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rjlong
02-05-2017, 10:58 PM
I'm trying to gauge the interest in lightweight brake rotors for the 500e. 30 to 50% reduction in rotor weight, better heat dissipation, better braking efficiency, quicker acceleration, longer range, better handling with reduced unsprung weight, and no adverse aerodynamic consequences from changing wheel design. These would be a direct fit replacement, using stock calipers.

We're a little limited on performance enhancements on the 500e, but I think this could be a good one that yields benefits across the board. Anyone interested?

rkw
02-06-2017, 02:15 AM
Doesn't the 500e have the same brakes as other Fiat 500 models (maybe Abarth is different)? Have you looked at what's already available for Fiat 500?

http://shop.500madness.com/index.php?route=product/search&keyword=brakes&category_id=143

rjlong
02-06-2017, 10:27 AM
Doesn't the 500e have the same brakes as other Fiat 500 models (maybe Abarth is different)? Have you looked at what's already available for Fiat 500?

http://shop.500madness.com/index.php?route=product/search&keyword=brakes&category_id=143

Yes, there are plenty of performance brakes available, some with limited weight savings, and some that actually add weight. For the 500e, most of our braking is accomplished electrically through the regeneration circuit. The hydraulic brakes really only come alive in extreme braking situations and below 8mph. I'm not sure the investment in a set of Wilwoods (and 17" wheels for clearance) is justified. However, Steel Clad Aluminum (SCA) rotors from litebrake.com may be worth a group buy situation. I sent them a quote request for special order, along with the measurements for our rotors. I'll update the thread when I get their reply.

DaveN007
02-07-2017, 03:55 PM
I applaud the effort, but would not personally invest in those kinds of improvements for my 500e.

I have wondered what kind of mods could be done to the propulsion system.

Thinking of things analogous to the world of RC cars. Lower resistance cables. Faster dumping of power into the motor. Etc. Etc.

One day we will have batteries that can support a Fiat sized AWD car that can do 0-60 in 4 or 5 seconds and be really fun.

charrigan
02-08-2017, 09:40 AM
I personally would not trust a steel clad aluminum rotor. Your best option for cutting weight in rotors is going with 2-piece floating rotors while utilizing stock calipers. Doing a small run of floating rotors would not be a cheap endeavor. Your best solution would be talking a company into doing a production run of Abarth 2-piece (stock size) rotors and converting the 500e to Abarth brakes.

Best thing you can do currently is to cut rotating mass from the wheels. There are a few options already out there that cut a few lbs per corner off of the stock wheels. You will lose the aero improvements the stock wheels have. (per fiat the wheel inserts improve range by ~1%).

Other things you can do to potentially help range is underbody aero. I am slowly designing a front under tray and a rear diffuser. Once temps start improving here Ill be able to start testing the real world range improvements you can do with the 500e.

rjlong
02-08-2017, 06:59 PM
I really appreciate the feedback. I haven't had a reply from litebrake.com as of yet, so this may all be a mute point anyway. For wheels, I've considered the Enkie RPF1's, at less than 10 lbs for 15's. Most of my commute is Turnpike, so 70-80 mph. I'm torn between weight and aerodynamics. Maybe I'll do both; wheels and light brakes. I just want the best performance and range from my 500e.

rkw
02-10-2017, 03:22 AM
Most of my commute is Turnpike, so 70-80 mph. ...
I just want the best performance and range from my 500e.You aren't helping with 70-80 mph. The energy required to overcome aerodynamic drag increases exponentially with speed.

http://www.phys.ttu.edu/~ritlg/courses/p1401/drag_plt.png


Other things you can do to potentially help range is underbody aero. I am slowly designing a front under tray and a rear diffuser.Should be interesting. Take a look at the Tesla S:

http://media.ed.edmunds-media.com/non-make/fe/fe_9171228_600.jpg

rjlong
02-10-2017, 09:28 AM
You aren't helping with 70-80 mph. The energy required to overcome aerodynamic drag increases exponentially with speed.

http://www.phys.ttu.edu/~ritlg/courses/p1401/drag_plt.png

Should be interesting. Take a look at the Tesla S:

http://media.ed.edmunds-media.com/non-make/fe/fe_9171228_600.jpg

So driving an electric car should keep me in the slow lane? That doesn't work for me.

rkw
02-10-2017, 12:17 PM
So driving an electric car should keep me in the slow lane?If you want to increase range, then yes.

rjlong
02-10-2017, 05:46 PM
If you want to increase range, then yes.

No thanks. I'll keep modifying my compliance car. Although Fiat did a good job engineering the 500e, there are still plenty points to improve. Lightening the load is what I'm currently focused on.

fox
02-12-2017, 04:48 PM
I'm focusing on weight savings, low weight wheels/tires, no backseet, small 12v lithium battery, how many pounds per axle are you thinking this would shave?

pr0d1gy9
02-12-2017, 08:15 PM
I'm focusing on weight savings, low weight wheels/tires, no backseet, small 12v lithium battery, how many pounds per axle are you thinking this would shave?

Depending on the wheels you get. O.Z makes some of the lightest wheels (13.6 lbs/wheel) available. On the other side of the coin though, the 500e wheels are designed to have less drag due to the nearly smooth surface. If you do more city driving then lighter wheels will probably help with range but at highway speeds you may be looking at negligible gains. With new wheels you may also see a small drop in tire weight as well due less material.

If you don't need the backseats then by all means put them away for when you want to sell the car. smaller 12v again will have minimal gains on efficiency but may net you a tid bit more range.

Overall you could probably get down at least 15-20 lbs/axle.

fox
02-13-2017, 08:59 PM
I ordered 15x7 Konig dial in, hankook 82h 195/50/15 tires, tpms sensors, wobbly bolts, hub rings = $720 - expected weight is 16lbs tire + 10.9lb wheel 26.9lbs = 8lb saving per corner. If you believe 20lbs per 1lb unsprung this is like shaving 160lbs x 4 from the body so 640lbs total meaning the car should accelerate much better. Someone here shaved off 10% of there 0-60 times doing this.

rjlong
02-13-2017, 11:36 PM
Wow, those wheels are nice and light! I'd like to know the real-world weight difference between the stock wheel and tire and these. Will you have a chance to check the weights when you swap them?

fox
02-14-2017, 12:15 PM
weight different is expected to be 7.5 to 8 lbs less for new.
http://www.fiat500owners.com/forum/11-fiat-500-wheels-tires-suspension/137265-light-wheel-tire-list.html