Tires And Other Priceless Ouestions

[betelgeuse]

Lots of info. Great help.
But Carl " don't drive in the rain" - now that hurt.
As with that Drifting thing , you guys pull no punches.
That apparently rooky-ish question about whether
R compound could fix an understeer tendency may have
upset you, but I've read in here that no question is too stupid,
so please have patience.
The correct speed will almost always deal with a stock
Understearing car, and finding that speed on the track is
half the fun but sometimes like when I'm blasting down T4
Mosport or flying out of the "S"s at WGI and it's front
Wheels give it up the ghost, and the car starts heading
off the track, I dream of the tire that would save my ass.

Love the Track
Robert

Robert, Robert,Robert

No tire is going to save your ass. A car with understeer is a hell of a lot safer than a car with oversteer.

Where do you have your front and rear toe set?
Have you tried different tire pressures?
Do you turn off the traction control?
I would think with the kind of torque/power your car has it should'nt be too hard to get the rear to rotate.

Greg

[Track wheels]

Greg, I said it was just a dream.
All these ideas are being looked at and are already being tried.
I didn't want to mod the suspension.
What I might try is a wider front tire.
Traction control is always off.

Robert

[blindsidefive0]

The drifting video was a joke and not meant as a comment towards your understeer issue...I don't take things seriously, and generally wear pajamas while driving.

Joking aside, my stock 325i has a bit of push as well. My alignment has just a little toe out - terrible to drive to the events (keeps you "awake" on the highway), but it helps turn in (which reminds me, I should probably have the car realigned for the winter so I don't end up turning in to a snowbank). After some trail braking I can usually get it to turn, but then it's a fight at the apex and coming out of the corner to keep it from pushing. I just try to keep the "bad" squealing to a minimum as it generally means I'm scrubbing speed.

I think it's just how these things were set up from the factory so people on the Autobahn don't kill themselves - like Greg said - understeer is generally safer than oversteer. Even the stock 964 has understeer - well, it can oversteer going into turns if you get greedy with speed/trail braking, but then it understeers coming out of them once you step on the gas and lift up the front.

[Track wheels]

Does anyone use the R3 Head and Neck restraint system here?
In the stock class, driving a car with many air bags, do you think safety is covered
or does the weight of a helmet put you at risk of severe injuries that
would make the R3 good insurance.
I understand it works wth a 3 point belt and no shoulder straps are needed.

Robert

http://www.safetysolutionsracing.com/ra ... es/r3.html

Is there anyone who can comment if this is something that drivers
should wear who are in the stock class and have no roll cage?

[TroyV]

So you ARE wearing pajamas Nick.....I was wondering if they were or not......not a very good example you are setting. LOL

[blindsidefive0]

So you ARE wearing pajamas Nick.....I was wondering if they were or not......not a very good example you are setting. LOL

Uh...ya.

I don't own a lot of pants - I lost my favorite sweat pants at Tremblant 2 years ago. After that I only have 2 pairs of jeans, some dress pants for work, and a couple pairs of pajama pants. Instead of buying new clothes I've been "saving" for car parts and track days, so I'm stuck with the pajama pants. According to the materials, they are no more flammable than jeans that most guys wear (if not wearing a real driver suit).

Supposedly Kimi Räikkönen was asleep 30 minutes before the start of his first F1 race - I just like to be ready to take naps between run groups if needed...although at NJ all I was doing between run groups was drying off (microwaving socks), and all I was doing at NH4 was cleaning oil off the exhaust of the 964 (now in the capable hands of Alex to find/fix the drip).

[TroyV]

Are you justifying the flammability of pajamas on this forum? LOL

[cfossum]

But Carl " don't drive in the rain" - now that hurt.

Yeah, sorry about that. The zinger was because you didn't want to hear reasonable advice (reduce your entry speed). But I'll step up and welcome you as my student (I'll promise I won't crash like your instructors from other clubs), but you'd better listen to me if I'm sitting in your passenger seat!
-Carl

[WillM]

Robert,

What are your front & rear cold tire pressures, and what are the hot pressures immediately after a session? How often do you check your pressures at an event? Have you tried to correct the problem by adjusting tire pressures?

Are the front and rear tires wearing uniformly, or are the tires on one end of the car wearing significantly faster than the other?

What are other BMW 135i track guys running?

I have read that stock 135's tend to understeer a bit. If your pressures and alignment are in check, then perhaps a stiffer rear sway bar would help.

The understeer you are experiencing - does it occur at corner entry (turn-in), mid corner, or corner exit? One of those, two of those, all three?

[Track wheels]

Only have a minute but can go into more detail later.
Carl, now that's what I like - your help one on one.
I listen well. At least that's what I've been told.

Will, the understeering thing will be looked at, but I've
accommodated the problem with trail braking and left foot
Braking. I don't want to mod the suspension ,if possible,
But I have had just a few rare scares, well past the apex
Under heavy throttle while the car is still in a turn.
It can be just a wee bit too much gas or just over heating
front tires- usually at or near 100 mph.
It's to be expected but , time and skill will help.

Robert

[Track wheels]

Hi Will. Running Dunlop Z-1 , 200 wear rate.
Fronts are 10mm wider :245/ 17- not much space in the well
Found this car is nearly untrackable with wider rears
Carl is correct, slow down and any car will start to turn.
You would not believe how slow the stock car has to go!
I don't want to complain but I've tracked a dozen cars including
CTS-V, SL500, BMW 330 , Etc and I guess somebody at BMW
Thought this car would generate buying interest in their new M version
That runs an extra wide M 3 front suspension that cures understeer.

http://jalopnik.com/comment/34044686/


So I tried lots of things including experimenting with the toe.
It's been to race shops since new.
I do have a big jump in tire pressures
and have to keep dropping them under 40.
As of late , I start with 28 and let it go to 34-35.
I noticed the tire doesn't roll on to the sides, so I am using
Less air.
That scare I mentioned at t4 Mosport
hopefully will never happen again because I
Felt I needed to go to left foot braking inorder
To trail brake as I crossed under the bridge.
It would not hold the inside of the camber down the shoot
But I stayed on the gas and allowed enough safe room just in case-
so no off but close.
The last time out was with Comscc. Used lots of trailbraking.
I only left foot brake now and this technique has
Eliminated any understeer.
This car still needs to be rotated inthe turn with heavy throttle
To force strong slip angles from the rear while trying to
Read the front grip and play that fine balancing act as
The car leaves the turn.
It is an amazing car when it's trained properly.
It has some other issues
It's on it's 3 rd Hi pressure fuel pump
The brakes fall apart from track heat.
I run Hawk Plus. Can not use race pads because there are just
too hot
Missed 3 track days end of year because the shop had my car
For 6 weeks on a rebuild and ended up taking calipers off
A new 2011- parts not around.
Try to go one more season with the 135, then maybe sell

[breakaway500]

"That scare I mentioned at t4 Mosport
hopefully will never happen again because I
Felt I needed to go to left foot braking inorder
To trail brake as I crossed under the bridge.
It would not hold the inside of the camber down the shoot"


I don't remember braking under that bridge...ever..matter of fact,I made sure I did not have to brake into 4 ...as the car is light and gently settling down hill/tad off camber.....of course it would feel scary on the brakes.

Done right, (for me anyways)... I don't use any brakes under the bridge and over the crest..just a monitor throttle and then back to the floor..

Maybe you crossed under the bridge too much to the right... or just too fast?

Doesn't sound like a car issue...no offense..

To go faster,sometimes you have to slow down. Boy,thought I'd never say that!

[Track wheels]

just caught that.
You`re right. It was some place past the bridge.
I checked this out with a few guys.
Would it be possible to
keep the speed and use a tiny bit of trail break to try to
keep the front end bite as one falls down the shoot?
They confirmed it on Y-tube because you can hear the motor
being held back just for a moment with trail breaking in some classes.
I learned something from that close call. Worked and tried to learn the technique
and used it at WGI. It provides an extra helping of control
and the car seems easier to drive.
In terms of that one incident being caused by driver error,
yes, it and every mistake, is mine.
I make lots,nevertheless I do want to leave enough on the plate to drive
another day.
By the way, 5 years without any contact- I try not to scare anyone ( re:Carl) .

Robert

[breakaway500]

"They confirmed it on Y-tube because you can hear the motor
being held back just for a moment with trail breaking in some classes."

I really doubt any of them are on the brakes into 4.If you hear the motor being "held back",that is called monitor or maintenance throttle..you are not adding or subtracting torque to the drive wheels. You are at a steady throttle position.

5 years without contact is good.Keep it up!

[blindsidefive0]

The brakes fall apart from track heat.
I run Hawk Plus. Can not use race pads because there are just
too hot

I'm not following - what is falling apart because of the heat?