Triumph Posted October 15, 2014 Report Share Posted October 15, 2014 ***Disclaimer*** I am by no means an expert on track driving. In a quest to learn as much as I can about driving (improving my lap times) I have attended several HPDE events. (plus it’s a blast!) Unfortunately the majority of driving instructors have encountered cannot explain how to drive faster other than teaching the “line” for that particular course. And even fewer can diagnose real time your mistakes and explain what you are doing wrong and how to improve. My co-worker that introduced me to track driving also instructs. He teaches his students to be able to self identify what they are doing wrong/right and what the feedback their car is telling them to be able to improve. He put together the following information that he hands out to his student drivers. It has been so helpful to me that I thought it would make for a good post for other aspiring track day drivers. Driving Techniques Big picture (Things to know and apply) 1.Visualize the track and where the car needs to end up – Visualize plan of attack/line ahead of where you are – this makes it possible to hit your reference points consistently. (for example know what turn is coming up next so you can plan for it instead of reacting to it) 2. It is better to enter slower into a corner to be able to get back on the gas sooner and harder than it is to enter a corner faster and have to delay accelerating out of the corner (missing the apex and not being able to start the unwind at the apex) 3. Using the following reference points can maximize (fine tune) lap time improvements: - Brake point - Turn-in point (turn-in setup point – at correct speed and correct place on track) - Apex point (note: there are double apex corners) - Accel point - Track-out point 4. The longer the corner the more reference points may be needed between the 4 key reference points - Braking - Turn-in - Apex - Accelerating 5. Common cornering errors to watch for: - Turn-in too early Leads to early apex-can cause being too wide on run-out (running off track!) - Apex too early Either turn-in too early / too sharply / too quickly (all or combination of) At speed causes big risk of being too wide on run-out (running off track) - Braking too late Leads to late turn-in and missed apex-off track (dirt time) is a valid risk - Not accomplishing the turn-in setup Leads to all of the above errors - Accelerating too early Leads to missed apex and or pushing too wide on run-out (running off track) 6. Tires – tire traction cannot exceed 100% of the tires capabilities – above 100% results in slip You can spread the 100% to different tasks but the max tire use sum cannot be greater than 100% --anything over 100% will result in slip angles/spinout/etc. You can do the following with any percentage split: 0%-100% acceleration (100% acceleration equals no corner forces) 0%-100% braking (100% braking equals no corner forces) 0%-100% cornering (100% cornering equals no accel or braking forces Example: 80% braking & 20% cornering Example: 20% braking & 80% cornering Example: 50% cornering & 50% acceleration Example: 90% cornering & 10% acceleration Best tire use (lowest lap times) during cornering is when just slightly more than 100% traction is being used (some slip) Slip angle degree >4° & <10° (direction front tires are pointing vs actual arc being cut) Percent slip >8 & <16 (direction front tires are pointing vs actual arc cut) 7. Typical pedal sequence for most corners requiring some level of braking: Full accel – Full brake – Trail brake/Turn-in – Unwind/Accel – Full accel Link to comment Share on other sites More sharing options...
Triumph Posted October 15, 2014 Author Report Share Posted October 15, 2014 Car Control (Proactive & Reactive) 1. Control (steering wheel, throttle, brake) movements should be smooth & limited – allows the car to SET quicker and stay SET (SET is when weight transfer has stabilized) – thus leading to better car feedback, better car control, and lower lap times - Note: limited movement means move the control the right amount the first time – i.e. if you turn-in too sharply you will have to turn-out some to correct the mistake – the car will have to take at least two SETs versus one when done correctly 2. Smooth control of weight transfer is best way to avoid too much oversteer or a possible spin - Braking causes weight transfer to front tires thus reducing the grip of the rear tires - Lifting off the throttle causes deceleration which causes weight transfer to front tires thus reducing the grip of the rear tires while increasing the grip of the front tires – the risk of oversteer/spin increases due to engine braking dragging on the rear tires and front end slip angle reducing (tighter arc being cut) 3. If a spin happens and cannot be recovered: - Apply full braking (you have best chance of staying on track with this approach) - Push clutch in (if applicable) when applying full braking 4. Correct understeer (excessive front tire slip—front end pushing too wide of an arc in a corner): - Increase front tire grip by proper weight transfer—lift off throttle or slightly apply brakes—thus causing weight transfer to front tires which increases front tire grip and decreasing rear tire grip (causing shift towards oversteer or at least less understeer) - Extreme excessive front tire slip angle may require turning out of the corner some to reduce/stop the slipping so some braking can be applied reducing speed so increased turn angle can be reapplied (making a tighter turn with less steering slip). 5. Correct oversteer (rear-end coming around to the outside of the corner—precursor to spin) - If oversteer occurs while off throttle then accelerate lightly to cause weight transfer to rear tires—thus shifting towards understeer or at least less oversteer - If oversteer occurs while ON throttle (too much acceleration) then partially** relax throttle to reduce acceleration forces on rear tires—this will allow the rear tires to get closer to their traction limit of 100% utilization (tire grip is being split between corner and acceleration forces—you want to reduce the acceleration part so more grip can be applied to the corner part of the equation (reduced rear-end slip angle)) -DO NOT abruptly let off throttle—this can compound the oversteer transferring weight to the front tires so quickly that the rear tires lose what little traction they had worsening the oversteer leading to a spin 6. High speed corners or corner where slip angle plays a part lasting more than one second—(for slight course/turn corrections steer more with the throttle than the steering wheel) - Lifting off the throttle in the corner causes weight transfer to front tires which generates more front tire grip so the car turns-in more (decreasing the front tires slip angle)—lifting off also decreases the rear tire grip (due to forward weight transfer) thus causing the rear-end to have a increased slip angle (shift towards oversteer) - Applying light throttle in the corner causes weight transfer to rear tires which generates more rear tire grip decreasing the front tire grip and increasing the front tire slip angle (shift towards understeer) thus forcing the car to cut a larger arc/turn 7. Important—downshifting (clutch engagement—causing engine braking) is a cause for spin (oversteer situation)—it is caused by weight transfer to the front tires while engine braking drags on rear tires—correct for this by: - Always try to downshift while in a straight line—try to negate downshift in a corner - Apply heel-toe downshifting—if you cannot heel-toe yet then: - Engage clutch slowly on downshift so engine RPMs come up slowly—thus greatly reducing the spike in engine braking on rear tires and lessening the aggressiveness of the weight transfer to front tires 8. Important—if at all possible do not come off throttle at the same time as turning into a corner (car becomes UN-SET)—rear tire grip decreases while front tire grip increases, due to forward weight transfer—combination for spin Link to comment Share on other sites More sharing options...
Triumph Posted October 15, 2014 Author Report Share Posted October 15, 2014 Handling and Tuning Charts—Note: All of these are inter-related. Adjusting one item affects others. Examples on how to read the following charts: To decrease understeer you would increase the front tire pressure To decrease oversteer you would lessen the front tire pressure Tires/Wheel Tuning Fixes Adjustment Decrease Understeer Decrease Oversteer Front tire pressure Higher Lower Rear tire pressure Lower Higher Front tire Width Wider Narrower Rear tire Width Narrower Wider Front tire Aspect Ratio Lower Higher Rear tire Aspect Ratio Higher Lower Front wheels Tracking Width Wider Narrower Rear wheels Tracking Width Narrower Wider Front tire Tread Depth / UTQG Reduce Increase Rear tire Tread Depth / UTQG Increase Reduce Front wheel weight Lighter Heavier Rear wheel weight Heavier Lighter Suspension Tuning Fixes Adjustment Decrease Understeer Decrease Oversteer Front Toe Toward Toe-Out Toward Toe-In Rear Toe Toward Toe-Out Toward Toe-In Front Camber More Negative More Positive Rear Camber More Positive More Negative Front Caster More Positive More Negative Front Springs Soften Stiffen Rear Springs Stiffen Soften Front Shocks Soften Stiffen Rear Shocks Stiffen Soften Front Sway-Bar Soften/Thinner Stiffen/Thicker Rear Sway-Bar Stiffen/Thicker Soften/Thinner Front Bushings Stiffen Soften Rear Bushings Soften Stiffen Other Tuning Fixes Adjustment Decrease Understeer Decrease Oversteer Front Brake Proportion Reduce pressure Increase pressure Rear Brake Proportion Increase pressure Reduce pressure Front Spoiler/Splitter Increase Downforce Reduce Downforce Rear Spoiler Reduce Downforce Increase Downforce Weight Distribution Move Rearward Move Forward Link to comment Share on other sites More sharing options...
silversurfer Posted October 15, 2014 Report Share Posted October 15, 2014 Great write up. Of course, if you have never done any of this, it may be nothing but Greek! 10 years ago I would have had no clue what you were talking about! Understanding is knowledge and knowledge is understanding.......... Link to comment Share on other sites More sharing options...
Kevin Patten Posted October 15, 2014 Report Share Posted October 15, 2014 All good points Triumph - Thanks for posting ! Link to comment Share on other sites More sharing options...
ViperNC Posted October 15, 2014 Report Share Posted October 15, 2014 My co-worker that introduced me to track driving also instructs. He teaches his students to be able to self identify what they are doing wrong/right and what the feedback their car is telling them to be able to improve. I'm always good at "self identifying" what I've done wrong as it is happening... DOH! Really great information here and always good to constantly refresh the correct techniques to get around the track quickly (dare I say fast) and safely. Set up notes are excellent as well. Something I always struggle with.... Link to comment Share on other sites More sharing options...
shlbygt Posted October 19, 2014 Report Share Posted October 19, 2014 ***Disclaimer*** I am by no means an expert on track driving. In a quest to learn as much as I can about driving (improving my lap times) I have attended several HPDE events. (plus it’s a blast!) Unfortunately the majority of driving instructors have encountered cannot explain how to drive faster other than teaching the “line” for that particular course. And even fewer can diagnose real time your mistakes and explain what you are doing wrong and how to improve. Two things are could be happening here. One, you need to know the line in order to go faster. Maybe you are not driving the line all that well and the instructor feels adding more information is premature. Second, it sounds like you have run into some crappy instructors. Don't tell me they rode with you for a session or two and then let you solo. Any semi competent instructor can tell what a student is going to do wrong well before they do it. It is called self preservation. When I ask a novice student what they did wrong in the previous turn they mucked up, their response 90% of the time is "too much speed". My response is often: not enough braking before the corner coming off the brakes too soon shifting in the corner turning in too early getting back on the throttle too soon not tracking out, etc More alarming, is when you ask them how a particularly poorly driven corner felt, and they respond with "fine". Also, there should be no discussion of lap times as a novice. Once a driver has mastered some consistency and car control skills, then timing can be helpful. A video camera that shows the driver's hands and vision is more beneficial than a lap timer. Here is a video of someone who has likely never had an instructor and has absolutely no clue how badly they are driving as shown by their comments as to what they did wrong. I literally can't find one thing he did correctly. Not a ton of track experience and unfortunately in the wipeout it looks like I made two mistakes. 1) I was to slow getting back to neutral after the initial counter-steer (which appeared timing wise I was ok on). 2) I let off the gas which is one of the reasons it started gripping sooner than I thought. My front right-tire got debeaded/flat and possibly some damage. Also some of my wheel well plastic got pulled out/lost and my washer fluid reservoir cracked. Sucks there was some damage and the huge amount of sand that got in the car but still glad I got the experience with no major damage. I felt sorry for the car and was waiting for the shifter to come off in his meaty hand. The stability control was working overtime and finally had enough. If this car had no traction or stability control, he would not have made a single lap before doing some agricultural driving. BTW, he now has a GT-R. Link to comment Share on other sites More sharing options...
ViperNC Posted October 19, 2014 Report Share Posted October 19, 2014 Well.... That was "interesting". Clearly this guy doesn't understand the concept of "smooth is fast". Link to comment Share on other sites More sharing options...
svttim Posted October 28, 2014 Report Share Posted October 28, 2014 Good collection of stuff. I would like permission to use it. Can you ask him? Link to comment Share on other sites More sharing options...
desire2bfast Posted November 15, 2014 Report Share Posted November 15, 2014 Ouch! That was. . . .painful to watch. Link to comment Share on other sites More sharing options...
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