liftback weight distribution

[reznunt]

Originally Posted by Pavel Olavich

For Front Wheel Drive cars, you DON'T want the weight distribution to be 50-50. Better to keep most of the weight on top of the driving/steering wheels, in other words, the front wheels.

for drag racing, this is true. but i'm not building a drag car. i am more interested in road racing.

here's a good article about road race weight distribution:
http://www.articlecity.com/articles/...cle_1601.shtml

[Black Yaris]

Originally Posted by reznunt

for drag racing, this is true. but i'm not building a drag car. i am more interested in road racing.

here's a good article about road race weight distribution:
http://www.articlecity.com/articles/...cle_1601.shtml

Pavel lives in his own world... just smile and nod

[03Z33]

Originally Posted by reznunt

THIS is exactly what i need them for as i was going to do a battery relocation into the spare wheel well. most people think i'm asking about just front-rear distribution when i really was interested in corner balancing. i just wanted to know how far to mount the battery to the right to offset the fuel tank.

i'd love to put my car up on the scales... but i have nothing to offer you in return other than maybe a case of beer and a bucket of chicken. what's your price?

or, if you need tires (and i'm assuming you do since you track your car), i can give you my cost on tires. paint too. let me know

Just send me a PM, I'm sure we can work something out. I'll be out of town until Tuesday next week though.

As far as battery goes, I didn't bother with relocating it since it is only 13lbs. (light weight battery). I never liked the idea of having the battery inside the cabin and most times when you add up all the heavy gauge wiring and battery boxes that SCCA require, you end up adding more weight than it's worth.

BTW, the gas tank is pretty well centered in this car, just the filler is on the drivers side. If I was to mount the battery in the back, I would do it on the drivers side since that would help with your corner/cross weight the most. That's if you couldn't mount it in the center, below where the passenger feet would be.

[Vanderkitten]

I don't think 50/50 would provide much benefit to this car, and here's why I say this:

The car turns in well and in sweepers I find it has just the right amount of tail rotation. Left foot trail-braking also helps bring the back around a little, which is key to counter-act understeer.

There is a problem with traction when pushing these cars out of corners in quasi stock form. The inside wheel lifts and spins. I have the MR coil-overs and 205/50/15 Avon Tech R's, and it still happens. A LSD would help this out alot.

Numbers are cool to talk about, but learning how to drive (uh oh, here I go again!) your car to the limit is the best investment you can ever make... so, I say spend your next $250 on upgrading the driver, and worry about the weight distribution when you are closer to your peak potential and it warrants improving your set-up.

03Z33, I'd love to come down your way for a track day! We'd tear it up! Let me know when you're heading out again.

[03Z33]

Originally Posted by Vanderkitten

03Z33, I'd love to come down your way for a track day! We'd tear it up! Let me know when you're heading out again.

Sounds great Maybe meet up half-way around Laguna Seca? I'll bring my cyclocross fixie too

[Vanderkitten]

Nice! Laguna is still probably closer to me than you, but I'm not complaining about the 89 mile drive! Cyclocross Fixie, sounds like you have to be in shape to ride something like that!! =) Buttonwillow might be half-way... depending on where you are.

It's funny: There's Buttonwillow, Willow Springs, Streets of Willow and Thunderhill Raceway which is in Willows, CA... thanks for confusing the crap out of us!

[eTiMaGo]

I guess californian track designers really liked that 80's fantasy movie with the short guy

but seriously, I dream of going round Laguna Seca one day, done far too much virtual racing on it, it seems like a really nice track...

[kurokoma-kun]

Originally Posted by Vanderkitten

Left foot trail-braking also helps bring the back around a little, which is key to counter-act understeer.

hee, i just learned how to do this the other day, yes i'm a beginner glad to hear someone say it's a useful technique in this car...

[reznunt]

Originally Posted by 03Z33

Just send me a PM, I'm sure we can work something out. I'll be out of town until Tuesday next week though.

As far as battery goes, I didn't bother with relocating it since it is only 13lbs. (light weight battery). I never liked the idea of having the battery inside the cabin and most times when you add up all the heavy gauge wiring and battery boxes that SCCA require, you end up adding more weight than it's worth.

BTW, the gas tank is pretty well centered in this car, just the filler is on the drivers side. If I was to mount the battery in the back, I would do it on the drivers side since that would help with your corner/cross weight the most. That's if you couldn't mount it in the center, below where the passenger feet would be.

actually, you're right about the added weight. i forgot to add the weight of the 1/0 cable, battery box, distribution block, blah blah.

also, i just got up under the car today and it's just as you described. the tank is smack dab in the center.

i think i'll just drop in a lightweight battery in the stock location and call it a day. saves a lot of hassle.

thanks for the offer though! it's the thought that counts!

[reznunt]

Originally Posted by Vanderkitten

I don't think 50/50 would provide much benefit to this car, and here's why I say this:

The car turns in well and in sweepers I find it has just the right amount of tail rotation. Left foot trail-braking also helps bring the back around a little, which is key to counter-act understeer.

There is a problem with traction when pushing these cars out of corners in quasi stock form. The inside wheel lifts and spins. I have the MR coil-overs and 205/50/15 Avon Tech R's, and it still happens. A LSD would help this out alot.

Numbers are cool to talk about, but learning how to drive (uh oh, here I go again!) your car to the limit is the best investment you can ever make... so, I say spend your next $250 on upgrading the driver, and worry about the weight distribution when you are closer to your peak potential and it warrants improving your set-up.

03Z33, I'd love to come down your way for a track day! We'd tear it up! Let me know when you're heading out again.

good advice... thanks!

[Pars]

Yep, the Yaris could really use a quasi, especially up hear in Canada where bad weather traction is a priority. If you live in the snow belt and have a Yaris, snowtires are a most have.

Having a sport car that can't plant it while coming out of a sharp turn is a real turn-off (a problem that I didn't have with my old Civic which was graced with a double wishbone suspension up front). But then, the Yaris doesn't pretend to be sports car, so it's forgiven. One car that I couldn't forgive was the RSX-S, after dropping 2 gears to power around a right turn, I totally fried the inside tires...primitive.

Another disadvantage of having a car that doesn't maximize on traction up front is tire wear. Again, something that didn't happen with my old 98 Civic Hatch (and it's not do to understeer since both my new Yaris and my old Civic rotated about same).

[Pavel Olavich]

Originally Posted by reznunt

for drag racing, this is true. but i'm not building a drag car. i am more interested in road racing.

here's a good article about road race weight distribution:
http://www.articlecity.com/articles/...cle_1601.shtml

I tried to load that article but it wouldn't....for rear wheel drive cars, 50-50 is more important....but a front wheel drive "pulls" you along, and as far as handling goes, curves and such, you don't want 50-50 with a front wheel drive car....rear wheel, perhaps.

[Pavel Olavich]

Originally Posted by Black Yaris

Pavel lives in his own world... just smile and nod

Man, I thought I blew you out my rear and slammed the flush lever down hard....how'd you get back out?!?

Wow!

[reznunt]

Originally Posted by Pavel Olavich

for rear wheel drive cars, 50-50 is more important....but a front wheel drive "pulls" you along, and as far as handling goes, curves and such, you don't want 50-50 with a front wheel drive car....rear wheel, perhaps.

"If your car has a 60% front 40% rear weight distribution, then when you corner, your outside front tire will be the most heavily loaded. A 50/50 split is desirable for many reasons, one of them being that when cornering, BOTH outside tires - not just one - will have the bulk of the load."

this quote i agree with. it tells me why i will see less understeer at the limits with a 50/50 rather than a 60/40.

maybe you can better explain your reasoning behind favoring a front weight bias in a ff car. anyone feel free to chime in to set me straight. i still believe that 50/50 is best for any drivetrain when it comes to cornering.

[Pars]

Originally Posted by reznunt

"If your car has a 60% front 40% rear weight distribution, then when you corner, your outside front tire will be the most heavily loaded. A 50/50 split is desirable for many reasons, one of them being that when cornering, BOTH outside tires - not just one - will have the bulk of the load."

this quote i agree with. it tells me why i will see less understeer at the limits with a 50/50 rather than a 60/40.

maybe you can better explain your reasoning behind favoring a front weight bias in a ff car. anyone feel free to chime in to set me straight. i still believe that 50/50 is best for any drivetrain when it comes to cornering.

I agree with Pavel, having some extra weight up front on a front-drive is useful. However, there's always a trade-off. For instance, a very tiny car, like the Yaris, might need a more balanced weight distribution, since stability is a priority over traction at the lights (or on the snow).

In the heavy weight category, the rear drive will probably have an easy advantage. But, a longer wheelbase, lightweight front-drive could be tweaked to make maximum use of the available rubber, while still returning great dynamics and not put undo pressure on the front tires. I wonder how a Celica GTS, that's tweaked for the track, would fair against the Mazda Miata. I'd bet on the Celica.