Track forum general chit chat.

[redpriest]

Originally Posted by Kong Sheng Han

Drifters, I need advice.. Skip to 12:20

The sideways action was no mistake. I purposely induced the spin by adding more gas at apex than necessary to practice a bit of car control.

At the point where I released the gas, the car was done, I guess I'd say, going more sideways. Right after I released the gas, the car turns the other way, and I enter the point of no recovery. So, at the point where the car stopped getting more sideways (where I released the gas pedal), should I have maintained/added throttle and "reeled" in the steering wheel? I honestly have no idea why I lifted.

The day before, I did the same thing at the same corner, but I believe I did not lift that time. Will have to go back and watch video to confirm. That time, I was able to straighten the car up but ended up driving straight into the infield grass.

I'm no pro but I think I would have stayed on the throttle if I was in your shoes. I've only had bad experiences with lifting, and it's always been a conscious effort on my part to resist the urge. Everytime I successfully fought the urge to lift I've been able to recover (mostly). Maybe you started returning the steering angle back to neutral too soon - or perhaps that was a consequence of losing so much speed in the turn.

[elim11]

Originally Posted by redpriest

I'm no pro but I think I would have stayed on the throttle if I was in your shoes. I've only had bad experiences with lifting, and it's always been a conscious effort on my part to resist the urge. Everytime I successfully fought the urge to lift I've been able to recover (mostly). Maybe you started returning the steering angle back to neutral too soon - or perhaps that was a consequence of losing so much speed in the turn.

Im not a pro either but I think only agree w RP. Keep on the throttle and maybe too early to return back to neutral, esp since you were off throttle. Upset the balance and took weight off rear. (Is that called snap oversteer? )?

[ThunderMoose]

Originally Posted by Kong Sheng Han

Drifters, I need advice.. Skip to 12:20

The sideways action was no mistake. I purposely induced the spin by adding more gas at apex than necessary to practice a bit of car control.

At the point where I released the gas, the car was done, I guess I'd say, going more sideways. Right after I released the gas, the car turns the other way, and I enter the point of no recovery. So, at the point where the car stopped getting more sideways (where I released the gas pedal), should I have maintained/added throttle and "reeled" in the steering wheel? I honestly have no idea why I lifted.

The day before, I did the same thing at the same corner, but I believe I did not lift that time. Will have to go back and watch video to confirm. That time, I was able to straighten the car up but ended up driving straight into the infield grass.

You have to stay on throttle.

[Kong Sheng Han]

Yes, snap/liftoff oversteer. I'll have to keep practicing, hopefully attend a rainy track day, so I can save on tire wear. Autocross is no good for practicing high(er) speed car control.

[ThunderMoose]

Originally Posted by Kong Sheng Han

Yes, snap/liftoff oversteer. I'll have to keep practicing, hopefully attend a rainy track day, so I can save on tire wear. Autocross is no good for practicing high(er) speed car control.

MSRH has a skid pad. If it starts raining when I am there, I usually go out on it to channel my inner drifter.

[roastbeef]

my track day with HPDU.org at auto club speedway was very pleasant. they present themselves as a more premium track day host, and they are. it was an open day- no run groups, not many cars. everyone was familiar with track driving and had good etiquette, no cars/drivers that didn't belong. it was a really smooth day given how informal the setting was.

i opted for the coaching they provided and it was a decent value. the coach reviewed my gopro videos after i went out for sessions and provided immediate feedback, which was very constructive. i did improve, but i was only using harry's lap timer and sometimes forgot to turn it on sometimes. i hit a 1:57:0, which was a personal best, but i think i did a few smoother laps a little later in the day as i got more into a track mindset.

the only part of the day that sucked was having to leave the course for gas. auto club doesn't make it easy to get gas at their facility, its cash only at the top of the hour and the guy wasn't there reliably. even when he is there, its like $7 a gallon for 91. i logged 185 track miles (including a few miles here and there to go to the gas station). longest session i did was about a half hour, my only limitation was having to refuel and it was a little warm so fatigue set in after a while.

someone wrecked their cayman gt4, which was a huge bummer, but he was ok physically.

[redpriest]

Originally Posted by roastbeef

my track day with HPDU.org at auto club speedway was very pleasant. they present themselves as a more premium track day host, and they are. it was an open day- no run groups, not many cars. everyone was familiar with track driving and had good etiquette, no cars/drivers that didn't belong. it was a really smooth day given how informal the setting was.

i opted for the coaching they provided and it was a decent value. the coach reviewed my gopro videos after i went out for sessions and provided immediate feedback, which was very constructive. i did improve, but i was only using harry's lap timer and sometimes forgot to turn it on sometimes. i hit a 1:57:0, which was a personal best, but i think i did a few smoother laps a little later in the day as i got more into a track mindset.

the only part of the day that sucked was having to leave the course for gas. auto club doesn't make it easy to get gas at their facility, its cash only at the top of the hour and the guy wasn't there reliably. even when he is there, its like $7 a gallon for 91. i logged 185 track miles (including a few miles here and there to go to the gas station). longest session i did was about a half hour, my only limitation was having to refuel and it was a little warm so fatigue set in after a while.

someone wrecked their cayman gt4, which was a huge bummer, but he was ok physically.

Glad you made it out safe, and your car too. Sounds like a good time - the gas station isn't that far away fortunately.

[roastbeef]

right. i think i got gas three or four times. not too far, but kind of annoying. still burns about 20-25 minutes, so three trips is over an hour of driving to/from the gas station.

i forgot to mention- this was my first track day with solid subframe and diff bushings. the car was noticeably more rigid and seemed to transition smoother. however, i feel like now the car can really benefit from some aftermarket suspension. some transitions were great, but there are a few corners in the autoclub infield that are bumpy. i don't remember the car getting as unsettled in those spots the last time i was at autoclub a few months back.
they setup cones and a tire stack as a chicane at turn 9/10 which wasn't there last time. this is one of the areas where the car did well. i could go flat out through there and the car transitioned well without any interruptions in power delivery.
the car was a bit unsettled through the bumpy 16 before the roval, but going deeper into the corner helped out a bit with that. regardless, bumpy track is going to magnify the shortcomings of the oem suspension. in the smoother parts of the track, the car felt great.

[Kong Sheng Han]

Originally Posted by ThunderMoose

MSRH has a skid pad. If it starts raining when I am there, I usually go out on it to channel my inner drifter.

I didn't think a TT racer could have an inner drifter in him.

[dogbone]

Originally Posted by roastbeef

its likely a combo of heavy braking plus mdm using the rear brakes to make adjustments.

(Just so you know, MDM uses the front brakes 99% of the time. It rarely uses the rear brakes. I have extensive AIM data to support this. I talked about this topic and showed a bunch of charts in this post: http://www.m3post.com/forums/showpos...7&postcount=27 )

[dogbone]

Originally Posted by roastbeef

i'm getting a nervous rear end under heavy braking, and i think its simply the oem rears getting too hot.

In me and my friends' experiences, we have found that alignment is a huge contributing factor to an unstable feeling in the rear of the car during heavy braking. You want to make sure the rear is Toe-in a little bit. Rear Toe-out can contribute to that unstable feeling.

[roastbeef]

Originally Posted by dogbone

(Just so you know, MDM uses the front brakes 99% of the time. It rarely uses the rear brakes. I have extensive AIM data to support this. I talked about this topic and showed a bunch of charts in this post: http://www.m3post.com/forums/showpos...7&postcount=27 )

Originally Posted by dogbone

In me and my friends' experiences, we have found that alignment is a huge contributing factor to an unstable feeling in the rear of the car during heavy braking. You want to make sure the rear is Toe-in a little bit. Rear Toe-out can contribute to that unstable feeling.

this is great insight, thanks!

[roastbeef]

so the girlfriend and i adopted a german shepherd and she wants to take it to the track. i'm trying to get the most out of my track tires, so i've been swapping wheels at the track. packing everything in my trunk for two people, plus four wheels/tires in the back seat, there isn't much room for this horse-dog. this is causing me to revisit my roof rack tire holder plan.
found this, but it might be a little bit over the weight limit.
http://www.1addicts.com/forums/showthread.php?t=423634

[ayao]

Originally Posted by dogbone

In me and my friends' experiences, we have found that alignment is a huge contributing factor to an unstable feeling in the rear of the car during heavy braking. You want to make sure the rear is Toe-in a little bit. Rear Toe-out can contribute to that unstable feeling.

This is really interesting. I've always ascribed this to a brake bias issue but in truth that unstable feeling was the same with PFC08s on all corners or now with DS1.11 in the front and DS2500 in the rear. I'm currently at zero rear toe so may try your suggestion. Other modifiable variables include rear tire pressure and rear coilover stiffness (ohlins r/t dfv). Any suggestions on those?

[dogbone]

Originally Posted by ayao

Other modifiable variables include rear tire pressure and rear coilover stiffness (ohlins r/t dfv). Any suggestions on those?

With these cars, it seems that most people are always fighting for more front grip. I have been experimenting with running the fronts with lower psi than the rears. I like the results. I haven't considered psi for rear braking.

As far as suspension setup, I can't give you any specific advice on Ohlins R/T as I'm a JRZ guy, but in general, I don't like the rear to be too edgy. If the rear is too edgy, the car starts to feel nervous everywhere which doesn't appeal to me at all. I imagine braking falls into the same line of thought. If the car is setup with an active rear end, it will contribute to a feeling of instability during braking as well. I usually setup the front with a bit more aggressive settings than the rear. Having experienced plenty of oversteer moments, plus having a very light rear since it's gutted, I like to setup the car so that it encourages the rear of the car to stay in the rear. For me this means setting up the suspension so that the rear moves more slowly. (Having a wing on the rear really helps settle things too.) I also don't have killer stiff springs in the rear either.

When I replaced my diff with an OS Giken Super Lock, braking was one of the areas that felt noticeably different and better. During braking, the OS Giken diff forces the rear wheels to spin at the same rate. As a result the car tracks straighter and more predictably. The best way I can describe it is that it feels like a parachute is behind the car during braking. It's quite a nice feeling.

[roastbeef]

Is it more punishing if you were to have to get on the brakes if you aren't straight? Does it kill your ability to trail brake at all?

[dogbone]

Originally Posted by roastbeef

Is it more punishing if you were to have to get on the brakes if you aren't straight? Does it kill your ability to trail brake at all?

Are you asking this question regarding the OS Giken diff? If so, my OS Giken does not punish me on braking at all since it's setup as a 1.5 diff. (I talk about this extensively on my build thread on page 8 where I show the charts of those rear wheels: http://www.m3post.com/forums/showpos...&postcount=176 ) As far as braking goes, my opinion is that there are no negative side effects to a 1.5 diff when braking. It only makes the rear wheels spin the same speed on initial brake press when the braking load is super high. As soon as brake pressure reduces a bit, the diff unlocks and the wheels can do whatever they need to do to make it into the corner. Even if you're trail braking, that brake pressure would not be enough to lock a 1.5 diff as you're entering the turn.

You should be as straight as possible when doing an initial [big] brake press. If the wheel is turned during a big brake press, it can't turn AND slow the car at the same time very effectively---you're asking too much of the tires, and you encourage the rear of the car to come around you by lightening the rear end and having the car at an angle. Trail braking is fine, but that's more of a refinement late in the braking cycle. You should not be massively on the brakes at that point. If you are, then you're probably braking too late and you're attempting to "fix" things, as opposed to a purposeful and generally mild hold on the brakes to encourage a controlled rotation. A 1.5 diff doesn't prevent you from doing that.

[admranger]

dogbone's advice is spot on.

Pics of GSD or it didn't happen, roastbeef! Glad you found the dog a good home. Don't do a Romney and put the dog on the roof!

[ayao]

Full disclosure: I'm driving a 1M so there may be an apples and oranges component to frame of reference.
Currently I'm on 275/35/18 square with -2.5 camber in the front and -2.0 in the rear. I'm generally happy withy the feel of the car but I'm obsessed with the instability in the rear that I feel in turn 1 at Thunderhill. Every. Single. Time. I don't feel like there's enough track to get the car smoothly right of the blend line to brake in a straight line to setup for T1. No other turn makes the car feel unsettled like this, oddly. So it must be the timing of my inputs. Indie look at my alignment and noticed that I'm neutral toe in the rear. So I think I'll maybe toe-in 1/8 total as a start, in addition to really focusing on my inputs and footwork.

Good stuff.

Originally Posted by dogbone

With these cars, it seems that most people are always fighting for more front grip. I have been experimenting with running the fronts with lower psi than the rears. I like the results. I haven't considered psi for rear braking.

As far as suspension setup, I can't give you any specific advice on Ohlins R/T as I'm a JRZ guy, but in general, I don't like the rear to be too edgy. If the rear is too edgy, the car starts to feel nervous everywhere which doesn't appeal to me at all. I imagine braking falls into the same line of thought. If the car is setup with an active rear end, it will contribute to a feeling of instability during braking as well. I usually setup the front with a bit more aggressive settings than the rear. Having experienced plenty of oversteer moments, plus having a very light rear since it's gutted, I like to setup the car so that it encourages the rear of the car to stay in the rear. For me this means setting up the suspension so that the rear moves more slowly. (Having a wing on the rear really helps settle things too.) I also don't have killer stiff springs in the rear either.

[elim11]

Originally Posted by dogbone

In me and my friends' experiences, we have found that alignment is a huge contributing factor to an unstable feeling in the rear of the car during heavy braking. You want to make sure the rear is Toe-in a little bit. Rear Toe-out can contribute to that unstable feeling.

I would agree 100% with this. The rear would dance around under hard braking in a straight line, and would make it difficult to control. I brought it to my alignment shop (westend). The one thing they told me to try was to reduce the negative camber delta/difference between the front and the rear. Previously i was somewhere -2.7 and -1.8 rear (-0.9 difference). The told me to keep a ~0.5 degree difference between the front and rear and added a little toe in in the rear (1/8 or 1/16) to stabilize it. Currently run -2.6 and -2.1.

Helped tremendously. The guys at west end know their stuff. Real gurus and its a pleasure bringing it there and picking their brains.

[Malek@MRF]

Originally Posted by dogbone

In me and my friends' experiences, we have found that alignment is a huge contributing factor to an unstable feeling in the rear of the car during heavy braking. You want to make sure the rear is Toe-in a little bit. Rear Toe-out can contribute to that unstable feeling.

Very true.

[M3 Number 86]

Originally Posted by macdude357

Stock brakes or BBK? I find that I spend the most time trying to get the stupid guide pins screwed back into the caliper carriers when I'm changing my pads (Stock brakes). Last time, I messed up the threads in one of the carriers and had to take the whole carrier off so I could clean up the thread. Everything else seems to go pretty smoothly. Would love to here any tips anyone has on making the process quicker though.

From inside the caliper push the pins back so they are flush to the brackets.

Set caliper flush against rotor. Press in the bottom one first and you'll hear a click. Screw in a couple turns to set them.

Now push the top of caliper against rotor, press in pin. Done.

About 40 quarter turns to tight. If not it didn't thread in.