Am I going to regret big brake added weight

[Ritroman]

I purchased Girodisk steel front rotors for my ACR stock brake calipers. The rotors have to weigh about 25 pounds each. I fear their weight will impact handling badly. I like the handling as is. Am I right to be worried about the weight of the steel brakes?

[Lawineer]

Will it show up in lap times? Yes.
Will you notice it off the race track (or even on the track without looking at a lap timer?)? no.

Probably pretty close to having a passenger. Does having a passenger impact your handling poorly enough to care?

[13COBRA]

Unless you're near the cars potential already, you won't notice... in my opinion.

[99RT10]

There will be no difference in your time unless you are driving at the edge and good enough not to put it in a wall.

[Lawineer]

Unless you're near the cars potential already, you won't notice... in my opinion.

Yeah for sure. It may feel a tiny bit less nimble, but I would bet money that, unless you're a very good driver, you wouldn't even notice unless you were told. If you drove two of the exact same car back and forth even, you'd be hard pressed to notice it. The only reason why you might is that the steering would feel a bit different (as opposed to a passenger in the car).

I've done a fuck pile of laps in a 2500lb/200hp car. My lap times are definitely slower with a 170lb passenger, but if there was some way to drive blind, I doubt I'd notice. And 170lbs in that car is a heck of a lot more than heavier rotors (I get they are unspring rotating mass) in a 3400lb/700hp car.

On the street- zero chance. Honestly, weight isn't a big deal on the street at all. You're not trying to rotate the car on the brakes or throttle steer and etc. You shouldn't even be running into TC on street mode, and you're really going to notice the dynamics of a car until well past that threshold. Weight is actually kind of nice on the street. It's a mass damper. The AMG is almost 6000lbs and aside from eating a set of brake pads and tires every 15k miles, I couldn't possibly care less. It feels nice and stable cruising at 120mph

[SRT_BluByU]

i donno.. i think youll feel it in the steering on the street marginally.. will it matter... not really.

[13COBRA]

It feels nice and stable cruising at 120mph

Must be nice being an attorney haha

[Lawineer]

Must be nice being an attorney haha

More a function of being a resident of the city of Dallas. I’ve driven like a complete and total asshole here for 15 years without a ticket.
I’ve received at least 7 or 8 outside dallas and I bet 90% of my driving is within dallas. There aren’t enough cops and they don’t have time for tickets.

I drop down to 10 over when I leave city limits.

[JonB ~ PartsRack]

I purchased Girodisk steel front rotors for my ACR stock brake calipers. The rotors have to weigh about 25 pounds each. I fear their weight will impact handling badly. I like the handling as is. Am I right to be worried about the weight of the steel brakes?

G5-ACR? If you are a novice-intermediate clubber you wont notice. Randy Pobst, Ben Keating, etc and a small handful of drivers here would notice.

HOWEVER: Did anyone else notice you stated you only swapped the FRONT carbon rotors to Steel? You just changed your Brake Bias F-R by reducing your all-important Front braking. You added significant, evil, un-sprung rotating mass to your front brakes.The inertia also adds heat.

That, even I would notice driving at (my) limits on track.

What did you do to your Pad Choices? Also Affects Bias.......

Being concerned about SS line weight vs OE line weight is a nit-pick unreasonable concern, versus you may have missed the mark on Bias....

[Aevus]

More a function of being a resident of the city of Dallas. I’ve driven like a complete and total asshole here for 15 years without a ticket.
I’ve received at least 7 or 8 outside dallas and I bet 90% of my driving is within dallas. There aren’t enough cops and they don’t have time for tickets.

I drop down to 10 over when I leave city limits.

I should move there.

[serpent]

OP, what wheels are you running? If ACR wheels, you can lose some weight from the brake setup by getting lighter Forgeline wheels. The stock ACR wheels are pretty heavy.

[13COBRA]

G5-ACR? If you are a novice-intermediate clubber you wont notice. Randy Pobst, Ben Keating, etc and a small handful of drivers here would notice.

HOWEVER: Did anyone else notice you stated you only swapped the FRONT carbon rotors to Steel? You just changed your Brake Bias F-R by reducing your all-important Front braking. You added significant, evil, un-sprung rotating mass to your front brakes.The inertia also adds heat.

That, even I would notice driving at (my) limits on track.

What did you do to your Pad Choices? Also Affects Bias.......

Being concerned about SS line weight vs OE line weight is a nit-pick unreasonable concern, versus you may have missed the mark on Bias....

Definitely overlooked that! OP, you should swap the rear out as well.

[theacr_viper]

OP, what wheels are you running? If ACR wheels, you can lose some weight from the brake setup by getting lighter Forgeline wheels. The stock ACR wheels are pretty heavy.

Forglines are light. even my steering gotten very light with it. I'm actually considering girodisc too as I'm not a fan of the CCB initial bite. I think I could actually be faster with iron rotors and proper race pads than stock CCB. I hate them when they are cold and hate the initial bite.

[Arizona Vipers]

There will be no difference in your time unless you are driving at the edge and good enough not to put it in a wall.

Sure there will be. ACR brakes versus standard Gen 5 brakes are over 70 lbs lighter. And this is rotating mass. Just in acceleration (not including shorter braking distances and better cornering) it will make a noticeable difference in lap times even for the least experience drivers. 100 lbs is worth about 1 tenth in the quarter mile accelerating, and a lot more if it was rotating mass. How many 1/4 miles are on your average road course? 5? 10? 15?
But as far as noticing the difference in handling? Probably not. The car will be a lot more compliant over bumps etc though with 20 lbs less unsprung mass at each corner

[pokeyl]

I put CCM on my front, it steers lighter always! Bite is not as good as steel. There is always a trade-off.

[ForTehNguyen]

you wont, especially when you consider the cost of replacing ACR ceramic rotors (no longer made) and how much the brake pads cost. $13k for Racing Brake rotors and $1k for pads. Or $8500 for brembro ACR fronts and pads if you can find them. Girodiscs is just $1600 for a full set of rotors that you can repair for $700 with new rings.

Forglines are light. even my steering gotten very light with it. I'm actually considering girodisc too as I'm not a fan of the CCB initial bite. I think I could actually be faster with iron rotors and proper race pads than stock CCB. I hate them when they are cold and hate the initial bite.

IMSA races with all steel rotors for the consistent feel despite many of the production versions of the race cars having ceramics rotors

[Arizona Vipers]

you wont, especially when you consider the cost of replacing ACR ceramic rotors (no longer made) and how much the brake pads cost. $13k for Racing Brake rotors and $1k for pads. Or $8500 for brembro ACR fronts and pads if you can find them. Girodiscs is just $1600 for a full set of rotors that you can repair for $700 with new rings.

They are expensive, but last almost forever. I have 7000+ hard track miles on my car and I've only replaced the front rotors ONCE. I've never replaced the rears.
I'm getting my rotors for about 1/3rd of what you quoted above, you have to look around.

[Arizona Vipers]

OP, what wheels are you running? If ACR wheels, you can lose some weight from the brake setup by getting lighter Forgeline wheels. The stock ACR wheels are pretty heavy.

The ACR wheels are indeed extremely heavy. Boat anchors. Forgeline/Hoosiers were over 80 lbs lighter than ACR wheels on the oem Kuhmos. For the record, Sidewinders are only 1 pound heavier than 18" Forgelines.

[Lawineer]

The ACR wheels are indeed extremely heavy. Boat anchors. Forgeline/Hoosiers were over 80 lbs lighter than ACR wheels on the oem Kuhmos. For the record, Sidewinders are only 1 pound heavier than 18" Forgelines.

And wheels are a much bigger deal as their weight is much further from the center than a rotor.

Man if that car came with decent forged wheels and an aluminum frame. It would have been the equivalent of 400lbs lighter. What a monster.

[serpent]

They are expensive, but last almost forever. I have 7000+ hard track miles on my car and I've only replaced the front rotors ONCE. I've never replaced the rears.
I'm getting my rotors for about 1/3rd of what you quoted above, you have to look around.

Cable, are you running titanium springs and ti lugs/ti studs for the wheels? Figured I'd ask in your pursuit of weight reduction in either of your Vipers.

[Arizona Vipers]

Cable, are you running titanium springs and ti lugs/ti studs for the wheels? Figured I'd ask in your pursuit of weight reduction in either of your Vipers.

No on the springs only because I run different rates than what is available, but yes I do run titanium lug nuts and studs, from Doug Shelby.

[Ritroman]

Where can I get Viper front CCB rotors at a reasonable price? Did anyone go down this rabbit hole? The same CCB rotors for a C7z06 Corvette list at least half the price of the Viper rotors and are the same rotors I am told. Wholesale parts will not move on price and the dealers I talked to don't care to negotiate much at all. Would buy a decent used set if I could.

[13COBRA]

Where can I get Viper front CCB rotors at a reasonable price? Did anyone go down this rabbit hole? The same CCB rotors for a C7z06 Corvette list at least half the price of the Viper rotors and are the same rotors I am told. Wholesale parts will not move on price and the dealers I talked to don't care to negotiate much at all. Would buy a decent used set if I could.

Just buy the Corvette rotors then?

[Arizona Vipers]

Just buy the Corvette rotors then?

Has anyone ever adapted these?

[13COBRA]

Has anyone ever adapted these?

I have no idea... he just stated they were the same, so I was confused as to why he wouldn't just buy those. I have my doubts that they're the same.