1M on circuit: gearing (Phillip Island Grand Prix Circuit).

[timbo_3101]

[u2b]https://www.youtube.com/watch?v=4-j0QHjImsY&feature=youtu.be[/u2b]

The setting is Phillip Island Grand Prix Circuit in Australia.

There are two slow corners (65km/h=40mph) at T4 (Honda) and T10 (MG). As a matter of technique, is it preferable downshifting to second gear on entry, or is third gear more efficient?

Thanks,
Timbo

[Piets94]

I was using 2nd at both of these corners all day. Incidentally the one time I used 3rd was my best time but I felt more comfortable in 2nd. Just have to be careful with throttle application through the corner in 2nd.

Check out my video of the 1m at the Island on YT under 1m HMS Phillip Island using 2nd gear as well.

Have fun!

[Zuzu]

Awesome video Timbo..

[timbo_3101]

Originally Posted by Piets94

I was using 2nd at both of these corners all day. Incidentally the one time I used 3rd was my best time but I felt more comfortable in 2nd. Just have to be careful with throttle application through the corner in 2nd.

Thanks Piets for sharing your in-car footage. This video was intended to raise the issue of responsiveness-predictability (as a function of gearing), rather than traction limits.

There are experienced drivers on this forum, who have to attack slow corners every time they are on circuit, and who may share their rationale re lower or higher gearing.

Originally Posted by Zuzu

Awesome video

Thanks Zuzu.

[Piets94]

Originally Posted by timbo_3101

Thanks Piets for sharing your in-car footage. This video was intended to raise the issue of responsiveness-predictability (as a function of gearing), rather than traction limits.

Interestingly Timbo, I was using 5th through turn 1 and 4th across the top of the rise (I think it's Siberia?), whereas I think you were using 4th and 3rd respectively. You could argue that in a car like the 1m with such high engine torque, being in the higher gear would give you the full overboost earlier, but would be less responsive (probably preferable for the longer higher speed corners). More time on track and some trial and error to work out what's quickest.

And you're about 6 secs quicker than me if that's any indication

[timbo_3101]

Thanks Piets.

Another 1M driver here, considerably more proficient and experienced than myself, also prefers a higher gearing strategy - as you have alluded to.

I believe you are referring to Lukey Heights (T9), the sweeping off-cambered corner (left-turn) which descends steeply into T10 (MG). This has parallels to the (left-turn) T5 sweeper at Winton Raceway, where he would remain in fourth gear (110km/h=70mph).

Whilst the overboost can theoretically provide us with +50Nm for 5sec, and peak torque is delivered between 1500-4500rpm, I feel output is more predictable and immediately accessible between 4000-5000rpm ie second gear at 65km/h.

Given my poor downshifting technique, I would strongly have preferred third gear on corner exit, but for the (unacceptable) brief delay in power delivery when the engine is 2000-3000rpm at 65km/h.

This is from limited personal experience only; I am still learning how to drive manual transmission

[Hobbe]

"Use the torque Luke!"


Third gear would be my choice.
It also gives you a less tail happy turn, a much smoother acceleration after the turn, and the lower rpm keeps the oil temp down.

[timbo_3101]

"I want to learn the ways of the Force and become a Jedi like my father."


Unfortunately, my vehicle exhibits low-speed understeer - so I am forced to brake early, cannot rotate on entry, etc

Track time is limited, but I might have to sacrifice a couple of sessions with higher gearing, then recheck data.

[M3 Adjuster]

Originally Posted by Hobbe

"Use the torque Luke!"


Third gear would be my choice.
It also gives you a less tail happy turn, a much smoother acceleration after the turn, and the lower rpm keeps the oil temp down.

I agree.. it sure seems like the driver in the video was over-slowing the car in order to get to second gear. On turn 4... i would try braking less and pitching the car into the turn with the intent of carrying as much speed as possible and getting back to the throttle as soon as possible. Note how you had to accelerate to get out of the corner here... this is speed that you braked and took away that you didnt need to.

While second feels more fun to POWER out of a slower corner... in general.. the time you take to make the shift down (and then back up on corner exit) results in it being quicker to stay in the higher gear (third in this case) if you can carry some momentum. . IN a car with a TON of tiorque like the 1M... definitely use the torque. in a car with low torque... perhaps the lower gear may be needed.


I found video of a 1M at another track with some slow corners... Hallet in Oklahoma.

. Sorry.. no track map or speeds or other stuff,...There are two slow hairpins.... (one at 40 seconds and the other at 1:23 or so ). One can drop to second.. and feel faster coming out... but terminal speed at the end of the straight is what you are looking for here.. not how powerful the car feels coming out of the corner. the driver in the video keeps the car in THIRD gear in those slowest corners as opposed to going to second gear. The second corner (1:23 or s0..) is called The bitch. It's a tough corner... downhill braking, then turns to uphill and accelerate out and is similar to the turns you have at the track in melbourne.

I had a student last year with an E90 M3 that wanted to use second gear in these corners.. After spinning up the wheels several times feeling the power in second.. I got him to try third and we found that the terminal speed at the end of the straight was 2-3 mph slower going down to second gear.

At Mid Ohio.... a couple of times I have came out of the keyhole in the wrong gear.. 1 gear higher in 4TH gear.. not third. Completely by accident.. the 1M has so much torque that I didnt notice until I realized... oh.. I don't need to shift from 3-4 at the track out... Even though the car felt like a dog coming out of the corner.. my speed at the end of the straight was very close in both gears. As hobbes said.. less wear on the car is nice... along with better stability coming into the corner.

Originally Posted by Piets94

I was using 2nd at both of these corners all day. Incidentally the one time I used 3rd was my best time but I felt more comfortable in 2nd. Just have to be careful with throttle application through the corner in 2nd.

[MDORPHN]

Great advice.

I've been working on eliminating downshifts on many turns where I've done so in the past for the reasons Mark articulated.

Neil

[timbo_3101]

Thanks Mark and Neil for taking the time to review that footage from a foreign circuit; if third gear proves to be more efficient (higher terminal speed, lower sector times) then I shall be eternally grateful.

I did see the link provided, and accept that third gear can be used (even though the driver appeared to be inconsistent in gearing between laps - experimenting?)

Aside from gearing, it is true that I am deliberately over-slowing the vehicle because my current setup cannot handle the slow sections well. Pete alluded to this in May 2013 when he was using similar tyres (Dunlop Sport Maxx Race).

You can see what happens between 1:32 to 1:34 on the video below (lap timer 1:27 to 1:29) when the front is loaded on tight corners

[u2b]https://www.youtube.com/watch?v=6gzat_DkXmM[/u2b]

(This was lap seven of session two, so please forgive the brake fade and tyres overheating.)

[MPoweRo]

You know my thoughts on this Tim!

Quick lap times are about smooth weight transition to maximise available tyre grip. I'm with the mob here on gear choice.

I leave it in 5th for turn 1, 3rd for Southern Loop, 3rd for Honda and MG. I even leave it in 5th over Lukey Heights (but concede shifting down to 4th might be a good idea - need to try it).

Loved the in-car by the way - very detailed but it would be good to see you hands (and you may glean more useful "data" from that too). Also, on the exit of MG you should try and leave in the middle of the corner (ie sacrifice MG exit) to set you up for the all-important final complex of corners leading on to the straight.

Rohan

[Hobbe]

Regarding 1:32-34.

A stupid question.
Have you turned off everything incl. the MDM mode?
Why I ask is because it looks like a "correction" made by computer.

You might have upgraded your brakes ( I don't know), but brake fade problems are resolved with minor upgrades such as brake pads, brake fluid, and learning how to brake short and hard.
I've done numerous laps on old F1/F2 tracks where you need to go from 230-240 km/h down to 70-80 km/h in a "flash".
Almost soiled my paints once or twice, but never experienced brake fade.
(I run Toyo 888 semi slicks, Carbotech XP10 and XP8, and Motul 600F)

[timbo_3101]

Thanks for the suggestions.

Originally Posted by Ro1M

I'm with the mob here on gear choice.

OMG you make them sound like gangsters

Also, on the exit of MG you should try and leave in the middle of the corner (ie sacrifice MG exit) to set you up for the all-important final complex of corners leading on to the straight.

Would love to; however under these same circumstances (front loaded on corner entry), I am striving to avoid crippling and recurring low-speed understeer (subtle on the first video "SLY @ PI", but readily apparent on the subsequent video "SLY errs").

I do not feel there is any opportunity for me to trail brake, or to rotate ... all I can do is to maximise the arc or cornering radius, and remain smooth mid-corner. For me to sacrifice T10 (MG) and exit middle as you suggested, would involve washing off more speed (whilst remaining on the traction limit ie 1.0g to 1.2g).

Basically, I have lost any advantage (agility) over heavier vehicles (eg E92) since instituting this hardcore setup. Perhaps I will have this re-tuned, without compromising high-speed stability.

Originally Posted by Hobbe

Regarding 1:32-34.
Have you turned off everything incl. the MDM mode?
Why I ask is because it looks like a "correction" made by computer.

You might have upgraded your brakes ( I don't know), but you won't have problems with brake fade if you do some minor upgrade such as brake pads, brake fluid, and learn to brake short and hard.
I've done numerous laps on old F1/F2 tracks where you need to go from 230-240 km/h down to 70-80 km/h in a "flash".
I have almost soiled my paints once or twice, but never experienced brake fade.

Hobbe, I use MDM mode. Traction control (and likely corner brake control) is occasionally flashing, since I am cornering hard (overdriving). I have no issues with the computer intervening, but this problem is an unsettling jarring/vibration of the whole chassis if I push on slow corners. As I mentioned, it has occurred ever since moving from stock suspension to KW CS in October 2013. Have you had any issues with KW Competition?

My Pagid Yellows have completed seven (single-day) events, and have sufficient thickness for perhaps another three to five more events. The fade is likely attributable to melting of the brake pad compound, although perhaps they were more potent during the first few events (?). Of the six common circuits in Victoria (Australia), intense braking from 240km/h to 80km/h is not necessary, and thankfully so - because it is very likely that my vehicle lacks this braking power

[M3 Adjuster]

Originally Posted by Ro1M

You know my thoughts on this Tim!

Quick lap times are about smooth weight transition to maximise available tyre grip.
Rohan

I agree with Rohan - he has an important take home lesson.

the fastest way around the track is to maximize braking, and also, transition smoothly. from power to brakes back to power



The second video - Sly Errors - shows what I presume are some of the worst moments of the day....your line appears to be quite good in most areas... I think some time working on your braking is in order..

Entering Turn 4 .. based on the video and the GPS icon.. it seems like you moved from power to brakes at the correct time, but your initial application of the brakes was light.. then you REALLY hit the binders when it was clear that you were going to run out of room. for this corner.. either you needed to brake HARDER, SOONER... or you needed to brake a lot earlier. it appears you began braking at the 150 marker... but you still needed to lose 100 km/hr of speed to make the corner.


I just want to interject that this is a beautiful circuit. How neat to be on the island with the view of the water wow!
What a fun, fast, technical track... ! The Series of corners from turn 5-11 all really build on each other. Do turns 5-9 quickly and you will come into 10 with a HUGE satisfying grin on your face... and perhaps too much speed ! It appears that in the video that you hit the brakes just a bit before the 50 marker... but then are on them too long. I think the best thing to do in this corner is give a good squeeze on the brake pedal, look through to the exit of the corner and carry as much speed as possible *through* the corner.

At the 1:32 mark or thereabouts, I believe is the JUDDERING of the tires you mention under braking. you asked about suspension... I wonder if the Dunlop Maxxx tires were alos a change? it's a new tire... is this your first set?

the reason I ask is that while MOST tires squeal when they slide (as heard in the video in turn 4)... some tires will SKIP across the pavement when they lose grip and go to terminal understeer... causing the juddering and shaking of the vehicle you experienced. I think that your aggressive late (over)braking is the cause. The Nitto NT-01 also will exhibit this behavior... I have a friend that I rode with that cursed his Nittos as not being as grippy as his normal favorite tire (hankook R tires)... when he pushed his car to the same limit.

other factors that support that you are overbraking
driver acknowledges he is aware he is over braking - hooray !
brake fade
possible melting of pads
possible boiling of fluid


As far as Pads.. the Yellows I believe should be fine. For Fluid.. stock fluid is actually quite good.. but if you are looking for better fluid I highly recommend Castrol SRF. I think that your braking style is contributing to your brake issues..

You are plenty fast and have a very good line and drive very well in the fast bits.. however you are overbraking in the two slowest corners and should work on releasing the brake and transitioning back to power to continue through the corner. In turn 10... i think if you remove the downshift to 2nd.. it will make this section easier.. giving you time to focus on a short quick firm braking and then releasing ghe brakes, getting back into the power slightly, and carrying speed in the proper line through 10 and you will be a Jedi !

Do you have instructors available to you? I would say that a session or two with an instructor in the car with you to focus on timing of your braking as well as maximizing braking in a short distance, combined with working on releasing the brakes smoothly transferring back to power. Riding with another driver or instructor also may help as well.

[timbo_3101]

Originally Posted by M3 Adjuster

I agree with Rohan - he has an important take home lesson.

Thanks Mark for taking all this time to evaluate the circuit and data

Your input is very much appreciated; however many hours our group of 1ers spend on analysis, it is invaluable receiving feedback from a different perspective and at an instructor level.

The second video - SLY errs - shows what I presume are some of the worst moments of the day....your line appears to be quite good in most areas... I think some time working on your braking is in order..

Entering Turn 4 .. based on the video and the GPS icon.. it seems like you moved from power to brakes at the correct time, but your initial application of the brakes was light.. then you REALLY hit the binders when it was clear that you were going to run out of room. for this corner.. either you needed to brake HARDER, SOONER... or you needed to brake a lot earlier. it appears you began braking at the 150 marker... but you still needed to lose 100 km/hr of speed to make the corner.

Thank you for pointing this out; your impressions are entirely correct. From my own evalution, the contributing factors were:
(a) Overdriving ie wide entry to T4, to allow a greater radius;
(b) The wide entry was actually on ripples (!), so there was reduced tyre traction - in addition to overheating tyres (lap seven); and,
(c) Brake fade and loss of confidence

On my return to Phillip Island after the winter, I shall emphasise early and forceful braking as you have suggested.

I just want to interject that this is a beautiful circuit. How neat to be on the island with the view of the water wow!
What a fun, fast, technical track... !

Our group in Melbourne are fortunate to have access to arguably the fastest and most picturesque dedicated circuit in Australia. The elevation change is 18m (60ft).

It certainly demands a level of commitment beyond that required for our other circuits.

(We are also concentrating on this circuit because it is comparatively less stressful on brakes and tyres than our other local tracks, and has extensive run-off due to it being a motorcycle circuit.)

The series of corners from turn 5-11 all really build on each other. Do turns 5-9 quickly and you will come into 10 with a HUGE satisfying grin on your face... and perhaps too much speed ! It appears that in the video that you hit the brakes just a bit before the 50 marker... but then are on them too long. I think the best thing to do in this corner is give a good squeeze on the brake pedal, look through to the exit of the corner and carry as much speed as possible *through* the corner.

(Apologies the OBD-II data was not available for this messy lap.)

Perhaps I did carry too much speed entering T10 - but comparing with similar vehicles, I would like to be comfortable around 65-70km/h (40-42mph) at these tight corners. As with the T4 approach, I also try to hammer the brakes at T10 given the short segment between T9 and T10 and steep descent.

Unlike yourself, I have no background experience in autocross/motorkhana - I am therefore not confident on tight corners. Whilst I would like to improve through all sectors, I realise these slow sections are less relevant to lap times - per Ross Bentley's approach to prioritising corners.

As a newbie who is beginning to push the limits of my current setup (and trying to minimise stress/emotion):
(a) I made only one conscious decision from previously (maximise terminal speed on the main straight ie multiplicative effect, and on the minor straights), and
(b) One more subtle change (continuous tyre squeal, which represents 1.0g and above).

At the 1:32 mark or thereabouts, I believe is the JUDDERING of the tires you mention under braking. you asked about suspension... I wonder if the Dunlop Maxxx tires were alos a change? it's a new tire... is this your first set?

I was stock PS2 in 2012, then PSC+ in 2013-14. This was my third event (front 245/35/19) and ninth event (rear 265/35/19). The juddering on tight corners was only a problem following KW CS in 2013. It's a love-hate relationship with this car!

(My car is nicknamed the "tin can" because of how terribly uncomfortable it is.)

the reason I ask is that while MOST tires squeal when they slide (as heard in the video in turn 4)... some tires will SKIP across the pavement when they lose grip and go to terminal understeer... causing the juddering and shaking of the vehicle you experienced. I think that your aggressive late (over)braking is the cause. The Nitto NT-01 also will exhibit this behavior... I have a friend that I rode with that cursed his Nittos as not being as grippy as his normal favorite tire (hankook R tires)... when he pushed his car to the same limit.

The explanation you have provided is what has been suggested to me on video reviews ... the tyres are skipping across the pavement. So it is a matter of either correcting the setup or correcting driver behaviour. Thank you for highlighting this, because some other racers seem dismissive at times
... they expect my track-prepped vehicle to simply dominate. If only they could sit in (no passengers permitted) or drive the tin can (too uncomfortable or unfamiliar) ...

I also wondered if this is what Pete experienced since he was one of the first to report on another similar tyre (Dunlop Sport Maxx Race) in 2013. Hmmm, Nitto NT-01 too ...

Fortunately manufacturers are now offering more options for stock sizes. I can revert to 18" wheels at any stage, but in principle I will not simply "upgrade" to achieve a given result. It has taken me two years to develop a confidence in PSC+ and my setup, which I am not willing to sacrifice. These tyres are superlative (control-predictability-longevity), despite Bimmer and Porsche owners complaining about the expense. So my current focus is driver technique.

(When I do reward myself with 18", it will almost certainly be for full slicks. I am not yet at this competency level, nor at a physical fitness level to sustain 1.2g and above.)

other factors that support that you are overbraking
driver acknowledges he is aware he is over braking - hooray !
brake fade
possible melting of pads
possible boiling of fluid


As far as Pads.. the Yellows I believe should be fine. For Fluid.. stock fluid is actually quite good.. but if you are looking for better fluid I highly recommend Castrol SRF. I think that your braking style is contributing to your brake issues..

Yes, I am surprised why fade should occur with Pagid Yellow; I did not think even the M3 racers had these issues. I do have PF two-piece rotors and fresh pads ready to go, if and when this problem becomes insolvent.

(I will have one opportunity to test brakes at another circuit and refit new equipment as necessary, to be ready for spring. Consistent with my philosophy above, I am trying to avoid a BBK.)

You are plenty fast and have a very good line and drive very well in the fast bits.. however you are overbraking in the two slowest corners and should work on releasing the brake and transitioning back to power to continue through the corner. In turn 10... i think if you remove the downshift to 2nd.. it will make this section easier.. giving you time to focus on a short quick firm braking and then releasing ghe brakes, getting back into the power slightly, and carrying speed in the proper line through 10 and you will be a Jedi !

Thanks but OMG in reality the image I try to maintain is more Sith than Jedi

Avoiding the downshift, as almost all of the experienced drivers here have suggested, is something which I shall also investigate. With limited access to this legendary circuit, there is danger (methodology) in trying to institute more than one change at a time (impure data, confounding factors, invalid conclusions).

Do you have instructors available to you? I would say that a session or two with an instructor in the car with you to focus on timing of your braking as well as maximizing braking in a short distance, combined with working on releasing the brakes smoothly transferring back to power. Riding with another driver or instructor also may help as well.

Instruction is limited, but available at the two of the "simpler" circuits - of which I can replicate the juddering at one (Winton Motor Raceway). This is full of tight corners, where it is possible to be embarrassed by modified Toyota 86 (Scion FR-S) and MX-5/Miata vehicles

I believe you have a more structured pathway in the United States where in-car instruction is necessary to progress through different stages before club racing. In Australia, it is possible to simply jump in a car and drive (although I attended various driver training type courses before 125i/128i and now 1M).

Once again, many thanks for your input.

(Sorry for the long reply.)

[MPoweRo]

What access we have to knowledgeable and experienced drivers from across the globe!

I agree you would gain much from an experienced driver sitting in with you. I wonder if some more trail braking would help with your low speed understeer/shudder.

[Smiley1175]

Hey Tim,
You know I'm no expert around PI either, but in your video are you lifting-off/holding-steady around turns 7/8? Just after Siberia? It sounds like you may be.
From memory here I'm on full power and I think you could gain a little, perhaps not much but it all adds up!.

Not sure if this helps, but perhaps something else you can try next time you're out.
Speaking of which, when's the next event?

[timbo_3101]

Originally Posted by Ro1M

What access we have to knowledgeable and experienced drivers from across the globe!

Agree, I think constructive criticism of objective data may be beneficial (instructive) to many of us - whatever our standard, and where ever we are based.

I agree you would gain much from an experienced driver sitting in with you. I wonder if some more trail braking would help with your low speed understeer/shudder.

Thanks Rohan for this suggestion.

In fact, this was also my approach initially, but further nose-dive has not seemed to help. So I am sceptical about this, since I am already trail braking on all tight corners (apparent from deceleration on entry, and periphery of traction circle).

I was not able to elicit this at Sandown (two tight left-handers, 0.8g to 1.0g), so for the moment it seems to be confined to slow right-handers at Phillip Island (T4, T10) and Winton (T7 and T9).

(In fact, the juddering is occurring in the mid-corner phase rather than entry.)

Originally Posted by Smiley1175

Hey Tim,
You know I'm no expert around PI either, but in your video are you lifting-off/holding-steady around turns 7/8? Just after Siberia? It sounds like you may be.
From memory here I'm on full power and I think you could gain a little, perhaps not much but it all adds up!.

Funny how many of the comments are coming from experienced drivers, all claiming to be novices

I reviewed it again, since this issue could potentially disadvantage me (a lot); after all, it is one of the high-speed corners.

I am holding for 2-3sec (!) whilst the car is in transition and at maximum cornering load (0.9g to 1.0g). Only after it has taken a set do I resume throttle. This behaviour occurred consistently, lap after lap. At no other stage am I so reluctant, and otherwise I feel that maximum traction is being utilised on the other corners (1.0g to 1.2g, perhaps slightly less at T3 but this is 190-200km/h). Consequently, I am around 5-10km/h off Christian Fitzgerald's 135i pace at T8 (hayshed).

Thanks again for highlighting this. Actually, it is possible that I am nervous here (adverse incident, August 2013), and my vehicle can unsettle on esses-type formations. It is certainly a segment for potential improvement (behavioural not technical).

Not sure if this helps, but perhaps something else you can try next time you're out.
Speaking of which, when's the next event?

Considering Sandown (AROCA-BMW) on Saturday 10th May, but I have admin/work to attend to before travelling in May-June. Am looking to return possibly August-September, unless the others need pit support

Calendar 2014:
http://www.1addicts.com/forums/showthread.php?t=923529