The 370Z Weight Reduction Thread

[wstar]

On a more-serious note about the wiring: I did put a big chunk of the removed harness stuff from the front half of my car in a plastic trash bag and weigh it. My bag came out to 16 pounds. This was most of the removed wire itself + electric tape, some of the small plastic modules for the key sensors and TPMS sensor, some of the conduit. It includes all the wiring up there for things like keyfob sensors, tpms, interior lighting, mirror, everything in the doors, and the airbag system (but no actual parts other than those dinky tpms/key receivers, just wire+tape+conduit and a few whole plastic wire-to-wire connectors where I wasn't using any circuits running through them). Doesn't include the stuff from the rear hatch area that I had unwired months ago and tossed.

It's probably closer to 20 lbs since I left out some conduit and threw away some things before I started saving them to weight later, but on the other hand I'll be putting back a little bit of tape and conduit, too, so 16 lbs might be a decent approximation of a net figure for the wiring conversion in the front. I could roughly guestimate that the rear half would've been more like 8 lbs (again just for wire/tape).

Worth it for the time investment for weight alone? Hell no, it's hard work. But if you're disconnecting all those accessories and circuits anyways, it's nice to have the car cleaner and simpler, and make it easier to diagnose other issues, etc. Most of the harness runs just get thinner, but notably at this level of stripping accessory circuits, the *entire* harnesses that run down the outer passenger edge and down the center console from front to rear get removed. Those all run needless accessory stuff. The necessary stuff in the rear (tail lights and a couple little circuits to the diff area and the evap canister) all run through the wiring harness on the outer edge of the driver's side.

[critical]

not going to be totally accurate but i did assemble two front shocks/springs today so i got out the bathroom scale.

OEM Front Shock/Spring assembled ~10lbs
OEM Rear Shocks ~6lbs
OEM Rear Spring ~5.5lbs

[wstar]

So I got the Evo2 16-cell installed and tested. Bottom line is it works great, just as ChipsWithDips said it would. Install/test info here: wstar's Journal . It's really a much nicer solution than relocating a heavier battery. As with all minimal battery solutions, I wouldn't recommend it (or at least, would recommend caution) on a regular street car where you might run the stereo or the lights for a while with the engine off. Especially with this battery, since the manual specifically states that if you drain an LiFePo4 battery below a certain critical voltage the (rather expensive!) battery is basically toast and can't be recharged.

[Shamu]

Lots of weight reduction in braking system if you are willing to ditch ABS. Stock pedals, master cylinder , all the abs crap weigh a ton. Replace with nice lightweight Tilton setup. About 25 lbs of weight savings.

[SPOHN]

Originally Posted by Shamu

Lots of weight reduction in braking system if you are willing to ditch ABS. Stock pedals, master cylinder , all the abs crap weigh a ton. Replace with nice lightweight Tilton setup. About 25 lbs of weight savings.

That system is very expensive. But still would love to ditch the ABS.

[Shamu]

Originally Posted by SPOHN

That system is very expensive. But still would love to ditch the ABS.

It's a matter of priorities I guess. To me its worth $1500 to have top notch pedal and master cylinder setup. Having separate master cylinders allows for more precise brake balancing. Also nice to be able to adjust pedals. But weight reduction is nice added bonus. Stock pedals are boat anchors.

[Shamu]

Roof and floors weigh a lot!

Over 130 lbs of weight!

[TrinityRacer]

How much does the roof weight out of curiosity?

[Shamu]

Going to HR heads

31.5 lbs!

[synolimit]

Just weighed in at 3083 lbs fully fueled. So I'm under 3k with a empty tank (2965) so I can now use DOM 1.75x0.095" steel for the roll cage. However rules say I could also use DOM 1.5x0.12" or DOM 1.625x0.12". But based off of a simple calculation I believe the area of the steel is not only the smallest in the 1.75x0.095" which should be the lightest, but it's also the strongest based off of I(cm^4).

I still want a lighter flywheel and rotors but I'll still be away from 3k fully fueled by 31.5 lbs. I need to find that some where.

O forgot about a racing seat. Might get 10+ pounds there plus the drivers seatbelt minus the difference of a racing seatbelt.

[wstar]

If I were you I'd still go 1.75x.120, which is the usual over-3K rules. I mean otherwise you're hovering right on the border of the rules, and while you might find more weight to strip, you might also add back some significant weight at some point (weight of the cage itself? cool-shirt system? fire suppression? diff cooler? aero parts? etc...). I'm not even sure which weight the 3K applies to honestly - dry or wet, driver or not, etc, but it's just kinda borderline all around, and with the .120 you don't ever have to worry about it.

[synolimit]

We'll there can still be more weight removed if I plan to pull AC, heater, dash etc. the weight per foot is also 0.573 lbs difference between 0.12 and 0.095 so going with 0.12 just means I'm adding more weight forcing me to go with 0.12. At the moment that adds 21.2 pounds of unneeded weight if I'm under 3k.

[Isamu]

Originally Posted by synolimit

Just weighed in at 3083 lbs fully fueled. So I'm under 3k with a empty tank (2965) so I can now use DOM 1.75x0.095" steel for the roll cage. However rules say I could also use DOM 1.5x0.12" or DOM 1.625x0.12". But based off of a simple calculation I believe the area of the steel is not only the smallest in the 1.75x0.095" which should be the lightest, but it's also the strongest based off of I(cm^4).

I still want a lighter flywheel and rotors but I'll still be away from 3k fully fueled by 31.5 lbs. I need to find that some where.

O forgot about a racing seat. Might get 10+ pounds there plus the drivers seatbelt minus the difference of a racing seatbelt.

[synolimit]

Originally Posted by Isamu

[travisjb]

Originally Posted by wstar

If I were you I'd still go 1.75x.120, which is the usual over-3K rules. I mean otherwise you're hovering right on the border of the rules, and while you might find more weight to strip, you might also add back some significant weight at some point (weight of the cage itself? cool-shirt system? fire suppression? diff cooler? aero parts? etc...). I'm not even sure which weight the 3K applies to honestly - dry or wet, driver or not, etc, but it's just kinda borderline all around, and with the .120 you don't ever have to worry about it.

Very much agree... plus you may find yourself in a class later on where you need to ballast weight for that class. Plus that cage may be involved with saving your life someday...