Going around the bend, quickly.
- Thread starter tscaptain
- Start date
AndrewT
Member
I use my Gen 2 Cayman 2.9 with manual gearbox for the occasional hillclimb where there is a particular 90 degree left hand bend which I need to get round more quickly - this is partly because I don't carry enough speed around the bend but mostly because in second gear the engine has insufficient torque and therefor bogs down a lot before the power comes back in. I want to avoid dropping down into first as to do so feels a little harsh on the gearbox. I generally approach the bend as quickly as possible then brake hard before turning in and accelerating again, although I have no time to look at the rev counter I guess that at this point it's dropped down to less than 2k rpm.
My thoughts are:
My thoughts are:
- In order to carry more speed around the bend could I gain an advantage by using left foot braking, assuming that I could master the technique (probably easier said than done for someone who qualifies for a bus pass!).
- My car has a Sport button which I always use on the hill climb, this makes the throttle respond more quickly and adjusts the ESP settings, as I'm sure you all know. I've been wondering whether in fact, on this particular bend, using the Sport setting causes the throttle to open too quickly causing the engine to bog down due to the low revs and that using the normal throttle mode would feed the power in more gently? I hope you understand what I'm trying to say.
Steve Brookes
Moderator
Sounds very strange that the car could bog down in a 2nd gear corner. My guess is that the PSM is cutting the power. Turn it off and be prepared for it to be a bit lairy because after all that's what sprinting/motorsport is all about. [
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Steve Brookes
Moderator
BTW your idea of left foot braking probably won't help much while the PSM is on because it will dumb down the throttle response while the brake is being applied.
I find the gearing on my '07 Cayman S to be so long that I'm regularly in 1st gear for tight corners or on hills.
I never really let the engine drop under 2k rpm under any load, whether I'm "pushing-on" or not. 1st gear gets a lot of use, but like all cars the ration difference between 1st and 2nd makes that down-shift pretty unpleasant on the synchros (if not impossible in some cars) if you're not double-clutching the down-shift.
Rather than worrying about left-foot braking, I'd always recommend spending the time to first learn to do a clean double-clutch down-shift (no braking) and then learn to do it with heel-and-toe (under braking). It's immensely satisfying, completely smooth and requires no additional force on the shifter when you get it right, and I've had more than one passenger assume that the car was doing the rev matching.
Had I not learned this skill years ago I think I would find my manual Cayman quite un-driveable around town due to the length of 1st gear. I would imagine that a 2.9 would be even worse for this (assuming the gearing is the same or similar).
Once you can drop into 1st quickly, and without any "jolt" or unbalancing of the chassis you will find that you use 1st gear a lot more often.
I never really let the engine drop under 2k rpm under any load, whether I'm "pushing-on" or not. 1st gear gets a lot of use, but like all cars the ration difference between 1st and 2nd makes that down-shift pretty unpleasant on the synchros (if not impossible in some cars) if you're not double-clutching the down-shift.
Rather than worrying about left-foot braking, I'd always recommend spending the time to first learn to do a clean double-clutch down-shift (no braking) and then learn to do it with heel-and-toe (under braking). It's immensely satisfying, completely smooth and requires no additional force on the shifter when you get it right, and I've had more than one passenger assume that the car was doing the rev matching.
Had I not learned this skill years ago I think I would find my manual Cayman quite un-driveable around town due to the length of 1st gear. I would imagine that a 2.9 would be even worse for this (assuming the gearing is the same or similar).
Once you can drop into 1st quickly, and without any "jolt" or unbalancing of the chassis you will find that you use 1st gear a lot more often.
AndrewT
Member
Thank you all for your suggestions.
Heal and toe gear changes would be a challenge for me, my old joints aren't as flexible as they used to be. Whilst I don't double declutch on the downshift from second to first the sport mode does help me jab the throttle enough to raise the revs and achieve reasonable rev matching. I think I'd find it difficult to master that procedure now, as I'm sure I'd find it difficult to master left foot braking.
I think I'll experiment at my next event and leave sport mode on but switch off the PSM, then try 1st and 2nd gear on separate runs (two practice and two timed runs are not really enough). I don't mind the occasional bit of 'lairy' but that can easily turn into 'scary'.
I do have a set of 17" wheels but with the tyres currently fitted the rolling radius is about the same as my 19" wheels. I could buy new tyres for the 17" wheels, as I could for the 19" wheels, and list 1B tyres are permitted but for me the challenge is to try and reduce my time by improving my technique rather than changing the car to mask my lack of skill.
Thanks again.
Heal and toe gear changes would be a challenge for me, my old joints aren't as flexible as they used to be. Whilst I don't double declutch on the downshift from second to first the sport mode does help me jab the throttle enough to raise the revs and achieve reasonable rev matching. I think I'd find it difficult to master that procedure now, as I'm sure I'd find it difficult to master left foot braking.
I think I'll experiment at my next event and leave sport mode on but switch off the PSM, then try 1st and 2nd gear on separate runs (two practice and two timed runs are not really enough). I don't mind the occasional bit of 'lairy' but that can easily turn into 'scary'.
I do have a set of 17" wheels but with the tyres currently fitted the rolling radius is about the same as my 19" wheels. I could buy new tyres for the 17" wheels, as I could for the 19" wheels, and list 1B tyres are permitted but for me the challenge is to try and reduce my time by improving my technique rather than changing the car to mask my lack of skill.
Thanks again.
Steve Brookes
Moderator
Looking forward to hearing how you get on. Keep us informed. []
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Brian_Innes
Member
I hillclimbed my Cayman R manual in 2014 & 2015. My local hillclimb Fintray, in Aberdeenshire, has a very tight right-hand hairpin which follows a short uphill straight.
My technique with the CR manual was as follows;
PSM OFF.
Sport mode ON.
Tyres Toyo R888 (2014) Michelin Cup 2's (2015)
The right-hand hairpin at Fintray had quite a fast approach, the CR was accelerating hard in 2nd gear topping 7000 revs, 60mph+ approximately. I braked firmly, very late, while heeling-and-toeing from 2nd to 1st, and trailing the brake into the hairpin bend to keep the weight on the front axle. This assisted swinging the rear end of the car around the hairpin as steering lock was applied and throttle modulated to avoid too much wheel spin on the late apex. Full power applied in 1st and 2nd took the CR over the finish line about 120 metres ahead. This technique never failed me and was a key factor in posting a competitive time.
I never had any problems with bogging down or over-revving using this technique. I am 70 years old and have been heeling-and-toeing in motorsport for more than 50 years so that skill is second nature to me. If you don't master heel-and-toe techniques at an early age it can be a bit of a hit and miss, but it's an essential part of motor sport driving in my opinion.
I hope this helps.
Brian
My technique with the CR manual was as follows;
PSM OFF.
Sport mode ON.
Tyres Toyo R888 (2014) Michelin Cup 2's (2015)
The right-hand hairpin at Fintray had quite a fast approach, the CR was accelerating hard in 2nd gear topping 7000 revs, 60mph+ approximately. I braked firmly, very late, while heeling-and-toeing from 2nd to 1st, and trailing the brake into the hairpin bend to keep the weight on the front axle. This assisted swinging the rear end of the car around the hairpin as steering lock was applied and throttle modulated to avoid too much wheel spin on the late apex. Full power applied in 1st and 2nd took the CR over the finish line about 120 metres ahead. This technique never failed me and was a key factor in posting a competitive time.
I never had any problems with bogging down or over-revving using this technique. I am 70 years old and have been heeling-and-toeing in motorsport for more than 50 years so that skill is second nature to me. If you don't master heel-and-toe techniques at an early age it can be a bit of a hit and miss, but it's an essential part of motor sport driving in my opinion.
I hope this helps.
Brian
AndrewT
Member
BJ Innes said:
Well it helps in that it is a good description of how it should be done, but I fear it excedes my capabilities - I have some way to go to catch up with your 50 years experience, I should be there when I'm 110 [
].I can but try heal and toeing but I think it will be a struggle. Does everyone who heals and toes use their heal on the brake and toes on the throttle or the other way round?
It's worth pointing out that "heel and toe" is probably overstating things.
Realistically you're using the ball of your right foot on the brake, on the right-hand side of the pedal. The RHS of your foot will be hanging over the side of the pedal a bit, so you should be able to use the right edge of your foot to touch the throttle at the same time just through movement of the ankle (with the leg straight). I have quite wide feet so this is easy for me. Some people achieve this by also rotating their leg counter-clockwise - this causes the heel to come out over the accelerator whilst the ball of the foot is on the brake. I've never really needed to do this so can't comment really.
It's also worth pointing out that heel and toe technique is distinct from double-clutching. You can do one or the other or both, for various reasons.
Without being overly detailed, the main benefit of double-clutching a downshift is that you have all the components in the gear box and drive-train rotating at [approximately] the right speeds. As has already been pointed-out, this isn't really that important on modern gearboxes, especially in gears 2-6. Where a lot of people struggle is getting the car into 1st gear whilst it's still moving. There's a couple of reasons for this - usually the synchros on 1st gear are designed to get you into 1st from a standstill, so they are a different design and material. The other reason is that the ratio difference between 1st and 2nd is much bigger than between any other pair of gears - you're asking a lot more of the synchros when down-shifting from 2nd to 1st.
In many cars, this translates into literally being unable to move the shifter into the 1st gear position with the clutch fully depressed whilst moving at speed. If that's the problem you're having, even a half-decent double-clutch will help with gear engagement, even if you then use the clutch to bring the engine revs back up.
If you're interested in double-clutching and/or achieving the smooth down-shift into 1st, I always recommend that you practice with the car travelling in a straight line, at a constant speed. This means that you aren't touching the brake at all - only the throttle and clutch.
Start by driving along in 4th, and practicing a downshift to 3rd and then back up to 4th. You should be able to do that over and over without any sense of force on the car. As you get the technique sorted, drop down to the lower gears (3 ->2) and finally 2nd into 1st. You'll find the 2nd to 1st shift easier to master at higher speeds (say 25mph) as the throttle blip is a much bigger movement.
If you think heel and toe is too difficult, I'd suggest that you get this downshift procedure perfected, and then just do it sequentially, i.e. do all your braking into the corner as normal in 2nd gear, then quickly double-clutch down-shift into 1st before getting on the power out of the corner. Alternatively, you could split your braking into two phases (i.e. come off the brake to do the down shift into 1st, then get back on it). You'll probably lose the same amount of time both ways, but sounds like it'll still be a lot quicker than what you're currently doing.
On the point of heel and toe: you can do this without the double-clutch procedure, but you may still have difficulty shifting into 1st at speed. Others may want to comment on that - I've actually never tried a 1st gear downshift without double-clutching in my Cayman. If you do that, all you're doing it blipping the throttle with the side / heel of your right foot whilst you're braking, and then shifting as normal. You're still asking a lot of the synchros, but regardless being in 1st gear out of the corner will make a big difference.
Thankfully, even with the PSM disabled the car will still do quite a lot to prevent you locking the rear axle if you get this wrong.
I wouldn't say that I'm particularly good at this technique - certainly I feel like I could be a lot better, but it's really gentle on the drivetrain, feels good when you get it right and (contrary to some claims) can be done extremely quickly. A decent example is my downshift into 2nd gear at Druids here https://www.youtube.com/watch?v=uT2gdYKGCJM at the 16s mark. If you turn the sound up and watch the rev counter you can see that it's a very smooth procedure, done under quite hard braking.
Realistically you're using the ball of your right foot on the brake, on the right-hand side of the pedal. The RHS of your foot will be hanging over the side of the pedal a bit, so you should be able to use the right edge of your foot to touch the throttle at the same time just through movement of the ankle (with the leg straight). I have quite wide feet so this is easy for me. Some people achieve this by also rotating their leg counter-clockwise - this causes the heel to come out over the accelerator whilst the ball of the foot is on the brake. I've never really needed to do this so can't comment really.
It's also worth pointing out that heel and toe technique is distinct from double-clutching. You can do one or the other or both, for various reasons.
Without being overly detailed, the main benefit of double-clutching a downshift is that you have all the components in the gear box and drive-train rotating at [approximately] the right speeds. As has already been pointed-out, this isn't really that important on modern gearboxes, especially in gears 2-6. Where a lot of people struggle is getting the car into 1st gear whilst it's still moving. There's a couple of reasons for this - usually the synchros on 1st gear are designed to get you into 1st from a standstill, so they are a different design and material. The other reason is that the ratio difference between 1st and 2nd is much bigger than between any other pair of gears - you're asking a lot more of the synchros when down-shifting from 2nd to 1st.
In many cars, this translates into literally being unable to move the shifter into the 1st gear position with the clutch fully depressed whilst moving at speed. If that's the problem you're having, even a half-decent double-clutch will help with gear engagement, even if you then use the clutch to bring the engine revs back up.
If you're interested in double-clutching and/or achieving the smooth down-shift into 1st, I always recommend that you practice with the car travelling in a straight line, at a constant speed. This means that you aren't touching the brake at all - only the throttle and clutch.
Start by driving along in 4th, and practicing a downshift to 3rd and then back up to 4th. You should be able to do that over and over without any sense of force on the car. As you get the technique sorted, drop down to the lower gears (3 ->2) and finally 2nd into 1st. You'll find the 2nd to 1st shift easier to master at higher speeds (say 25mph) as the throttle blip is a much bigger movement.
If you think heel and toe is too difficult, I'd suggest that you get this downshift procedure perfected, and then just do it sequentially, i.e. do all your braking into the corner as normal in 2nd gear, then quickly double-clutch down-shift into 1st before getting on the power out of the corner. Alternatively, you could split your braking into two phases (i.e. come off the brake to do the down shift into 1st, then get back on it). You'll probably lose the same amount of time both ways, but sounds like it'll still be a lot quicker than what you're currently doing.
On the point of heel and toe: you can do this without the double-clutch procedure, but you may still have difficulty shifting into 1st at speed. Others may want to comment on that - I've actually never tried a 1st gear downshift without double-clutching in my Cayman. If you do that, all you're doing it blipping the throttle with the side / heel of your right foot whilst you're braking, and then shifting as normal. You're still asking a lot of the synchros, but regardless being in 1st gear out of the corner will make a big difference.
Thankfully, even with the PSM disabled the car will still do quite a lot to prevent you locking the rear axle if you get this wrong.
I wouldn't say that I'm particularly good at this technique - certainly I feel like I could be a lot better, but it's really gentle on the drivetrain, feels good when you get it right and (contrary to some claims) can be done extremely quickly. A decent example is my downshift into 2nd gear at Druids here https://www.youtube.com/watch?v=uT2gdYKGCJM at the 16s mark. If you turn the sound up and watch the rev counter you can see that it's a very smooth procedure, done under quite hard braking.
AndrewT
Member
Timothy, thanks for taking the trouble to write the above description. I was impressed watching your video just how quick your double-clutching is. I'll practice and see how I get on but thankfully my car does go fairly smoothly from 2nd to 1st but perhaps needing just a little more pressure on the gear lever than for other changes although it's hard to remember exactly what happens in the heat of the moment!
Andrew.
Andrew.
Hi Andrew,
If that's the case then hopefully all you need to do is get that down-shift into 1st on your hill-climb and it will make a world of difference. The extra pressure on the gear lever is required as you engage the synchro rings - if you're doing it without the double-clutch I would suggest waiting as late as possible before making that down-shift. The synchros will be doing less work then.
Someone else can probably comment, but I have a feeling that 1st gear has "dog" type synchros (not gears!) on the Cayman gearbox which means that you might find the shift works a bit better if you "snatch" it in a quick movement, but still bear in mind that the problem is that the layshaft is spinning at the wrong speed, and shifting into 1st means the speed of the layshaft needs to be approximately doubled. At slower vehicle speeds there's less energy involved, so it's a bit kinder to the whole transmission.
I've seen people use that technique quite successfully on hairpin corners, where you're going to be coming onto the power very late, so the down-shift happens when the car is at at the slowest point in the corner near the apex.
Tim
If that's the case then hopefully all you need to do is get that down-shift into 1st on your hill-climb and it will make a world of difference. The extra pressure on the gear lever is required as you engage the synchro rings - if you're doing it without the double-clutch I would suggest waiting as late as possible before making that down-shift. The synchros will be doing less work then.
Someone else can probably comment, but I have a feeling that 1st gear has "dog" type synchros (not gears!) on the Cayman gearbox which means that you might find the shift works a bit better if you "snatch" it in a quick movement, but still bear in mind that the problem is that the layshaft is spinning at the wrong speed, and shifting into 1st means the speed of the layshaft needs to be approximately doubled. At slower vehicle speeds there's less energy involved, so it's a bit kinder to the whole transmission.
I've seen people use that technique quite successfully on hairpin corners, where you're going to be coming onto the power very late, so the down-shift happens when the car is at at the slowest point in the corner near the apex.
Tim
AndrewT
Member
PaulJ said:
Since I last posted on this thread I've competed in a couple more hillclimbs and tried some different techniques on that particular corner and have concluded that I can do it slightly quicker if I drop down to 1st.
I haven't made much progress on the double clutching front though, however, trying diiferent things on other parts of the hill enabled me yesterday to set a new PB of 39.83 (first ever run under 40 seconds), I'm quite pleased with this from my Cayman 2.9 on Michelin Pilot road tyres as a visiting Cayman R driver on 1B tyres managed a 38.25 at the previous meeting.
I think I'll struggle to improve on 39.83 so am now considering switching to 1B tyres. My thoughts were to aquire a set of 18" wheels but PaulJ's suggestion to use smaller wheels with lower profile tyres to make an effect on the gearing sounds interesting as I already have a set of 17" wheels I could use - my only concern is that any gains I make on the slower parts of the hill (1st/2nd gear) will be wiped out on the faster parts where I may find I'll need 4th instead of 3rd. My feeling is that I should keep the same rolling radius and that with 1B tyres I'll be able to carry more speed through the corners.
My thanks to Andy Fagan who challenged me to do a 39 yesterday, it worked!!
It's worth mentioning that you can heel and toe both ways ...
In the older cars with narrower pedal spacing I heel and toe with the ball of the foot on the brake and the heel hanging out to the right tweaking the accelerator on the way down the gears -- effectively equalising the revs for the next gear down ---
In the newer cars such as the Cayman where with a very firm brake pedal (which I like) the pedal gap between the brake and accelerator can be large, I prefer to brake with the heel and double de-clutch down the gears with the toe.
When braking for the corner on the edge of the ABS and then trail braking into the corners, I find that I can be very hard and late on the brakes, and then roll the foot to the trail braking phase onto the throttle and then squeeze the throttle flat out of the corner ... it's very smooth and enormously satisfying. And it's real-time ... your right foot is driven by your trajectory and the seat of your pants ...
My 2p ...
In the older cars with narrower pedal spacing I heel and toe with the ball of the foot on the brake and the heel hanging out to the right tweaking the accelerator on the way down the gears -- effectively equalising the revs for the next gear down ---
In the newer cars such as the Cayman where with a very firm brake pedal (which I like) the pedal gap between the brake and accelerator can be large, I prefer to brake with the heel and double de-clutch down the gears with the toe.
When braking for the corner on the edge of the ABS and then trail braking into the corners, I find that I can be very hard and late on the brakes, and then roll the foot to the trail braking phase onto the throttle and then squeeze the throttle flat out of the corner ... it's very smooth and enormously satisfying. And it's real-time ... your right foot is driven by your trajectory and the seat of your pants ...
My 2p ...
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