BRZ on weight scale - 2723 pounds

[carbonBLUE]

Originally Posted by fatoni

Ok why is he talking about that?

because when you corner, weight distribution matters, corner entrance, on the apex, and at the exit, if to much weight is transferred to the front you under steer, stiff anti roll bars shift the weight further back to balance out weight transfer while cornering, grip then is distributed accordingly between the tires that the car is leaning on through the corner

the result is less under steer, power on earlier when exiting a corner, faster cornering speeds, better turn-in all that equal better laps, so it does matter


the car could be light but if the weight is skewed and isnt distributed equally, the car will turn better one way or the other or will under steer more on right and vs left hand corners

if the left and right weight was 60/40 right hand cornering would be faster than left hand

or if 32% of the weight was on the front right tire, the limit for the tires breaking away and under steering would happen sooner on right hand corners



my celica under steers more doing left hand corners because the I4 engine and transmission placement,

[Dave-ROR]

But he was asking about it after traction was already lost, which is kinda pointless.

[Draco-REX]

Originally Posted by carbonBLUE

because when you corner, weight distribution matters, corner entrance, on the apex, and at the exit, if to much weight is transferred to the front you under steer, stiff anti roll bars shift the weight further back to balance out weight transfer while cornering, grip then is distributed accordingly between the tires that the car is leaning on through the corner

the result is less under steer, power on earlier when exiting a corner, faster cornering speeds, better turn-in all that equal better laps, so it does matter


the car could be light but if the weight is skewed and isnt distributed equally, the car will turn better one way or the other or will under steer more on right and vs left hand corners

if the left and right weight was 60/40 right hand cornering would be faster than left hand

or if 32% of the weight was on the front right tire, the limit for the tires breaking away and under steering would happen sooner on right hand corners



my celica under steers more doing left hand corners because the I4 engine and transmission placement,

Sway bars work side to side, not front to back. By increasing the size of a sway bar, you are increasing the corner rate of the outside tires and reducing the rate of the inner tire. This actually reduces total grip and can induce more slide from that end of the car.

However, by limiting suspension movement, this can actually increase grip by keeping the suspension within its optimal range. So the effect of a sway bar will depend on the application and the size increase/decrease.

Vehicle suspension is an amazingly dynamic thing that deals with nearly every form of practical physics. But it means that a single change can have varied and sometimes subtle results. Which is why I prefer suspension tuning over engine tuning.

Originally Posted by Dave-ROR

But he was asking about it after traction was already lost, which is kinda pointless.

You never have zero traction. Even in a slide, your suspension setup matters for car control. Believe me, my main hobby is playing outside the traction circle.

[fatoni]

Originally Posted by carbonBLUE

because when you corner, weight distribution matters, corner entrance, on the apex, and at the exit, if to much weight is transferred to the front you under steer, stiff anti roll bars shift the weight further back to balance out weight transfer while cornering, grip then is distributed accordingly between the tires that the car is leaning on through the corner

the result is less under steer, power on earlier when exiting a corner, faster cornering speeds, better turn-in all that equal better laps, so it does matter


the car could be light but if the weight is skewed and isnt distributed equally, the car will turn better one way or the other or will under steer more on right and vs left hand corners

if the left and right weight was 60/40 right hand cornering would be faster than left hand

or if 32% of the weight was on the front right tire, the limit for the tires breaking away and under steering would happen sooner on right hand corners



my celica under steers more doing left hand corners because the I4 engine and transmission placement,

sway bars dont transfer weight from front to back. i still dont know why he brought that up though. that has nothing to do with what the car weighs

[Dave-ROR]

Originally Posted by Draco-REX

You never have zero traction. Even in a slide, your suspension setup matters for car control. Believe me, my main hobby is playing outside the traction circle.

I don't disagree. I'm a big fan of the grip circle and exceeding it under control, but the last thing I worry about is weight transfer after it's already been exceeded, and really, the concept is the same as before grip is exceeded so I don't see the difference in discussing it separately.

[carbonBLUE]

Originally Posted by fatoni

sway bars dont transfer weight from front to back. i still dont know why he brought that up though. that has nothing to do with what the car weighs

i know they dont, but the relieve a bit of grip from the back tires causing more oversteer, it will be a mod if someone doesnt like the safety under steer

Originally Posted by Draco-REX

By increasing the size of a sway bar, you are increasing the corner rate of the outside tires and reducing the rate of the inner tire. This actually reduces total grip and can induce more slide from that end of the car.

and by making the car a bit more oversteer friendly the cornering characteristics change and weight is transferred to the cornering tires differently

[Draco-REX]

Originally Posted by carbonBLUE

i know they dont, but the relieve a bit of grip from the back tires causing more oversteer, it will be a mod if someone doesnt like the safety under steer

A larger front bar can easily increase understeer. Going to a larger rear bar can increase oversteer. Really, the best option for someone looking for a little more activity from the tail would be to step up the rear bar just a little.

Ideally, you'd want a matched set, preferably adjustable so you can tune the roll balance to your taste.

and by making the car a bit more oversteer friendly the cornering characteristics change and weight is transferred to the cornering tires differently

You have your order mixed up. Weight transfer happens first, then the grip characteristics change, which determines over- or understeer tendencies.

[tranzformer]

Originally Posted by ZDan

That is not what I'm talking about. That would add weight, take away rigidity, and doesn't move the engine and front-seaters aft.

What were you talking about then? Supposedly the car is already designed for this so it won't add much weight or take any rigidity away anyways. Not sure how the front seat placement is changed.

[WolfpackS2k]

Let's set one thing straight.

For a 2 door sports car the lightest design is a fixed roof coupe designed to be nothing but. A convertible designed from the ground up as a convertible will be light, but not as light as a fixed roof coupe. And a fixed roof coupe designed from the ground up to allow for a future convertible version will also be heavier than a fixed roof coupe.

This isn't rocket science. Anyone that thinks an S2000 would weigh more if it was designed from the ground up as a coupe instead of a convertible needs to get their head checked.

[tranzformer]

Originally Posted by WolfpackS2k

Let's set one thing straight.

For a 2 door sports car the lightest design is a fixed roof coupe designed to be nothing but. A convertible designed from the ground up as a convertible will be light, but not as light as a fixed roof coupe. And a fixed roof coupe designed from the ground up to allow for a future convertible version will also be heavier than a fixed roof coupe.

This isn't rocket science. Anyone that thinks an S2000 would weigh more if it was designed from the ground up as a coupe instead of a convertible needs to get their head checked.

Exactly. Which makes you wonder how much lighter the BRZ/FRS would have been if there was no plans for a convertible version.

[Dave-ROR]

Didn't they say "It's possible but there are no plans for a convertible." or similar?

With all the structure they put into the roof it seems kind of unlikely that it was really built with a convertible in mind.

[carbonBLUE]

http://www.ft86club.com/forums/showthread.php?t=3965 just read

[Dave-ROR]

Originally Posted by carbonBLUE

http://www.ft86club.com/forums/showthread.php?t=3965 just read

Ah so Tada changed his tune. Wouldn't be the first time sadly.

<<< doesn't read the FR-S.

[takchi]

Not exactly favoring the convertible FT86, but it is what it is. It'll look pretty good when it's running fast though!

The BRZ looks pretty light and probably has an ability to drop a few more pounds with the right wheels, seats, suspension system, and exhaust. Overall, I think a proper weight should be around 2650lbs. This would mean the car has high potential on the track. The turbo might make the car more potent if the weight can be minimized as well.