RWD understeer?

[volk613]

Hi Guys,
please help me understand the 135i "understeer issue". Now I know what understeer is, normally a FWD problem. I know what oversteer is, RWD fun. Or as someone put it " whether or not you want to see the tree you run into".
So with the 135i having understeer is this compensated for by using more power?:iono:
Thanks.

[Swift135]

There is understeer and understeer, stock these cars have a little understeer and finding no other reason to fault the car reviewers mention the understeer. BMW do this on purpose as neutral or oversteer on such a powerful car could be dangerous for unskilled drivers. With slightly wider 225 tyres on the front the car seems to be near neutral. Remember it easier for the stability control to save your ass if it has a little more time to intervene, so BMW have tuned the suspension for the masses.

[ichiban]

I have had little to no issues with the under steer. It's pretty much non existent when you turn of DTC. My lil 1 is pretty tail happy.

[takahashi]

If kevwrx is looking at this thread, he should write something about it. Coz he is the professor of drifting.

Swift said it all. All cars understeer, in fact all vehicles are built to have tendency to understeer. If anyone made a car to have tendency to oversteer, it will be a widow maker (much like the 996 GT2).

To answer your question of whether understeer can be cured by power.

NO

Most of the time when you are understeering is when you are going too fast. With ABS, you are pretty hard to go understeer under braking although it can still happen. Anyway, when you over speed and understeer, the natural response is to slow down.

Now what happen when you "power out" and do a Clarkson moment... "POWER" haha... sorry. When you insert power, the only thing that you do is to get the rear to slip. Therefore, you create a 4 wheel drift.

If you are going to hit a tree understeering, 4 wheel drifting will get you to the tree quicker. So NO.

But I let you in a secret on the track. When you understeer a little and there are still room for 4 wheel drift, as you are not TOO overspeed, it makes perfect sense to use the throttle as the front of the car will suddenly pointing to the right direction. When the car slow enough and you got grip, you are already on the throttle. That half a second on the throttle will get you 3-4 seconds a lap.

[WAY]

Taka drives like Clarkson on the track. Don't take his advice haha. Btw Taka, I'm going to be at O'Neil day next Thursday. Wanna come? I still don't have my wheels though, so stuck with the stupid lousy factory tyres and narrow front tyres. Should have my KW Clubsport suspension put in by then. May need to spend the day setting it up.

[volk613]

thanks for the info Taka

[professor]

Wayne, I am very excited to hear about what you think of the KW's. I feel they will truly shine on the track, but also I wonder how much they will remind your back of the AM. Give us a review when you get a chance. My preferred setup just got pushed back 1-2months.

[WAY]

As in the Performance Parts sports suspension? I don't know why you bother! Coilovers are much better!

[professor]

performance parts? no no. i ditched that idea long ago. its the CC one i'm after...it looks soooo shiny and clean.

[WAY]

Oh ok. You are brave in trying that though cos no one else seemed to have tried that.

[professor]

LOL!! porsche has them on some of their competition cars. and they have been running it for dog's years on the e87. so, perhaps i'm less "brave" than you give me credit for...

[WAY]

Yeah didn't think you were the adventure type. LOL. Have you been able to find a group test involving CC (or JIT or something that they are more commonly known as). In recent years there has been a massive move towards kw in the euro racing scene.

[takahashi]

Originally Posted by WAY

Taka drives like Clarkson on the track. Don't take his advice haha. Btw Taka, I'm going to be at O'Neil day next Thursday. Wanna come? I still don't have my wheels though, so stuck with the stupid lousy factory tyres and narrow front tyres. Should have my KW Clubsport suspension put in by then. May need to spend the day setting it up.

Can't do Thursday I think. I was going to take the car for all fluid change and install the water pump next Wednesday, the only day I think I am free .

[AussieRacer]

Originally Posted by takahashi

But I let you in a secret on the track. When you understeer a little and there are still room for 4 wheel drift, as you are not TOO overspeed, it makes perfect sense to use the throttle as the front of the car will suddenly pointing to the right direction. When the car slow enough and you got grip, you are already on the throttle. That half a second on the throttle will get you 3-4 seconds a lap.

When you read motoring mags, what takahashi has described they refer to as throttle adjustability, or balancing the car on the throttle. It is why I'll only ever drive and own RWD cars.....okay maybe one day I'll try a AWD/4WD :smile:

[takahashi]

I did not know there is a name for it.

Well you when eventually own an EVO, AussieRacer, the Yaw control or whatever the electronic does it for you . That is why all the sudden all EVO drivers are fast.