2G Big brake kit

[bmw335ikt]

Hello I'm looking at getting a big brake kit for my 2g awd

Here are some options
The ctsv kit
http://strictlyperformance.parts/shop/all/strictly-dsm-cts-v-big-brake-kit

Baer kit
https://www.maperformance.com/colle.../products/baer-claw-track-brake-system-2g-dsm

Wilwood dynapro kit
https://www.extremepsi.com/store/product.php?productid=26790&cat=1371&page=1

I want a kit that is a straight bolt on that doesn't need any modifications
Also if you recommend any other kit I would like to stay at 1000-1500

Thanks

 

[Vegas Smith]

Ohh yeah... What a dog!

Finally, we agree! JK man, I'm not trying to bash your setup.

 

[AdR]

Lol, I know hence the wink.

But it is really interesting that with the proper wheel tire package you can compensate the weight. That said, there is more concentration of weight in the rotational mass since the weight savings come from the caliper (non rotating). But it's a small price to pay to stop.

 

[Planckscale]

Here's my original setup vs my current setup for comparison:

Stock Setup (per corner):
Rotors: OEM GSX (276mm) = 13.15lbs
Calipers: GSX = 14.2lbs
Wheels: Stock GST 16" =22lbs
Tires: Hankook 205/55r16 = 22.2lbs
Total Weight = 71.55lbs per corner

Brembo Upgrade (per corner):
Rotors: Cobra 13" = 19.1lbs
Calipers: CTS-V 4 piston = 8.4lbs
Wheels: Kosei K6r 17x9 = 18.5lbs
Tires: Khumo XS 235/40r17 = 23.4lbs
Total Weight = 69.4lbs per corner

If I use your reference, I will end up with 76.7Lbs. That is 5lbs above Stock!

Brembo Upgrade (per corner):
Rotors: Cobra 13" = 19.1lbs
Calipers: CTS-V 4 piston = 8.4lbs
Wheels: XXR 530 18x8.75 = 23.1lbs
Tires: Federal SS595 255/35/18 = 26lbs
Total Weight =76.7lbs per corner


I will have to find lighter rotors for this to work for me. Anybody seen lighters for less that $500?

 

[AdR]

If I use your reference, I will end up with 76.7Lbs. That is 5lbs above Stock!

Brembo Upgrade (per corner):
Rotors: Cobra 13" = 19.1lbs
Calipers: CTS-V 4 piston = 8.4lbs
Wheels: XXR 530 18x8.75 = 23.1lbs
Tires: Federal SS595 255/35/18 = 26lbs
Total Weight =76.7lbs per corner


I will have to find lighter rotors for this to work for me. Anybody seen lighters for less that $500?

Actually the weight over stock you see has little to nothing to do with brakes...

Your Stock Brake Setup with wheels (per corner):
Rotors: OEM GSX (276mm) = 13.15lbs
Calipers: GSX = 14.2lbs
Wheels: XXR 530 18x8.75 = 23.1lbs
Tires: Federal SS595 255/35/18 = 26lbs
Total Weight = 76.45lbs per corner

That means the 5lb weight increase you have right now is not a factor of brakes you would use (stock vs Brembos) but rather your wheel and tire package. You'd just compensate for what you are already hauling around by buying two piece rotors.

 

[er82]

Anybody seen lighters for less that $500?

I think the Baer 2 piece rotors can be bought for like 450$ if wait for the site wide coupons from larger retailers like autoanything.com

 

[Planckscale]

Actually the weight over stock you see has little to nothing to do with brakes...

Your Stock Brake Setup with wheels (per corner):
Rotors: OEM GSX (276mm) = 13.15lbs
Calipers: GSX = 14.2lbs
Wheels: XXR 530 18x8.75 = 23.1lbs
Tires: Federal SS595 255/35/18 = 26lbs
Total Weight = 76.45lbs per corner

That means the 5lb weight increase you have right now is not a factor of brakes you would use (stock vs Brembos) but rather your wheel and tire package. You'd just compensate for what you are already hauling around by buying two piece rotors.

That is the reason why I said I need to find lighter rotors. While the calipers are lighter, they do however, require a heavier rotor, which is also contributing to increased rotational mass. Now don't get me wrong,
I prefer this mod over the Evo Brembo since the installation is much simpler. And your info was the tipping point balance
In the future, I may go for a 245/45/18 rim/tire set and shave may be a pound or so...

 

[AdR]

I fully understand your decision and I agree that any weight off is the best. I am just stating the obvious to help you determine the best bang for the buck in your quest to reduce unsprung weight.

IMO a lighter wheel/tire package will get you in a better performance advantage than two piece rotors. The reason being simply based on physics. Rotational mass derives from a center point and it's effects grow as you increase the radial location of said weight against that center point (moment arm). The weight reduction in a two piece rotor does not come from the braking surface (rotor) but rather the rotor hat which tends to be aluminum, meaning the weight decrease derives from extremely close to the center point which does little to nothing to reduce rotational inertia. Now on a wheel and tire package the weight is highly concentrated on the wheel tub (outer region) the spokes and the tire which is the outermost surface on the moment arm. Reducing that weight will significantly reduce the effort required to start and stop the assembly.

Cheers!

 

[orangedsm]

From the research I've done, if you are concerned with lightness, wheels and tires are the biggest thing, as AdR said, but if you want a light brake kit, seems like the Wilwood Dynapro 12.2" kit might be the best out there. I'm sure it will still resist fade and stop better than stock. Of course the 6-pot kit with bigger rotors would be better for heavy track use, but I know a few people who use the Dynapro kit for HPDE and amateur track days and they don't have many issues. But for steering feel and handling, a nice stiff sidewall tire combined with 40lbs of overall unsprung weight reduction on the front and you should feel a huge difference. Take another 10lbs off per side for well-made coilovers (which are partially unsprung weight) and you'll be at 60lbs of weight reduction from the front. That will make for a car that handles very well and steering that feels excellent.

From the setup I'm going for:

Rotors: Wilwood 12.2 = 8.8lbs
Calipers: Wilwood Dynapro 4-pot = 4.1lbs
Wheels: RPF1 17x9 = 15.6lbs
Tires: Bridgestone RE71R 255/40/17 = 24lbs
Total Weight = 52.5lbs per corner (front)

So that's a 19lb savings over the stock GS-T setup on the front.

Anyone have weight numbers for the rear brakes versus a rear Brembo setup?

 

[AdR]

That's quite a substantial weight decrease for the front suspension and not a bad price at $1,000 for the kit. I use Wilwoods on my track car and it works incredibly well but we would have to see how well it will work on a 3,000lb car at full speed to really know. My track car is 2,400lbs and slow .

 

[orangedsm]

That's quite a substantial weight decrease for the front suspension and not a bad price at $1,000 for the kit. I use Wilwoods on my track car and it works incredibly well but we would have to see how well it will work on a 3,000lb car at full speed to really know. My track car is 2,400lbs and slow .

Yeah, overall weight is absolutely a consideration. I've got a GS-T, and I'll be reducing weight by way of things like a FRP hood, seats, and of course wheels/tires/suspension. Stock weight for the GS-T is ~2840, hoping to get that down to 26xx after everything (I'm leaving A/C and sound deadening and all that stuff). I think with that weight the Dynapro Wilwoods should be able to handle it quite well for a hobbyist level track day or AutoX.

 

[AdR]

Yeah, overall weight is absolutely a consideration. I've got a GS-T, and I'll be reducing weight by way of things like a FRP hood, seats, and of course wheels/tires/suspension. Stock weight for the GS-T is ~2840, hoping to get that down to 26xx after everything (I'm leaving A/C and sound deadening and all that stuff). I think with that weight the Dynapro Wilwoods should be able to handle it quite well for a hobbyist level track day or AutoX.

At that weight level the Wilwoods shouldn't have many issues. It would just be a matter of proper brake pad selection.

The hood and hatch lids of these cars are the heaviest items that can be easily replaced to shed weight. The hatch unfortunately unless you remove the glass and replace with lexan, it won't be as substantial as the behemoth of a hood we have. If you have a sunroof at least substituting the glass with a CF of FRP replacement from Carbonetics will also help a little. It's just things here and there that will help lower the weight around to your target while still keeping the car in a derivable status. That is my focus on the long run but living on an island makes everything extremely expensive shipping-wise.

 

[Planckscale]

I fully understand your decision and I agree that any weight off is the best. I am just stating the obvious to help you determine the best bang for the buck in your quest to reduce unsprung weight.

IMO a lighter wheel/tire package will get you in a better performance advantage than two piece rotors. The reason being simply based on physics. Rotational mass derives from a center point and it's effects grow as you increase the radial location of said weight against that center point (moment arm). The weight reduction in a two piece rotor does not come from the braking surface (rotor) but rather the rotor hat which tends to be aluminum, meaning the weight decrease derives from extremely close to the center point which does little to nothing to reduce rotational inertia. Now on a wheel and tire package the weight is highly concentrated on the wheel tub (outer region) the spokes and the tire which is the outermost surface on the moment arm. Reducing that weight will significantly reduce the effort required to start and stop the assembly.

Cheers!

Unfortunately, shipping is too expensive so I cannot change the tires/rims. The only option is to play with rotor selection.

Come to think of it; if you consider the “Center of Mass” as the location where the mass distribution is, and where a system will spin about a given axis, then adding the rotor to the rim/tire system will definitely change things.

Putting the the rotor at the center will change the inertial "frame of reference" as the center of mass shifts towards the axis. The new system (rim/tire/rotor) will now require less torque to overcome the Inertia (moment of inertia for a rotating system). But, the new system is now also heavier, so this will somehow negate the benefit of moving the center of mass towards the axis. I guess the challenge is to find the optimum rotor mass for a given shift toward the axis. Just a thought...

I think the Baer 2 piece rotors can be bought for like 450$ if wait for the site wide coupons from larger retailers like autoanything.com

Thanks. $645 a little pricey, but I will keep an eye on those on eBay for deal

 

[AdR]

Unfortunately, shipping is too expensive so I cannot change the tires/rims. The only option is to play with rotor selection.

Come to think of it; if you consider the “Center of Mass” as the location where the mass distribution is, and where a system will spin about a given axis, then adding the rotor to the rim/tire system will definitely change things.

Putting the the rotor at the center will change the inertial "frame of reference" as the center of mass shifts towards the axis. The new system (rim/tire/rotor) will now require less torque to overcome the Inertia (moment of inertia for a rotating system). But, the new system is now also heavier, so this will somehow negate the benefit of moving the center of mass towards the axis. I guess the challenge is to find the optimum rotor mass for a given shift toward the axis. Just a thought...

There will be a very slight benefit but not as much as if you reduce the weight of a radial point farther away from the axis of rotation. Unfortunately two piece rotors do exactly the opposite (remove weight closer to the rotation axis point). It is what it is, no way around it. Good luck and happy modding!

Cheers!

 

[DM48]

The kit comes direct bolt-on with lines, brackets, everything. Only thing you have to do, same with all BBK's, is remove or modify the dust shield. I have mine removed.

TCE nor wilwood is going anywhere so brake pad options are endless. Replacement rotor rings are cheaper than any evo or bear rotor of equal weight by a long shot. (a few pounds per rotor) Lightweight two piece rotors to fit onto evo, ctsv, and bear calipers are dumb expensive.

I agree stupid expensive, wildwood is a good brand and have been around for a while.