28mm ? Will it fit?

[squeefoo]

Just wondering if anyone has tried to fit 300ZX rotors in a stock setup...

Stock: 280mm dia. X 28mm thk. 300ZX: 280mm dia. X 30mm thk.

Will the extra 2mm (thickness) fit and work? It's only .039" each side

Since I don't have the stock brakes anymore I can't try it. PS: they weigh 17.93 LBS ea.

[elwesso]

Ive thought about that... You could also take the new rotors and ask them to shave them down a little.....

[Falkdesigns]

Ive thought about that... You could also take the new rotors and ask them to shave them down a little.....

...at which point, you completely defeated the purpose.

[Rex]

...at which point, you completely defeated the purpose.

Agreed, and I'd be worried about the "thinness" of the remaining rotor mass. They're not solid.

[elwesso]

Except Z32 rotors are SIGNIFICANTLY cheaper than Q45 rotors... id do it for cost savings.....

i dont really care because i have the Z32 brakes.....

[Falkdesigns]

How much cheaper? I got Brembo OE rotors for mine for only like $35 each. So say you save $20 bucks, you still have to take them to get them machined down, which should cost about $10 bucks each, and your time to go there and back. Don't see any cost savings, unless first gen rotors are like $60 each vs. $30 each for Z rotors, it seems completely pointless to me.

[ceningolmo]

How much cheaper? ...unless first gen rotors are like $60 each vs. $30 each for Z rotors, it seems completely pointless to me.

I think the second guess is pretty close, actually. I decided to do the z32 upgrade because I could get rotors, calipers (used) with pads included, and the spacers I needed all for about the same price I was going to pay for new rotors/pads on my G50.

As I remember, the cheapest I could find rotors was about $50-55 per wheel. I think the cheapest I found it through one of the NICO partners (Tire Rack, I think) was about $60 per corner.

[Falkdesigns]

And second gen Q rotors are significantly bigger too! And cheaper!! hahahahah..

[elwesso]

whered you get your rotors, kev?

[Falkdesigns]

The garage I use & once worked at, Arrow Automotive, Rosecrans Ave., L.A. 310-973-9785

[elwesso]

If we're going to compare apples and apples..... The G50 and Y33 rotors from Joe are both $81.....

Brembo blanks can be had cheaper.. I paid close to what falker did for my Z32s.

[Falkdesigns]

I sure hope it's $81 for both...

[elwesso]

Nope thats each!!!

[squeefoo]

The real reason I posted this was b/c of this little tidbit:(Knew I saved it in the Q45 archives somewhere... ) My now warped Braadi drilled slotted 280mm X 30mm weighed 15 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/bf10312.htm> web.umr.edu/~enggrweb/seminars/PresentationSlides/ws2003/Bhat031703.ppt

[Q45tech]

Yep, weight of rotor is critical......even 0.5 pounds is 3%.If you think about it, they cannot save much on the hat portion.....only the critical number of support vanes or the metal vs air space thickness.

The cheap grade of cast iron alloy........skipping a few steps.

We have a local supplier that offers us 2 grades of Q Chinese rotors the economy [light weight] grade cost us $32 and the premium grade is $56 vs $80 for oem.........the $56 unit weights the same as oem and appears to be almost the oem.................still there is a difference in life and noise as one gets out to 40,000 miles. All products carry the same 12month/12k warranty.

Not sure that saving [price difference $50 x 4=$200] every 40,000 miles on brake rotors ......1/2 a penny per mile is a prudent thing to do.

As to 30 vs 28 mm remember each pad has ~~9mm of material so if there is enough clearance initially to fit at fully retraction, if not you could wear the pads down by 1 mm.............or backing plate....probably enough slack.

Could someone measure the front rotor metal vs air space vs metal {ACCURATELY} on 300zx 30 mm.

Some rotors have thicker inside than outside metal as inside gets hotter and less cooling.

[elwesso]

Tech, i got some dial calipers... hwoever my rotors have about 5000 miles on them with OEM pads, would one assume theyre still good as new???

Ill take some mesurments this week!

[Q45tech]

Depends on applications and durations per mile.........Takes over 40,000 miles to wear 1 mm per side without any trueing.

Primarily looking at ratios: 9.3mm;9.3mm;9.3mm

[squeefoo]

Just got my Brembo 300Zx from NOPI ($24.74 !) rotors and they measure:

Inner thickness: 10.03mm avg.

Airgap : 9.85 mm

Outer : 10mm avg.

They have 36 ribs... @ 5.8mm tapering to 5.3mm (in to out)

[Q45tech]

And each 300zx rotor weighs? = or 3% more based on guess of 7% thicker[10mm vs 9.3 mm Q]

[squeefoo]

I had to go to the post office and use their scale...

17.8125 LBS. Both the same !

Brembo's spec claims 17.93 LBS.

[squeefoo]

The old Braadi rotors were as follows: uncut with ~ 10K MI

Outer thickness: 9.38mm

Air gap: 11.07 !

Inner thickness: 9.04

36 ribs and skinnier

I had the weight wrong above it is actually 16.31 LBS -that's why I wanted to use the post office scale

[maxnix]

I had to go to the post office and use their scale...

17.8125 LBS. Both the same !

Brembo's spec claims 17.93 LBS.

Yeah, I remember Joe wighed them and they were more than stock.

I have been so pleased with my genuine drilled Stillen Brembo front rotors from him on my mom's G50 it has made me think seriously about the wisdom of big brake upgrades performance vs. cost.

They have been and still are outstanding after 15K. No, zero, zilch vibration. None at all. Much better than OEM.

[elwesso]

You got the brembo blank ones, right? the non slotted??