Ah.ha I read the whole thing.....someone give me my cookie
very repetative, but very informational

 

I have to think that those people who removed the panels on bottom are throwing things off. You need a smooth and flat bottom to create a pressure differential (versus the rounded top profile of the car) which then creates a sort of a vacuum under your car pushing it lower and lower to the ground. Think of it as a backwards wing, which is designed to lift off the ground (which you don't want). Without knowing the drag coefficients and other properties of the car I can say for sure but this pressure differential creates a downforce of easily 100+ pounds. This not only lowers your center of gravity but, increases traction (handling, breaking, accelerating), and plays a role in fuel economy.

You may never notice any kind of difference but on a serious track car (which is what I at least want to emulate), at the limit, these small differences are critical. Look at the Ferrari F430, no wings or spoilers because the Venturi tunnels (channeled air underneath) are more efficient.

Smooth on bottom, round on top.

 

I thought Nissan just promises the Z is a "zero lift" car with the aero package. I could be wrong, but don't think it generates 100lbs of downforce at any speed with the stock set up.

 

for a car to be zero lift, it has to create downforce in places, or the lift that naturally results from a car at speed will not be counteracted

 

Test pipes are way lighter than stock cats.

 

...the spare?...hmmm...

 

I've got to rewiegh mine, but it is as sparce as it gets:

Odysey battery
Xerd Headers
JIC Y pipe
Single exit exhaust
NO AC
NO heater core
NO interior
NO Dash
Sparce seats
HKS coil overs
Misc aluminum and Ti bolts
NO air bags
NO wipers
NO wiper tank
NO Underhood plastics
I started with the Track wheels so I stayedthe same with the WEDSPorts
JWT flywheel

The only weight added to the car:
Oil cooler
4 point kirk roll bar
6 point harnesses
Oil temp gauge
Wide band O2 gauge
UTEC
Wider Tires (275/295 35 18s)

Things still to come:
Hatch/Lexan

 

god dang...I'm tempted to find the photo on another Z site of a guy yanking out his entire interior for weight reduction....but alas, too much work. But the people who remember it know what I'm writing about.

 

The interior sound-deadening material/fabric will only knock off about 7 lbs...

 

how bout the tar? usually thats worth a good bit

 

Which Stoptech BBk to go to save weight + holding back on the track?
4 pist front 14"
2 pist rear 328mm ?

 

Those 14" BBK are HEAVY! I noticed reduced acceleration right off the bat. Unless your local tracks have brutal braking demands, I wouldn't recommend the 14" kit. The 13" kit seems to work well with DE folks who haven't gone FI.

 

OE brembos work fine for me. Stop tech Aero rotors except for the really hard braking tracks, I find they warp under a lot of duress.

 

I've dropped over 60lbs from mine, a lot of it also from my wheels. Michelins weigh 6 & 7lbs lighter than OEM Potenzas (front & rear) - so that's a total of 26lbs there. My Borla TD weighs 17lbs less than OEM, brings us up to 43lbs. My HFCs weigh 4lbs each, ~6lbs lighter than OEM for 55lbs shaved. I'll take out the front carpets, and one of the rear carpets sometimes, as well as the cardboard to get rid of about 20 more pounds.

With all of that and a 1/4 tank of gas, the car feels absolutely incredible, to be honest. 75lbs of weight is quite a hefty amount.

 

Weird to me how someone else can get such completely different weight measurements from the same parts!

My Borla was 12lbs lighter than the stock cat-back.

My HFCs were 14.4lbs lighter for the pair.

I tried to weigh the rear carpet, cardboard and front mats once and it barely registered on the bathroom scale. Yours weigh 20lbs?!

+1 for Michelins...much lighter than other brands of tires. But sorry to be the bearer of bad news, those Hotchkis springs you (and I) have add 18lbs! Make that 20.8 if you add the sways.

 

I had my Borla and OEMs weighed back to back before install, got a 17lb difference. My Hotchkis are 2lbs heavier for the front and back, a difference of 8lbs - no sway bars here (don't they replace the OEM ones anyway?).

The 20lbs also includes the jack & tool set, so that's my fault. But a little tip: if your scale doesn't register something do this; weigh yourself, then weigh yourself holding the items. Subtract and you've got your answer. =)

I also remembered that there's about 4lb difference between the OEM airbox and the JWT popcharger. I'll have to double check that again, but I'm pretty sure that was the difference.

All in all, weight savings ftw. It also helps that I'm a skinny bastard, fast metabolism ftw!

 

Yep that's how I did it too. I now have a very accurate postal scale that I'd like to reweigh everything on b/c I just don't believe my Hotchkis springs are 10 lbs heavier than yours. They did feel noticeably heavier than stock so maybe the truth lies somewhere between.

haha me too...I can really tell a difference when I'm toting around one of my fat bastard friends.

 

I have an 06, which has the revised springs. What year do you have? Perhaps there is a difference in weight between OEM springs?

 

I was comparing against the 2004.5 revised springs which I think have been the same from that point forward.

 

Well, I weighed the mutations that are the OEM cats...and my God are they heavy. 14.5lbs each! That's pretty much 30lbs of weight! I saved over 20lbs with my 4lb Ultimate Racing Cats, no wonder these things cost $430 new. I am even happier with them then I was before.