I notice something that fells unrealistic with this car!

When i go reverse i can accelerate at something like 1.3 g!
Even The BMW sauber doesn't accelerate that fast!

Here is the picture:

its an FWD car.
it has damn soft slicks.
and u were acclerating downhill.

Nop i was not accelerating downhill but i was closed to be!

And then can you explain me why the acceleration is divided by 2 when i accelerate forward?
It s a question , i m not sarcastic

Quote from Maelstrom :

And then can you explain me why the acceleration is divided by 2 when i accelerate forward?

Reverse gears usually have higher gear ratios, and weight transfers to the front wheels which gives you about twice as much grip as you do in forward gears.

One g is only 9.8m/s/s

1.3 * 9.8 = 12.74

After one second you will be going 12.74m/s (45kph). But, your gearing is so low that you can't go any faster then 20kph, which means you only accelerate for half a second before hitting the rev limiter. What's so weird about that?

Quote from Maelstrom :

Even The BMW sauber doesn't accelerate that fast!

Sure it does!

as i said, its an FWD car.
when acclerating backwards the most weight of the car will be on the front wheels (perfect) but when acclerating forward the weight will go onto the backwheels which means its gets "lighter" on the front = less grip.
thats why it can acclerate backwards much faster than forwards.

oh btw, the BF1 can acclerate much faster

Quote from [RCG]Boosted :

as i said, its an FWD car.
when acclerating backwards the most weight of the car will be on the front wheels (perfect) but when acclerating forward the weight will go onto the backwheels which means its gets "lighter" on the front = less grip.
thats why it can acclerate backwards much faster than forwards.

Ok that makes sense!

No, there's still something wrong.

Some data(driver incar):
__________________________UFR (on reverse)____FZR
weight dist. on powered wheels __62,6% ___________63,4%
power/weight ratio ___________272hp/ton _______425hp/ton
peak G force (race_s, R3) ______~1,28G ___________~1,25G


FZR has also 2x wider tires...

Another weirdos are:
- UF1 has 10sec 0-100km/h
- there's no need to control throttle. you go perfect with lot of spinning. as well with road tires, as with slicks.

Quote from pasibrzuch :

__________________________UFR (on reverse)____FZR
weight dist. on powered wheels __62,6% ___________63,4%
power/weight ratio ___________272hp/ton _______425hp/ton
peak G force (race_s, R3) ______~1,28G ___________~1,25G


FZR has also 2x wider tires...

Wider tires don't give more grip anyway. And, power/weight ratios actually mean nothing anyway. It has to do with the torque. Notice how you can't do a stoppie in the FZR. The FZR weighs more and therefore has more inertia.

So why low pressure tires gives you more grip while low pressure gives you only trouble + wider tires effect?

Both cars have enough torque to spin tires from beginning to the end of first gear, aren't they?

FZR has just better center of gravity. It's longer, wider, not so tall.

More weight gives more grip.

Quote from pasibrzuch :

More weight gives more grip.

No it doesn't. If I load up a FXO with passengers it definitely will not give better 'grip'. Grip = static friction of a tire?

More weight = more load on wheel = more grip

Now, it's your turn to list inertia and of-center force in corners, if we are going to post half true posts

Quote from pasibrzuch :

More weight = more load on wheel = more grip

Now, it's your turn to list inertia and of-center force in corners, if we are going to post half true posts

problem is you don't get 100% more grip with 100% more load, you get something around 70-80%, that's a factor of tire load sensitivity.

but you do get 100% more inertia with 100% more weight, so if you make a car heavier, it will have more grip, however because of the larger impact of extra weight, it won't be able to corner with as much G as a light car.

I do want to know pasibrzuch what is your source of those figures?

Quote from wheel4hummer :

Wider tires don't give more grip anyway.

Yes, they do. They lower the amount of pressure per unit area of rubber in contract with the ground, thus increasing the coefficient of friction.

Quote from wheel4hummer :

And, power/weight ratios actually mean nothing anyway. It has to do with the torque.

Power/weight ratio is a useful figure for approximating low speed straight line accelerative performance. It tells you nothing about how traction limits that psed though. Torque is important when you do a detailed simulation but on it's own, tells you nothing.

Quote from wheel4hummer :

Notice how you can't do a stoppie in the FZR. The FZR weighs more and therefore has more inertia.

Inertia is important but the key fact everyone seems to be ignoring is the height of the centre of gravity and the wheelbase. These together control weight transfer. The UFR has a higher centre of gravity and a shorter wheelbase, so a lot more weight transfers under acceleration/deceleration. This causes more weight to be on the driven wheels, hence the improved traction, as less weight is being "wasted" on the undriven wheels.

Quote from Bob Smith :

Yes, they do. They lower the amount of pressure per unit area of rubber in contract with the ground, thus increasing the coefficient of friction.

But two tires side-by-side have better grip then one.

Well, yeah, for the same load applied to the tyre, more rubber on the ground increases relative traction. So adding a whole second tyre certainly adds to the contact patch area, although it won't double it as each tyre will take half the load and thus compress less, reducing the length of the contact patch.

Only thing that puzzles me is that could you do similar wheelies in real life with similar UF1s...

Without super grippy front tyres...

Quote from Hyperactive :

Only thing that puzzles me is that could you do similar wheelies in real life with similar UF1s...

Without super grippy front tyres...

http://youtube.com/watch?v=mukuUETdjqA

Quote from Mikkel Petersen :

http://youtube.com/watch?v=mukuUETdjqA

Me accepts

Quote from Mikkel Petersen :

http://youtube.com/watch?v=mukuUETdjqA

Amazing

Quote from JJ72 :

I do want to know pasibrzuch what is your source of those figures?

It was amateur homemade looking at hot G force in lfs. It's not accurate at all.

After Bobs post, it can be more weight transfer in UFR that causes superb reverse acceleration.

More than 60% mass on driven wheels + powerful engine + more weight on driven wheels thanks to favourable weight transfer + super sticky slicks = excellent traction and acceleration.

Case closed.