Track forum general chit chat.

[Bartledoo]

Why do you keep calling them "cap 2"? It's killin me. If you want more rubber on the road just deflate your tires. Throw conventional out the window!

[dparm]

It's called the Cup 2, aka PSC2. Not Cap. :-)

[rhyary]

Originally Posted by dparm

It's called the Cup 2, aka PSC2. Not Cap. :-)

Sorry Cup 2 it is.

Deflating did not help as it destroyed the tire prematurely. Already tried that.

[Ximian]

Originally Posted by dparm

I think it's going to be much easier to diagnose this with some telemetry. You can also mathematically infer the maximum cornering speed for a given radius and then compare your speed. That's a theoretical fastest speed and doesn't take certain things into account, but it would give you a frame of reference to push harder. I've been fortunate enough to get telemetry from similar cars to see just how much faster I can go.

My opinion on overslowing (which I sometimes do) is that it's related to a lack of confidence in the car's ability to corner. In other words, you are slowing down more than necessary because you don't think the car can make the corner at a higher speed.

A secondary cause might be that your line is incorrect. You think it's a slower (tighter) corner than it really is.


In some ways, I have always believed that overslowing is a symptom of being stuck in a novice mindset. I don't mean this disparagingly, by the way. What I am getting at is that when you are new to HPDE or autocross, they always drill this into your head:

1. Slow the car
2. Turn
3. Accelerate out of the corner
4. Repeat

There's so much happening on the track so people tend to get narrow focus on doing those things in the correct order. They get their braking done, then they turn, then once the turning is finished they get back on the gas. What takes more experience and confidence, and makes for a faster driver, is seeing that these three activities are not discrete. You can slow the car while you start to turn, and you can turn while you begin to accelerate. Unfortunately, the instructor is no longer in your car by that point, and you never really learn how to connect those activities together.


Based on what you are saying, it sounds like you may need to start braking a little bit later. I would slowly push the braking zone a bit later until you over do it and can't make the corner.

I'm limited in telemetry so this is what I have from 10hz GoPro Hero 5 GPS. It's accurately lined up for the starting/finish point but I couldn't figure out how to get Dashware to read multiple different files without having major issues. Any suggestions on free alternatives? I need something better to analyze the details and sector times, which Dashware can't do.

Top is 2019 with an instructor, bottom is 2018 solo. The speed carried into the braking zones differs quite a bit as does the apex speed. I would say there is a 215 lbs increase with the passenger this year. Could that have such a significant effect on acceleration? Or rod bearing service robbed me of quite a bit of horsepower.

Same tires both years but 2018 had some high cross winds that made me reduce speed in the fast section (120 MPH to 95) compared to 2019 speeds (110 scrubbed to 100).

[roastbeef]

Originally Posted by slicer

With all due respect, unless I'm misunderstanding, I'm seeing you mix and match odd tire sizes and completely different tire compounds. Pretty much all conventional wisdom advises against that. I'm trying to figure out why the heck you are doing that. Hoping to help you. Knowing your wheel limitations will help with that advice. If you want it....

Or at least better understand your logic - maybe I can learn something.

this is his car.
https://www.m3post.com/forums/showth...ceramic+brakes

he likes running it as-is and is dismissive to any brake/wheel suggestions.

[rhyary]

Originally Posted by roastbeef

this is his car.
https://www.m3post.com/forums/showth...ceramic+brakes

he likes running it as-is and is dismissive to any brake/wheel suggestions.

Ogh, Roast please.
If someone share overheating DCT on the track, Should the Forum advise to get a manual?

I have questions about 19" wheels and available tires in the context of price, rubber compound, tread pattern etc. Have faith in me, if I wanted to go the 18" wheel route I know how to accomplish it.

Can we please get off the topic of my 19" wheels and brakes?

I am not dismissive, but at the same time doing 40 track days with countless laps and NO brake fade and replacing pads once a summer has also benefits. It is NOT all bad to have my brakes and 19" forged BBS wheels. Yes, I have limited tires selection and I have to live with that. At the same time, there are very few cars at the E92 M3 class that are faster than mine at NYST. So again while I am on the quest to get to 1:36, best time in the 1:37, few cars at my weight and narrow than 3xx width tires get below 1:40.

Again, I am very appreciative of on-topic suggestions and recommendations and have implemented countless improvements based on the collective wisdom of this board. My only hope is that my experiences that I share can be useful to someone else so I can also contribute and not just take.

[Montaver]

I think people get irritated because you seem to ask for advice, then when they give it if its not in your very narrow set of prescribed parameters you are dismissive. Maybe this has been covered, but if you are set on 19's why don't you just run 265/30/19, 295/30/19 in the Cup2's and be done with it? Your car seems to be no expense spared on mods

[SYT_Shadow]

Originally Posted by rhyary

At the same time, there are very few cars at the E92 M3 class that are faster than mine at NYST.

As I've suggested before, you will get better feedback if you leave the niche track (NYST) and go to a proper big boy track, like the Glen.

Plenty of people here go there and can offer better advice if they see the turn(s) you're struggling with or what you're feeling that you don't like in specific places.

Driving in different tracks also helps keep drivers humble, as instead of hitting one track 20 days a year they have to try to get better at say, VIR, where they can only do 3 days a year.
Becoming an expert at track A is not good for rounded driving skills if you do not put considerable time into track B, C, D and E.

I understand you added Limerock to the mix this year, but what about WGI, Palmer, Tarhel (or whatever the newish NH one is called)

[rhyary]

Originally Posted by SYT_Shadow

As I've suggested before, you will get better feedback if you leave the niche track (NYST) and go to a proper big boy track, like the Glen.

Plenty of people here go there and can offer better advice if they see the turn(s) you're struggling with or what you're feeling that you don't like in specific places.

Driving in different tracks also helps keep drivers humble, as instead of hitting one track 20 days a year they have to try to get better at say, VIR, where they can only do 3 days a year.
Becoming an expert at track A is not good for rounded driving skills if you do not put considerable time into track B, C, D and E.

I understand you added Limerock to the mix this year, but what about WGI, Palmer, Tarhel (or whatever the newish NH one is called)

Very reasonable suggestion, but not how I do things. I like to sort the equipment with introducing as few variables as possible.

The same track gives me control of the results and allows me to test and experiment with various setup and tires and data logging.

When I retire, I am surly to travel to any track but working a very demanding job that involved travel already, I am not looking to add travel to my life. LRP and NYST are 70 min from door to gate.

So, going to only two tracks is not ideal, as you point out, but still tons of fun anyway. The minute I will be suffering doing a track day, I would seek alternatives.

Some rainy trackday in the afternoon I was basically the only one doing laps for 2 hours at 1:55-2:00 pace. I can assure you I enjoyed every lap. Isn't it what is all about?

The way I see it, I have won EVERY HPDE I went to so far.

[gmx]

Originally Posted by PrimeBMW

Exactly. He wanted hot tire pressures. (Not that it was appropriate)

Still unacceptable. If you want hot pressures, you time it to pit a lap early...
Same shit here by an idiot in a Caterham. Didn't see checkered flag and passed two other cars through the esses before coming around the outside of me:
www.youtube.com/watch?v=9xOBTKH_UrM

Worse than accident damage, he probably would've died. Darwinism.

Originally Posted by dparm

Agreed, but defensive driving applies in HPDE, too. You have to assume that everyone else on track doesn't see you, won't follow the line, could have a blow-out or brake failure at any instant, etc.

Eh, I use to think like this and "point by" anyone that even remotely looked way too aggressive (but not on the timing sheet) by. Then someones top radiator hose burst and dumped coolant in front of me. You can never account for what is going to happen.

[dogbone]

Originally Posted by dparm

Can you post a more zoomed in view? The X-axis maximum value is quite large, it looks like an entire lap all at once. Would be more interested in seeing just one segment at a time.

Here's two pix: the first turn and last turn zoomed in.

I'm assuming it takes a moment for a pedal to return all the way to it's resting position. Most of the time, my movement is pretty quick from one pedal to another. But again, I do not left-foot brake. I did try it a few years ago. Didn't really take to it. I always laugh at myself because I feel like my left foot is a peg leg in terms of being capable of fine movement. I could never have been a drummer!!

[CorruptCommie]

Is the aim pulling actual brake pedal position from a sensor in the pedal, or is that brake pressure sensor, or is estimating? I know in the E46 there's no brake pedal position sensor.

[dogbone]

Originally Posted by CorruptCommie

Is the aim pulling actual brake pedal position from a sensor in the pedal, or is that brake pressure sensor, or is estimating? I know in the E46 there's no brake pedal position sensor.

I’m simply pulling data from the CAN bus with an AIM Solo 2 DL. I have not made any changes to the OEM brake pressure sensing system. It’s definitely not estimating. But I don’t know how it gets the info. Maybe someone else could shed some light on that.

[rhyary]

Originally Posted by CorruptCommie

Is the aim pulling actual brake pedal position from a sensor in the pedal, or is that brake pressure sensor, or is estimating? I know in the E46 there's no brake pedal position sensor.

The Aim shows two related brake information.
Total PSI
On Off switch

These are two separate variables

I addition it also shows each wheel brake psi.

[slicer]

Originally Posted by rhyary

I measure the space between the rubber
Here is a cap 2 air gaps
Mich Cap 2 265/35/20
260mm - 15 -15 -15 - 5 = 210mm

OK. Got it. You are comparing a slick to a street tire. Definitely going to get more grip with a slick. However, contact patch is more than just the width of the tread. Plus you need to consider the tire's rubber compound when comparing grip.

That being said, if you want the best grip, you should run a slick. Since the RR doesn't have any decent options for the front then I would go to the Hoosier as you have suggested. 265/35/19 will rub the fender liner at full lock but you don't go to full lock on the track. Given your constraints I would go to a 265/35/19 paired with a 295/30/19 Hoosier R7 or A7 combo. Not a big deal that the front will rub the back of the liner slightly. Also, based on the rubbing you are seeing in the inside of the rear I would install a rear spacer to get the tire away from the inner fender (or get a wheel that has a better spec (I acknowledge that there is a trade off as you will have a hard time finding a lighter wheel than the FI-R that you have). 10.5 et35 is an F8x spec. The e9x has a narrower track width, therefore you should be shooting for et25 to et30 with a 10.5. If you do a custom wheel (like an E88 for example), you could go to something wider (10" or 10.5" front and 11" rear) which would be heavier but would effectively increase your tread width (of same size tire) due to the extra rim width. I would be curious to see the results from data acquisition - comparing performance of a heavier/wider wheel to a narrower/lighter wheel with the same tires.

[rhyary]

Originally Posted by slicer

OK. Got it. You are comparing a slick to a street tire. Definitely going to get more grip with a slick. However, contact patch is more than just the width of the tread. Plus you need to consider the tire's rubber compound when comparing grip.

That being said, if you want the best grip, you should run a slick. Since the RR doesn't have any decent options for the front then I would go to the Hoosier as you have suggested. 265/35/19 will rub the fender liner at full lock but you don't go to full lock on the track. Given your constraints I would go to a 265/35/19 paired with a 295/30/19 Hoosier R7 or A7 combo. Not a big deal that the front will rub the back of the liner slightly. Also, based on the rubbing you are seeing in the inside of the rear I would install a rear spacer to get the tire away from the inner fender (or get a wheel that has a better spec (I acknowledge that there is a trade off as you will have a hard time finding a lighter wheel than the FI-R that you have). 10.5 et35 is an F8x spec. The e9x has a narrower track width, therefore you should be shooting for et25 to et30 with a 10.5. If you do a custom wheel (like an E88 for example), you could go to something wider (10" or 10.5" front and 11" rear) which would be heavier but would effectively increase your tread width due to the extra rim width. I would be curious to see the results from data acquisition - comparing performance of a heavier/wider wheel to a narrower/lighter wheel with the same tires.

Thank you.
Anyone know if A7 or R7 runs wide, true, or narrow?

My track set front is 28 offset. How does it affect the 265 rubbing issue?

[slicer]

Originally Posted by rhyary

Thank you.
Anyone know if A7 or R7 runs wide, true, or narrow?

My track set front is 28 offset. How does it affect the 265 rubbing issue?

You are welcome. Hoosiers generally tend to run wide and square. The rubbing of 265/35/19 is primarily diameter driven but an aggressive offset will exacerbate the issue. That being said, I would not put 9.5 et28 in the 'aggressive offset' category. There have been reports of people not having rubbing issues on street tires in the 265/35/19 size if installed on wider wheels (10"+) as the slight stretch of the tire can help. That being said, I would expect that they will rub with your current wheel spec. You might see less if you switch to a wider front wheel.

[dparm]

Originally Posted by Ximian

I'm limited in telemetry so this is what I have from 10hz GoPro Hero 5 GPS. It's accurately lined up for the starting/finish point but I couldn't figure out how to get Dashware to read multiple different files without having major issues. Any suggestions on free alternatives? I need something better to analyze the details and sector times, which Dashware can't do.

Top is 2019 with an instructor, bottom is 2018 solo. The speed carried into the braking zones differs quite a bit as does the apex speed. I would say there is a 215 lbs increase with the passenger this year. Could that have such a significant effect on acceleration? Or rod bearing service robbed me of quite a bit of horsepower.

Same tires both years but 2018 had some high cross winds that made me reduce speed in the fast section (120 MPH to 95) compared to 2019 speeds (110 scrubbed to 100).

Yes, carrying an extra 215 pounds will have a huge effect. I don't think the rod bearing service would've made any difference.

One of the things that jumps out to me is how "peaky" the lines are. Your speed plummets and then steeply rises. That is textbook overslowing, IMO. If you're trail braking and carrying more corner speed, the valleys of those lines will be more rounded off.

[dparm]

Originally Posted by dogbone

Here's two pix: the first turn and last turn zoomed in.

I'm assuming it takes a moment for a pedal to return all the way to it's resting position. Most of the time, my movement is pretty quick from one pedal to another. But again, I do not left-foot brake. I did try it a few years ago. Didn't really take to it. I always laugh at myself because I feel like my left foot is a peg leg in terms of being capable of fine movement. I could never have been a drummer!!

Man, that overlap is really weird. It's almost like the polling interval is just insanely slow and then there's a lot of smoothing being used.

[Ximian]

So for the next track day, I'm trying to find a good system with accurate GPS (10 hz) and throttle/gas measurements.

The options are -

1. Qstarz BT-Q1000eX, $200 with good analysis software with tracks built-in. It's able to break down a track into many sectors automatically which is helpful evaluating multiple laps.

For throttle/brake measurements, I can use my Carly adapter with manual work ($TIME) to analyze it.

2. Waylens Horizon, includes ODB2 adapter and 1080P camera ($500 + better mount)
No idea about any analysis software, but it seems like the best value for the hardware you get.

3. AIM Solo 2 DL OBD2 GPS Lap Timer with ECU Connection ($700)
It seems way too expensive for what you get. Race Studio 3 looks very dated but being able to analyze the lap from the timer might be useful.

4. ApexPro - no way to measure throttle/brake but it looks like it has the best analysis software and you can review other people's laps. It's limited to iPhones which is odd. ($450)

If you have one of those, would you still go with that option or something else?

[dogbone]

Originally Posted by Ximian

So for the next track day, I'm trying to find a good system with accurate GPS (10 hz) and throttle/gas measurements.

The options are -

1. Qstarz BT-Q1000eX, $200 with good analysis software with tracks built-in. It's able to break down a track into many sectors automatically which is helpful evaluating multiple laps.

For throttle/brake measurements, I can use my Carly adapter with manual work ($TIME) to analyze it.

2. Waylens Horizon, includes ODB2 adapter and 1080P camera ($500 + better mount)
No idea about any analysis software, but it seems like the best value for the hardware you get.

3. AIM Solo DL OBD2 GPS Lap Timer with ECU Connection ($700)
It seems way too expensive for what you get. Race Studio 3 looks very dated but being able to analyze the lap from the timer might be useful.

4. ApexPro - no way to measure throttle/brake but it looks like it has the best analysis software and you can review other people's laps. It's limited to iPhones which is odd. ($450)

If you have one of those, would you still go with that option or something else?

The only device in that list that will give you throttle and brake is the AIM.

If you want maximum data, there's only one device in your list that gives you access to CAN bus data---the AIM Solo 2 DL. Yes, the software interface looks old. Yes, you'll get over it.

Since you have a modern day car with sensors everywhere, and this information can be recorded by the AIM, you can really take advantage of the AIM's abilities. None of the other devices in your list can provide you with nearly as much direct data/information.

When you have CAN data showing your brake pedal pressure, throttle position, steering wheel position, RPMs, gear selection, individual wheel speeds, oil temps, coolant temps, ambient air temps, there is NO guesswork. You know what you did and since the info is tied to GPS, you know exactly where you did it. You don't have to look at a small dip in a speed chart and then guess what's going on. (Watch a data analysis video of ApexPro data. The guy says, the driver PROBABLY did such and such here. You do not need to guess when you have full access to CAN bus data.)

As interesting as an ApexPro is, and as nice and modern-looking as the software is, many of the conclusions you draw from an ApexPro are deduced or inferred. You are looking at a speed chart and doing guesswork. The ApexPro could make an interesting secondary device in the car because, while driving, it can give you instant feedback on whether you are maximizing the car's performance in a corner. But my hesitation on the ApexPro is that the instant feedback is relative to your driving----meaning that it's comparing the current driving by you to previous laps by you. If you never drive the car to maximum, then how is the ApexPro supposed to learn what max is on your car? I think the ApexPro is a tool for Advanced drivers who can always push the limits of the car.

Waylens makes data overlay easy, but I don't believe there's any analysis software. And the videos I've seen have no throttle or brake graphics even though it has an OBD connection.

QStarz is totally passive. GPS only. No hard data.

If you've ever visited my build thread, you've seen me posting countless screenshots from the AIM software. Don't get hung up on the dated look of the software; instead, look at all the hard data/empirical evidence we've been able to use to draw conclusions about a wide variety of topics from differential performance to traction control characteristics to braking performance to oil and coolant temp behavior and of course doing very detailed lap analysis. And the Solo2 DL is DEADLY accurate. No other system at a similar price point can do all that.

Is the AIM perfect? Of course not. The Windows-only software can be archaic and is not user-friendly to a beginner. The CAN bus connection sniffs CAN data even when the car is off and forces the device to turn on and drain the battery. AIM is woefully behind on their iPhone app. While you can create pages on the device with specific parameters that you want to see while driving, the screen layout graphics are not configurable which leaves wasted space on the device's screen. But regardless of these nuisances, it's still a fantastic platform, and I highly recommend it.

[rhyary]

Originally Posted by Ximian

So for the next track day, I'm trying to find a good system with accurate GPS (10 hz) and throttle/gas measurements.

The options are -

1. Qstarz BT-Q1000eX, $200 with good analysis software with tracks built-in. It's able to break down a track into many sectors automatically which is helpful evaluating multiple laps.

For throttle/brake measurements, I can use my Carly adapter with manual work ($TIME) to analyze it.

2. Waylens Horizon, includes ODB2 adapter and 1080P camera ($500 + better mount)
No idea about any analysis software, but it seems like the best value for the hardware you get.

3. AIM Solo DL OBD2 GPS Lap Timer with ECU Connection ($700)
It seems way too expensive for what you get. Race Studio 3 looks very dated but being able to analyze the lap from the timer might be useful.

4. ApexPro - no way to measure throttle/brake but it looks like it has the best analysis software and you can review other people's laps. It's limited to iPhones which is odd. ($450)

If you have one of those, would you still go with that option or something else?

AiM connected to the CAN.
The software is difficult, but comprehensive.
Adding the AiM camera later gives you comprehensive solution to data analysis.