- 4,803
- Dearborn, MI
- MotorCtyHamilton
It is challenging to build a really special tune. It can be time consuming and you never really feel like you were able to test every available option. At some point in time you need to call the tune finished and post it. I spent lots of time tuning the Subaru WRC '08 and took good notes through the process. I thought I would open up those notes to the public. I would hope that two things happen within this thread. First, someone who is learning how to tune will learn something from these notes. Second, that I may learn something from some of the more experienced tuners who may look at this and wonder why I didn't test something or would have approached settings in a different order. Feel free to post your thoughts below.
Dirt Testing - Eiger Nordwand G Trail Reverse
Subaru WRC '08 testing
Tune - Change - Comments
Stock Base Gearing too low. Never out of 4th gear. Downhill braking needs work. Car a bit drifty on 180s
Transmission Final Gear to 6.000, Top speed to 112 Never out of 5th gear. Capable of 4th and 5th gear in uphill section, but loss of accelleration here.
Transmission Max 6th gear, evened out 4th and 5th Gearbox is close. Looking for slight improvement in the uphill section.
Transmission 4th and 5th gears higher Better. Still think there is a tiny bit more in the uphill. Try 5th maxed and play with 4th a little higher.
Transmission 5th maxed. Evened out 3rd and 4th Pretty good. Wish I could get 5th to pull a little bit more up the hill, but it is maxed out.
Brakes to 10/10 Slightly shorter stopping distance, but very easy to lock up fronts and rears. Faster than stock, but not smooth. Lock up is indicated by the engine sound ceasing.
Brakes to 0/0 Longer braking zone, with zero lock up and the ability to trail brake while still having steering control. Lower settings likely to work well on dirt.
Brakes to 3/3 Shorter braking distance than 0/0 and still able to trail brake down to apex with no lock up. Try increasing rear to achieve braking zone rotation, but watch downhill section.
Brakes to 3/4 Slightly shorter stopping distance, but no noticeable difference in rear rotation. Try more rear.
Brakes to 3/5 Couldn't tell a difference. Kinda felt like it didn't stop as well, but still just as fast and no noticable rotation. Keep going.
Brakes to 3/7 Defanetly longer braking zone. Engine sound indicating that car is getting close to lock up. Try with ABS 0.
Brakes ABS 0 Instant lock up and very long braking zones. Try front higher than rear.
Brakes to 4/3 compared to 3/4 Similar stopping distances, but 3/4 has more steering response under braking. Try 2/4.
Brakes to 2/4 This. 2:05.544 Still learning this track a bit so time will improve naturally
Note NA Need to settle the rear of the car down a little and find more forward bite off the corners. Still learning this track a bit so time will improve some naturally. Tune Torque Split and LSD next.
Torque Stock 30/70 205.544
Torque 50/50 I thought this would kill the car's cornering ability. Instead, it greatly reduced the rear end driftiness and provided more forward bite off the corners.
LSD Stock 10/20/10 and 10/40/20 Start with what I am trying to solve. A little more rotation at entry and around mid corner and more forward bit off the corners?
LSD 10/45/7 and 10/20/12 A bit of the spool thoery - keep the front pretty locked under acceleration, but open under decel. Set the rear more like a FR car but with more decel stability because of the downhill sections. Needs more mid corner and a bit less stability under downhill braking.
LSD 10/35/7 and 10/18/11 Better mid corner and exit. Looking for more stability on entry and better turning ability on exit.
LSD 10/35/7 and 10/12/15 Better exit. More stable entry - too stable.
LSD 10/35/7 and 10/12/13 13 was too loose. Went back to 14. The LSD seems to be even more important on dirt than on tarmac. Small changes seem to pay big dividends. Car has reached a bit of a plateau. Front/rear balance seems to be close. The car needs much more side bite. Still running defaul suspension settings so the gain may come from there. Would still like to test a few more LSD settings just to see what they do.
LSD 15/35/7 and 10/12/14 Adding front initial torque let the car turn in better off throttle and I was more able to hug the apex.
LSD 15/35/7 and 15/12/14 Adding rear initial torque made the car actually get tail happy mid corner.
LSD 15/35/7 and 12/12/14 Hard to tell a difference.
LSD 15/35/7 and 10/12/14 Not sure there is much left to gain from the LSD. Car feels pretty well balanced, a slight tail happy mid-corner, but it feels pretty good. 205.071 lap time
Camber 3.0/2.0 Stock is 2.0/1.0. More grip and no loss of straight line traction or braking. Dirt cars like high camber. Time to test the limits. 204.493 lap time so far.
Camber 4.0/3.0 A surprising amount of increase in the feeling of grip. The lap time is only slightly better at 204.273 but the car was way more consistent and easier to get it down to the apex. The increase in rear grip felt more than the increase in front grip. Could be that I am getting close to the sweet spot for rear camber?
Camber 5.0/4.0 It took me a while to match the ghost, so this setting is definitely a little slower than the previous. The car did feel more stable in the massive downhill section of the track but was not as grippy in the uphill or top section of the track. I also felt like turn in was improved, but then mid corner the back would come around and cause that drifty, slidy no grip thing.
Camber 4.5/3.0 203.180 kinda says it. Good turn in, but a bit of snap oversteer mid corner, but driveable. Great grip from all four wheels on corner exit. I will stick with this camber for now, but think there may be some more fine tuning later to find a few more tenths. Try 4.2/3.0 and 4.5/3.3 later during tuning.
Rear toe from 0.20 to 0.00 Lift off the throttle and she wants to rotate. This did not add any grip, just allowed the car to rotate to be pointing at the apex. The increased rotation on entry was offset by a negative effect on corner exit and on downhill stability. I could run on top of the ghost, but there was very little room for error. I think the car still needs some rear toe in.
Rear toe 0.10 then 0.15 0.15 was better. Allowed for a little rotation over stock setting. Still a little unstable on exit. Thinking about 0.18 for this setting.
Rear toe 0.18 Best. Good entry rotation without killing exit. Now I am chasing more mid corner front grip which I hope will either maintain or slightly increase corner exit grip.
Front toe from 0.00 to -0.15 Front toe works as advertised and much like it does on tarmac. Better mid corner turning which also improved exit. Only a slight drop in lap time, but a better feeling car.
Front toe -0.25 Great turn in, but made the rear loose on exit. Two choices: a) less front negative toe b) more rear positive toe. Choosing closer to zero on the front.
Front toe -0.20 The car is working so well right now, I am not sure what to expect from the left side of the suspension settings.
Ride height from zero to +0.20/+0.20 Maxed ride height showed absolutely no difference.
Ride height -0.20/-0.20 Noticeably better. More able to hug the curves. Better control in transitions from one corner to the next. Felt like more grip.
Ride height -0.40/-0.40 Had to work hard to stay with ghost. Close lap times, but not as in control. A bit more drifty than the previous setting. Not as grippy.
Ride height -0.50/-0.50 Can't believe that this actually drove o.k. on dirt. It was still drifty and even a tick slower on the lap time.
Ride height -0.30/-0.30 Ride height for this car on dirt is between -0.20 and -0.30.
Ride height -0.25/-0.25 Baseline for further suspension testing. Come back here for fine tuning of front to rear balance. 202.124 lap time
Dampers Ext 2/2, Comp 2/2 Stock is all sixes across the board. First attempt is to soften dampers to be closer to spring rates.
Dampers Ext 1/4, Comp 1/4 Not much difference in dampers at all. Think the lap time is getting down there for this car and there may not be much more to gain. This setting felt more comfortable. Was very easy to drive right on top of the ghost and to run 202s
Aero from 15/20 to 10/25 Was looking for more corner exit rear stability. This did that, but took away some corner entry.
Camber 4.5/3.2 What I was looking for - a bit more stable on exit without killing turn in. Did that slightly. Keeping this setting for now.
ARBs from 6/6 to 2/2 Not much difference. I couldn't keep up with the ghost as well which means this is a touch slower or I a getting sleepy.
ARBs to 4/4
Dampers Ext 4/4, comp 4/4 Car is pretty good. Try spring and damper combinations.
Springs Front stock 8/rear from stock 6 up to 7.5 More grip mid corner.
Springs 7.5/7.5 Little more entry and exit grip.
Camber 4.2/3.2 Back to 4.5/3.2.
Only fine, fine tuning left. This car is going to be a low 2:02 lap time for me.
Dirt Testing - Eiger Nordwand G Trail Reverse
Subaru WRC '08 testing
Tune - Change - Comments
Stock Base Gearing too low. Never out of 4th gear. Downhill braking needs work. Car a bit drifty on 180s
Transmission Final Gear to 6.000, Top speed to 112 Never out of 5th gear. Capable of 4th and 5th gear in uphill section, but loss of accelleration here.
Transmission Max 6th gear, evened out 4th and 5th Gearbox is close. Looking for slight improvement in the uphill section.
Transmission 4th and 5th gears higher Better. Still think there is a tiny bit more in the uphill. Try 5th maxed and play with 4th a little higher.
Transmission 5th maxed. Evened out 3rd and 4th Pretty good. Wish I could get 5th to pull a little bit more up the hill, but it is maxed out.
Brakes to 10/10 Slightly shorter stopping distance, but very easy to lock up fronts and rears. Faster than stock, but not smooth. Lock up is indicated by the engine sound ceasing.
Brakes to 0/0 Longer braking zone, with zero lock up and the ability to trail brake while still having steering control. Lower settings likely to work well on dirt.
Brakes to 3/3 Shorter braking distance than 0/0 and still able to trail brake down to apex with no lock up. Try increasing rear to achieve braking zone rotation, but watch downhill section.
Brakes to 3/4 Slightly shorter stopping distance, but no noticeable difference in rear rotation. Try more rear.
Brakes to 3/5 Couldn't tell a difference. Kinda felt like it didn't stop as well, but still just as fast and no noticable rotation. Keep going.
Brakes to 3/7 Defanetly longer braking zone. Engine sound indicating that car is getting close to lock up. Try with ABS 0.
Brakes ABS 0 Instant lock up and very long braking zones. Try front higher than rear.
Brakes to 4/3 compared to 3/4 Similar stopping distances, but 3/4 has more steering response under braking. Try 2/4.
Brakes to 2/4 This. 2:05.544 Still learning this track a bit so time will improve naturally
Note NA Need to settle the rear of the car down a little and find more forward bite off the corners. Still learning this track a bit so time will improve some naturally. Tune Torque Split and LSD next.
Torque Stock 30/70 205.544
Torque 50/50 I thought this would kill the car's cornering ability. Instead, it greatly reduced the rear end driftiness and provided more forward bite off the corners.
LSD Stock 10/20/10 and 10/40/20 Start with what I am trying to solve. A little more rotation at entry and around mid corner and more forward bit off the corners?
LSD 10/45/7 and 10/20/12 A bit of the spool thoery - keep the front pretty locked under acceleration, but open under decel. Set the rear more like a FR car but with more decel stability because of the downhill sections. Needs more mid corner and a bit less stability under downhill braking.
LSD 10/35/7 and 10/18/11 Better mid corner and exit. Looking for more stability on entry and better turning ability on exit.
LSD 10/35/7 and 10/12/15 Better exit. More stable entry - too stable.
LSD 10/35/7 and 10/12/13 13 was too loose. Went back to 14. The LSD seems to be even more important on dirt than on tarmac. Small changes seem to pay big dividends. Car has reached a bit of a plateau. Front/rear balance seems to be close. The car needs much more side bite. Still running defaul suspension settings so the gain may come from there. Would still like to test a few more LSD settings just to see what they do.
LSD 15/35/7 and 10/12/14 Adding front initial torque let the car turn in better off throttle and I was more able to hug the apex.
LSD 15/35/7 and 15/12/14 Adding rear initial torque made the car actually get tail happy mid corner.
LSD 15/35/7 and 12/12/14 Hard to tell a difference.
LSD 15/35/7 and 10/12/14 Not sure there is much left to gain from the LSD. Car feels pretty well balanced, a slight tail happy mid-corner, but it feels pretty good. 205.071 lap time
Camber 3.0/2.0 Stock is 2.0/1.0. More grip and no loss of straight line traction or braking. Dirt cars like high camber. Time to test the limits. 204.493 lap time so far.
Camber 4.0/3.0 A surprising amount of increase in the feeling of grip. The lap time is only slightly better at 204.273 but the car was way more consistent and easier to get it down to the apex. The increase in rear grip felt more than the increase in front grip. Could be that I am getting close to the sweet spot for rear camber?
Camber 5.0/4.0 It took me a while to match the ghost, so this setting is definitely a little slower than the previous. The car did feel more stable in the massive downhill section of the track but was not as grippy in the uphill or top section of the track. I also felt like turn in was improved, but then mid corner the back would come around and cause that drifty, slidy no grip thing.
Camber 4.5/3.0 203.180 kinda says it. Good turn in, but a bit of snap oversteer mid corner, but driveable. Great grip from all four wheels on corner exit. I will stick with this camber for now, but think there may be some more fine tuning later to find a few more tenths. Try 4.2/3.0 and 4.5/3.3 later during tuning.
Rear toe from 0.20 to 0.00 Lift off the throttle and she wants to rotate. This did not add any grip, just allowed the car to rotate to be pointing at the apex. The increased rotation on entry was offset by a negative effect on corner exit and on downhill stability. I could run on top of the ghost, but there was very little room for error. I think the car still needs some rear toe in.
Rear toe 0.10 then 0.15 0.15 was better. Allowed for a little rotation over stock setting. Still a little unstable on exit. Thinking about 0.18 for this setting.
Rear toe 0.18 Best. Good entry rotation without killing exit. Now I am chasing more mid corner front grip which I hope will either maintain or slightly increase corner exit grip.
Front toe from 0.00 to -0.15 Front toe works as advertised and much like it does on tarmac. Better mid corner turning which also improved exit. Only a slight drop in lap time, but a better feeling car.
Front toe -0.25 Great turn in, but made the rear loose on exit. Two choices: a) less front negative toe b) more rear positive toe. Choosing closer to zero on the front.
Front toe -0.20 The car is working so well right now, I am not sure what to expect from the left side of the suspension settings.
Ride height from zero to +0.20/+0.20 Maxed ride height showed absolutely no difference.
Ride height -0.20/-0.20 Noticeably better. More able to hug the curves. Better control in transitions from one corner to the next. Felt like more grip.
Ride height -0.40/-0.40 Had to work hard to stay with ghost. Close lap times, but not as in control. A bit more drifty than the previous setting. Not as grippy.
Ride height -0.50/-0.50 Can't believe that this actually drove o.k. on dirt. It was still drifty and even a tick slower on the lap time.
Ride height -0.30/-0.30 Ride height for this car on dirt is between -0.20 and -0.30.
Ride height -0.25/-0.25 Baseline for further suspension testing. Come back here for fine tuning of front to rear balance. 202.124 lap time
Dampers Ext 2/2, Comp 2/2 Stock is all sixes across the board. First attempt is to soften dampers to be closer to spring rates.
Dampers Ext 1/4, Comp 1/4 Not much difference in dampers at all. Think the lap time is getting down there for this car and there may not be much more to gain. This setting felt more comfortable. Was very easy to drive right on top of the ghost and to run 202s
Aero from 15/20 to 10/25 Was looking for more corner exit rear stability. This did that, but took away some corner entry.
Camber 4.5/3.2 What I was looking for - a bit more stable on exit without killing turn in. Did that slightly. Keeping this setting for now.
ARBs from 6/6 to 2/2 Not much difference. I couldn't keep up with the ghost as well which means this is a touch slower or I a getting sleepy.
ARBs to 4/4
Dampers Ext 4/4, comp 4/4 Car is pretty good. Try spring and damper combinations.
Springs Front stock 8/rear from stock 6 up to 7.5 More grip mid corner.
Springs 7.5/7.5 Little more entry and exit grip.
Camber 4.2/3.2 Back to 4.5/3.2.
Only fine, fine tuning left. This car is going to be a low 2:02 lap time for me.
