Brake info

[Q45tech]

Stock 240SX 300ZX Turbo Slyline GT-R (R34) Infiniti Q45 Rotor Diameter: 10 inch 11 inch 11.6 inch 11 inch Rotor Thickness: 18mm 30mm 32mm 28mm Rotor Weight: 12.5 lbs 17.5 lbs 19 lbs 17.5 lbs Caliper Type: 1-piston sliding 4-piston fixed 4-piston fixed 2-piston sliding Caliper Weight: 9.5 lbs 6.5 lbs (alum), 10lbs (iron) 6.5 lbs 11 lbs

As you will note the Q front rotor at 17.5 pounds unfortunately many replacement rotors [same size] can be as low as 16.0 pounds.

Studying BMW M cars indicates 56 pounds of rotors for 3500 pound cars therefore one could assume [that a 4300 pound Q would need [4300/3500= 1.228 x or 68-69 pounds of rotors........something like a 22 pound front rotor with thicker/heavier rears [10>12 pounds] ............too achieve the same brake mass as a 1988 M5 BMW.

The newer LS430 has 20.1 pound front rotors vs 18.8 lbs in the 1998 LS400 vs 16.8 pound in the orginal LS400 [1990].

"One brake manufacturer showed us a cutaway of an offshore "economy" rotor for a particular vehicle that had 32 ribs. The OEM rotor, by comparison, had 37 ribs and provided up to eight percent better cooling than the economy rotor when tested in the laboratory. And because the OEM rib design ran cooler, pad life was 28 percent longer than the economy rotor. Another aftermarket brake manufacturer showed us test results that proved their rib design improves cooling and makes their rotor three times quieter than a competitive rotor. The recorded sound levels showed noise as high as 85 decibels screaming out of the Brand X economy rotor compared to only 40 to 50 decibels from their own "premium" quality rotor. "

http://www.babcox.com/editorial/bf/bf10 ... ionSlides/ ws2003/Bhat031703.ppt

[PalmerWMD]

Good Info as usual Dennis.

One of us should collect these posts of yours for our article/archive section.

Fred..

[SOCAL91Q45a]

So .... after the decrypter on the first post over heated and shut down ..... I am left asking.

What rotors and caliper setup should I use on my 91 "A" ? :-)

Prior owner always complained of the car being somewhat "under braked" ... Ive yet to feel that sensation to affirm or deny.

Homeboy did warp a set of drilled Brembos in the past and went back to stock. Guess he thought those turned that 4000 lb beast into a VW Golf ....? hehehe

[docsmile71]

For Q's, stock parts seem to work best. Aftermarket companies just don't seem to have the resources to fully R&D good products for such an elite car. The Q is not a dime a dozen here in the states and people who own them don't usually mod them. Thus, the aftermarket is very slim.

If anything, stick 300Z TT brake rotors on.

[sijoko]

You can also upgrade to Nissan Skyline GT-R (R32) front brakes.

They are bigger (~11.6 inches) and also thicker (32 mm) than the Q45 brakes. You will need to upgrade to 16 inch wheels though.

[Q45tech]

That was the point - stock 16.5-17.5 pounds in a 28 mm thick x 11" rotor obviously warp. Currently 2,500-3,000 pound performance cars use the same diameter x thickness brake systems as the old Q.

On heavy Lux cars 30-32 mm seems to be the common thickness now, but since the ratio [metal, air space,metal] is 1:1:1 or less [why don't the thicker rotors weigh significantly more].

You either increase the rotor mass [weight] or increase the air space between the parallel outside planes [while increasing their thickness 1-1.5mm [oem Q is at 9mm per plane and 10 mm of air space].

http://www.statixbrakes.com/ap_competition2.asp

For 350Z/G35:Front Type Vented Disc, 2 caliper pistons Rotor size diameter and thickness (in.) 11.65" x .95" [24.5mm?]Rear Type Vented Disc, single caliper piston Rotor size diameter and thickness (in.) 11.50" x .63"

Brembo (Standard on Track) Front Type Vented Disc, 4 caliper pistons Rotor size diameter and thickness (in.) 12.76" x 1.18" [30mm]Rear Type Vented Disc, 2 caliper pistons Rotor size diameter and thickness (in.) 12.68" x .87" [22mm]

Even the Z Brembo fronts are only 30mm but then again this is a 3500 pound car.

http://www.zeckhausen.com/E39_...l.htmh ... pgrade.htm

[AlabamaDan]

Hi Q45, Fred, and everyone,

I've been offline for a while, but glad to be back. Sorry to revive an old thread, but I have a few questions. My J30 is starting to have some vibration when I press the brakes and a pulls to the right a little. I know it could be lots of things, but I'm concerned it might be the brakes and driving in this Atlanta traffic you can't afford for brakes to not perform well. I thought I'd get the tires balanced and replace the pads.

The concensus seems to be OEM pads. Is that true?

I've changed pads on muscle cars and a 94 Sentra before. Should I have a problem? Anyone have any instructions? On those older cars all I did was pull off the caliper, compress the piston with a c-clamp, replace the pads, and put everything back together. Is that about it?

Do you really have the have the rotors turned if the pads aren't down so low they're digging into the metal?

Any tips on things I should do to prevent squeeks and rattles?

Any help for an old member is appreciated?