Viper Brakes on a 3/S

[aaronatstate]

Time for it's own separate thread...

After having tons of issues (alignment issues namely could not get passenger side to be in spec for camber) trying to get the EvoX brakes to work on my Stealth, I decided to try my own setup using Viper brakes.

The reason I chose the Viper brakes, is they use the same pad size as the EvoX (I had already bought pads and rotors), and they are radially mounted. The pads on the Viper are technically thicker than the EvoX, but they are the same design. The next time I buy pads, I'll just get the Viper, so the pads will last longer.

After doing more research it turns out the calipers on the Viper are the same basic caliper that comes with the Brembo BBK for our kits. So with the bracket I made, I was able to get the same basic kit but for a lot less money.

Items, steps, and costs needed for Viper brake conversion:

1. 2008-2017 Dodge Viper Front Calipers ~$500 used on eBay/~$600 new from MOPAR
2. EvoX Front Rotors 350x32mm Varies, I got Duralast from AutoZone for $44/rotor
3. EvoX or 2015-2017 Viper T/A Front Brake Pads (Viper are thicker). I got Carbotech pads, which were $198 for the fronts. Carbotech PN CT1001A for EvoX, CT1001 for Viper T/A. DO NOT GET CT968 pads (also for Viper, but not TA, as they are slightly shorter and won't make full use of the rotor face width). The Calipers are the same though, just different pads and rotors used on different Viper Trims.
4. Custom front brake lines. I had them made locally out of stainless steel braided lines for $75. I forget the length right now, but can get this when I get home
5. Custom brackets. I used T6061 Aircraft grade aluminum. For materials and machining I paid ~$250.
6. Total costs for conversion bare bones was ~$1,125
7. Viper calipers need to be "flipped" i.e. flip the bleeders and crossover tube. The Viper calipers are mounted towards the center of the vehicle and the bigger piston needs to be the second piston the rotor travels through, so they need to be flipped.
8. Stock 18" rims are required, along with a 5mm spacer for 5 spoke Stealth rims. I haven't tried any other rims, so I cannot comment on fitment.
9. Optional hub spacer to maintain the hubcentric for rims. My rims needed this, can't comment on other rims. Note: my rims are stock replicas. Also, I ran without this spacer for 500 miles with no issues, and no vibrations, so not 100% necessary.

Caliper Bracket


Hub Spacer


Caliper Mounted in Wheel


Caliper Mounted on Knuckle (note knuckle is upside down)


Centering of Caliper on Rotor

[ChargerX3]

Great write up. I too have the 5 spoke, but I really want to stay away from wheel spacers. Which part of the caliper comes into contact? Would there be any benefit to shaving the face down, or would there be too much material to remove? Is the Brembo part raised, or just a sticker?

Also, looking back how much better is braking and brake fade with the new combo?

[aaronatstate]

[quote=""ChargerX3""]Great write up. I too have the 5 spoke, but I really want to stay away from wheel spacers. Which part of the caliper comes into contact? Would there be any benefit to shaving the face down, or would there be too much material to remove? Is the Brembo part raised, or just a sticker?

Also, looking back how much better is braking and brake fade with the new combo?[/quote]

You could maybe shave them down, but I didn’t want to do that. It’s the outside forward edge of the piston housing that hits (if that makes sense). Brembo part is just a sticker. I had mine re powder coated to the color in the pictures.

GT500 rotors would push the calipers further inboard, but they won’t be hub centric. 370Z rotors also push the caliper a bit further inboard, but they use a 68mm hub, and it’s enough smaller that it doesn’t work unless you machine it out.

5mm spacer is not that much. I did get longer lug nuts for peace of mine, but they aren’t 100% needed with a 5mm spacer.

Braking is significantly improved, just like any big brake kit. I can lock up the front wheels with ease now (I had trouble locking them up before with good tires). I haven’t driven it hard enough long enough to notice a difference in fade, but that has a lot to do with pads too. Good pads on stock brakes can significantly reduce fade from stock. But the bigger rotors should help. Also since there are TONS of options for EvoX rotors, 2 piece etc, you can really make a nice setup for your needs.

I plan on doing the EvoX rear brakes as well to get the balance back close to stock. I have those calculations done as well, but they’re on my work computer so that’ll have to wait till tomorrow. The bias is better with the Viper calipers that EvoX front calipers because the Viper calipers use 40/44mm pistons and the EvoX uses 40/46mm pistons.

[aaronatstate]

Caliper Location w/Various rotor setups:

Note: All "inboard" movements are calculated based on where the EvoX rotor puts the caliper.

2010 GT500 rotors push the rotor 0.090" inboard (so not very much), and you may still need a spacer. Still won't be hub centric.

2018 Mustang GT rotors push the rotor 0.716" further inboard, but they won't be hub centric. This could be better, but I'm not sure if they would interfere with the knuckle, because the 370Z rotors are close to the knuckle and they only sit 0.216" further inboard.

The really interesting thing is, if you wanted to get bigger wheels, you could in theory fit GT-R brakes. They push the caliper 0.193" further inboard, and gets you a 390mm rotor and 6 piston calipers!

Brake Bias

• Stock
• Stock 1G Bias: 2.49 F/R
• Stock 2G Bias: 2.53 F/R
• Stock EvoX Bias: 2.46 F/R
• EvoX Front Rotors - Various F/R Caliper Setups
• EvoX Front-1G Stock Rear: 3.17 F/R
• EvoX Front-2G Stock Rear: 3.03 F/R
• EvoX Front-EvoX/9/8 Rear Caliper-2G Rear Rotor: 2.74 F/R
• Viper Front-EvoX/9/8 Rear Caliper-2G Rear Rotor: 2.60 F/R

You can see that with the Viper Front calipers, EvoX/9/8 rear calipers, and 2G rear rotors, the brake bias is very close to stock, just slightly shifted forward.

[aaronatstate]

[quote=""aaronatstate""]The really interesting thing is, if you wanted to get bigger wheels, you could in theory fit GT-R brakes. They push the caliper 0.193" further inboard, and gets you a 390mm rotor and 6 piston calipers![/quote]

If you wanted to get 20" wheels (or maybe 19" wheels would clear), and then spend ~$15,000 more for used GTR calipers, custom brackets and lines, slight machining of the rotor hats, and this kit, you could have carbon ceramic brakes on a 3/S

http://www.boostlogic.com/parts/nissan- ... -2011.html

[ChargerX3]

So my best bet is to shave off 5mm of the outer leading edge or get a spacer and hub centric spacer? Wouldn’t be opposed to shaving so long as there is enough material.

[aaronatstate]

[quote=""ChargerX3""]So my best bet is to shave off 5mm of the outer leading edge or get a spacer and hub centric spacer? Wouldn’t be opposed to shaving so long as there is enough material.[/quote]

Yeah, I personally went with the spacers. I have had zero issues with it, and it actually makes the wheel sit better in the wheel well too.

[Jeff V.]

Vira is running 5mm spacers on the front of her car. We installed extended studs just in case.

[aaronatstate]

[quote=""Jeff V.""]Vira is running 5mm spacers on the front of her car. We installed extended studs just in case.[/quote]

Yup, forgot to note that I did as well, just in case.

[ChargerX3]

I wouldnt mind the 5mm space if there was a hubcentric version.

[ChargerX3]

Another question. After looking over your bracket I notice that you have the material step up toward the caliper (as in gets thicker). Is there a reason for that? I might try a slightly simpler route of sourcing some thick steel plate and then just drilling out the holes and cutting out the excess material. Essentially just being on big flat piece with a half moon in it.

[Jeff V.]

Vira's spacers are hub centric. I don't remember the brand though.

[aaronatstate]

[quote=""ChargerX3""]I wouldnt mind the 5mm space if there was a hubcentric version.[/quote]

[quote=""Jeff V.""]Vira's spacers are hub centric. I don't remember the brand though.[/quote]

I tried to find hub centric 5mm spacers, but couldn't. So our machinist in Rochester Hills made those spacers that go on the hub for me.

[quote=""ChargerX3""]Another question. After looking over your bracket I notice that you have the material step up toward the caliper (as in gets thicker). Is there a reason for that? I might try a slightly simpler route of sourcing some thick steel plate and then just drilling out the holes and cutting out the excess material. Essentially just being on big flat piece with a half moon in it.[/quote]

The reason for the step up is so the caliper would be fully supported at the bolt locations (orange arrow). The small step (blue arrow) was to position the caliper properly. The large step (red arrow) was because I didn't want to buy new bolts If that step isn't there, you can't reuse the stock caliper mounting bolts.

[ChargerX3]

Yea, wish Jeff could remember which hubcentric spacers he got. That would be the ideal scenario by far.

After looking at it for a while I figured that had to be the reason. Being steel and that the braking forces are vertical, I might opt for a slightly skinnier bracket and skip the machining to keep the stock bolts.

[aaronatstate]

[quote=""ChargerX3""]Yea, wish Jeff could remember which hubcentric spacers he got. That would be the ideal scenario by far.

After looking at it for a while I figured that had to be the reason. Being steel and that the braking forces are vertical, I might opt for a slightly skinnier bracket and skip the machining to keep the stock bolts.[/quote]

That should work.

Those rings I got work great, they fit inside the ring on the hub as is, and extend the hub lip out 5mm. I held them in with a thin coat of JB Weld

If I did it again, I would make 59.5mm diameter a bit larger, and press fit them in. Either way with the way the stock lug nuts work they get the wheel centered on the hub anyway (I ran like that for 1000 miles), having that ring just makes it easier putting the wheel on..

[ChargerX3]

Ok so to clarify that’s thinner part is 1.093” and 1.181” for the thicker end?

You had those rings specially made though right? Not an off the shelf part.

[aaronatstate]

[quote=""ChargerX3""]Ok so to clarify that’s thinner part is 1.093” and 1.181” for the thicker end?

You had those rings specially made though right? Not an off the shelf part. [/quote]

Yeah. Basically the small step (blue arrow) needs to be 0.088”

Those rings would be very easy for any machine shop to make.

I can send the cad file if you want too.

[ChargerX3]

Ok perfect. Ive got several things on my plate at the moment. I will have to circle back around to this but my email is chargerx3@gmail.com

[Chris GTO TT]

[quote=""ChargerX3""]Ok perfect. Ive got several things on my plate at the moment. I will have to circle back around to this but my email is chargerx3@gmail.com[/quote]

[Jeff V.]

I always wanted to do an AMG kit.