Race Tracking Your Supra - Information exchange

[decodeddiesel]

1 click turns off traction control. Long press turns off traction control + stability control. VSC = Vehicle Stability Control.

Stability control basically modulates the brakes if you are getting out of control. Also cuts some timing. It's not very invasive unless you are driving like an ape.

Traction control basically neuters everything: throttle, brakes, timing. If you are lowered on different size tires, etc it can be VERY invasive on the 2020's. It seems like each year after the 20, it was programmed to intervene a little less. On my 2020, it's basically undrivable on track with everything on. I run with 1 click off.

Just daily driving at the speed of traffic on the square V730s will ofter trigger TC on my 2020 during some turns. ? I can't believe how invasive it is on tires with a higher μ than stock.

My question is does Sport mode have any affect on the TC/VSC/allowable slip angle/wheel speed delta?

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[rwense]

Just daily driving at the speed of traffic on the square V730s will ofter trigger TC on my 2020 during some turns. ? I can't believe how invasive it is on tires with a higher μ than stock.

My question is does Sport mode have any affect on the TC/VSC/allowable slip angle/wheel speed delta?

Don't quote me but I believe it does allow for more slip angle. I only drive on track in sport with 1 click (meaning TC is off). I've only really had VSC be invasive once and that was the other day coming out of the gulch at Pitt Race on Nankang CRSs that were probably way over temp. According to the tire temp monitor they were high 130-140°F. I squeezed the throttle adding more and more as I straightened out and gave it the boot a bit too early. Felt the tail step out a bit and as it started going a bit more I felt it kick in and straighten me out. Other than that I've never felt it other than trying to set it off.

 

[FLtrackdays]

Just daily driving at the speed of traffic on the square V730s will ofter trigger TC on my 2020 during some turns. ? I can't believe how invasive it is on tires with a higher μ than stock.

My question is does Sport mode have any affect on the TC/VSC/allowable slip angle/wheel speed delta?

You know me, I don’t know shit about the engineering but (I’ve stayed at a Holiday Inn ?) I‘ve driven a ton in both modes. Bryan is right. It’s really hard to get VSC to come on (to feel it), unless I’m trying to induce a slide.

As far as the sport button, I’ve forgotten to hit it a whole session and was surprised how fast my lap times still were. So who knows how much it really makes a difference for what we’re doing. I’ve read in another thread somewhere that the drag guys turn if off. But I could be wrong about that.

Like you amigo, I’m just driving for fun. But love these questions! It is nice to know….

 

[FLtrackdays]

Question came up in a Florida BMW chat I’m in with a fellow Supra owner. He‘s driving “off season” during our hottest times and is getting ”fuel starvation“ for the 1st time ever. Dude has been tracking his Supra longer than me. He’s in a 2021. I’ve never experienced true fuel starvation but have heard y’all mention it. Additionally, he hasn’t changed anything else in his car since we’ve driven together.

Could this be heat related? I’ve driven on fumes and my car was fine - same track. Mega odd it’s just starting to happening now. However I’ve seen the craziest stuff happen in this swamp heat over the years. Someone on the BMW chat suggested maybe he’s driving faster, exposing that limits he didn’t notice before ?‍

 

[decodeddiesel]

Question came up in a Florida BMW chat I’m in with a fellow Supra owner. He‘s driving “off season” during our hottest times and is getting ”fuel starvation“ for the 1st time ever. Dude has been tracking his Supra longer than me. He’s in a 2021. I’ve never experienced true fuel starvation but have heard y’all mention it. Additionally, he hasn’t changed anything else in his car since we’ve driven together.

Could this be heat related? I’ve driven on fumes and my car was fine - same track. Mega odd it’s just starting to happening now. However I’ve seen the craziest stuff happen in this swamp heat over the years. Someone on the BMW chat suggested maybe he’s driving faster, exposing that limits he didn’t notice before ?‍

That's a great question.

Is it happening in long right handers like how it is often described? It seems that sustained lateral acceleration (lateral g's) are usually what causes it, not a shorter very high g corner.

It could very well be that he's getting more grip from a hotter road surface, but that becomes diminished quickly as tires overheat faster.

I'm trying to think of how else the heat could cause this. ?

 

[FLtrackdays]

It could very well be that he's getting more grip from a hotter road surface, but that becomes diminished quickly as tires overheat faster.

Wow, that seems so possible… I’ll have to look back on the chat and/or ask him. Great suggestion!

 

[Rocksandblues]

Fuel starve is a real thing. Until I add a surge tank I have to keep tank 3/4 or full. Places like VIR I top off after each session

your friend could be driving harder and just now finding the Gs or could be a combo of heat soak and fuel

the sport button only firms up the stock struts, opens exhaust valve, and makes the pedal response more aggressive and maybe some more exhaust pops. Does not add hp

 

[decodeddiesel]

Fuel starve is a real thing. Until I add a surge tank I have to keep tank 3/4 or full. Places like VIR I top off after each session

your friend could be driving harder and just now finding the Gs or could be a combo of heat soak and fuel

the sport button only firms up the stock struts, opens exhaust valve, and makes the pedal response more aggressive and maybe some more exhaust pops. Does not add hp

Agree on all points.

The Sport mode also changes quite a bit of transmission behavior. Fully automatic mode is a lot different. Different shift points, holds gears longer, etc. It also seems to make a difference with the shifting speed in Manual mode.

Speaking of that, does anyone use the xHP transmission tuning on their car?

 

[Evolution]

Speaking of that, does anyone use the xHP transmission tuning on their car?

I do and love it.

 

[kaj]

Speaking of that, does anyone use the xHP transmission tuning on their car?

I do and love it.

I'm letting others test it out for about a year before I jump in. I haven't found a need for anything different, but willing to try as long as I know the car will survive.

 

[razorlab]

Is anyone logging oil pressure on track? I've had this interesting thing that at the beginning of the year, I logged 78-80psi or so at WOT on the street. Now for the last couple months I see mid 60's, but the target oil pressure is the same. I didn't log target oil pressure earlier in the year so wasn't sure if it was higher because of the oil additive I used for the turbo install or not.

Since target is the same as actual i'm not too worried but that data point that it was 10-15psi higher before has me slightly concerned.

WOT:

 

[razorlab]

Adding to the above after finding the Oil pressure target table in the ECU...

5500 hPa = 79psi - 14.4psi ambient = 65psi (exactly what I log at WOT)
2500 hPa = 36psi - 14.4psi ambient = 21psi (exactly what I log at idle)

Okay, I feel better now.

 

[Evolution]

I'm letting others test it out for about a year before I jump in. I haven't found a need for anything different, but willing to try as long as I know the car will survive.

I'm fine with being the test victim. But I do have to say, once you get the tune, you will be kicking yourself for not doing it earlier.

 

[FLtrackdays]

I'm fine with being the test victim. But I do have to say, once you get the tune, you will be kicking yourself for not doing it earlier.

You and @kaj can easily apply additional knowledge, time, resources needed. No doubt it’d be more fun! But for me, one stupid thing were to go wrong and I’d be at someones mercy.

Meanwhile, I’m still looking at Bryan’s picture above trying to figure out what the difference between those two oil temp pics/graphs ?

 

[razorlab]

Meanwhile, I’m still looking at Bryan’s picture above trying to figure out what the difference between those two oil temp pics/graphs ?

ahah oops, I accidentally put the exact same screenshot for both. lolz

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