My plans: weight distribution

[Ratko]

As we all know, the camry was never meant to be a handling car, especially an autocross/track car. With its 4-wheel independant suspension with soft struts and 98 lbs/in spring rates, well... you understand. Im not sure what the exact weight distrubution is on the V6 or I4 but im sure its better on the 4 bangers since the engine is lighter and more mounted towards the middle of the vehicle which is always good.

Anyways, here are my plans to make something of my V6 Coupe.

- carbon fibre hood : should take off a good 30-50 lbs off the front end of the car and shouldnt look to shabby on my dark green car.

- tranny swap : besides the givens (better economy, more power, better control) it will also save approx 100 lbs off the belly of the car.

- battery relocation : i have an optima yellow top 750 CCA battery thats been sitting in my garage for months now, and wont fit in my stock location because terminals are reversed. So... why not relocate it to the trunk an into a marine battery box. Thats 30-45 lbs shifted from the tip of the front to the tip of the rear of the car.

- springs : right now me and jeff are getting custom developed coilover collars from a company in hamilton and they are selecting the Eibach ERS line for the springs. Anyways, I was thinking of having a stiffer spring rate in the rear to combat the camry's tendancy to understeer. Maybe something around 250-300 lbs/in for the rear and 150-200 lbs/in in the front.

- shocks : if i wanted to be hardcore id go with tokico or even koni, but im gonna opt with only slightly stiffer than stock KYB's just to control a bit of the bounciness and to maintain some confort in the ride.

- rear swaybar : obviously the stock rear just wont do, so the whiteline 18mm rear sway is on its way. should also stiffen up the rear in turns and reduce body roll with the help of the springs.

My wheels this summer will probably be some 16" Rota Slipstreams in gunmetal (about 15 lbs each!) wrapped in Kumho Ecsta 712's for the street and maybe Kumho V700's for the track/autocross.

With all this I'll report sometime this summer if I get a chance to goto Shannonville and use their skidpad how much lateral G's i pull.

latez.

[goodcookiedrift]

I think what a lot of people over look when they weight reduce is corner balancing the car. Just pulling things at random is not good as you can severly alter the weight distribution of the vehicle. I think if you do such dramatic weight reduction, arm your self with some lead plates, and corner scales...i learned the hard way.

Another thing to consider when changing the susp. is making sure the geometry of the susp. is correct. a helpfull book is Automotive Math Handbook. all the calculations neccessary to build a sound race car.

Nick

[Ratko]

Thanks Nick!

[Rice Rocket]

If you have some extra cash you could by those semi forged SSR wheels from the Tire Rack. To give you an idea of how light they are a 15x7 wheighs in at only 9lbs. Once you put your manual tranny in maybe you could use a Fidanza, or Clutch masters light weight flywheel. Less rotational mass...more power going to drive your wheels.

[Flashmn]

I doubt the carbon fiber hood would do much to increase handling, especially if it has a lot of fiberglass in it. Infact there are fiberglass hoods that even weigh more than the OEM steel one (sounds funny, I know).

Anyways, soft springs arent necessarily bad, if you look at specs, the "new" supra has softer springs than the older one, as does the soarer. Stiff isnt necessarily good... :wink:

[speedemn]

Oh yeah Ratko, just so you know, the Kumho Ecsta Supra 712s that I have that you were asking me about are between 20 and 22 lbs depending on whether you get 16" or 17" sizes. :smile: Just thought it might help in your planning.

[boroEF]

having the front end too soft will cause understeer too. i think if u wanna fool with that kind of stuff, u should just toy with sway bars and not spring rates. and a front wheel drive car, its better to have stiffer spring rates at the front. afterall, ur engine and entire driveline is at the front!!!

[SCEPTER300RR]

On 2002-03-17 16:36, Shaun wrote:
having the front end too soft will cause understeer too. i think if u wanna fool with that kind of stuff, u should just toy with sway bars and not spring rates. and a front wheel drive car, its better to have stiffer spring rates at the front. afterall, ur engine and entire driveline is at the front!!!

he's right... no point relocating ur battery to the back i think its a waste of time and effort... extending the cables should do u just fine... in my opinion... i like the other stuff u are doing to the car though... u got ur 5spd already???

humpty...

[JAC91]

Hello Everyone
You are going in the right direction on most of your modds.
Weight reduction is always going to improve your cars performance.
Every member in my club has had a stage 1 weight reduction.
It will improve your brakes, steering, and acceleration.
For every 100lbs you gain or lose 8 hp.(depends if you add or remove that 100lbs.)
Take your interior out and strip all the tar from the floor pans. Then put everything back in and your car will now be 50-100 lbs. lighter.(all depends on size of car and make)
As for the susp. tuning:
For the most part all FWD's need ,front strut bar,rear swaybar,stiff rear springs.
The reason for strut bar is to keep your alignment in hard cornering, the rear bar helps the rear from twisting so much and adds to turn in.
The stiff springs in the rear allows for better launching and also helps the car step out alittle in hard corners(improve exit speeds)
Adj. struts/shocks would allow you to tune all of that together for one hell of a ride.

Btw the reason companys are able to reduce sping rates is by improving torsion rigidness of the car.(less body flex)
If you were to put a rear floor bar and a rear brace set up you would beable to drop your spring rates some also.
Just my 2 cents!!
C-YA!!

[budking686]

I like the idea of moving the battery because it becomes very easy to make your own Ram Air system in your camry!!!! I have been thinking about it for a while but my car is an everyday wear and tear car and I don;t want to move the battery to the back because of the possibility of not starting in the cold winters etc.....Good luck and good ideas!!!

[Flashmn]

Well, theoretically 8hp ;P But I wouldnt go too far, as how are you gonna get girls with that car? :wink: heck most girls hate my car already as it is.. everyones complaining that my car is too loud... well, except girl racer types.
Just think about it, if you were a girl, would you go into a dinky-tin can car, or a car with a nice interior?

[JAC91]

Hello
Well, I guess it's all what you are into.
I race my car!!
Circle track drag racing ,Auto-x ,drag race,and what's that racing that were not supposed to do o ya street racing. :smile:
I can give a shi* less about girls.
90 % of girls hate cars anyways!!

Bottom line:
Weight reduction works!!
I have 120-125 hp and run a 16- 16.1 in a 4dr.
Can't do that if you have 20 lb rims and 100 lb system in the trunk.
My two cents!!
C-YA!!

[Flashmn]

Yeah, I "race" my car aswell... mostly drifting and twisties ;P and it doesnt weigh alot either, something like 2010lb :razz: according to the manual.

[JAC91]

Hello Everyone
What is your ride there Flashmn?
Is it the AE-92 4dr in your cartoon?
I also have a 4dr (91 Prizm SDN).
It is the same as yours though.
- the hood and rear door windows are different.
My EW is 2348(w/ no options) from the factory and I have got it down to 2260 w/ a full tank of gas in it.(2400 w/ me in it)
After I switch out rims, get rid of P/S pump and heavy ass battery (dyno batts a coming)I should be down to 2200 w/ full interior.
Can't wait!!
Much less than most 4drs weight!!
Anyways, kind of board got into the typing to much. he! he! he!
Gotta go C-YA!!

[speedemn]

Holy cow!!! 2000lbs, 2300lbs??? You guys are lucky!!! I wish I could do some weight reduction on my car. It is almost 3100 lbs stock + I have 130 lbs in the trunk and about 40 lbs more in car audio equipment inside! Also, I'm not willing to forego all the power accessories! :grin:

I'm so torn in between the two - sound and comfort vs performance+sound and comfort. I would consider CF hood in the future though... and also I already do have lightweight rims - 11 lbs a piece. So I still AM half-and-half! :grin:

But 100lbs = 8HP? That seems a little optimistic doesn't it? I don't know if it is that much of a difference, but I don't know that for a fact. Do you have any kind of proof? I don't even know how you could try to prove that on the dyno, since the dyno is disjoint from vehicle weight... only wheel weight could, if at all, make a difference on the dyno. Track times could be one way to compare, but that wouldn't tell you "8HP" per-say. So I'm curious.
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<font size=-1>[ This Message was edited by: speedemn on 2002-03-20 11:57 ]</font>