The Diet Thread

[Maxim]

Pretty self explanatory.

I've got another thread in the engine tech forum to complile information so I can teach myself what all I need to upgrade N/A power in a small displacement engine.

The other part of the performance equation is reducing the mass that said engine has to push around. This is especially important with a small displacement, non-turbo mill, since it won't be making gobs of torque.

Obviously there are also massive gains to be had in braking and transient response (tires play a larger role that weight when it comes to lateral G's and overall braking performance though).

Transient response is directly responsible for the "telepathic" handling feel that great handling cars have. Excellent turn in, a fast steering ratio and small wheel also contribute.

So....what are some excellent ways to reduce weight without spending a fortune?

I am not interested in completely removing the audio system or air conditioning. While those things would eliminate perhaps 50lbs....the car is still going to be primarily used on the street.

So what's left? I'm not interested in carbon fiber hoods or decklids. Aluminum or a plastic composite material saves nearly as much weight and is significantly cheaper as well as more durable.

Lightweight racing style seats can save a ton of weight.

A rear-seat delete can too, although it may muck-up the weight distro and it really hurts the utility of the vehicle. Small kids will be comfy back there at least....

Lightweight rims can save unsprung mass...the most important kind.

Removing sound insulation can get rid of maybe 20lbs...probably not worth it based on the noise trade-off.

Help me out guys. What can I do to put a vehicle on a diet for cheap, without drastically compromising other elements?

Over at the 370z forums, there is a master-thread that's been stickied where users report the weights of components they've removed as well as weights of the replacement part. It's a great way to track this stuff for other people who want to make similar mods, and a great way for people to prioritize their mods. I suggest the same on this forum once the car is released.

[bofa]

I'm confused... so you don't want to do anything drastic, but also don't want to lose any of the basic utility of a street vehicle? And what is considered cheap?

It's hard to really tell without knowing what all comes in the car, especially if the engineers are already focusing on weight management. There's usually a good amount to be saved swapping out the stock exhaust system.

[Ryuu0u]

If I get back into hardcore cardio and watch what I eat I'm sure I can save 10-15lbs. Don't lose any utility and virtually free :3

[tranzformer]

Just remember that this car will be lightweight from the factory. So to find more weight to drop will be harder vs. a car that didn't have the focus from factory, i.e. an overweight car.

[Maxim]

Originally Posted by tranzformer

Just remember that this car will be lightweight from the factory. So to find more weight to drop will be harder vs. a car that didn't have the focus from factory, i.e. an overweight car.

It remains to be seen how lightweight this car is. I am expecting ~2700lbs, which I wouldn't actually consider all that lightweight.

Granted, you're not going to pull out the same amount of poundage as you would with something like that Mustang or Camaro....but you can probably pull out an equal PERCENTAGE of weight.

[Maxim]

Originally Posted by bofa

I'm confused... so you don't want to do anything drastic, but also don't want to lose any of the basic utility of a street vehicle? And what is considered cheap?

It's hard to really tell without knowing what all comes in the car, especially if the engineers are already focusing on weight management. There's usually a good amount to be saved swapping out the stock exhaust system.

I don't want to compromise the comfort. I regularly have to drive long distances, so I need to keep the AC and stereo, otherwise I'd go crazy.

Lots of weight can be saved via the "nickel and dime" method....replacement of numerous small parts instead of focusing on really big stuff, like polycarbonate windows, AC delete, interior stripping, etc.

[RRnold]

Originally Posted by Maxim

I am not interested in completely removing the audio system or air conditioning. While those things would eliminate perhaps 50lbs....the car is still going to be primarily used on the street.

So what's left? I'm not interested in carbon fiber hoods or decklids. Aluminum or a plastic composite material saves nearly as much weight and is significantly cheaper as well as more durable.

Lightweight racing style seats can save a ton of weight.

A rear-seat delete can too, although it may muck-up the weight distro and it really hurts the utility of the vehicle. Small kids will be comfy back there at least....

Lightweight rims can save unsprung mass...the most important kind.

Removing sound insulation can get rid of maybe 20lbs...probably not worth it based on the noise trade-off.

Help me out guys. What can I do to put a vehicle on a diet for cheap, without drastically compromising other elements?

If you are driving around the street, why would you be concerned about reducing the weight?

Have you been in a car with the seats gone, no radio, no emissions, no air con, no carpet, no sound deadening material etc? Its not fun for a daily driver.

[bofa]

Originally Posted by Maxim

I don't want to compromise the comfort. I regularly have to drive long distances, so I need to keep the AC and stereo, otherwise I'd go crazy.

Lots of weight can be saved via the "nickel and dime" method....replacement of numerous small parts instead of focusing on really big stuff, like polycarbonate windows, AC delete, interior stripping, etc.

Well.. you could always ditch the spare and drive around with 1/4 tank of fuel all the time...

Other than the whees/tires, seats, and maybe getting a salad over a cheeseburger, I think the exhaust will be your best bet given your critera, plus the potential performance gains. Lighter alloy headers, HFCs, pipes and muffler.

[blacknbean]

bucket seats, remove rear seats, cf hood/trunk (if they arent aluminum), then lightweight battery, rims/tires, exhaust sytem. you can do all that without compromising the usability of the car on the street.

[tranzformer]

Originally Posted by Maxim

It remains to be seen how lightweight this car is. I am expecting ~2700lbs, which I wouldn't actually consider all that lightweight.

Granted, you're not going to pull out the same amount of poundage as you would with something like that Mustang or Camaro....but you can probably pull out an equal PERCENTAGE of weight.

Originally Posted by Maxim

I don't want to compromise the comfort. I regularly have to drive long distances, so I need to keep the AC and stereo, otherwise I'd go crazy.

Lots of weight can be saved via the "nickel and dime" method....replacement of numerous small parts instead of focusing on really big stuff, like polycarbonate windows, AC delete, interior stripping, etc.

The thing is you don't want to compromise comfort but yet you are still looking at losing weight. You want a full stereo system? You can swap out the seats, but depends on what kind of seats the stock comes with. You willing to give up the stock seats to save 10-15lbs total at the added expense? Are you willing to swap out body panels? Roof? Trunk? Lighter spoiler? If you have unlimited $$$$ you can drop weight, but if you are on a realistic budget there is a point of diminishing returns.

[Random_Art]

I agree with most here. On a limited budget, there's not much you can do without compromising comfort. You're only realistic options for a tight budget is to remove plastics and seats. I would leave the spare, personally, unless you're at the track. a blow out on the freeway sucks when you have no donut to drive home on.

[tranzformer]

Originally Posted by Random_Art

I would leave the spare, personally, unless you're at the track. a blow out on the freeway sucks when you have no donut to drive home on.

This. If you want to be practical, leaving the spare at home in a DD just doesn't make sense. At the track, sure. But why risk it.

OP, if you want help I think you should mention what "comforts" you are willing to give up.

[PAImportTuner]

This is all a replacement list.. not a take away list. - I tried to stay at a reasonable cost.

Low profile lightweight speakers

Full titanium exhaust, bolts/nut throughout the chassis

Enkei RPF1s or lighter

Aluminum bodied shocks/struts

Aluminum control arms and links

Aluminum front and rear crossmembers

Aluminum uprights

Aluminum engine and trans mounts

Aluminum/Carbon drivershaft

Fiberglass/CF hood,trunk, and Sparco or Corbeau bucket seats, aluminum seat brackets.

I'm sure it will come with plastic intake manifold and valve covers like almost every Subaru these days come with.

[RRnold]

Originally Posted by PAImportTuner

This is all a replacement list.. not a take away list. - I tried to stay at a reasonable cost.

Full titanium exhaust, bolts/nut throughout the chassis

Do you really plan to replace the chassis bolts with titanium? That could add up quickly.

http://www.racebolts.com/index.php?m...ndex&cPath=623