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brakes - tire size THE faq..


Guest scca

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copied from Jim...in regards to brakes..

Okay... so far as I know all had power brakes. In order of "upgrades" here's how I see it based o nthe research I've done:

1) Stock everything with upgraded pads. Okay performance but watch your speed and following distance

 

2) Toyota calipers with good pads using stock solid rotors. Better but not super duper. I had these on my car until recently and I thought they worked well. The pad size is about twice sttock and you'll have 4 pistons on each side for even pressure.

 

3) Toyota calipers with vented rotors. Damned nice with the same size pad as #2 but with better fade resistance due to superior cooling. Can be done 4 or 5 lug.

 

4-small)Outlaw (or similar) calipers that will bolt onto stock location, utilizing a 11.3" vented race type rotor with a aluminum hat to mount it to the hub.

 

4-big) Outlaw calipers with 12+ inch rotors up front on aluminum hats. Sprung weight plummets, you get 4 pistons at each corner (SCCA is working up a rear disk setup for me using this), looks awesome! Only downside I'm aware of is lack of dust seals on the calipers. Tire traction will be your biggest problem here as I expect this to stop to the limits of your tires

 

REARS.

1) 82 ZX caliper and rotor with maxima bracket (ScottieGNZ for details)

 

2) similar but weld on brackets.

either can be done 5 lug as well

 

3) outlaw/wilwood rear caliper no integral ebrake......

 

 

Wheels...

 

unflared cars- max width is 7" with stock springs. without spacers or custom made wheels or wheel adapters.

if changing to coilovers a 9" wheels will fit on the rear (Pete- add your stuff in)

spring goes above tire etc..

 

there seems to be a general movement to going to 5 lug wheels for a larger variety of choices. There are those still 4 lug but the majority are those who already have custom 4 lug wheels that fit.

The other alternative is to use a adapter to run honda pattern rims - Evan is the one to post about this..

 

MIkelly can tell about cobra R rims..

ALsil or SCCA re 300ZX rims

 

am i missing anyone/thing???

 

 

add what you feel is needed and keep reposting??

 

 

------------------

Mike

mike@fonebooth.com

http://www.outlaw-brakes

raceparts and brake upgrades.

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If this is an option list for members considering upgrades, I applaud you guys.

 

I would like to add a couple but of course the evaluation is IMO and not scientific.

 

Front Brakes - 82-83 ZX calipers with 84 vented rotors. With KVR pads, they outperm the Toyotas/stock rotor, IMO.

 

Booster/MC Upgrade - Because I have an automatic and eliminated the stock throttle linkage, I went with the ZX 2+2 monster booster with the early ZX M/C. If I have it right, 240Z-260Z/manual can use the 280Z booster, 280Z/manual and all automatics can use the 280Z 2+2 booster.

 

Rear Spring Mod - I did the JTR rear spring perch mod. I moved the perch up and cut down 280ZX 2+2 springs. I know some think it is sacrilige, but it works. My spring perch now clears a 26" tall tire, so a shorter tire can use a wheel with more backspacing.

 

HTH

 

------------------

Scottie

71 240GN-Z

Scottie's GNZ

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What we still need:

 

1) What year 4 piston calipers work for the Toyota upgrade for both vented and solid front calipers.

 

2) What rotor works up front for the vented Toy upgrade.

 

3) What (max) width rim will work with stock suspension and with 10inch coilovers. 8 inch coilovers too if it's different (I think it is). I believe that an 8inch wheel width is the max for a stock fendered 240Z in the back with 10inch springs. I know that Pete is at 9 inches but I think he's either got some funky rear end work or has 8inch springs to fit his 9's.

 

4) What backspace is needed for a car with standard fenders to fit say a 245 tire. Need this info for front and back. Will need this for the various brake packages if they change the offset.

 

5) Some sort of agreement on spring rates for stock type suspension, 10inch springs, and 8inch springs. I'll be running 10inch and have got 225200 springs.

 

6) For bonus points we could add alignment reccomendations, some sort of guidline on when to section a strut, and what struts work best for th evarious shortened struts. Yes, some of this has been answered here.

 

P.S. The Toyota upgrade info is at Zcar.com but my damned browser crashes when I try to go over there right now. Doh! And yes, I didn't stick to just brakes but I think all of these questions have been burning with all of us for awhile. smile.gif

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Could one of the moderators please take all this great info and put it into a tech article type of format, so it is NOT a dangling thread? That way (obviously so) all we have to do is say, "look at the tech article for the info." Thanks for your efforts SCCA, BLKMGK, Pete, et al.

 

David

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quote:

Originally posted by BLKMGK:

What we still need:

 

3) What (max) width rim will work with stock suspension and with 10inch coilovers. 8 inch coilovers too if it's different (I think it is). I believe that an 8inch wheel width is the max for a stock fendered 240Z in the back with 10inch springs. I know that Pete is at 9 inches but I think he's either got some funky rear end work or has 8inch springs to fit his 9's.

 

Jim, scca, thanks for doing this. I can't make up pages, only SuperDan can do that wink.gif.

 

Here's that bit of info you're looking for in regards to unflared rear fender, with an 8" free length coil over. I'm going to list ALL the details, if you want to edit some of them out, feel free.

 

Assumptions:

 

-1/2" thick rotor hat. This is what my Arizona Z brakes have. If you're using stock drums or an OE cast iron rotor, this will be thinner and the backspacing I give below will have to be reduced by the difference in the thickness between my 1/2" thick hat and the other part, at the wheel flange.

 

-240Z strut tube. The 280Z tube is a slightly larger diameter (I believe) and will take a bit of clearance away.

 

The rear wheel is 17"x9", with 1/2" thick rim lips has 149mm (5.866") backspacing. With 8 inch coil overs, and a Carerra PN1974 coilover tube situated so that it is all the way up on my 1.5" shortened strut, the bottom of the threaded tube is next to the rim lip. On one side of the car, there's an 1/8" of clearance between the wheel and the threaded tube. On the other side, I had to remove a portion of the tube in that area to gain clearance.

 

With 255/45-17 (rear) Michelin Pilot SX MXX3 tires, the tire clears the 8" spring by 3/16" or so. Be aware that if you go to another tire manufacturer or model, the tire sizes for a given designation (i.e., 255/45-17) change enough that the tires could be smaller or larger than desired.

 

Note that the coilover springs used with these tires must be the 8" free length version so that the adjusting collar does not interfere with the tire. The springs must be stiff enough that they do not allow coil bind on large dips. For a car with 600 pounds on each rear tire, a rate of 275 or 300 lb/in will give enough stiffness to not coil bind.

 

Since the bottom 1 inch or so of the threaded sleeve is not used and it's added thickness to the strut in this area causes small tube to wheel rim clearance, the threaded sleeve can be slightly shortened so that it is above the rim lip height on the strut.

 

The tire has more clearance inboard than the rim, but a section width of 10.55" is maximum. The tires presently on the wheel are 255/45-17 Michelin Pilot SX MXX3s., which are 10.5" at the widest point. On Jim Biondo's car, these tires rubbed just a bit on a large dip on the outer wheel house. Note that the top area (~4" on either side of the highest point) of the rear quarter opening must be "rolled" so that the short horizontal portion of the fender lip is bent at the outboard edge (still unseen from outside the car) in a straight up fashion.

--------------------

 

I know, lots more than you wanted to know, but this is a very tight fit and the details really matter.

 

Regards,

 

 

------------------

Pete Paraska - 73 540Z - Marathon Z Project

pparaska@home.com

Pete's V8 Datsun 240Z Pages

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Okay, I've got to point this out. There's what 10mm difference between a 245 and a 255 tire? It sounds like Pete really had to work hard to get that puppy squeezed in there! Pete, if you had to do it again would you sacrifice the 10mm of width and be satisfied with a 245 series tire?

 

BTW - I took a look at the tires off a friends 97 Cobra - solid rear axle. 315 series tire! I've seen them on the car - they fit fine. No rolled lip either - I swear the wheel well doesn't look wider than ours! I'm going to measure that puppy next time I get over there. Also, the Cobra rear vented rotor looks like it's hat is close to the same height as the rotor I've got for my rear conversion and I know the bolt pattern is the same. Might be worth looking into. The rear calipers on the Cobras are a joke - teeny tiny one piston jobs but I guess they work fine...

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Okay - looks like the first upgrade option is to use Toyota 4WD calipers from a 1979-1984 truck. I'm not yet sure if this is the 4cyl version or the 6cyl and I think these parts use the solid rotor. This from -> http://www.zhome.com/ZCMnL/tech/Calipers/toyotaCalipers.html Here's more info too -> http://www.geocities.com/dave240z/fbrake_1.htm

 

Hrm, I've not upgraded my master cyl yet...

 

And some more that mention the vented front rotors. However I think there's a STOCK rotor that will work for this if you keep 4lug. -> http://www.sonic.net/~kyle/maxima.html

 

Ah, and a GOOD hit on Zcar.com "The first using the 83-84 toyota 4x4 pickup brakes calipers that still use our stock rotors, and the 88-90 toyota 4Runner 4x4 3.0l v6 conversion that uses the larger vented rotors from a 84 300zx" from -> http://www.zcar.com/forums/read.php?f=1&i=137767&t=137764 that confirms that there's a stock rotor out there smile.gif

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quote:

BLKMGK wrote:

Okay, I've got to point this out. There's what 10mm difference between a 245 and a 255 tire? It sounds like Pete really had to work hard to get that puppy squeezed in there! Pete, if you had to do it again would you sacrifice the 10mm of width and be satisfied with a 245 series tire?

 

Jim, very little trouble for me wink.gif (except for writing the check for all of it).

 

Jim Biondo did all the leg work for me, as he had this set up on his car. All I had to do is go with the 8" coilovers, and that's a sacrifice, as your tied down to stiff (275lb/in+) in the rear, unless you use something that's a good bit shorter than the stock upper spring perch and isolator.

 

Agreed, 10mm isn't much. But getting anything much wider will not work in the stock wheel wells unless you take the strut out or locate it further inboard (and do something about the severe camber that would give).

 

------------------

Pete Paraska - 73 540Z - Marathon Z Project

pparaska@home.com

Pete's V8 Datsun 240Z Pages

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