Track forum general chit chat.

[Visceral]

Originally Posted by CorruptCommie

I run NT-01's on -3.5F, -2.5R and they wear evenly. On an E46 M3.

I'm at -2.5f/-1.5r with NT-01s on a full Dinan suspension (non-coilover), and there's slightly more outer wear in the front and inner wear in the back (thankfully its a square setup I can rotate).

These numbers are a function of roll angle, so if you have a suspension with better roll control (or less sticky tires that cant create as much grip/roll), you will need less camber to achieve even wear and best available grip.

[dogbone]

Originally Posted by FMLYSDN

Thank you. I have read alot the items regarding dogbone recommendations.

Max Camber in the Front and -2.2 in the rear. I did not see a mention of Toe for front or rear. Perhaps I missed it. I did read his comments regarding the minimal changes in toe when he was going from a track camber to street camber.

In the last 6 years, I’ve always run with a bit of toe in. Either 1/8 or 1/16 total toe in on front. And 1/4 or 1/8 total toe in on the rear. Lately, I’ve been 1/16 front and 1/8 rear. Max camber front, -2.2 rear.

In my early days of tracking, I valued stability. Slight toe in gives stability, but perhaps less turn in power. Toe out is inherently less stable, but can provide more turn in ability.

Later this year, I plan on experimenting with front toe out to see if I like it. I don’t have turn in issues, but I would like to see what it feels like.

[Visceral]

Originally Posted by dogbone

I don’t have turn in issues, but I would like to see what it feels like.

Co-drive someone's stock-ish Fox body at an autoX?

[dparm]

Originally Posted by Visceral

I've been using a Simpson Hybrid Pro for awhile, but now that I've added a Schroth Quick Fit Pro set of 4-point harnesses, I'm considering a more simple HANS like the regular Simpson or the Schroth. I've heard the SHM isnt all that comfortable from a number of folks, and I had no issues using a standard HANS in Chump and Lemons for several years... so I'll probably look at the standard HANS one. Thanks for the tips.

Simpson owns HANS, including the patents, so all HANS are made by Simpson. Schroth just gets their sticker put on it and has the tethers embroidered with their name.

[Chris_PDX]

Originally Posted by ricardofors68

As far as having a passenger, this experience will make me extremely gun shy about getting the most out of the car with a passenger.
So on to my next project. Next track day is in August, VIR.

I never, ever, drive even remotely close to the limit when I have a passenger, unless several conditions are met:

1. They have a HANS device
2. They fit well in my passenger seat all harnessed up
3. It's someone I trust implicitly (fellow instructor, race driver, etc.) to follow my instructions if shit goes sideways
4. And finally, they understand that we can literally kill ourselves doing this

There's maybe 2-3 people I would include in that group where I would go 90%, instead of the usual 60-70% with a passenger.

[macdude357]

Originally Posted by Visceral

I've been using a Simpson Hybrid Pro for awhile, but now that I've added a Schroth Quick Fit Pro set of 4-point harnesses, I'm considering a more simple HANS like the regular Simpson or the Schroth. I've heard the SHM isnt all that comfortable from a number of folks, and I had no issues using a standard HANS in Chump and Lemons for several years... so I'll probably look at the standard HANS one. Thanks for the tips.

I use the Necksgen Rev with my QFP harness and I love it. Can't even tell it's there (other than I can't look too far right or left).

[SQ13]

Originally Posted by scotty_miller

Just ordered the Schroth SHR neck restraint. Seeing all this stuff the past few days has really spooked me. Can't put a damn price on safety... or your life

Yeah, I don’t regret spending thousands on good, proper safety equipment. And I am perfectly fine with the stock power output of my E46 (+10 hp bc headers) and won’t be going for power mods for another year or two. Harness bar is as far as I’m willing to go though, I can’t justify a full cage at this point even though I would prefer one over a harness bar.

I cringe when people try to go with cheap/replica crap like seats.

[dogbone]

Originally Posted by Visceral

Co-drive someone's stock-ish Fox body at an autoX?

Nono, I meant I don’t have turn-in issues so I’m not desperate to try a bunch of alignments, but I AM curious what a different alignment would feel like on my car.

Believe me when I tell you I had plenty of understeer in this car when it was new to the track.

[Ximian]

Originally Posted by D1ESEL

Did my first HPDE at BIR in my E90. While it's super well setup and fast I think I will be taking my E46 ZHP the next time to learn the track a little better before going so fast.

Also I think I want to get some BMW Performance seats to hold me in a little better, I don't want to loose reclining abilities and my car has cloth so at least I am sticking in the seats.

My car is setup with the following

-Stoptech Trophy F&R BBK
-TC Kline DA's
-Fall-line catalog of suspension (endlinks, tow links, monoballs) everything
-MRF Solid Subframe Bushings
-Delrin Turner Diff Bushings
-Hotchkis Sway bars front and rear
-Autosolutions SSK
-Active tune with Macht Schnell X-pipe and MPE
-Eventuri Intake

Wheels are BBS E05 and Tires are Pilot Sport Cup 2's

Untitled by MNBoarder, on Flickr

Untitled by MNBoarder, on Flickr

Untitled by MNBoarder, on Flickr

When did you go? North Star BMWCCA had a weekend there starting on the 1st and it was mostly a great time with one rainy day and one cool and partially sunny day.

[roastbeef]

I got one for you guys- does the E-fan turn off at high speeds?
For example, if there is enough air flowing to push through the radiator on its own, does the fan still run?

[kyippee]

Fun day at Laguna Seca yesterday. Had a friend who's a better driver do a few laps in my car. He beat my PB by a little under a second and had way better car control - I felt the rear end get some nice slip angle and the throttle steering was great!

Also ran into forum members Ganz and Obi Wong

[dparm]

So per the video I posted recently of some "virtual coaching" from my telemetry, it seems like I have developed a weird habit in my technique that I need to work on: I am "overslowing" the car / not carrying enough mid-corner speed.

Does this mean I need to ease off the brakes very slightly towards the end of the braking zone? Should I be easing back onto the throttle a little earlier but more gradually? What are symptoms of overslowing & poor mid-corner speed?

I'm trying to understand why I developed this habit and what I need to start doing differently, including any obvious signs of you just overslowed/you're about to overslow.

[roastbeef]

Originally Posted by dparm

So per the video I posted recently of some "virtual coaching" from my telemetry, it seems like I have developed a weird habit in my technique that I need to work on: I am "overslowing" the car / not carrying enough mid-corner speed.

Does this mean I need to ease off the brakes very slightly towards the end of the braking zone? Should I be easing back onto the throttle a little earlier but more gradually? What are symptoms of overslowing & poor mid-corner speed?

I'm trying to understand why I developed this habit and what I need to start doing differently, including any obvious signs of you just overslowed/you're about to overslow.

let me preface my response with this, i don't directly know the answer and you know me (i'm an amateur). however, its an interesting question we can all learn from and a few things come to mind.

could you go deeper into the braking zone and let off the brakes at the same time you are now? you're going faster entering the corner, and are better off carrying that speed rather than letting off the brakes sooner and going to maintenance throttle sooner at a lower speed.

did you try to start working on trail braking or something and are maybe doing it too long?

being on the brakes for too long isn't the same as overslowing the car. whoever pointed this out to you didn't see that as the problem though... i wonder if your release is too gradual and if you could speed that up, but remain smooth? if you could shorten that up, you could probably brake a little later, too.

i know i've been talking about ross bentley content a lot lately, but this might be a cool submission for the "ask ross" q&a thing he does.

[M3MPH1S]

Originally Posted by dparm

So per the video I posted recently of some "virtual coaching" from my telemetry, it seems like I have developed a weird habit in my technique that I need to work on: I am "overslowing" the car / not carrying enough mid-corner speed.

Does this mean I need to ease off the brakes very slightly towards the end of the braking zone? Should I be easing back onto the throttle a little earlier but more gradually? What are symptoms of overslowing & poor mid-corner speed?

I'm trying to understand why I developed this habit and what I need to start doing differently, including any obvious signs of you just overslowed/you're about to overslow.

I had an instructor talk about this one time. He had a pro coach ride along with him to evaluate his driving and the coach noticed it immediately. The coach said "I need you to trust me" so he agreed, and the next corner they came to, the guy slowed down (too much) and took his foot off the brake and went for the accelerator and the coach grabbed his leg and wouldn't let him press it. The guy responds with "what are you doing? I need to speed up" and the coach says "why?". And then it clicked.

So...long anecdote aside, I don't have a "trick" for you aside form the advice he gave me was that he resolved the issue by spending some laps focusing only on entry speed and braking and would move up in 2 mph increments until he went in a bit too hot and messed up the corner.

[ThunderMoose]

Originally Posted by dparm

So per the video I posted recently of some "virtual coaching" from my telemetry, it seems like I have developed a weird habit in my technique that I need to work on: I am "overslowing" the car / not carrying enough mid-corner speed.

Does this mean I need to ease off the brakes very slightly towards the end of the braking zone? Should I be easing back onto the throttle a little earlier but more gradually? What are symptoms of overslowing & poor mid-corner speed?

I'm trying to understand why I developed this habit and what I need to start doing differently, including any obvious signs of you just overslowed/you're about to overslow.

I was just comparing my data to pro driving my car. In two spots, he started braking earlier than me but was softer on pedal. So he carried more speed mid corner than me. Maybe try that.

[dparm]

Originally Posted by roastbeef

let me preface my response with this, i don't directly know the answer and you know me (i'm an amateur). however, its an interesting question we can all learn from and a few things come to mind.

could you go deeper into the braking zone and let off the brakes at the same time you are now? you're going faster entering the corner, and are better off carrying that speed rather than letting off the brakes sooner and going to maintenance throttle sooner at a lower speed.

did you try to start working on trail braking or something and are maybe doing it too long?

being on the brakes for too long isn't the same as overslowing the car. whoever pointed this out to you didn't see that as the problem though... i wonder if your release is too gradual and if you could speed that up, but remain smooth? if you could shorten that up, you could probably brake a little later, too.

i know i've been talking about ross bentley content a lot lately, but this might be a cool submission for the "ask ross" q&a thing he does.

My braking application and release is quite fast already, which you can see in the data, and the coach even mentioned. I am a fairly late braker, and yes, I do trail brake a lot. The guys at Bondurant said these cars actually like to be trail braked. Bear in mind that the brake data in that video is the pedal position, not the actual pressure.

Originally Posted by M3MPH1S

So...long anecdote aside, I don't have a "trick" for you aside form the advice he gave me was that he resolved the issue by spending some laps focusing only on entry speed and braking and would move up in 2 mph increments until he went in a bit too hot and messed up the corner.

Originally Posted by ThunderMoose

I was just comparing my data to pro driving my car. In two spots, he started braking earlier than me but was softer on pedal. So he carried more speed mid corner than me. Maybe try that.

That's what I was trying to say above, but you've said it more succinctly. I think my instinct, and maybe it's incorrect, is to just push the brake pedal as hard as possible so you aren't "dragging" the brakes. The car has enormous tires and brakes so maybe my fear of overheating them isn't justified. So that's what I need to try at the next event: apply & release the brakes at the same spot on the track, but don't stand on the pedal with all of your might -- maybe try 9/10, then 8/10, etc., until you blow it and overshoot the apex.

The PTM & electronics are quite sophisticated and do adjust the ABS, slip, thresholds, etc. based on tire temps and other variables.



Here's the video from earlier in case you guys didn't see it:

[CorruptCommie]

I noticed the same last year after having a friend ride along. I was over slowing for entry on some faster corners, and getting back on throttle too early, unloading the front. After fixing that it clicked.

Brake technique is also tricky and something I need to keep working on.

[admranger]

So are you guys braking to the apex on most corners or accelerating prior to the apex or ?

For the corner before the longest straight I always try to get on the gas as early as possible as it will pay dividends at the end of the straight. Other corners I might brake past the apex if that corner is a "throw away" b/c it saves time to do so. For instance, on the back straight of Spring Mountain motorsports park when they use the chicane, I'll brake into the chicane vs. getting my braking done and then whizzing at max cornering speed through the chicane. The exit of the chicane leads to the corner before the front straight, so you want to get on the gas there early anyway so you can throw the back half of the chicane away to set up for an early throttle application on the last corner.

I have heard that you want to brake down to the apex and then accelerate out, but I'm not sure that is on 100% of the corners. Maybe I should try it for a few laps next time I'm out. Without data it's hard to tell overall lap time improvement, but I can judge corner by corner w/exit speed and speed right before the braking zone (or rams, pick your poison).

Nah. I'll drive flat out like always...lol

What do you guys do?

[dparm]

Originally Posted by admranger

So are you guys braking to the apex on most corners or accelerating prior to the apex or ?

For the corner before the longest straight I always try to get on the gas as early as possible as it will pay dividends at the end of the straight. Other corners I might brake past the apex if that corner is a "throw away" b/c it saves time to do so. For instance, on the back straight of Spring Mountain motorsports park when they use the chicane, I'll brake into the chicane vs. getting my braking done and then whizzing at max cornering speed through the chicane. The exit of the chicane leads to the corner before the front straight, so you want to get on the gas there early anyway so you can throw the back half of the chicane away to set up for an early throttle application on the last corner.

I have heard that you want to brake down to the apex and then accelerate out, but I'm not sure that is on 100% of the corners. Maybe I should try it for a few laps next time I'm out. Without data it's hard to tell overall lap time improvement, but I can judge corner by corner w/exit speed and speed right before the braking zone (or rams, pick your poison).

Nah. I'll drive flat out like always...lol

What do you guys do?

You are correct, and with Pi Toolbox I've been able to see just how a minute difference in throttle application or cornering technique before a long straight will ruin a lap. This is pretty easy to prove even without telemetry and I encourage everyone to try it out so the idea really sticks.

If you do get telemetry at some point, build a math channel for instantaneous corner radius. When you start looking at the relationship between time, lateral acceleration, and corner radius, your perspective on "run a wide arc through corners" and late apexing will change. As Dr. David Redszus of Precision AutoResearch explained to me quite succinctly, you should run a larger arc only if the lateral acceleration doesn't decrease...otherwise the larger arc is just extending your lap time. I didn't grasp this concept right away but when I started to see the difference in distance from those unnecessarily wider arcs start to add up over the course of a lap, I realized where that extra second or two of lap time came from. But from this, I also realized how defaulting to a late apex can hurt me as well -- the corner speed drops which causes the max speed on the straightaway to plummet. Late apex is safe, not fast.

For those wondering, the formula is (speed^2)/(15 * lateral acceleration), where speed is in MPH and lateral acceleration is in Gs. The output is in feet.


tl;dr: don't fuck up corners before long straights, because 0.1s lost there multiplies to a full second or more by the end of the straight.

[Ximian]

Originally Posted by dparm

So per the video I posted recently of some "virtual coaching" from my telemetry, it seems like I have developed a weird habit in my technique that I need to work on: I am "overslowing" the car / not carrying enough mid-corner speed.

Does this mean I need to ease off the brakes very slightly towards the end of the braking zone? Should I be easing back onto the throttle a little earlier but more gradually? What are symptoms of overslowing & poor mid-corner speed?

I'm trying to understand why I developed this habit and what I need to start doing differently, including any obvious signs of you just overslowed/you're about to overslow.

Are you threshold braking? It causes overslowing for many people, including me. My current problem is getting used to the feel of the car at various speeds to I can adjust braking and turn points accordingly. So far I'm either overbraking or braking, letting off the brake, realizing I'm carrying too much speed still, and braking harder. It's not pretty.

This one is nearly impossible to improve without detailed telemetry. If you're overslowing by 10 MPH, yeah, that's easier to work on. But a couple of MPH is very difficult to tell through what you feel in the car. What you'll end up doing is reviewing telemetry, adjusting reference points, and testing the new reference points. Once you've got the ideal speed, you'll just trust the reference points and ignore what you feel.

[scotty_miller]

So I got my schroth shr flex today. Comparing it to my friends hans III in a medium (same size as my shr) it is night and day. The SHR offers a better fit around the neck and collar bone area. The Hans III makes me feel as though my neck is being pushed forward and down while the SHR remains neutral in neck position. SHR also offers a better range of neck movement while the Hans seems to restrict it (when straps are connected to helmet in a relaxed position). Although the Hans does seem a tad lighter it's padding rubs my neck raw. My friend who has the Hans is currently returning it and buying an SHR. Him and I are both the same build. Just little guys. 5'5 and 150lbs. Not knocking on the Hans but it's seems to be better fitting for a person of a bigger build while the SHR seems to fit a person of smaller build. Just my .02. Hope this quick little reviews helps anyone looking into neck restraints

[CorruptCommie]

Scotty are you guys setting the seat back reclined to 20 degrees? When I first set my seat up, it was close to upright and the hans was not comfortable until I changed the angle. No issues with it now - I have the European Schroth which is basically a copy of the III.