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If you are still concerned about protecting the integrity of the rear crumple zone, I'll offer up a cheap idea that will let you save some weight for a track day. Lay out some plastic sheeting in the bottom of the donut shaped hole used to store the spare and use a high density expanding foam to fill the void between the sheet metal and the foam tool kit holder. If you are careful, you will end up with a removable foam insert to replace the much heavier spare wheel and tire. The plastic sheeting is just to make it easy and clean to swap in and out.
In summary, the spare just serves as a way of transferring force from a collision into the main structure of the uni-body, by filling the void with foam, you can achieve the same effect as the spare.
By the way, I've loved following along with your build and I appreciate your focus for performance over aesthetics.
Thanks! More fun things planned this year for the car.
Maybe you can help me with your engineering experience. Right now, I am just trying to fix the airbag light that does not seem to go off with the resistor that worked perfectly fine before. It might come down to something as simple as the fact that I got a 2 ohm resistor instead of 2.2 ohm.
The light did not go on until I kept the wiring the same on the airbag sensor when I plugged in the factory seat. I had the airbag light reset, but then when I re-wired in the resistor the airbag light came back on. I am thinking that maybe the car noticed the main wiring harness on the stock seat at 2.2 ohms and my resistor at 2.0 and now it always notices that? I think if I re-wire it up like stock with the stock seat, reset the airbag light, disconnect the battery (so the car never senses the difference in wiring), and re-wire my resistor, it should work. Thoughts?
I like your idea with the foam, but I am not sure you would get the same support with soft foam as you would with an aluminum wheel. Either way, I keep it in for track days as I figure taking weight off the rear end is the wrong end to do it for weight balance.
Originally Posted by slartibartfast
I don't even bother anymore at track days. I've sighted my spare only once, not sure it has air...
I installed Z1 2pc. front rotors today to shave another 8.2 lbs/corner. (Not quite the 10 lbs. that Z1 claims) This takes me to just over 80 lbs. shaved off the car now.
I installed Z1 2pc. front rotors today to shave another 8.2 lbs/corner. (Not quite the 10 lbs. that Z1 claims) This takes me to just over 80 lbs. shaved off the car now.
That's interesting. Didn't realize that Z1 exaggerated their weight claims. I mean... why do that? Weight is just a fact, there's nothing objective about it. So weird.
Wait, aren't those the rears you're measuring? I thought the rear weight loss is 5lbs per rotor, whereas the front weight loss was 10lbs, in which case they under-reported the difference.
Anyway, isn't the point (or maybe the most important point) of the lightweight rotors is to improve launch response and braking control? Although reduced unsprung inertial mass (?) is significant, the overall weight loss to the car is minimal. And obviously they look fantastic, that's a given.
Last edited by Rochester; May 24, 2018 at 11:12 AM.
Dang it, I don't want to spend that kind of money but those rotors have bubbled up near the top of my to-do list. A tune to improve shift is at the top.
Wait, aren't those the rears you're measuring? I thought the rear weight loss is 5lbs per rotor, whereas the front weight loss was 10lbs, in which case they under-reported the difference.
Nope, those are all front rotors. Not sure how you mixed that up.
Originally Posted by slartibartfast
Dang it, I don't want to spend that kind of money but those rotors have bubbled up near the top of my to-do list. A tune to improve shift is at the top.
These have been on my list for quite a while. They seem to be of good quality and engineering. Good bang for the buck.
The rotor on the scale has Z1 branding on the hat, the rotor on your car doesn't.
I thought that too for a second,
The oncar picture is the outside of the rotorhat... the one on the scale is the inside...the pic is dead on so its hard to see the reversed depth
That's a M.A.S.H. reference! My boss says that all the time.
I didn't realize it was that tough to tell the inside of the rotor from the outside as they look pretty different, but I guess maybe if you didn't see them in person. I'm still trying to figure out how you thought they were rear rotors or why I would take the time to pull the rear rotors off the car.
Originally Posted by zer099
Z1 actually advertises their 2-piece rotors at ~20 pounds. I think the variance is the weight of the OEM rotor, new.
That's what I thought too, but my calipers slid right on without having to open the brake pads after coming off the used stock rotors. From that I concluded that there is no way I shaved almost 2 full pounds off of each rotor from use.
I do not doubt your scale or the info. Just seems everyone else is convinced the OEM rotors are 30 pounds. I'm guessing they went off of someones posted information then just feed off of each other but no one actually checked the facts. Do a quick google search. EVERYONE claims 30 pounds, even Centric. Typically how bad information gets spread. At least know we have the truth!
Good catch.
