Q45/ (J30?) 6 pot calipers!?!
Q45/ (J30?) 6 pot calipers!?!
Has anyone installed the 6 piston calipers supposedly available for the Q45 up front from Stillen/AP? I saw it in the stillen catalog and was wondering if anyone has actually installed these. Since the rotors and pad size are the same as the J30 up front, i would assume the calipers and associated mounting points are the same. Anyone think this could be a direct bolt on or simple mod for a J30 install? (Not that the J30 needs brake improvement, but if basic engine and suspension mods are done, brakes seem just as important.)
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Q45tech
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- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
The larger calipers and rotors require 17" wheels even the smaller front 300zxtt brake swap requires 16".The heavier the calipers and rotors [and to some extent the wheels] the more heat the system can hold [or transport from the pads].Don't expect any single stop improvement [time or distance] over properly functioning oem, but of course mountain or pursuit braking will improve.
I realize this kit would be best suited to track or mountain use. Are the J30 and Q45 calipers the same/ mounting points? if so, would this kit be easily transferrable to the J30, of course assuming wheel diameter increase? The question in my mind is why Stillen would develop this kit if no one buys it, which makes me think its a direct transfer or adaptation from a kit for another nissan model, maybe a 300zx...? What does the 300zx->Q45 brake upgrade entail? thanks!
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Be prepared for a difference in pedal feel [slack distance and slope of pad contact vs pedal depression] because of the difference in total caliper bore area vs master cylinder bore.
The brake proportioning valve [inside master cylinder] is set for oem calipers so you may not have optimum rear braking.In fact the oem psi setting is 54% front vs most cars 60-65% front so the rear brakes are actually utilized much more than most think .........they were designed to wear at equal rates vs most car's rears lasting 2-3 times as long.
If your rears are not wearing out fast you have a problem in braking.........they [design engineers] wanted to change tires and brake pads and turn [replace] the rotors every 17-20k to assure optimum performance............unfortunately owners were not use to such a design......so we got progressively harder pad compounds.The Q pads you can buy today are nothing like the pads produced in 1990-1993 nor even the pads available till 1999.
The brake proportioning valve [inside master cylinder] is set for oem calipers so you may not have optimum rear braking.In fact the oem psi setting is 54% front vs most cars 60-65% front so the rear brakes are actually utilized much more than most think .........they were designed to wear at equal rates vs most car's rears lasting 2-3 times as long.
If your rears are not wearing out fast you have a problem in braking.........they [design engineers] wanted to change tires and brake pads and turn [replace] the rotors every 17-20k to assure optimum performance............unfortunately owners were not use to such a design......so we got progressively harder pad compounds.The Q pads you can buy today are nothing like the pads produced in 1990-1993 nor even the pads available till 1999.
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
When comparing parts designed for a 300zxtt remember its weight was only 3500 pounds so a 4000 pound Q may have stiffer requirements.
80mph-0 braking is mostly a function of tires assuming reasonably soft pads and true rotors. The oem brake system has 2-3 times the power of the engine at least for 4 seconds!
245/50/16 soft tires vs 215/65/15 hard tires obviously the tire load on a Z is less than that on a Q if you just used the percentage of weight a Q tire would need to be roughly 200 pounds stronger assuming the same braking G load.........1738 pounds vs the same 1521 pounds used [shipped] on both........really hard to find tires that are above 1620 pounds so you see why I am always pointing out how under tired the Q is.
See the stock Q loaded front tires are overloaded on a max G stop when 100% inflated [44 psi] and nobody keeps them that high.....they are 300 pounds overloaded at 35 psi [on a 44 psi tire] but then again a 1620 tire only improves things by 70 pounds at the same psi.
80mph-0 braking is mostly a function of tires assuming reasonably soft pads and true rotors. The oem brake system has 2-3 times the power of the engine at least for 4 seconds!
245/50/16 soft tires vs 215/65/15 hard tires obviously the tire load on a Z is less than that on a Q if you just used the percentage of weight a Q tire would need to be roughly 200 pounds stronger assuming the same braking G load.........1738 pounds vs the same 1521 pounds used [shipped] on both........really hard to find tires that are above 1620 pounds so you see why I am always pointing out how under tired the Q is.
See the stock Q loaded front tires are overloaded on a max G stop when 100% inflated [44 psi] and nobody keeps them that high.....they are 300 pounds overloaded at 35 psi [on a 44 psi tire] but then again a 1620 tire only improves things by 70 pounds at the same psi.