- 11
- Australia
I'd like to share a few observations on the tyre ("tire" across the pond) model and the driving practices it elicits. Feel free to tell me I'm wrong, I've had limited experience with this game and no sim racing for a long time before that. I'm trying to test my understanding of what's going on rather than hold court. In the distant past I was a motorcycle road racer and I've previously designed the driving model for a series of driving games. While they were primarily dirt track games with vastly different parameters the fundamentals of slip angle and ratio and tyre load still apply.
I'll state from the outset that I'm enjoying the game. Force feedback in particular has come some way since I was working in the space in the late 90s and early 00s. That said, despite the updates (and I haven't driven the earlier versions) the transition from grip to slip seems excessively abrupt, even for a sim. In the mid engine cars this manifests as a sudden loss of rear traction on a trailing throttle most particularly in corner combinations. In the front engine rear drive cars it's a sudden uncorrectable spin under acceleration while the tyres are experiencing lateral turning forces. And the 4WD vehicles seem to suffer from a lesser combination of both. As for the rear engine cars, I endured the Porsche cup through the Cafe Menu system and I'm in no hurry to go back.
Without more experience or access to the internals it's difficult to determine where this is coming from. The drop in lateral force with slip angle might be excessive, it could be an excessive drop in longitudinal force with increasing slip ratio (wheelspin relative to forward velocity of the tire), an unhappy marriage of both or errors in the effect of tyre load (weight transfer) on grip coefficient. Whatever the cause, for my money the accuracy of a driving experience is most meaningfully measured by the driving behaviours that top competitors employ and it's here that GT7 is found somewhat wanting. Note that even an entirely accurate model may illicit unrealistic driving practices if real world driving cues are absent. For this reason my bias (if any) would be to make the model slightly more forgiving than reality so that drivers can still push as hard and consistently as they might in the real world. As an example when my race bike would break traction exiting a turn there would be a set of rotational motion and vibrational cues that would be absent in all but the most dedicated sim rig allowing faster response and a greater chance of saving the slide even before the engine note changed.
I've been particularly focussed on the Group 3 daily races at Red Bull Ring this week and particularly using the WRX. It seems the drivers getting into the 1:27s and 1:28s are doing some radical short shifting. 1st to 3rd etc or 2nd straight through to 4th. At first I thought there might be some odd low range torque boost they were getting in the WRX but it was only when I switched TCS from 1 to zero that I finally grokked. It's simply the surest way to get the power down without your lateral tire forces shrinking to near zero in the blink of an eye. You can get similar results by judiciously riding the throttle but given the delay in response and difficulty in gauging exactly what your throttle setting is its more reliable and just as effective to be running a higher gear. I'd thought that I wasn't losing much by running TCS at 1 and getting the physics model to behave with a little more predictability but as I gained more experience at Red Bull I realised it was cutting in on fast turns which I could otherwise take flat out. As such having it off is the best way for me to make significant improvements in my lap times but it also means I'm spinning out more frequently.
The other thing that strikes me as a little odd is the downshift of an extra gear purely for the purposes of getting the car to turn in. While a bit of turn in might be expected it's enough that you have to counter steer when you get it wrong. Once again this might be down to inaccuracies in weight transfer, tyre load to grip or excessive loss of rear lateral traction under engine braking.
I'll state from the outset that I'm enjoying the game. Force feedback in particular has come some way since I was working in the space in the late 90s and early 00s. That said, despite the updates (and I haven't driven the earlier versions) the transition from grip to slip seems excessively abrupt, even for a sim. In the mid engine cars this manifests as a sudden loss of rear traction on a trailing throttle most particularly in corner combinations. In the front engine rear drive cars it's a sudden uncorrectable spin under acceleration while the tyres are experiencing lateral turning forces. And the 4WD vehicles seem to suffer from a lesser combination of both. As for the rear engine cars, I endured the Porsche cup through the Cafe Menu system and I'm in no hurry to go back.
Without more experience or access to the internals it's difficult to determine where this is coming from. The drop in lateral force with slip angle might be excessive, it could be an excessive drop in longitudinal force with increasing slip ratio (wheelspin relative to forward velocity of the tire), an unhappy marriage of both or errors in the effect of tyre load (weight transfer) on grip coefficient. Whatever the cause, for my money the accuracy of a driving experience is most meaningfully measured by the driving behaviours that top competitors employ and it's here that GT7 is found somewhat wanting. Note that even an entirely accurate model may illicit unrealistic driving practices if real world driving cues are absent. For this reason my bias (if any) would be to make the model slightly more forgiving than reality so that drivers can still push as hard and consistently as they might in the real world. As an example when my race bike would break traction exiting a turn there would be a set of rotational motion and vibrational cues that would be absent in all but the most dedicated sim rig allowing faster response and a greater chance of saving the slide even before the engine note changed.
I've been particularly focussed on the Group 3 daily races at Red Bull Ring this week and particularly using the WRX. It seems the drivers getting into the 1:27s and 1:28s are doing some radical short shifting. 1st to 3rd etc or 2nd straight through to 4th. At first I thought there might be some odd low range torque boost they were getting in the WRX but it was only when I switched TCS from 1 to zero that I finally grokked. It's simply the surest way to get the power down without your lateral tire forces shrinking to near zero in the blink of an eye. You can get similar results by judiciously riding the throttle but given the delay in response and difficulty in gauging exactly what your throttle setting is its more reliable and just as effective to be running a higher gear. I'd thought that I wasn't losing much by running TCS at 1 and getting the physics model to behave with a little more predictability but as I gained more experience at Red Bull I realised it was cutting in on fast turns which I could otherwise take flat out. As such having it off is the best way for me to make significant improvements in my lap times but it also means I'm spinning out more frequently.
The other thing that strikes me as a little odd is the downshift of an extra gear purely for the purposes of getting the car to turn in. While a bit of turn in might be expected it's enough that you have to counter steer when you get it wrong. Once again this might be down to inaccuracies in weight transfer, tyre load to grip or excessive loss of rear lateral traction under engine braking.
