Front Brake Upgrades

[240ZX]

Aussie260z,

There is a guy by the name of Terry Oxandale (Blueoval @ HYBRIDZ)who has written articles on a couple of different brake conversions for the early type Z cars (240, 260, 280), using Datsun/Nissan parts. He provides details for what he calls his Street conversion as well as a Race conversion. I actually did his Street conversion on my 1970 240Z and couldn't be happier with the results, without spending the big dollars necessary for the way cool aftermarket brake upgrades. The only things I did, on top of Terry's Street conversion, was to use some really good pads along with S.S. flex line to the calipers. You might want to check out his website.....you can usually find it by typing just his name (Terry Oxandale) into what ever search engine you use. I know I'm a happy camper now, when it come to stopping my Z.

[TomoHawk]

Thanks for the "update" on Mr. Oxandale's work. His method seems to be very well implemented. I forget if the ZX calipers are 2 or 4 pots. I was probably going to do the Toyota caliper upgrade (fronts) because I figure there are more Toyota 4x4s in the JY than ZXs for the cheaper route on calipers. Do you have details on the calipers you used (price & availability)?

Now that I think of it, did anybody check the Toyota 4-pot calipers to see how they compared to the 280ZX calipers?

thx

[Aussie260z]

240z,

Checked out that site and the "Street" version seemed like an extremely simple & effective upgrade,

Its just...........At some point in the future i wanna install an RB25DET, so if i upgrade now i want it to be suitable for the increase in HP that this kind of conversion would require, just go over-kill,

There is his "Race" version option, but this requires re-locating the stock Caliper Mounts,

But from what i've learned it appears if you wanna go bigger front disc's you havent got much alternative to either re-locating the caliper mounting points or using some kind of bracket???

But...........If i did go the HoppersStoppers route i think i would have the same problem this bloke had, with way to power front brakes and very oridinary rear brakes,

So doing his rear brake conversion would make sense,

Was just wondering though, and i couldnt tell when reading through his write-up, but when you do either his front or his rear brake conversion, does the wheel off-set change at all or does it remain stock???

[messenger]

FWIW, there is still 30% of the car's weight on the rear tires at 1-g braking, unlike a motorcycle which has a MUCH shorter wheelbase and higher center of gravity. Stock setup biases the fronts. Further biasing towards the front should actually INcrease ultimate stopping distances, as the rears will be doing even less at impending front lockup. Fortunately, the Toyota truck calipers only have 4% more piston area than stock. Still, I don't really consider this mod (front 4-pot truck calipers ONLY) an "upgrade".

That is a interesting point of view. 4% piston area huh, well lets not forget about the size of brake pad. I dont have them side by side in front of me but off memory I would wager to say the 4x4 pad is roughly 30-40% larger. Can anyone disagree that a larger pad would make more contact with rotor thus causing more friction? :stupid:

Also the piston size does come into play like you mentioned, but the fact that you have 4 pistons compressing larger pads instead of 2 pistons and smaller pads makes a huge difference. The clamping force is more evenly distributed across the pad.

[TomoHawk]

WHAT IS YOUR POINT!!????

What you "quoted" wasn't what I ORIGINALLY SAID, too. When you QUOTE someone, you need to keep their point consistant, not twist things to make your point important, whatever it is.

You must have a terrible headache using that hammer on yourself.

[240ZX]

That is a interesting point of view. 4% piston area huh, well lets not forget about the size of brake pad. I dont have them side by side in front of me but off memory I would wager to say the 4x4 pad is roughly 30-40% larger. Can anyone disagree that a larger pad would make more contact with rotor thus causing more friction? :stupid:

Also the piston size does come into play like you mentioned, but the fact that you have 4 pistons compressing larger pads instead of 2 pistons and smaller pads makes a huge difference. The clamping force is more evenly distributed across the pad.

messenger, Your statement regarding larger contact area is true however, it does not necessarily cause more friction unless the force being applied is greater. As an example...if we have a given piston area and applied pressure, and it is the same for both examples, and a pad area of 2" x 4" verses a pad with 2" x 3" area. there will be more friction per given area on the smaller pad...it's just basic physics. But if you increase the applied pressure to the larger pad it will then have more friction for a given area.

[Bambikiller240]

WHAT IS YOUR POINT!!????

What you "quoted" wasn't what I ORIGINALLY SAID, too. When you QUOTE someone, you need to keep their point consistant, not twist things to make your point important, whatever it is.

The quoted text is EXACTLY (word for word) what you said. The fact that you prefaced that statement by indicating that you finally figured out where Aussie260 "might" be located is irrelevant. You still had the gall to make the quoted statement.

Here's a suggestion for you.

READ THE WHOLE POST, USE SOME COMMON SENSE (you can borrow some if you're short on it) BEFORE YOU START INTIMATING THAT SOMEONE ELSE IS AT FAULT FOR YOUR MYOPIA.

[Dan Baldwin]

That is a interesting point of view. 4% piston area huh, well lets not forget about the size of brake pad. I dont have them side by side in front of me but off memory I would wager to say the 4x4 pad is roughly 30-40% larger. Can anyone disagree that a larger pad would make more contact with rotor thus causing more friction? :stupid:

Theoretically, it's only normal (clamping) force times coefficient of friction that dictates frictional force, irrespective of area of contact. The 4x4 pads have 4% greater area => with the same coefficient of friction, they give 4% more braking force than the original calipers. Again, it's a good thing they don't give MORE, because there's already too much front bias!

Also the piston size does come into play like you mentioned, but the fact that you have 4 pistons compressing larger pads instead of 2 pistons and smaller pads makes a huge difference. The clamping force is more evenly distributed across the pad.

True. Also, less heel/toe action, better wear characteristics, should give better modulation, should run cooler, etc.

But to me it isn't worth it to JUST do the front 4x4 caliper mod, as it increases front bias, and stock is already conservatively biased to the front. More front bias => rears are doing less braking at front lockup => less total braking force at front lockup => longer stopping distances.

[messenger]

I understand the front end bias issue in theory. But on my car when I get on the brakes about as hard as you would ever possibly be on them the rear end locks first.

It is actually rather scary, I have never had a car that the rears locked up first. The rear end starts to step out.

[TomoHawk]

If the rear end locks up first, is the nose diving in really bad? It's the only reason I can think of for the rear wheels getting light enough to lock up- even in my front-wheel drive escort. We do the same stuff on bikes in panic stops- you dump your butt off the back of the seat as far as you can to get more weight over the back wheel.

[Aussie260z]

Messenger/Dan Baldwin/ 240sx, and other folk who are talking bout brakes in here :nervous:

Have read through your coments on the Toyota 4by4 upgrade,

Im curious - what if i put on massive front brakes, like those supplied by HoppersStoppers (300mm slotted rotors with Big 2-Piston Calipers) but kept the rear brakes on the Z stock,

From what ive read, this seems like a fairly unwise idea - as the Z already has a biasis towards the front brakes, this kind of conversion would massively increase this biasis, thus leading to front-brake lockup...........

Is this pretty much right?

And if it is, what can i do to counter-act this?

Put massive brakes on there rear?

[speedyblue]

It would cost a lot, and stop very well, but you wouldn't see all the performance for the $$$ you spent because the back wouldn't be able to keep up. Braking while cornering would be a situation where having the fronts do most of the work wouldn't be very good. Go with a cheaper option and spent the extra money elsewhere.