) Just look EVERY serious car...Mclaren, Ferarri, Lambo, Porsche, Audi, BMW etc etc... except the R35. The only reason I can think of going the other way is packaging.

So back to the cooling, With the caliper in the back and out of the way of airflow, there's plenty of room for ducting to the brakes
Steve
# Steve
Friday, June 25, 2010 2:46 PM
Excellent article and detailed walk-through of the design "whys" and "hows". Having tracked a stock 350Z with thankfully just stock power I can relate to the ridiculously under-spec non-Brembo brakes. Even the Brembo's on my G Coupe came with questionable pads, heavy and cheap rotors. W/o track use even they were done well before 25k street miles. Due to the OEM pad compound choice they wouldn't have lasted long on a track, either.

The Stoptech attention to detail and real-world use is impressive. I particularly like the thought put into the proportioning issue, that really helps when you're working with a dual use car like a lot of us and don't really want to mess with dual MC's, etc.

Nicely done!
Steve
# Steve
Friday, June 25, 2010 3:06 PM
Hmmm...looks like Nissan bolted up my Brembos in about the same spot as OEM Nissan, have to think about that:

http://homepage.mac.com/stracy01/.Pictures/v35CLEARSIDES/DSC00410.JPG

Not the ideal spot and I really want to dump the one-piece rotors, I just run into clearance issues in front with the 18" Winter Wheels (yes I drive it 4 seasons) going to even larger than stock (Front 324 × 30, R 322 × 22). But for all the reasons covered here they will be 2-piece sooner or later.

http://www.facebook.com/photo.php?pid=239519&l=482ea450ed&id=1746021421

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