Front Brake Upgrade: Toyota 4x4 Calipers - Solid Rotor vs. Vented Rotor

[Hardway]

As part of my front suspension upgrade I will be doing a brake upgrade as well. My stock calipers are stucking and I will not be rebuilding them. If I choose to continue with them I will buy some reman. units. My car will not be raced, just enthusiastically driver around town and on cruises. Currently I have sitting on the parts shelf is all new SS braided lines F&R, new rear brake shoes, wheel cylinders, and hardware, a pair of new rebuilt 4-piston S12 calipers for use with my original solid rotors that have been turned. Also on the way is a new 15/16 brake MC for a 280zx. I have been told by a few members that using the solid rotors and 4-piston calipers is not a real upgrade over the stock setup. Yes the car will stop quicker but also have a large front bias. This I can understand and the use of an adj. proportioning valve may be in order. I really do not want to stick with the stock brakes. I will have everything apart and this will be the time to upgrade everything. My question is, should I move forward with what I have right now? If not should I return the 4-piston calipers I have for the solid rotors and get a set of S12's with the groove for the vented rotor, buy a set of '84 300zx vented rotors, and the spacer from Modern Motorsports? My other train of thought is to just go all in and get a pair of S12W calipers since I am going to be buying all of the other hardware anyway. Driving in the city, I want all the stopping power I can get. Any thoughts and experience with each system is great appreciated.

[Oiluj]

I have the toyota 4x4 brakes with solid rotors, rear drums and adjustible proportioning valve. It's the best stopping car we own. More than adequate for city driving.

[Hardway]

I have the toyota 4x4 brakes with solid rotors, rear drums and adjustible proportioning valve. It's the best stopping car we own. More than adequate for city driving.

This is good to hear. May I ask which adj. PV you are using? Did you remove the stock PV and install the adj. PV in its place?

[EuroDat]

The setup I have seen used the standard proprtioning valve with an extra in the rear brake line behind the engine. Front had toyota S13-8 with slotted non vented rotors. He also upgraded the rear brakes with a 240sx (S13) setup. Dont know if he used an MSA brackat or fabricated his own. Master cylinder was a 1" willawood. He estimated 50% more braking power.

[LeonV]

As part of my front suspension upgrade I will be doing a brake upgrade as well. My stock calipers are stucking and I will not be rebuilding them. If I choose to continue with them I will buy some reman. units. My car will not be raced, just enthusiastically driver around town and on cruises. Currently I have sitting on the parts shelf is all new SS braided lines F&R, new rear brake shoes, wheel cylinders, and hardware, a pair of new rebuilt 4-piston S12 calipers for use with my original solid rotors that have been turned. Also on the way is a new 15/16 brake MC for a 280zx. I have been told by a few members that using the solid rotors and 4-piston calipers is not a real upgrade over the stock setup. Yes the car will stop quicker but also have a large front bias. This I can understand and the use of an adj. proportioning valve may be in order. I really do not want to stick with the stock brakes. I will have everything apart and this will be the time to upgrade everything. My question is, should I move forward with what I have right now? If not should I return the 4-piston calipers I have for the solid rotors and get a set of S12's with the groove for the vented rotor, buy a set of '84 300zx vented rotors, and the spacer from Modern Motorsports? My other train of thought is to just go all in and get a pair of S12W calipers since I am going to be buying all of the other hardware anyway. Driving in the city, I want all the stopping power I can get. Any thoughts and experience with each system is great appreciated.

Get the calipers rebuilt, or buy fresh ones and get some quality tires. These two things will get you all the stopping you need. There is no way to get "50% more braking" by upgrading the system. It's not physically possible. Braking force depends on your tires. A properly maintained stock system can lock them up, i.e. the brakes can overwhelm the tires. It's not the other way around.

Bigger calipers and vented disks are just buying you more heat-capacity, which is only necessary on the track. Plus, by messing with the brake balance you have the chance to not only make stopping distances worse but also to make the car dangerous to drive if not set up for variable conditions (i.e. set brake balance for highest grip case).

[280~Master]

I have autocrossed my car and I have stock brakes on it. There was never a braking problem, as a matter of fact we would lock them up sometimes.

For braking your stocks will hold up just fine. If you want the brakes to look cooler then up grade. Just my opinion..

[EuroDat]

There is no way to get "50% more braking" by upgrading the system. It's not physically possible. Braking force depends on your tires.

I agree. If you can lock up your tyres, your already at 100% braking capacity. The only thing you achieve is less force on the peddle to reach 100%. Seems a lot of effort and money to do that.

I was thinking of upgrading but in the end I just kept my standard set up with some small mods: new MSA slotted rotors, rebuild my calipers myself, new cylinder and brake shoes for the rear and SS braided hoses all round.

Braking has improved out of sight (for regular street use).

[Walter Moore]

It all depends on how fast you are going when you hit the brakes and how many times in a row you have to stop.

The tires are only the limiting factor if the brakes can disipate the heat fast enough to keep the brake fluid from boiling. Car brakes work by converting the kinetic energy of the vehicle into heat. KE = MV^2 so a panic stop from 120 MPH requires disipating 4 times as much energy as a panic stop from 60 MPH. If you have to stop often enough, in a short enough period of time, from high enough speeds, the stock brakes are not going to do the job for you. The brakes on nearly all cars from the 70's were woefully undersized by today's standards.

But if you use the car as originally intended, and aren't breaking the posted speed limit, the stock brakes should be OK. Just don't expect them to bring you safely to a stop from triple digit speeds very often. (or perhaps at all...)

[John Coffey]

It all depends on how fast you are going when you hit the brakes and how many times in a row you have to stop.

If you have to stop often enough, in a short enough period of time, from high enough speeds, the stock brakes are not going to do the job for you. The brakes on nearly all cars from the 70's were woefully undersized by today's standards.

But if you use the car as originally intended, and aren't breaking the posted speed limit, the stock brakes should be OK. Just don't expect them to bring you safely to a stop from triple digit speeds very often. (or perhaps at all...)

Well... I've done the CalClub 6 hour Enduro (E2 class) in an ITS 240Z using stock brakes (Hawk Blue pads, air ducting to the fronts, and Porterfield rear shoes) in which we had to do a pad change at the 3 hour mark. With lap times around 2 minutes and four hard braking zones from 100mph on each lap, that means (excluding a 10 minute fuel stop) we did 340 hard stops from over 100mph in three hours. That's one hard triple digit stop every 30 seconds - and doesn't count the 4 additional under 100mph braking zones needed in each lap.

I beg to differ... :-)

[Hardway]

I truly appreciate everyone's feedback and details on this subject. I have decided I am going to return the 4-piston calipers I bought from Rock Auto and have canceled my order for the 280zx MC I placed on Friday. In turn I will be picking up a set of Fenco rebuilt stock calipers and some ceramic pads from the local parts store after work today. Even though they won't be going on the car for a few weeks at least they will be on the shelf waiting. With the ceramic pads and SS hoses I should be in good shape.

[coop]

Hey John, I've run Hawk, Carbotech, and Porterfield in various combinations and still get only about 2 - 3 hours out of my pads in my ITS car. I'm always complaining and messing with the shoes trying to get them to bite without dragging too much. It is an art to get it right and I still can't get enough bite in the rear. I start every(double)race weekend with fresh pads and play the shoes by ear, looking at/staring at and bleeding them often. As far as brake upgrades go, I would never spend money in that area on a street car unless I was going to do something like track days and only if I was going to really push it. That mod just isn't needed for autocross as even street pads and shoes work pretty well at autocross speeds. As far as serious racing goes, however, if the rules would allow, the first thing I would do is put simple disk units on the rear and sort them out over a season. I think that is what the vintage guys do and they seem to like it. Not totally sure but I think that is what the E-Production guys do too.

[John Coffey]

The fix for the rear bite was the Ferrodo Green Stuff rear brake shoes. Unfortunately they are NLA. Porterfield R4S seemed to work the best and they work better if you machine about ten .020" deep grooves in the drum surface and then bed the shoes hard to match the groove pattern. More surface area.