HPDE experiments, results and observations

[rhyary]

WGI tire configuration
Rear used from last year 305/30/19 Corasa (60 tw)
Front used from last year 265/35/19 ADOR8

The ADOR8 still have some tread left but are glazed and some missing rubber. At $125/tire not worth squeezzing the last milage out of them.

The rears are still good.

Since I bought the same Corsa for the front but 285/30/19 because well, they went on sale and I could not ressist. I will be for short time on the tire but not my ideal sizing.

So next is Corsa 305/30/19 rear (used) and 285/30/19 front (sticker and heat cycled) going to LRP.

[DRLane]

Time to go straight water with wetter, to avoid dumping gallons of coolant. Would’ve been a major bummer to send someone behind you into a wall through no fault of their own.

[rhyary]

Originally Posted by DRLane

Time to go straight water with wetter, to avoid dumping gallons of coolant. Would’ve been a major bummer to send someone behind you into a wall through no fault of their own.

Yes, but we are 30 cars on the track with 28 cars with coolant

[DRLane]

Originally Posted by rhyary

Yes, but we are 30 cars on the track with 28 cars with coolant

It’s a single step in the right direction, right? Which would you prefer to be behind with that rebuilt car?

[rhyary]

Originally Posted by DRLane

It’s a single step in the right direction, right? Which would you prefer to be behind with that rebuilt car?

When you right you right.
We had a Ford GT spill coolant at T-9 , a few other cars spill oil. Spills can and do happen. You just hope to not be the one behind.

I already tried the water wetter route and it did not work for me. In October I am heading to the track at below freezing temp and so is the end of March here.

If you advise me to get a heated garage, a trailer and a tow vehicle, you won’t be the first, and you will be right again. :-)

[DRLane]

Originally Posted by rhyary

When you right you right.
We had a Ford GT spill coolant at T-9 , a few other cars spill oil. Spills can and do happen. You just hope to not be the one behind.

I already tried the water wetter route and it did not work for me. In October I am heading to the track at below freezing temp and so is the end of March here.

If you advise me to get a heated garage, a trailer and a tow vehicle, you won’t be the first, and you will be right again. :-)

You can put the smallest amount of coolant in and test the freezing rate. It doesn’t take much to have protection to 32°. Also, the cars coolant won’t freeze during a track day down time. Maybe it you left it out all night in 15°, but 1.5 hour paddock stints? Naw.

Don’t trailer We both riding that line.

[rhyary]

My oil pressure last year (green line) was terrible compares to this year.

New oil pump, Carbahn buffled oil pan, rebuild engine all contributing. But 25psi at 7000 rpm at the esses is not a good thing.

Having oil pressure sensor connected AIM logger? that is a good thing.
.

[rhyary]

I have been interested in brakes and braking for a long time. One reason is that when I go to the track, my accelaration is determained by the car. But the braking is more in my control. The less I brake, the faster I go.

It is hard to find braking information from a professional driver on street tires. And for once I found a video that shows brake PSI.

It is amazing to see that he never goes above 600 psi. And I thought my 800-900 is light braking.

https://youtube.com/watch?v=JCOVs_hm...4gMpBM79z20zKV

At VIR he goes to 688 into T-1. Still much lighter than my “light” brake.

I am making assumptions. The dispaly says B% but this looks to me like PSI.

The Supra (BMW M2) has front brakes and rear brakes. It does not have a pedal brake like the E92 M3. So I don’t know how hard he press on the pedal. I only know what the car does. Again, I am making assumptions since the car might have brake pressure sensor installed, or it is non-aim CAN ECU that found away to get pedal pressure.

So take this post with some healthy dose of skepticism.

[M1500Z]

I think you'll find it pretty difficult to make direct comparisons between cars and brake pressures. As you mentioned, the F8X and Supra can provide front and rear brake pressure through the CAN bus where the E9X has brake pedal pressure (lucky), but it's also likely master cylinder piston size, number of pistons and sizes for the brake calipers, and then how much clamping force is needed because of bias, rotor diameters, etc.

I don't know what the number that's being represented in that video is, but the factory race cars have custom configurations for their data systems—the M2 CS Racing provides a lot more data than is available through Aim and I've sadly not been able to get a CS Racing protocol.

Just to humor you, the PSI is pressure at the pedal, yeah? What are your front and rear brake axle pressures? Simple math should get you that. For reference, my max pressures are ~1600psi front and 2300psi rear, but unfortunately I have no pedal pressure to reference.

[rhyary]

M1500Z
The E92 M3 is unique from what I have seen.
I get pedal pressure, and all four individual brake pressue. So it alows me to see what I do, and what the wheels get from the ABS.

Otherwise, your points are well taken.

[rhyary]

I had the pleasure of driving a student’s car yesterday at LRP.

It was a brand new Porsche GT4 RS with 1800 miles on it. It was drizzling and I could not be too agressive on it. I am never aggrssive on students car, but on wet track I am extra carful. Well what can I say, the car felt terrific. What impressed me the most was how wonderful the PDK feels compairs to the DCT. There are no clutch slipping. It does not try to make you comfortable. The gear changes are literally feels like a shotgun went off.

Changing gears are an event withing HPDE event.

If I had this car I would just take for a ride so I can change gears.

[D_SheerDrivingPleasure]

Originally Posted by rhyary

I had the pleasure of driving a student’s car yesterday at LRP.

It was a brand new Porsche GT4 RS with 1800 miles on it. It was drizzling and I could not be too agressive on it. I am never aggrssive on students car, but on wet track I am extra carful. Well what can I say, the car felt terrific. What impressed me the most was how wonderful the PDK feels compairs to the DCT. There are no clutch slipping. It does not try to make you comfortable. The gear changes are literally feels like a shotgun went off.

Changing gears are an event withing HPDE event.

If I had this car I would just take for a ride so I can change gears.

Long gearing no? Big Bend is probably a 2nd gear corner in that car vs 3rd in most other cars.

Anyway, another forum member was on track with a 4RS recently at WGI and while it was fast it was outmatched by a better driver in a F82 GTS. It just reminds you that this 80% driver / 20% car. It's fun to be the underdog. Don't get me wrong, I'd love to have a 4RS but I'd feel mighty inadequate giving point bys.

[DRLane]

Originally Posted by D_SheerDrivingPleasure

Long gearing no? Big Bend is probably a 2nd gear corner in that car vs 3rd in most other cars.

Anyway, another forum member was on track with a 4RS recently at WGI and while it was fast it was outmatched by a better driver in a F82 GTS. It just reminds you that this 80% driver / 20% car. It's fun to be the underdog. Don't get me wrong, I'd love to have a 4RS but I'd feel mighty inadequate giving point bys.

What if a better driver was in the 4RS?

[rhyary]

Originally Posted by D_SheerDrivingPleasure

Long gearing no? Big Bend is probably a 2nd gear corner in that car vs 3rd in most other cars.
.

That depends on how fast you go :-)

[D_SheerDrivingPleasure]

Originally Posted by DRLane

What if a better driver was in the 4RS?

Assuming equal drivers the GT4RS must be faster. BUT, I'd bet that with a few GTMore go-fast parts and tune that the GTS could hang.

For the sake of science I'd like to organize this TT.

[DRLane]

Originally Posted by D_SheerDrivingPleasure

Assuming equal drivers the GT4RS must be faster. BUT, I'd bet that with a few GTMore go-fast parts and tune that the GTS could hang.

For the sake of science I'd like to organize this TT.

If we’re going GTMore power, shouldn’t be a question. The GTS will run with it.

[razorlab]

Originally Posted by rhyary

I have been interested in brakes and braking for a long time. One reason is that when I go to the track, my accelaration is determained by the car. But the braking is more in my control. The less I brake, the faster I go.

It is hard to find braking information from a professional driver on street tires. And for once I found a video that shows brake PSI.

It is amazing to see that he never goes above 600 psi. And I thought my 800-900 is light braking.

https://youtube.com/watch?v=JCOVs_hm...4gMpBM79z20zKV

At VIR he goes to 688 into T-1. Still much lighter than my “light” brake.

I am making assumptions. The dispaly says B% but this looks to me like PSI.

The Supra (BMW M2) has front brakes and rear brakes. It does not have a pedal brake like the E92 M3. So I don’t know how hard he press on the pedal. I only know what the car does. Again, I am making assumptions since the car might have brake pressure sensor installed, or it is non-aim CAN ECU that found away to get pedal pressure.

So take this post with some healthy dose of skepticism.

That is a Supra GT4 which is based on a BMW Z4, not M2, although it does share some parts, like most BMWs. The Supra GT4 runs a standalone ECU (not OEM). That said, the normal factory Supra ECU has brake % and brake pressure front/rear over CAN. I have logged it on my Supra.

Since you are also familiar with Lime Rock. Last year before I put Aero on, I logged around 46% brake pedal at 1270psi front / 970psi rear braking into turn 1.

[rhyary]

Originally Posted by razorlab

.
Since you are also familiar with Lime Rock. Last year before I put Aero on, I logged around 46% brake pedal at 1270psi front / 970psi rear braking into turn 1.

.
What tires? At these brake pressures I would guess you are on slicks.

[razorlab]

Originally Posted by rhyary

.
What tires? At these brake pressures I would guess you are on slicks.

275/40/18 Nankang CRS 200tw

Also, about 1.6g decel.

[MaX PL]

Originally Posted by DRLane

If we’re going GTMore power, shouldn’t be a question. The GTS will run with it.

The Catalyst leaderboards show that a GT4RS has run a 1:58 at WGI. Third fastest time there this year from a Catalyst user.

[rhyary]

59.68 at LRP.
Finally.
Details later but car is awesome again.

59.99, 59.96, 59.68 and many laps below 61sec.

[tsk94]

Originally Posted by rhyary

59.68 at LRP.
Finally.
Details later but car is awesome again.

59.99, 59.96, 58.68 and many laps below 61sec.

Nice