BimmerFest BMW Forum banner
21 - 40 of 82 Posts

·
Double Bimmers
Joined
·
1,176 Posts
nate328Ci said:


How can you roll over that far?

Mine don't roll off the tread at 40psi on 16" wheels :dunno:
I guess, high G's (I do drive it at M3 speed or faster), high body roll, and crapy camber:p

I have 17 X 8 inch rims with 235/40 S-03's.

At the autoX both the front and rear roll over to the seam beyond the tread, but before the sidewall. I would think I need more PSI, but it seems to handle so well, also I would think 44 PSI should be more than enough (44F, 40R). I have another autoX Sunday (YEAH TWO IN ONE WEEKEND!!!), and for now I plan to go with it as is.

When I drive around town I can see that I never roll over this far, so it is only at the autoX.
 

·
I like cookies.
Joined
·
18,102 Posts
CD-55 said:


I guess, high G's, high body roll, and crapy camber:p

I have 17 X 8 inch rims with 235/40 S-03's.

At the autoX both the front and rear roll over to the seam beyond the tread, but before the sidewall. I would think I need more PSI, but it seems to handle so well, also I would think 44 PSI should be more than enough (44F, 40R). I have another autoX Sunday (YEAH TWO IN ONE WEEKEND!!!), and for now I plan to go with it as is.

When I drive around town I can see that I never roll over this far, so it is only at the autoX.
I'm not exactly sure what you are referring to when you say "the seam beyond the tread" Are you talking about the treadblocks on the top of the sidewall, on the shoulder as I call it?

More tire pressure does not always equal more grip. If you have too much front pressure, the tires will just slide across the pavement. You want the tire to wear on the outer tread blocks, you will get more grip. At the last auto-x, I helped a guy out with his M roadster. He was running very high in front and low in rear trying to get rid of understeer. He kept on taking air out of the rear and adding the front, I told him to take air out of the front. He got so much oversteer that he nearly spun out.

I let it roll out on the shoulder. With only 1 PSI higher in the rear, my car was very well balanced. Easy oversteer on demand, I was tail out more than I was pushing...

I took this just now, damn dealer put tire shine on :tsk:
 

Attachments

·
Double Bimmers
Joined
·
1,176 Posts
Thanks for the pic.

On mine the front and rear rub off the shoe polish and show wear to the end of the tread to that seam where my arrows are (see attached pic). The shoe polish remains in this seam, but towards the tread it is all worn off.

The front show more wear, but still do not wear off the shoe polish beyond the seam.

On the front the triangle indicators are long worn off even on the new tire I just installed Friday (June 14th) night. On the rear they are visible, but almost worn off.

 

·
I like cookies.
Joined
·
18,102 Posts
CD-55 said:
Thanks for the pic.

On mine the front and rear rub off the shoe polish and show wear to the end of the tread to that seam where my arrows are (see attached pic). The shoe polish remains in this seam, but towards the tread it is all worn off.

The front show more wear, but still do not wear off the shoe polish beyond the seam.

On the front the triangle indicators are long worn off even on the new tire I just installed Friday (June 14th) night. On the rear they are visible, but almost worn off.

hmm, that is suprising. I would expect your tires you roll over less due to the lower profile

How smooth are you?
 

·
Double Bimmers
Joined
·
1,176 Posts
nate328Ci said:
How smooth are you?
Haven't we discussed this before?:p Anyway I chilled out, none of that WRC stuff today.

Today, my first two runs were no good (49.xxx) with several issues like overdriving into understeer situations.

My last two runs were smooth and the 4th (fastest) having no understeer or oversteer at all and being completely smooth. I am sure the cornering forces were greatest on my 4th (smooth) run. I did my best to corner at the max speed.

No kidding, I think my times were equal to most of the M3's (actually quicker than any I noticed); we know the M3's out accelerate me, so I must be making up some time on the turns?
 

·
OMGWTFBBQ
Joined
·
11,262 Posts
TD said:


Going into the last loop, I am sure we were under 15 MPH.
Nick said that he did the first and last loops in 1st the whole way. When I thought about it, for our cars, I thought that he was probably right. Coming out of the loops in second the revs were way too low and it took forever to start developing torque. The way i did it a couple times was shifting too often.

Like CD, my downshifts are done under braking, and I don't think that I'm losing time. I know that I'm not using any real concious thought on it. My upshifts, OTOH, have been lousy. Maybe its partly due to the CDV that probably lives in my car? Maybe my technique? Maybe both? Anyway, on my way home it occurred to me that maybe the fast way after the last loop would have been to hold it at redline in first until crossing the line? Maybe it depends on car/gearing?
 

·
OMGWTFBBQ
Joined
·
11,262 Posts
Nick325xiT 5spd said:
I look forward to doing this again... I REALLY need to start using that pedal on the right side a bit more. My runs were pretty smooth, but didn't REALLY push things.
Nick, you looked VERY smooth pretty much the whole time. On your first run, I thought that you were holding back a lot because you looked really slow. But your time didn't reflect that...turned out that you were just being smooth. :)

The xiT is VERY forgiving of excess throttle.
I didn't know that I could apply excess throttle in my xiT :D

Next time, I think I'll concentrate a little more on getting faster and a little less on nailing the gates exactly right. :p I KNOW that i wasn't looking ahead enough.
I ran across something the other day. Basically it said that on a 60 second course you may have 100 or more decision points. Points to lift, brake, gas, turn, etc. A 1/10 hesitation or miscue ads up to 10 seconds or more.

The guy that I'm cribbing that from wrote it a lot better, but it made a lot of sense to me. I wish that I could find it again.
 

·
Registered User
Joined
·
10,856 Posts
Discussion Starter · #31 ·
I think that one of my issues was that I was never going fast enough to need the brakes, really. I braked at two points... The sharp off camber turn on the back stretch and going into the second loop.

I should have gotten on the gas a bit more. :p
And Hunter... I wish I could say a 49 second run was no good. :D
 

·
I like cookies.
Joined
·
18,102 Posts
clyde325xiT said:


Nick said that he did the first and last loops in 1st the whole way. When I thought about it, for our cars, I thought that he was probably right. Coming out of the loops in second the revs were way too low and it took forever to start developing torque. The way i did it a couple times was shifting too often.

Like CD, my downshifts are done under braking, and I don't think that I'm losing time. I know that I'm not using any real concious thought on it. My upshifts, OTOH, have been lousy. Maybe its partly due to the CDV that probably lives in my car? Maybe my technique? Maybe both? Anyway, on my way home it occurred to me that maybe the fast way after the last loop would have been to hold it at redline in first until crossing the line? Maybe it depends on car/gearing?
What's the max speed in first in your car? Should be pretty low, I would guess ~33 or so. That is incredibly tight, I'm usually able to get to 55 or so on every course that I have driven on. I'm always in 2nd at auto-x and usually 3rd on road courses, except the straights. Plenty of torque down low in 2nd :angel:
 

·
OMGWTFBBQ
Joined
·
11,262 Posts
nate328Ci said:


What's the max speed in first in your car? Should be pretty low, I would guess ~33 or so. That is incredibly tight, I'm usually able to get to 55 or so on every course that I have driven on. I'm always in 2nd at auto-x and usually 3rd on road courses, except the straights. Plenty of torque down low in 2nd :angel:
I think that first maxes ~33. For the sections that I was talking about, it would have been entirely appropriate. The torque of the 2.5l down low leaves a lot to be desired when it has to pull the extra wagon glass and the AWD hardware. :rolleyes:
 
G

·
BTW, I saw this thread at bimmerforums about todays event- http://www.bimmerforums.com/forum/showthread.php?threadid=35596

While I did not write the original post in that thread, I could have. The similarities are striking, down to the guy's times. I'm not quite as insecure about it, but I do definitely want to know what I need to do to get better. I'm defintely not embarassingly bad or anything, but I'm still a solid 3-5 seconds behind the truly leaders. And my times today were all 50.X s, just like the post's author.

Anyway, IMO, there was some good advice in the follow-ups, so, since I know a few of you are as new or newer than I am at this, I figured you might apprecite it.
 

·
OMGWTFBBQ
Joined
·
11,262 Posts
TD said:
BTW, I saw this thread at bimmerforums about todays event- http://www.bimmerforums.com/forum/showthread.php?threadid=35596

Anyway, IMO, there was some good advice in the follow-ups, so, since I know a few of you are as new or newer than I am at this, I figured you might apprecite it.
I read it too.

I think that 90% of my problems are mental :confused: After walking the course, my goal was to run a 55. After watching the first heat, my goal was still a 55. My first run was a 52. I didn't know what to do after that. I think that's why I screwed up the rest of my runs. One of the other things that I need to do is take what I learn from each run and apply it to the following run. As I make my runs, I'm like a sponge, soaking up every last detail, but like an insane person I keep making nearly identical runs and expect faster times.

I think that I'm getting closer though. Things behind the wheel are starting to slow down a lot now and i can hear myself thinking as I go (or maybe I'm just hearing the rocks between my ears rolling around).

I'd like to get tires and some other parts, but even if they help me go faster, they won't help me go better. Driver needs improvement.
 

·
M Mad
Joined
·
10,475 Posts
Nick325xiT 5spd said:
I even met my goal... I stayed on the course all four times and only knocked over one cone. :)
Better than me. 3 off course runs. :dunno:

At least my last run counted.

I guess I thought the course was so easy I didn't need to pay attention.
 

·
M Mad
Joined
·
10,475 Posts
CD-55 said:


We may have been as slow as 15 - 20 MPH?

I pull off the shift to first while braking... so there is no speed loss there, but the shift back into 2nd was at full blast on a straight almost at the stop bo. I just hammered it as qucik as possible and lit-up the rear tires just the right amount. I noticed that many of the fastest people were doing the same thing.
Where were you downshifting? For the last loop?

I thought about it, and if I had managed to stay on course early, I might have tried it.

I ran the first loop in 1st, upshifted exiting the loop.

BTW I was running the Roadster yesterday.
 

·
Double Bimmers
Joined
·
1,176 Posts
Pinecone said:


Where were you downshifting? For the last loop?

I thought about it, and if I had managed to stay on course early, I might have tried it.

I ran the first loop in 1st, upshifted exiting the loop.

BTW I was running the Roadster yesterday.
Yeah at the last loop. I downshifted while braking while at the double gate the first time. I drove around the loop in 1st, then just before crossing the stop timer I hit red line and QUICKLY shifted into 2nd.

As for the first loop I short shifted before getting there. I thought there was no need for 1st gear power there so I shifted into second at that first gate where you turn right to enter the 1st loop. At this point (the lanuch) I doubt I took 1st gear above 4,500-RPM before the shift.
 

·
Double Bimmers
Joined
·
1,176 Posts
Nick325xiT 5spd said:
I think that one of my issues was that I was never going fast enough to need the brakes, really. I braked at two points... The sharp off camber turn on the back stretch and going into the second loop.

I should have gotten on the gas a bit more. :p
And Hunter... I wish I could say a 49 second run was no good. :D
I did not brake much more than that.

I braked at the double cones in that cross over from one side of the course to the other. I braked both times there.

I braked in the two corners at the far back of the course.

Then I braked at the double cones entering the last loop.

That was it.
 

·
Registered User
Joined
·
10,856 Posts
Discussion Starter · #40 ·
CD-55 said:


I did not brake much more than that.

I braked at the double cones in that cross over from one side of the course to the other. I braked both times there.

I braked in the two corners at the far back of the course.

Then I braked at the double cones entering the last loop.

That was it.
There certainly weren't many braking points, but I was DEFINITELY short changing myself on the two fast parts. :)
 
21 - 40 of 82 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top