Weight loss suggestions: For cars

"Lekker" (z34nismo)
03/10/2014 at 11:23 • Filed to: auto-x

Opponauts, I come to thee with something I've been thinking about. I do auto cross for fun, as a hobby and hopefully it will lead to a car related job. I have one car dedicated for it (at the moment it is also my DD) but eventually I'd like to strip it out to bare bones and rebuild with racing in mind. The car in question is a 370z nismo, I've had it for around 7 months and is brand new and stock.

I am wanting to make slow progress with the car, first to keep it in the same class and second to spare the wallet since the car was a big purchase. Here's what I have in mind:

-Cat-back exhaust (Keeps me in BStock), which would help me drop around 10 lbs
-HFC's (not sure where it puts me at) would drop about 8 lbs
-Racing seat (FIA Approved, would bump me a class) would drop a good 20lbs per seat.
-Lightweight battery (not sure it changes my class) would help a few pounds as well.

Other than that, I am sort of out ideas with what to replace for a light weight component that would improve performance as well. What other things can you all recommend? Items that wouldn't be ridiculously expensive at first of course then eventually full on cage build.

Have a picture of my cramped interior, ugh it sucks being tall.

DISCUSSION (68)

jkm7680 > Lekker
03/10/2014 at 11:26

Take the extra seats out, dashboard parts. I bring my dd to track days, and all I do is swap the rims out.

N/A POWAAAHH > Lekker
03/10/2014 at 11:27

Carbon fenders/hatch/doors/hood/bumpers. Take all sound deadening/matting out. Plastic trim all out, just keep gauges and shifter.

Arch Duke Maxyenko, Shit Talk Extraordinaire > Lekker
03/10/2014 at 11:29

When trying to loose weight in a car, it is important to keep the weight distribution of the factory car, unless you can adjust the suspension to calibrate for the difference.

AdmiralAkbar > Lekker
03/10/2014 at 11:32

Go on a diet. It's free and won't change your class.

But actually, lighter rims and tires (the whole package) are always good because it lowers unsprung and rotational mass.

mazdaspeed2 > Lekker
03/10/2014 at 11:32

If you really want to get crazy, strip all the interior you can, lighter wheels, ac delete, etc. Basically anything that isn't essential take out. I don't know if you want to go that far or not haha, but I would say a general rule of thumb would be anything you don't need should come out.

Party-vi > Lekker
03/10/2014 at 11:35

I'd keep your Z as a daily driver/part-time track car and pick up an actual dedicated track car. It's going to suck if you sideline your car at an event and can't go to work. Plus with increases in crash testing and safety requirements you'll probably get more bang for your buck if you strip an older car. See if you can find a salvage-title Z for cheap and go with that, and then sell the interior bits that you remove.

If you do choose to strip your 370Z Nismo, be prepared for no one to ever buy it from you unless you put the interior back in it. Also prepare for state safety inspections - I doubt they'd be happy if you remove any airbags and are still commuting to work.

OK now that that is out of the way you need to lose the passenger seat, stereo and speakers, doors skins, carpeting/sound proofing, headliner, interior trim (like pillar covers), glovebox, center console, spare tire, any tools, etc. (assuming you didn't already remove these for track use), etc. If you get really crazy you can pull everything inside except the dash. Really anything black and plastic in your interior needs to go.

Lekker > jkm7680
03/10/2014 at 11:39

I want to do this, but it would take me forever to get the dash out and put it back on after a race. Once it is a dedicated track car that would be a different story.

Lekker > AdmiralAkbar
03/10/2014 at 11:40

This isn't a bad idea. I should go on a diet.

I want to get smaller wheels since I have 19" from factory, so there is a lot of mass on there. But the problem is the calipers are so large, I doubt I'd be able to go to an 18 without difficulties.

crowmolly > Lekker
03/10/2014 at 11:40

Do not go crazy until it's no longer your DD.

Stripping out a car of all its creature comforts while it still sees much more street time than track time can and usually is a mistake.

I know plenty of guys that have stripped out carpet, sound deadener, A/C, all seats but the driver's, hood insulation, spare + jack, radio and speakers, etc etc only to regret it later when they are in a hot, rattle can noisy car in traffic with no entertainment. Those lightweight wheels do you no good after you hit a small pothole.

Lekker > Arch Duke Maxyenko, Shit Talk Extraordinaire
03/10/2014 at 11:40

Very much so. I've read about it a bit, and at this point I don't plan to put that much into the suspension. Thanks for that reminder

Lekker > mazdaspeed2
03/10/2014 at 11:41

Eventually yes, I do want to do that. Although it might be a pain to remove the AC when I get back to AZ

Ryanator122 > Lekker
03/10/2014 at 11:41

Be sure you check with your club rules before you just start taking everything out. Certain classes require that some things remain in your car. It would suck to pull EVERYTHING out and end up in some crazy Mod class where you're seriously out-gunned on tyre type, suspension, and engine mods.

AdmiralAkbar > Lekker
03/10/2014 at 11:42

I was only kidding about the diet, but if racing leads to a healthier life, then double bonus!

mazdaspeed2 > Lekker
03/10/2014 at 11:44

Yeah it definitely comes with a price, but if you ever need a reason why...

Kinja'd!!!

Lekker > Party-vi
03/10/2014 at 11:45

I've thought about that long and hard. The idea is that once I start getting serious with the mods, the car will become track only. I don't expect anyone to buy it after, I actually want it in my life forever if possible as it represents a big step in my life.

I do however see the point of getting something cheaper that I can strip out knowing the cost of the car didn't just go from 40k to 10k.

As you assumed I didn't take those components out given that, well, its my daily for the meantime. The mods I have planned out are supposed to allow it to DD while taking it for some fun at the track. I do take out spare and all things when I go, but no actual parts (like speakers or stereo, dash, etc) which only take a few minutes to put back on. I do like the idea of driving a stripped out nismo tho. I would get near the 2k's in terms of weight since all i need to drop is around 300lbs.

Lekker > crowmolly
03/10/2014 at 11:47

This. I totally agree with you which is why I want to do this in stages, for example: At the moment I need to lighten it with an exhaust system, and later HFC's. Other than that it will have to be a bold on mod that replaces an existing piece in order to not lose functionality or form, over function.

Lekker > Ryanator122
03/10/2014 at 11:48

This is another serious point, in my class is am no good at the moment since I have power, but the weight of the thing makes me slower. That and I am not necessarily the best yet, but that comes with time.

Lekker > mazdaspeed2
03/10/2014 at 11:49

Haha I've seen so many cars like that around here. Some because racecar and some others because...well... who knows really.

Party-vi > Lekker
03/10/2014 at 11:50

Driving a car with no interior is not as fun as it sounds. Plus the sound of that VQ engine would make me drive into oncoming traffic :P

crowmolly > Lekker
03/10/2014 at 11:50

Yup! Replace, just don't start deleting yet.

And as you probably know, some "race only" parts are that way because they don't hold up to street use.

Exhaust is a good place to start. Pipes can be heavy. Headers will give you power and save weight since they aren't cast iron (dunno what's factory on your car).

There may be lightweight wheels that are a middle ground between heavy cast stockers and full race featherweight frisbees made of eggshells and platinum.

Lekker > Party-vi
03/10/2014 at 11:53

I did it for a while back in college, since I bought the car for near to nothing and It had,well, near to nothing. No power steer, AC, back seats or front passenger seat, no interior panels or trunk lining. It worked fine for about 3 months. Omg do VQs sound mechanical. They should learn from other manufacturers to make the sound pretty not raspy. A good exhaust would change that :p

mazdaspeed2 > Lekker
03/10/2014 at 11:56

Haha, I want to start auto crossing this summer so I am sure I will see my fair share of those.

Lekker > crowmolly
03/10/2014 at 11:56

Well the Rays included are supposed to be lightweight, but still weigh a big chunk. My problem with the whole smaller/light weight tire/rim is that I have massive calipers. I mean that as in there is about an inch of clearance between the 19's and the calipers so I would like to get something smaller to decrease mass, but not sure how much lighter it will get. How about going for narrower? I was hoping to get 275's on the front and 300's in the back (currently has 235's and 285's respectively). Would the increase in the contact area be worth the added unsprung weight?

Lekker > mazdaspeed2
03/10/2014 at 11:56

Too much fun! Do it....do it......do it....

puddler > Lekker
03/10/2014 at 11:59

my truck has factory swiss engineered weight reduction

Kinja'd!!!

jkm7680 > Lekker
03/10/2014 at 11:59

Yeah, door panels, radio. I don't really remove anything, the GPS is too hard to take out. I'd like a dedicated track car though

crowmolly > Lekker
03/10/2014 at 12:00

Tires will be heavy too. Big steamrollers will look cool and give you traction but you may not need all it.

As for the calipers, I am *fairly* sure that there's 17" wheels that will still fit with your calipers. I do not know whose but some searching will probably turn something up.

BiTurbo228 - Dr Frankenstein of Spitfires > Lekker
03/10/2014 at 12:01

Lighter alloys? They're usually only a couple of kilos lighter each, but it's unsprung weight so anything is significant.

Lekker > jkm7680
03/10/2014 at 12:01

I'm actually building a mini iPad thing that fits in the cubby whole and is easily removable. I already got the ipad so now begins the fabricating.

Lekker > BiTurbo228 - Dr Frankenstein of Spitfires
03/10/2014 at 12:02

They already come with the lighter Rays, which "save " according to specs around 7 lbs per wheel.

jkm7680 > Lekker
03/10/2014 at 12:04

That's pretty badass, make sure to post when it's done! Id like to try something like that with my next car

mazdaspeed2 > Lekker
03/10/2014 at 12:06

I'm sold... I am getting a Mazda 2 next week and I already have looked up what the scca b-spec 2s use for mods, and it is not good for my bank account how affordable the mods are haha.

Lekker > jkm7680
03/10/2014 at 12:13

Definitely! I've only just now got the ipad so I still have a lot of planning and whatnot. I already did the tech side of figuring out the connections and how its going to run, I even test ran it yesterday tethered off my phone and it worked amazing. Having such a large nice looking display for anything from seeing who is texting you (imessage) to listening to music and apps like Waze, it is great fun.

Lekker > mazdaspeed2
03/10/2014 at 12:14

CONGRATS!!! The first mod you need is imperative:

The driver mod. Practice and practice! I am still at that stage, along with planning for future real mods.

jkm7680 > Lekker
03/10/2014 at 12:17

That's nice! If I did that, Gf couldn't drive my car (She can't anyways, she doesn't drive manual) she would be a distracted driver all the way. Glad to hear the techy features work though!

Lekker > crowmolly
03/10/2014 at 12:17

I figured as much, I'll stick with stock sizes then for the tires.

I know some 17's work but only on the Base package, anyone I've known personally with sport package can't fit anything below 18's. I am a part of the370z.com and have asked around, but I got the same results as I already knew and most people don't take this car to the track due to the price and weight of the thing.

BiTurbo228 - Dr Frankenstein of Spitfires > Lekker
03/10/2014 at 12:19

That's really not bad.

What do the specs allow tyre and brake pad-wise? They'd probably be a more noticeable performance improvement. How about adjustable suspension?

Does it have an LSD from stock? If you're thinking of bumping up a class anyway, you might get a lot more freedom (at the expense of a lot more cost).

Lekker > jkm7680
03/10/2014 at 12:24

I made my wife learn, since I had a manual 350z when we met. Besides, that means she now can have a BRZ with a manual tranny, and I can hoon the crap out of it.

jkm7680 > Lekker
03/10/2014 at 12:26

Haha, I wish I could convert her to manual. It's going to be a long road though. She didn't get the part about pressing the clutch while downshifting, it smelled like straight up burned in my car.

Lekker > BiTurbo228 - Dr Frankenstein of Spitfires
03/10/2014 at 12:26

Brake pads are already really good, they can stop teh car quicker than I can handle a turn so no need there. They're huge calipers tho, so big in fact I can't go below an 18 from what I know. Tires are summer-only advan's so they're already grippy. I am replacing them with same size RE-11's hopefully soon.

It comes with a viscous LSD, and I've heard about people replacing them with locking diffs, but the cost is what scares me and I am not really too sure how much it would help.

Lekker > jkm7680
03/10/2014 at 12:28

Oh man. Did you try explaining it to her before the car was moving? I made her do a full cycle, from dead-stop start to sixth, back down and to a proper halt before even starting the car. I usually teach them with someone they understand, that usually seems to get the point across. If that doesn't help, be more visual.

jkm7680 > Lekker
03/10/2014 at 12:29

That's a good strategy, she misunderstood I guess. I was due for a new clutch anyways. The bad part is the shift was also from 5th to first

Lekker > jkm7680
03/10/2014 at 12:33

See thats the trick, I never tell them they can do that. I make them downshift gear per gear. I did also exclude the part where I was due for a clutch too lol

BiTurbo228 - Dr Frankenstein of Spitfires > Lekker
03/10/2014 at 12:35

I'd say a viscous is probably fine. You won't be 1-wheel peeling out of corners at least.

Can you get brackets to fit lightweight alloy 4-pots? Wilwoods or Hispecs. I've found that they can be a good few kilos lighter than cast OEM Brembos for instance.

Do you need foglights? If not then they can go. Would open holes for cooling as well :)

Lekker > BiTurbo228 - Dr Frankenstein of Spitfires
03/10/2014 at 12:39

I never considered that, wouldn't that run me a pretty penny though? If you'd be so kind to post an example that'd be great!

And my model does not come with foglights or a space for them at all. This is the front:

Kinja'd!!!

mazdaspeed2 > Lekker
03/10/2014 at 12:59

I've been dying to do that mod haha. Twisty back roads are fun but I really want to try a closed course without trees only a few feet away so I can drive harder and not worry about hitting things haha.

BiTurbo228 - Dr Frankenstein of Spitfires > Lekker
03/10/2014 at 12:59

They're definitely not cheap, but you might be able to find a cheap set on eBay. Here's their webiste: http://www.wilwood.com/

They just make a range of calipers. You either need to buy a set of purpose-made brackets from an aftermarket supplier if there is one, or get a set fabricated to fit your struts.

Weight-wise, it's based on comparing some Wilwoods for a 106 GTi and the 4-pot Brembos from a 406 that were fitted to it previously. Yours might already be lightweight ones though.

Lekker > mazdaspeed2
03/10/2014 at 13:08

I just went to a big parking lot, asked the owner if it was ok to put a few cones and drive around them. Nobody has minded so far.

mazdaspeed2 > Lekker
03/10/2014 at 13:10

That's a great idea I will have to try that out.

CPT Speedbump > Lekker
03/10/2014 at 13:18

I need to save some weight on my Z33 as well..not a fully dedicated track car yet, but even if it wont be soon, I'd probably be fine DD'ing a fully stripped car, just more focued on a LSD, suspension and brakes right now

CPT Speedbump > crowmolly
03/10/2014 at 13:20

What's not entertaining about hearing nothing but engine? O.o

Lekker > CPT Speedbump
03/10/2014 at 13:42

Driving a stripped car makes every ride interesting. What do you plan to do suspension wise? Adjustable?

crowmolly > CPT Speedbump
03/10/2014 at 13:43

Try taking a two hour drive with no radio in traffic.

Ryanator122 > Lekker
03/10/2014 at 14:15

I only mention it because it happened to a friend. He brought his "track day/street monster" 2007 Mustang GT-CS to my club, which runs SCCA regs. He has minor aero and the interior is stripped, racing buckets, but he showed up on his street tyres and his engine only had a cat-back. He got annihilated in CSR against STi's, M3's, and the like.

Lekker > Ryanator122
03/10/2014 at 14:18

Yeah in my area which also runs SCCA regs I'd be against a ton of Evos Minis and STIs. Which I can't compete with now, but maybe once I get some experience.

Ryanator122 > Lekker
03/10/2014 at 14:19

I hate Mini's with a passion. I run H Stock in a Camry, do pretty well, and then they blitz my time by like 3 seconds on their first attempt.

Lekker > Ryanator122
03/10/2014 at 14:21

Oh its so frigging annoying. The worse part is, the two chaps that had me ride along them before my first event ever, had an early 200-'s m3 and a brand new mini (whatever the model that has the roof chopped is called) and they did a massively quick time. I could hardly keep up with my eyes! And then I went out on my heavy...slow (in comparison) run. I was over 5 seconds slower :( They were suggested for a reason, they're the RWD masters of the region and it shows!

Ryanator122 > Lekker
03/10/2014 at 14:31

The guys that are good in my region have Supercharged Lotus 7's and Miatas, there's some carryover but I think FWD changes how you have to attack the course. Getting the back end to rotate without loosing it is tricky.
If I could have a Miata I would, but I don't fit in the damn things.
Practice is probably the best way to shave time, but our runs are usually longer than 100 seconds. Pretty easy to make an early mistake and have everything get all screwed...

Lekker > Ryanator122
03/10/2014 at 14:42

Damn supercharde lotus 7? That is quite a car. We have a number of Miatas but the most prevalent are Evos, sti's and minis. I'm not even kidding, I think we have like 10 at least of each. I happen to be too tall for a Miata :/

Yeah our runs average at 50 seconds so not nearly as much time to have fun OR mess up a lot.

CPT Speedbump > Lekker
03/10/2014 at 14:48

preferably, coil overs for sure of course, getting a LSD once I've got the extra money for it first though (had the money, but I bought a gun...worth the same as a LSD actually, so..back to building money up -.-)

Lekker > CPT Speedbump
03/10/2014 at 14:50

What'd you buy?

CPT Speedbump > crowmolly
03/10/2014 at 14:50

Valid point, lol...though thats exactly how far I'd have to drive to get to the closest road course or Auto X anyway..so regardless id end up doing that seeing as I dont have a truck to tow with

CPT Speedbump > Lekker
03/10/2014 at 14:59

IWI Tavor (Tar-21)

Lekker > CPT Speedbump
03/10/2014 at 15:00

I would have gone for that instead of a LSD. Just saying.

How much did it run you if you don't mind me asking

CPT Speedbump > Lekker
03/10/2014 at 15:10

Lol, well my Z is drivable either way, just now I'm ready for the Zombie outbreak :P and about 2100-2200, was around 2 for the gun, but I got upgrade iron sights too. About as much as the 1.5 LSD with output shafts I was looking at, lol

Lekker > CPT Speedbump
03/10/2014 at 15:16

Haha Nicely chosen. I only have a custom AR I built, nothing fancy upgrade BUIS as well. But every time I go buy ammo all those 7.62 ARs look very appealing so I am thinking I need to get me one of those, with a 21" barrel or something of the sort. The current one with a BCM upper and Spike's Lower, spike's 16" barrel, PSA internals with BCM bolt carrier and a Gunfighter charging handle.

CPT Speedbump > Lekker
03/10/2014 at 15:18

I was also looking at the 7.62 Ruger on the AR platform..but .223/.556 is cheaper, so that made my choice, lol

Lekker > CPT Speedbump
03/10/2014 at 15:22

Yeah if I get one it would be as a backup weapon with no more than 100 rounds on stock