Lexus LS460 brake calipers mated with 370z sport rotors on a 350z.
Not a how to, just stating that it is possible use these calipers on the 350z as an alternative BBK and nobody seems to have tried it out yet along with some issues that you may come across when trying out different calipers

Made adapters with 3/8 mild steel, and steel braided brake lines in the front. The steel is strong enough for daily and occasional hard braking. Mild steel will also bend instead of snap so is also better in terms of safety and warps less when welding. Aluminum is expensive and would be better off being machined if you want to g

o that route.

The brake lines have the same connection to the hard line of the body which uses an inverted flare incase you want to use the brake lines off of the Lexus calipers. The fronts are the same, but they're too short so I used Stoptech steel braided brake lines.

Akebonos and Brembos are easy ways to get a bbk with lots of research behind them and the adapters, but I felt like trying something new. Replacement calipers and pads are also significantly cheaper. Many people have done this with the Brembos off of SRT8s, CTSVs, Porsches and there are kits for those, but I just didn't feel like getting them at the time.

They work very very well and all the issues are sorted out. Very tight clearances between caliper and wheel as well as caliper and rotor so I had to add thin shims to make the caliper align perfectly to the rotor.

 

I feel like that's a "visual" mod, rather have something made for the car like the new Nismo (Stoptech) kit if you shop around you can get that for $3k which is very reasonable for new parts.

 

They are deffinitely functional and offer more stopping power than stock. 4 piston fronts and 2 piston rears and they are positioned farther from the center for more leverage on the rotor

 

Ahh the regularly regurgitated idea that larger bakes are what make you stop faster. They will not improve initial stopping performance, and larger/heavier rotors will actually decrease stopping distance. They altered piston bores will likely make the pedal feel terrible. You're running truck brakes on a car. I doubt you can get high performance pads for these either, which you can for the oem brakes.

They are bigger. That is all.

With how easy it is to get a set of adapters made at a local machine shop, or even one of the online machine shops, I would absolutely not trust homemade non billet brake adapters. Its basically just asking them to tweak under heavy braking and then you have dragging brakes because they are no longer aligned.

 

Respect the work that went into this, but those are some sketchy work-arounds for a safety critical system. I'd be interested in seeing your adapters for the front.

These calipers will shift the brake bias well forward of factory - IIRC OE Brembos use 38/42mm pistons and it looks like the LS uses 43mm pistons all around. Without a few other numbers that I don't feel like researching I can't say how far, but even a couple % can upset the balance and possibly confuse your ABS/TCS. The larger pistons will also require more pedal stroke (~15%) to displace.

Maybe if you had them powder coated it would make sense as an aesthetic mod, but as is it's a decrease in safety, a decrease in performance, probably similar weight, and a similar bare-metal finish.

edit: stopping distances will almost certainly increase since you're now over-utilizing the front brakes and under-utilizing the rears. That said, I sure as sh*t wouldn't attempt any max braking events on untested adapters.

 

stopped by my local machine shop and it was going to cost me $500 for them to draw it up in a program and then machine it. Plus the cost of the material.

but I see what you're saying about decreased stopping power and its a valid point. Pedal feel seems to be about the same as my oem brakes.

 

thanks for the information, I was also curious about the brake bias as well as abs/vdc/tcs issues that might arise. So far after about 2000 hard miles on them, abs hasn't kicked in when I think it shouldnt, it still seems to be working fine. Checked for warpage front and rear and so far none.

All calipers were powdercoated chrome 😅😅 I may redo them in the future since I touched it before it had cooled with acetone soaked gloves.

 

as for the front adapters I made sure to chamfer the edges to a 45 degree angle and preheat to reduce warping and increase weld penetration. I'll take a photo of the welded adapters next time they come off

 

I also want to add that I appreciate everyone's input into this. Definitely more informed now than I was before, didn't seem like there was enough information on caliper swaps or general information on what works or what doesn't.

Also a good test of my own mechanical ability. I'd appreciate more input on what to do better next time and what to avoid.

 

Haha I see the chrome now - doesn't really pop on an unmachined cast surface.

Do you have an engineering background, and/or did you run any numbers to determine if "The steel is strong enough for daily and occasional hard braking."?

I'll hold further comment until I see pictures of the finished adapters, but incase any other readers are considering doing this, please make me the beneficiary on your life insurance first.

 

An acquaintance of mine from the machine shop says that he likes to use 6061 Aluminum for his brake adapters, most used on Toyota Tacomas and Tundras with no failures yet.
I went with A36 Mild steel for my brake adapters

A36 has an ultimate tensile strength of 58,000- 79,000psi
Elasticity of 200 GPa (gigapascal- some sort of measurement of elasticity)

6061 has an ultimate tensile strength of around 42,000psi
Elasticity of 70 GPa

For some perspective on elasticity, rubber has an elasticity of 0.01Gpa. Higher the number from what I learned means its less elastic.

The tensile strength and elasticity made me favor steel A36 over 6061 Aluminum in not only cost but also ability to take a load


Elasticity chart:
https://www.engineeringtoolbox.com/y...lus-d_417.html

Where I got my info on Aluminum 6061:
https://www.fergusonperf.com/the-per...l%20properties.

Where I got my info on A36 Steel:
https://www.metalsupermarkets.com/gr...ide-a36-steel/

 

I see no issue with that you did. I was going to do the same a while back, but with CTS-V calipers, but it would of just been for the visual. I think the factory brakes work very well

 

I agree that for a well designed adapter, tempered 6061 will be adequate for most cars and light trucks. 7075-T6 would be the next step up, and steel would be the last, strongest resort - again assuming the adapter is well designed.

My main concern then, as you can probably tell, is with the adapter design. Nearly all of the force will be concentrated on the material between the knuckle mount bolts and the caliper mount bolts. Again, without seeing the finished product it's all speculation, but from the pictures I've it looks like there are stress concentrators that could lead to failure, especially on a part that will be heated and cooled repeatedly.

 

These are all good points, and I hope this is stuff that you looked up before hand rather than after. Steel can be good for this, but I can explain why aluminum is the more common choice.
At 400 degrees the yield of a36 is 33ksi. At 400 degrees aluminum is 14.9ksi. Steel is 2.5 times heavier, but only 2.2 times stronger. So you can make an equivalent strength adapter with less weight with aluminum.

For the elasticity, the aluminum is much lower, but elasticity is in relation to stiffness. Stiffness of a part is a function of the cube of the thickness. Meaning that the aluminum needs to be 44% thicker to be equal stiffness to the steel. Because you need to be 2.2 times thicker than steel to have equal strength, this means with an equivalent aluminum part, it will be 3 times stiffer. So for the same strength of part, aluminum will be 12% lighter and 300% stiffer.

Aluminum takes way more energy to heat up also, meaning it is slower to get hot, and also it transfers heat much better than steel. This means that the aluminum adapter can absorb more heat from the caliper and can also transfer more heat into the knuckle, which is effectivly just a large heat sink.

Welding reduces the material strength at the point of the weld on a professional weld. An amateur weld would be drastically reduced and should not really be considered even close to the strength of the steel itself.

Regarding the price, sourcing the material yourself from ebay can be super cheap. Drops to cut adapters would likely cost less than 30$ for all four. There at quite a few free CAD softwares out there, or just a paper drawing with dimensions. This is obviously the hard part to do if you are not familiar, but some time on youtube could help you draw up exactly what you need from a shop and get that machining price down to 150or so. You would end up with a better component.

TLDR; Aluminum at the same strength as steel is lighter, stiffer, and keeps the caliper cooler.







On a second note I do wonder if there are any high performance pads for these calipers, or are you limited to the stock lexus options.

 

Hence why I said it was a visual mod. Pad=stopping, rotor size=cooling..
I'd say about 90%of the people with 14" brakes on these cars are doing it for show, to fill out the wheel lol.
Honestly can't hate on the show thing as I am doing the same with the Nismos, albeit I'm not going up in size, it's all brembo sized equipment with the calipers shifted to a better location for this platform.

 

Ah I see why people use Aluminum 6061-t6 rather than any sort of steel. I guess I did it mainly for show, never really take it to the track. What setup are you running? I think you mentioned the Nismo kit made by Stoptech but I wasn't sure if you were running it

 

Yes, I haven't installed it yet but I have them chillin in my basement. It's a kit Nismo sells as an upgrade for brembo equipped cars, they relocate the front calipers to the 9&3 location as opposed to the stupid factory location. They are bigger 4 piston/2 piston calipers that are forged, radial mounted calipers made by Stoptech.
In a nutshell it's the trophy sport 4/2 13" BBK kit minus the rotors and they say Nismo instead of stoptech.

 

 

I've seen these on the Z1Motorsports Youtube channel. Never seen or heard anything about them other than on there. Sounds like a nice upgrade, keep us posted when you do install them

 

Honestly don't know why people aren't doing these more.
The price is good, they look nice and have a hard anodized finish. The calipers can be had for around 2k if you shop around, the Nismo pads are expensive but you don't have to use them.
The rear uses the same pad as the Brembos and the front is a commonly sold pad so you can get whatever you want there and get cheaper blank rotors. I went for the 2pc units just because I wanted to offset some of the weight added by my 19"wheels.