|
|
Post by Reuben on Jul 20, 2009 21:07:51 GMT
Something thats been bugging me a while is I seem to suffer from Mid race slow down.
I dont know whether its tyre heat, motor temp, speedo temp, cells, me or all of the above.
Eg running 17.5 sunday, my fastest qually was an average lap of:
16.09 over 5 minutes.
Interestingly spliting this into 2 halves gives
1st half: 15.96
2nd half: 16.24
further more spliting the race into 4 parts:
Q1: 15.81
Q2: 16.14
Q3: 16.23
Q4: 16.22
Help??
Any one else suffer with this? or seen and cured this in the past?
|
|
|
|
Post by yellowshark on Jul 21, 2009 22:14:15 GMT
Not quite the same Reubens but out of interest I went onto the STCC site and analysed Craigs finals at Bashley. Left out final 1 as he only did 2 laps!. Also left out lap 1. This showed F2 Q1 15,82 Q2 15.04 Q3 15.08 Q4 15.14 F3 Q1 15.7 Q2 15.16 Q3 15.20 Q4 15.39 (15.17) F3 Q4 had a big off on the last lap. If I replace that lap time with the worst average, 15.7, that gives 15.17 Q1 times will be due to cut and thrust of racing unless you get well away eg in F2 Craig fell from 2nd on grid to 7th by end of first lap due to multiple grid pile ups on first 5 bends. Anyway differences to me are pretty marginal and in F3 the adjusted Q4 time is back under Q3. I guess it is reasonable to assume that tyre grip is going to gradually reduce. Then again in F2 Craig set his fastest lap time on lap 19 which sort of dispels the tyre grip point.  |
|
|
|
Post by Simon Crabb on Jul 21, 2009 22:40:28 GMT
Mine usually slow down a bit too. But strangely there's sometimes a quick one towards the end.
I personally put it down to concentration dropping off.
Other factors might be:
Lipo voltage falling
Motor heat increasing
Tyres heat increasing
Shock oil thinning out
|
|
|
|
Post by mattsedgley on Jul 21, 2009 23:14:12 GMT
Q4 20/315
Sector 1 = 15.87
Sector 2 = 15.35 Half 15.61
Sector 3 = 15.96
Sector 4 = 15.93 Half 15.94
what is clear, at the end of the run, my concentration is going - the last few laps really tailed off.. - could this be psychological? do we on some unconscious level know that the race is ending?
Whilst i'm sure not all the club would agree, or even be willing to do it, but it would be an interesting experiment to run 330 seconds in qualifying and finals for four weeks, and then return to 300 to see if there is any improvement in lap times during just 300 seconds..
I'm sure people who race/ have raced at Dorset will notice it's a lot easier to race for 4 minutes.. i'm sure you feel alot less "tired" at the end of four minutes than you do at the end of 5..
food for thought certainly!
Matt
|
|
Darren
Hitting the Tyre
It's better to crash and burn than to fade away
Posts: 88
|
Post by Darren on Jul 22, 2009 6:53:15 GMT
For about 4 meetings i've noticed this aswell and put it down to motor temp/esc temp. Yet haven't noticed it when i race at yeovil. Plus my car feels and looks always quicker in the first two Q's then drops off in the second two Q's ... As for racing at dorset for 4 mins yeah it feels like the race was quick but so does 5 mins as the track is short and sweet so you dont really get settled in a race its corner after corner
|
|
|
|
Post by lesbaldry on Jul 22, 2009 6:58:00 GMT
Try racing for 45mins with 6 fuel stops and one tyre change,you come off the rostrum with a thousand yard stare and numb legs ;D
Mid race fade could be tyre additive going off,overheating tyres, but you pick up the pace towards the end of the race sub consciously....also mid race is the time a driver may pick up some back markers or be laped by faster cars ....just a thought.
|
|
|
|
Post by mattsedgley on Jul 22, 2009 8:53:26 GMT
It makes you wonder what temperature a Sorex goes off - Interestingly on a cool day, I heat sorex 32s at 60... reuben only heats at 45 - I don't notice the tyres going off, via getting to hot, I recently drove Martin Youngs car, and managed to over heat the tyres in 3 minutes, so setup of the car to a particular driving style I guess plays a part. some time ago I had an issue with a 3:40ish greasy tyre, however the addative i'm currently using isn't oil based - What's that got to do with it??? Not wishing to go into to much detail about the composition of the tyre, one of the major ingredients in Sorex slick tyres can absorb 6 times it's own weight in oil, it's ability to hold that is compromised as temperatures go up - so what I hear some of you Ask? Back at a Yateley practice a few months ago, Jay Westood (I think it was Jay, no doubt i'll get stick at the weekend if it's not  ) re - explained the process of applying wfx, as I was having an issue with "greasy" feeling tyres, from what he said I concluded I was putting to much wfx on/in the rubber. and as the tyre heated up it was coming back out of the tyre. Is there anything else common between those people who have commented so far? - all use Sorex? all use WFX? all heating tyres? anything like that? Was this happening 12months ago? - we all say the tyres don't seem to be lasting could it be a change in composition causing the issue for all of us? |
|
|
|
Post by lesbaldry on Jul 22, 2009 9:51:09 GMT
Was this happening 12months ago? Yes its just that some members are getting faster and are starting to notice things |
|
|
|
Post by Reuben on Jul 22, 2009 12:06:42 GMT
I wasn't using addative Sunday, just heat. And was using STCC tyres still (apart from 2 runs on Sorex) all though the tyres may still have addative in them from last week? does addative stay in the rubber very long? But yes when using addative it is wfx.
|
|
Darren
Hitting the Tyre
It's better to crash and burn than to fade away
Posts: 88
|
Post by Darren on Jul 22, 2009 12:24:16 GMT
I always use sorex 32's which are in good condiction (not many runs done on them) but i dont always heat them, also tried different temps and theres been times when i've not used additive yet car has dropped off. I use to think maybe at the start the car felt and looked quick yet as the race went on i got settled/complacent and got use to the car so it didnt look or feel as quick and rather than pushing i was being consistent. But now more people have the same problem i dont think it me, more the car and rather than an handling problem its more of a power problem
|
|
|
|
Post by lesbaldry on Jul 22, 2009 13:22:10 GMT
Additive its use and the amount of heat applied should be assessed on the days conditions,too much of either can be detrimental. Most tyres are only good for about three runs after that the performance can drop of dramatically (track Dependant) In my experience heating and "gooping up " well used tyres will only give them reasonable grip for the first few laps,then they revert back to the "well worn" feeling very quickly normally with out much warning (suddenly no grip the next lap  ) Set up especialy Akerman can have a big big effect on a tyres mid race perfomance..wrong Akerman (toe out in turns)can cause scrub steering causing the fronts to over heat mid race putting the car "out of balance"...this can make you slow down untill the tyres cool down and you have the confidence to push harder or adjust your corner entry to compensate...this may be one of the reasons for mid race slow down? ....A good clue "too me" is if my front tyres are badly graining compared to the rears there is somthing wrong with my set up! Be warned a "quick fix" Akerman adjustment to make a car drive smoother(slight understeer) can bite you in the backside during the midle of a race buy overheating the tyres,the chances are there is "another" probelm,roll centers,too much lock,springs,shocks etc etc I hope this makes sence  |
|
|
|
Post by gwesty on Jul 22, 2009 15:58:02 GMT
I'm sure people who race/ have raced at Dorset will notice it's a lot easier to race for 4 minutes.. i'm sure you feel alot less "tired" at the end of four minutes than you do at the end of 5.. Matt [/quote] theres your problem , trying too hard if your getting tired ! try relaxing and dont over drive also tyres will and can over heat very quickly during a race especially if your set up isnt quite right or your pushing . gw |
|
|
|
Post by oldtimeracer on Jul 22, 2009 16:03:16 GMT
I agree about tyres for sure. They certainly can go "off" during a race. I also think what happens during your race can be a factor as well. If you find yourself on your own in the middle of the race then maybe you do not push as hard as if you are following someone or have someone right on your tail.
My fastest laps are usually at the start of the race but I put that down to the tyres being extra grippy for the first few laps and then they settle down/go off a bit.
My front tyres do take a hammering and are usually grained up after a few runs while the rear ones appear perfect. Les you are saying then that my set up is wrong?
|
|
|
|
Post by yellowshark on Jul 22, 2009 17:45:41 GMT
Payback for your tight turn in Ian ;D
|
|
|
|
Post by yellowshark on Jul 22, 2009 18:05:44 GMT
OK here it is. Yes there will always be exceptions to the following but as a general assessment. Lipos. No Engine. No. We are all so conscious of blowing expensive brushless technology I am sure we all AT BASHLEY do not overheat our engines. Tyres. Yes. As Les said after 2 or 3 runs with tyre prep you will get grip at the start which fades Driver "fatigue". Yes. What happens in the latter stage of the race? You settle into a pattern. If you haven't caught the guys in front of you are not going to. If the guys behind haven't caught you, they are not going to. And if you are battling with someone you are only going to slow both of yourselves down anyway. This argument, at least in theory though, falls down in qualifying where you should have the motivation to beat your best qualie time. So I have failed. Someone else take it and run with it |
|
|
|
Post by mattsedgley on Jul 22, 2009 21:29:59 GMT
theres your problem , trying too hard if your getting tired ! try relaxing and dont over drive gw God you sound just like les, if i had a quid for every time he'd said that - i'd not need to worry about 3 sets of 32s a weekend! |
|
|
|
Post by lesbaldry on Jul 22, 2009 21:53:32 GMT
My front tyres do take a hammering and are usually grained up after a few runs while the rear ones appear perfect. Les you are saying then that my set up is wrong? No Ian,I would never question a quick drivers set up maybe a newbys though! A drivers style may heat/grain tyres more than others,its purely my observation of my own set up.Tyre wear does give you a clue if your set ups working....put it this way if my fronts were graining but not the rears,to me it would be either a set up problem or I was pushing too hard into corners......or if my car needed full lock (understeer) to make most corners the chances are I will be graining my fronts too....time to dial in more front mechanical grip or remove it from the rear...Any understeer off or on power will overheat/grain front tyres. Just my thoughts,I dont want to start a "best set up/style " war  |
|
|
|
Post by yellowshark on Jul 22, 2009 22:05:52 GMT
My front tyres do take a hammering and are usually grained up after a few runs while the rear ones appear perfect. Les you are saying then that my set up is wrong? ....or if my car needed full lock (understeer) to make most corners the chances are I will be graining my fronts too..... Question Les. Depends on your inner wheel angle, yes? If you are set at 25 degs and X is set at 15Degs, his full lock will be less than your lock at 70% ie 17.5 degs. His full lock would be likely to grain his tyres less than your 75% lock yes? What angle is your inner wheel set to on full lock (if not a trade secret)? |
|
|
|
Post by Simon Crabb on Jul 22, 2009 22:20:38 GMT
I looked at my lap times tonight, and I put in a couple of quick laps near the very end of the run. That pleased me, though it took 4 runs until I could concentrate for 5 minutes, I'm a bit rusty after a few weeks off!
I was careful not to over-heat my tyres before hand, and it was a cool night, it took a couple of laps to get the heat into them, and then they performed nicely, without any sign of going off.
On a % steering note, I set mine to be 100% at maximum physical lock, then dial it down to 85% and set up around that. If I find myself increasing lock to get adequate turn in, I change setup to suit, and get back to 85%.
|
|
|
|
Post by Reuben on Jul 22, 2009 22:27:51 GMT
Interesting stuff all this inner wheel angles. Never really done that stuff myself - could be where the problem lies?? i have a little toe-out (not sure how much or even if its equal anymore :S ) and havent ever checked my wheel angles at full lock. thanks |
|
|
|
Post by lesbaldry on Jul 22, 2009 23:32:57 GMT
....or if my car needed full lock (understeer) to make most corners the chances are I will be graining my fronts too..... Question Les. Depends on your inner wheel angle, yes? If you are set at 25 degs and X is set at 15Degs, his full lock will be less than your lock at 70% ie 17.5 degs. His full lock would be likely to grain his tyres less than your 75% lock yes? What angle is your inner wheel set to on full lock (if not a trade secret)? No trade secret Pete,to be honest I never study specific angles and worry about the odd degree here and there I adjust the car on the day to the conditions and track, generally the more Ackerman (larger degree difference between wheels on lock) will stabilize the steering but going too far will cause scrub steer wear as will if the wheels are too parallel. As far as Im aware there is no rule of thumb correct measurement to cure scrub steer/graining/wear perhaps because the foot print of the tyre on lock and roll has many other dependants??...One or two of the latest chassis have a radial Ackerman adjustment for just this!,the degree combinations on the Photon are mind numbing...Ill stick to kit settings and keep a close eye on my rubber ;D...One chassis seems to of got these problems well sussed , the 416 worlds seems to of found the correct geometry that suits most conditions...some manufactures are trying to copy it  ...cue Ed lol Ps roll on Yeovil...dont worry about Ackerman the tarmac will tare your rubber to shreads anyway ;D |
|
|
|
Post by lesbaldry on Jul 23, 2009 7:05:48 GMT
Going back to Ians set up comment,Personally I have never suffered bad front only graining,I dont think our other faster Cyclone drivers have either??
This may help: I used to run quite a lot of front camber and toe out but I found this gave that "nasty " little wear line/lip on the inside of the tyre, theses days I dont use more than 1.5 deg neg camber with 0 deg toe,this gives good trye wear and strait line stability,should I need more steering I work else where...A slight bit of toe out is a last resort if I am suffering turn in.(more toe out also increases the angle difference on full lock)
Luckily enough the Cyclone is very basic with Ackerman adjustment I tend to use this to alter the steering "feel" really!(more or less aggressive)
I hope this hasn't strayed to far off subject but it could be relevant to mid race slow down???
Ps for the newby.....having the Track rod arms of equal lenght with the steering post arm dead central with equal left and right steering throws is vitaly important to the handling and the above Ackerman checks and adjustments.
|
|
|
|
Post by mattsedgley on Jul 23, 2009 10:00:38 GMT
What happened at STCC? were all the "top" boys the same?
Matt
|
|
|
|
Post by lesbaldry on Jul 23, 2009 10:34:17 GMT
What happened at STCC? were all the "top" boys the same? Matt We will never Know Matt. I allways found the Xray a bit "vauge" with Ackerman,I never seemed to get a good feed back when I played with it,might of been me though  the car had develpoed some slop buy the time I got round to it,so I expect the odd degree woud'nt of made much differenc...plus when ever I checked other drivers cars they wre all running something different... Radial Ackerman settings/adjustment seems to be the in thing at the moment...Apparently its very critical on carpet with foams. |
|
|
|
Post by mattsedgley on Jul 23, 2009 10:47:04 GMT
a quick add up of Barry staples from his 20/304.98 run shows the following
Sector 1 14.96
Sector 2 15.8 half average 15.38
Sector 3 15.1
Sector 4 15.1 half average 15.1 Overall Average Lap 15.25
Fastest being 14.8 and slowest 18.88 showing a pretty consistent run,
I wonder if RC timing can export race data to excel!?
|
|
|
|
Post by lesbaldry on Jul 23, 2009 10:53:52 GMT
What happened at STCC? were all the "top" boys the same? Matt We will never Know Matt. I allways found the Xray a bit "tetchy" with Ackerman,I never seemed to get a good feed back when I played with it,plus when ever I checked other drivers cars they wre all running something different. Radial Ackerman settings/adjustment seems to be the in thing at the moment...Apparently its very critical on carpet with foams. Sorry Matt I missread your meaning ...we were talking about overheating tyres |
|
|
|
Post by mattsedgley on Jul 23, 2009 11:47:49 GMT
I'm lost - like yellowshark trying to setup a Cyclone!!  |
|
|
|
Post by lesbaldry on Jul 23, 2009 11:58:21 GMT
What happened at STCC? were all the "top" boys the same? Matt LOST??? you bet the previous post to this was about Cyclone Ackerman,I thought you were asking what setting the other HB drivers were using |
|
|
|
Post by yellowshark on Jul 23, 2009 12:14:20 GMT
I looked at my lap times tonight, and I put in a couple of quick laps near the very end of the run. That pleased me, though it took 4 runs until I could concentrate for 5 minutes, I'm a bit rusty after a few weeks off! I was careful not to over-heat my tyres before hand, and it was a cool night, it took a couple of laps to get the heat into them, and then they performed nicely, without any sign of going off. On a % steering note, I set mine to be 100% at maximum physical lock, then dial it down to 85% and set up around that. If I find myself increasing lock to get adequate turn in, I change setup to suit, and get back to 85%. Simon the 100% in theoretical terms is not the point. It is WHAT is it a 100% of, ie the inner wheel angle? Fair enough in your terms you are saying full physical lock, whatever that is in degrees, and if 85% of that seems right to you that is what is important. But you get into trouble comparing your 85% with someone else's 80% if the WHAT is different. |
|
|
|
Post by mattsedgley on Jul 23, 2009 12:16:58 GMT
I don't hold out much hope for the weekend if we can't manage to work out what each of us are talking about now! - Bring on the beer!
|
|
) re - explained the process of applying wfx, as I was having an issue with "greasy" feeling tyres, from what he said I concluded I was putting to much wfx on/in the rubber. and as the tyre heated up it was coming back out of the tyre.
)
...cue Ed lol
the car had develpoed some slop buy the time I got round to it,so I expect the odd degree woud'nt of made much differenc...plus when ever I checked other drivers cars they wre all running something different...