The Diet Thread
 

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.

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.

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

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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

Lugnuts, flywheel, driveshaft to diff and trans yeah I would. :party0030: Chassis no.

I'd also want CNC aluminum uprights.

haha I was gonna say, that is a bit over the top to go through the entire chassis with titanium! Less unsprung weight with titanium for the rotating stuff -> :thumbsup:

Read my post, you must have only skimmed it; deleting the radio, air-con and sound deadening were specifically mentioned as things I didn't want to do.

The little things can quickly add up. Apart from the above mentioned items, there are many ways to drop weight in a vehicle without drastically altering the usability. Dropping 100-150lbs should be do-able. Can you notice the difference between driving around alone and driving around with another person in the car? I sure can.

That's why I'm interested in it.

There we go, this is the kind of thing I was looking for. All this stuff could be done and significant weight could be dropped while still being totally usable as a daily driver.

That means better handling, more enjoyable day-to-day driving, better performance on the occasional trackday, and maybe a 1-2 mpg's better economy.

I'm hoping for a carbon driveshaft from the factory, like the 370z, but I'm definitely not counting on it.

Fully aluminum suspension bits would actually drop a significant amount of weight....how cost prohibitive is something like that?

Dropping 5% (based off 2700lbs car) is going to be hard if you don't want to delete AC, stereo, carpet, insulation, rear seat, front passanger seat, use of polycarbonate windows...etc.

Yeah I get your point but 100lbs of weight reduction may only increase about 2mpg. That's may seem like a hefty price to pay just for 2 more points.

I fully read your post but as tranzformer mentioned, it seems like you want to reduce weight but add more in other areas!?! Not bashing but trying to make sense of the situation. I can see weight reduction becoming a factor if it's say a 60/40 or even 70/30 car.

I don't think you're reading the same posts I'm writing. Nowhere have I mentioned adding anything. I've re-read my own posts and am completely unable to see where you got that from. :iono:

Ill give you my list..

-Titanium single exhaust(if I can afford it) -~45 lbs
-Titanium headers (ditto) -~25 lbs
-Race pipe/test pipe -~7 lbs
-Intake -~10lbs
-Bumper bars -~30 lbs
-Entire trunk tool kit and spare -~40 lbs
-Lightweight wheels -~25 lbs
-CF Trunk(ditto) -~15 lbs

That's about 197 lbs. Thats as far as I'll go. At this point the car will be loud, wont have a spare and the bumpers will damage more easily. I can live with that. After those, I'll be looking into sway bars, TRD springs/coilovers, sticky rubber, and possibly a tune. Cosmetics last.

Yeah, that would be a hefty price to pay for a 2 mpg increase. Good thing that reducing weight pays dividends to every aspect of performance...braking, cornering, acceleration, mpg, tire life....

I guess I don't see why you're having trouble understanding why I would want to reduce weight. This car centers around being light-weight. Of course I want to make it more-so.

It's a mass produced car. There will be numerous things that can be swapped out for better quality, lighter weight components without impacting the day-to-day comfort.

:iono:

honestly you should do this e. g.

http://www.ft86club.com/forums/showthread.php?t=1229

- get rid of all the crap it´s in it and have fun otherways you just waste your money!

sorry but :slap:

be real!

These are all good ideas. I might be ok with the idea of getting rid of the spare and replacing it with a tire patch kit and pump....though I hesitate to remove weight from the rear. Maybe replace the spare and tool kit with sealant and a pump....and relocate the battery to the rear?

I'm not sure that the exhaust and headers would save that much weight though. Maybe 40 pounds total if you did both? I'd skip the race pipe too. More compact, high-flow mufflers (or perhaps a conversion over to only one side with one muffler) would save a good 10-15 pounds and give the car a better sound.

How much weight does a WRX save by converting to single side with titanium components? That would give us a pretty good estimate for weight loss.

The wheels are probably the most important aspect to change....it really depends on how much the stock pieces weigh. Some cars are coming from the factory with damn good wheels now...the RX-8 R3 for example.

Seriously? What is with people on this forum. :mad0259:

No, my exhaust weight estimates are from other cars.. Stock exhausts usually weigh around 45-55 lbs due to cast iron construction, titanium weighs 11lbs. Big difference. Same with headers, stock about 25-35, titanium are 5-10 lbs. You pay big bucks for these kind of weight savings though. An exhaust runs for over a grand, and I'd be willing to say the headers would run 800 or more. However, theres a loss of 87 lbs in the exhaust system alone, as well as more power, more response, and some cosmetic appeal. As an engineer however it's just cool to have so much titanium in your car.

Agreed on all points. Massively reduced corrosion for the exhaust system that way too.

I didn't realize the weight differences would be that great. I'd be more than willing to shell out that kind of money for a headers-back system that saved that much weight while increasing power and sound quality!

Now I'm interested in how hard/expensive it would be to do the same thing with suspension components. I was thinking that would be prohibitively expensive.

Honestly though, if your weight estimates are semi-accurate, I'd probably be willing to stop there too. That's a damn good amount of weight to lose, and several of those components also increase engine performance at the same time.

sorry i had to correct my comment a lil´ bit! I´m not a native english speaking! :)

honestly, all the shit they´re talking about of the sort I want a "straight line F§$% all u up" car or the big AE86 revival or what ever, will never happen!

You have to get your one approach, feeling or/and sense to get to this vehicle, otherwise you will get dissapointed!

I hope you (all of you) get it clear and know what I´m saying!

If not, I will try to explain you! :happy0180:

Well, suspension wise there would be less bang for buck. And yes, these mods serve multiple purposes :)

Ok, I didn't realize english was not your primary language. It looked like you were ignoring everything I said in my posts and telling me to just go buy a completely stripped out car - which I specifically said I did not want...repeatedly.

:)

I see where this is going. I plan to auto-x this car in the stock class, maybe G-stock. More likely D-stock.
Reducing weight can gain performance everywhere.
First, aftermarket cat-back,
Double adjustable aluminum shocks.
Remove everything that is not bolted down, spare tire and jack.
Empty water in the windshield wiper washer container.
Empty radiator overflow container.
Half filled master cylinder, half fill radiator.
Turn brake rotor down, sand brake pads down.
Hollow front sway bar.
Update/backdate parts from lesser model.
Of course there is more, but you get the gesture.


Cliff
369 "sts" civic

Yeah, this car's goal is to be well balanced p/w ratio, w/ a lower COF making it fun to drive. I absolutely agree, there are going to be plenty of aftermarket parts available for this car.

I'm sure it makes for a good forum discussion but the weight hasn't even been announced and you're already talking about making it lighter yet you want to keep the AC and radio in it and it's going to be a DD car!?! Offramp...ooooohhh how fun! :bellyroll::bellyroll:

wait, I have a little bit of imagination to understand what you said and secondly, I´m sorry I didn´t read all of it because all of that ish some plp here´re postin´ :bellyroll:, but i don´t feel it´s gonna be THAT car you are thinking of, come on a VerV GOLF GTI driver ;) and truely I read a lot of your posts it´s gonna be hard for Toyota to overtrump this (not that a V Golf GTI is the best) but if it´s not going to overperform my MR2 then I WILL INVEST SOMEWHERE ELSE (do you hear me TOYOTA) ;)

Belive me, TESTDRIVE it! It´s all about that, then you can decide and JUDGE!

belive me! :happy0180:

I always test drive cars I'm interested in even if some of the stats are not what I was hoping. I'm all about giving things a fair shot to impress me.

And yes, I'm aware that the car has a definite up-hill battle in terms of refinement compared with my GTI. I fully expect the interior to be significantly lower quality, which I am ok with so long as it is still of equal comfort. Just the fact that the car is rear-wheel drive is worth a lot to me though....it's so much more fun than front wheel drive.

You can always improve on things. Part of being a car-guy.... :happy0180: You would probably be unhappy if the car weighed 2900lbs...you'd either avoid it or look for ways to lighten it. Why not do the same for a 2750lb car? Bring it down to 2600lbs.

If the car weighed like 2200lbs (which is the next-gen Miata's target weight, BTW), I think I'd be ok with leaving it alone haha. Come to think of it, depending on when this thing actually gets released, I may have a real hard decision between a next-gen Miata and an FR-S. Hurry the F up Toyota!

On/off ramps are fun....but a true drivers road, like the dragon's tail, is infinitely more-so. I plan on the occasional trackday, plus frequent pleasure drives on surrounding roads. Finding a twisty, deserted road on a Sunday afternoon is one of my favorite things to do.

as it should be!

it´s not about the up/down-hill plus and the extraordinary interiour ;) or rwd, it just has to MATCH you and your driving style or prefernce, everything else is secondary!

Sorry, if you don´t get me (or any one of u), I will try to explain it to u in German! ;)

No, I completely understand you. The car needs to match my personality.

right, and if it don´t, it don´t!

As long as it can do 60 in 2nd gear. :happy0180:

Nelson
22 ESP Cobra