kolosy build / track journal-ish

[omgzirra_exe]

Originally Posted by kolosy

How'd you guys wean yourselves off of TC?

drift lessons.

[911r]

Originally Posted by kolosy

well that's a wrap for the season, folks. at least for this ride — I'm going down to the P-car school at Barber in December, but the M3 is going into winter cleanup + hibernation.

Good last day at blackhawk. Last time I was here I was stoked to crack 1:28 and get moved up to intermediate. Today, I was running 1:25s, with a 1:24.9 PR. Consistent 1:24s is what they want to move you into the advanced group. I'm no hurry for that, but it's nice to know I'm on pace.

Attachment 3297371

Attachment 3297372

The yokos are beat to sh*t, so I think I'm going to go to something else for next season. I like the idea of Cup 2s, but also want to learn to drive with less traction first, then add it later. Maybe I'll get some PS4s or something equivalent, not sure. Also have some work to do on the brake system. The stopping power is there, but I've got more pedal travel than I'd like and I'm going to look into an ISTA reset procedure Ximian pointed me to, and possibly get a used master cylinder to swap out the 150k one that's there now. We'll see.

All in all, super happy with how the season's gone and how this 150K mile, 10 owner beater has held up.

I’d consider Hankook RS4s. They wear like iron, are predictable, and aren’t too sticky to serve as a crutch.

I tracked on MP4S and they fell off really quick. Not good track tires. Great street tires.

Also, no reason to buy cup2s for these cars imo. There are tires that are faster, cheaper and wear better.

[kolosy]

Originally Posted by omgzirra_exe

drift lessons.

can't tell if you're being facetious or not...

[kolosy]

Originally Posted by 911r

I’d consider Hankook RS4s. They wear like iron, are predictable, and aren’t too sticky to serve as a crutch.

I tracked on MP4S and they fell off really quick. Not good track tires. Great street tires.

Also, no reason to buy cup2s for these cars imo. There are tires that are faster, cheaper and wear better.

yeah, i ended up with a set of Kumhos. They'll be going on before the next track day.

[911r]

Originally Posted by kolosy

yeah, i ended up with a set of Kumhos. They'll be going on before the next track day.

V730s are great!

[omgzirra_exe]

Originally Posted by kolosy

can't tell if you're being facetious or not...

I am very serious; my biggest fear when I first turned off MDM was not being able to control my car in an oversteer situation or if I were to suddenly snap into oversteer somehow. Drifting teaches you how to handle these situations as you are purposefully inducing them. In other words, it's like taking basic car control classes.

Alternatively, you could rent a skid pad location and practice doing controlled donuts and figure 8s

[kolosy]

Originally Posted by omgzirra_exe

I am very serious; my biggest fear when I first turned off MDM was not being able to control my car in an oversteer situation or if I were to suddenly snap into oversteer somehow. Drifting teaches you how to handle these situations as you are purposefully inducing them. In other words, it's like taking basic car control classes.

Alternatively, you could rent a skid pad location and practice doing controlled donuts and figure 8s

yeah, that makes sense. i should do that now before i put new tires on lol

[kolosy]

oh and obligatory best lap catalyst vid of the day

[CamasM3e93]

Originally Posted by kolosy

yeah, that makes sense. i should do that now before i put new tires on lol

That’s a fine approach, too. My local driving school offers a skid pad course in a Vehicle equipped to simulate icy conditions. You spend 90 minutes behind the wheel of someone else’s car and tires to learn to arrest slides over and over until the reaction is imprinted in your brain. You might see if similar is offered locally. They are marketed to teach winter driving skills.

I was on track yesterday for the first time since the class and 6 hours in i was chuckling at just how casual a slide at 85mph heading toward a wall can feel.

Not local to you but this is the idea: https://www.prodrive.net/car-control...driving-course

[jmeenach]

When I was younger, my dad's friend ran the Bridgestone Winter Driving School in Steamboat, so I was lucky enough to go to several clinics. That knowledge has been really helpful with car control on track.

[kolosy]

So I did it today. Turned off tc on a slower track that I’m very familiar with at a private track day with low traffic. And proceeded to shave 3 seconds off my pb. So … yeah.

Felt great, especially going through corners where before tc would kick in and make me think I’m way overdoing it only to see that it was overreacting and I had plenty of room. Obviously I’m being extra cautious but definitely felt the rear end move around and was able to rein it in so I’m feeling good about my abilities relative to how hard I’m pushing.

Big issues I’m having is brake pads. I’m just demolishing them. What are you all seeing for pad life? I ran the new set of xp20s down to about the “as thick as the backing plate” limit today. Now, it was a full open track day so about double the track time of a typical 5 session hpde, and the track is super tough on pads. Is that just a fact of life on a full interior car? Or am I doing it wrong? I’m running at advanced group speeds, and now with dsc off I’m not expecting any unprompted activations.. just not sure what the baseline is.

[CamasM3e93]

You've inspired me to give it a try. I will be on new rear tires at the next session in 2 weeks - so maybe not that specific day - but committing here to go TC off as a next step.

I'm using stock brake calipers/rotors and a low cost semi metallic track pad from dynamic friction. I'm getting 6-8 sessions on the front and more on the rear - plus all the driving in between because they are adequate for the street. But my home track really only has one severe braking section and 3 mild to moderate braking sections - so that probably doesn't extend to your situation. I've got a set of Hawks going on here shortly - I don't recall exactly what I bought but I'll let you know how that goes.

[kolosy]

would love it if someone wanted to critique my braking. here's the solo 2 dl output of a good lap. to my eye it doesn't look like i'm dragging the brakes.. i may be overslowing certainly, but still:

[jmeenach]

Originally Posted by kolosy

Big issues I’m having is brake pads. I’m just demolishing them. What are you all seeing for pad life? I ran the new set of xp20s down to about the “as thick as the backing plate” limit today. Now, it was a full open track day so about double the track time of a typical 5 session hpde, and the track is super tough on pads. Is that just a fact of life on a full interior car? Or am I doing it wrong? I’m running at advanced group speeds, and now with dsc off I’m not expecting any unprompted activations.. just not sure what the baseline is.

How many sessions did you do with TC off? With TC on, you'll run through pads considerably faster than without.

[kolosy]

Originally Posted by jmeenach

How many sessions did you do with TC off? With TC on, you'll run through pads considerably faster than without.

All of them until yesterday morning

The pads I used yesterday were new though. I ran about 15-20 laps with tc on, and the rest of the day with it off.

[Ximian]

Sounds like a heat issue. Any brake ducts for cooling? Even titanium shims between the pistons the brake pad backing plate helped me quite a bit.

[kolosy]

Originally Posted by Ximian

Sounds like a heat issue. Any brake ducts for cooling? Even titanium shims between the pistons the brake pad backing plate helped me quite a bit.

oh good reminder -- i actually have a set of titanium shims from the BBK that i never (for some reason) installed. will definitely try that.

yes on cooling -- i've got a functional gt4 lip w/ ducting going to burkhart cf backing plates. the rotors are definitely getting the business -- you can see tiny smears of iron starting to fill in the slots.

[amg6975]

You're eating pads that fast with the Paragon kit? Geez. My first suggestion is definitely run with DSC off and see if that helps but even with DSC on, with that kit, a good pad should last a really long time.

Two data points somewhat related: 1) On my car (sort of an E92 M3, 3200lbs) with stock calipers, and Girodisc front rotors, no cooling, DSC off, I can run a whole season (20-25 days) at Watkins Glen in the Advanced/Instructor group (2:09-2:11 pace) on a set of PFC11s. I actually got all of last season and the first two days of this year on one set.

2) My wife's MINI would eat a set a pads every couple days, over the winter we installed the 4 piston Paragon kit for it (largely from yours and other reviews here so thanks) with GLoc R10 pads and the first two days this year [at Pittrace] we shared the car and were really mean to it and barely have a measurable amount of pad wear.

The data is really hard to interpret without a reference trace, especially if we don't know the track well. If there is anyone around that's faster than you in a similar car (doesn't need to be exactly the same) ask them if they have AIM data or if you can stick your Solo in their car for a session. Laying your speed trace over theirs will make it super obvious if you're doing everything right, or where you can improve. For braking you want to see where they brake, how sharp the "point" is at the top, and then how steep the deceleration phase is.

[kolosy]

Originally Posted by amg6975

You're eating pads that fast with the Paragon kit? Geez. My first suggestion is definitely run with DSC off and see if that helps but even with DSC on, with that kit, a good pad should last a really long time.

Two data points somewhat related: 1) On my car (sort of an E92 M3, 3200lbs) with stock calipers, and Girodisc front rotors, no cooling, DSC off, I can run a whole season (20-25 days) at Watkins Glen in the Advanced/Instructor group (2:09-2:11 pace) on a set of PFC11s. I actually got all of last season and the first two days of this year on one set.

2) My wife's MINI would eat a set a pads every couple days, over the winter we installed the 4 piston Paragon kit for it (largely from yours and other reviews here so thanks) with GLoc R10 pads and the first two days this year [at Pittrace] we shared the car and were really mean to it and barely have a measurable amount of pad wear.

The data is really hard to interpret without a reference trace, especially if we don't know the track well. If there is anyone around that's faster than you in a similar car (doesn't need to be exactly the same) ask them if they have AIM data or if you can stick your Solo in their car for a session. Laying your speed trace over theirs will make it super obvious if you're doing everything right, or where you can improve. For braking you want to see where they brake, how sharp the "point" is at the top, and then how steep the deceleration phase is.

yeah that's a good idea.. i'll ask around next time i'm at the track, i'm sure there's someone else there running an AiM.

could it be a brake imbalance? as i think about it -- i was having reasonable brake pad life (7-8 days on a full weight car) when i ran ds 1.11 all around. then i tried bringing down the rears to a ds2500, and destroyed the 1.11 and the rears in a day. it should've occured to me to go back to 1.11s all around, but given a paragon caliper up front and a stock one in the rear, did i just shift all the braking to the front?

interestingly, when i switched to carbotech, i started with XP10 all around, and the fronts are gone and the rears look brand new. then I put XP20s up front, same thing. do I need more pad in the back?

[omgzirra_exe]

Originally Posted by kolosy

interestingly, when i switched to carbotech, i started with XP10 all around, and the fronts are gone and the rears look brand new. then I put XP20s up front, same thing. do I need more pad in the back?

it's just not using the rear brakes as much since your doing MDM off.

rears almost never wear out that fast.

[M3SQRD]

Originally Posted by kolosy

yeah that's a good idea.. i'll ask around next time i'm at the track, i'm sure there's someone else there running an AiM.

could it be a brake imbalance? as i think about it -- i was having reasonable brake pad life (7-8 days on a full weight car) when i ran ds 1.11 all around. then i tried bringing down the rears to a ds2500, and destroyed the 1.11 and the rears in a day. it should've occured to me to go back to 1.11s all around, but given a paragon caliper up front and a stock one in the rear, did i just shift all the braking to the front?

interestingly, when i switched to carbotech, i started with XP10 all around, and the fronts are gone and the rears look brand new. then I put XP20s up front, same thing. do I need more pad in the back?

Do you think you’re braking earlier in the brake zones as well as over slowing the car? The first part, braking early causes more heat to remain stored in the rotors and pads. This can accelerate wear. Over slowing just adds more stored heat. Threshold braking is when you stay on the brakes for the shortest time duration and this is actually better for the brakes.

The XP20 is similar to Hawk DTC70 or PFC 05 (slightly less CoF of PFC 13 which is the replacement for 05 but apparently the 05 is still available - my favorite PFC race compound) so I’m surprised you’re going thru a set in a 2-3 day track event. The data presented above shows no major braking zones (~120 mph max) that would explain the rapid rotor wear rates. What suspension are you running? On the XP20 how many track sessions/laps with MDM on and how many with MDM off?

Do you know the piston area of the Paragon front six-piston fixed caliper? The static brake bias could be shifted far forward compared to stock and then the dynamic brake bias shots it another 8-9% forward. Your description of the long pedal travel before engaging the pad suggests the Paragon caliper area is considerably larger than stoke which translates into a long pedal. The Paragon pad profile they designed the caliper to use has a large pad compound area. The 17-18 mm thick pad is on the thin side of aftermarket track/race calipers. Do the pads wear evenly or is there taper on the pads?

[kolosy]

Originally Posted by M3SQRD

Do you think you’re braking earlier in the brake zones as well as over slowing the car? The first part, braking early causes more heat to remain stored in the rotors and pads. This can accelerate wear. Over slowing just adds more stored heat. Threshold braking is when you stay on the brakes for the shortest time duration and this is actually better for the brakes.

The XP20 is similar to Hawk DTC70 or PFC 05 (slightly less CoF of PFC 13 which is the replacement for 05 but apparently the 05 is still available - my favorite PFC race compound) so I’m surprised you’re going thru a set in a 2-3 day track event. The data presented above shows no major braking zones (~120 mph max) that would explain the rapid rotor wear rates. What suspension are you running? On the XP20 how many track sessions/laps with MDM on and how many with MDM off?

Do you know the piston area of the Paragon front six-piston fixed caliper? The static brake bias could be shifted far forward compared to stock and then the dynamic brake bias shots it another 8-9% forward. Your description of the long pedal travel before engaging the pad suggests the Paragon caliper area is considerably larger than stoke which translates into a long pedal. The Paragon pad profile they designed the caliper to use has a large pad compound area. The 17-18 mm thick pad is on the thin side of aftermarket track/race calipers. Do the pads wear evenly or is there taper on the pads?

It’s certainly possible that I’m doing both (braking too early and for too long), though my mid corner speeds for that corner seem on par with others in a similar weight class there (and based on an AiM comparison that a forum member here did for me). I do know that that particular track has a reputation of being tough on brakes despite not being particularly fast. I wonder if it’s the back to back front/back straights going into a 90* corner.

Car isn’t here and I didn’t measure when I put it away after the last session, but visually the pad had less than half of the friction material left at the end of that day. It was an open track day, so I did 72 laps vs the normal average there (for me) of 40-44 laps. Sessions were also 20-25 laps instead of 10-11. I ran the first 20 lap session with MDM on, then turned it all off for the rest of the day. I’m running the 3DM dedicated track kit, with upgraded swaybars and all solid/spherical rear end and mono balls up front. -3.5 camber front, -2 rear.

W/r/t the paragon caliper dimensions, it’s nominally identical to an AP 9660. I went and dug up the group buy thread where some of the specs were rehashed. From there:

Piston size:
PA015 / PA035 front calipers: 27/31.8/38.1mm (I’m running the 035 front, stock rear)
PA025 rear calipers: 27/27mm

Per crazydrummer
That’s a 2500mm^2 piston area vs stock 2826. With stock rears that’s going to give a 60% front bias vs stock 63% and around around 8% less total area.

So according to the above, the Paragon kit with stock rears actually shifts the brake bias rearward.

I’m going back to that track on the 10th, and in addition to some braking adjustments I’m going to make, I’m putting in a set of XP24s up front, and wondering if I should put a stronger pad out back, either a 12 or a 20. I realize that the fronts should wear more but the discrepancy is pretty significant. I’ve worn down to almost the backing plate a set of XP10s, and close to it a set of XP20s, and the rears look almost new (they’re XP10s).