OMG!!!!! Really?Quote:
Originally Posted by N.O.T
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OMG!!!!! Really?Quote:
Originally Posted by N.O.T
:D
Do you have a problem with N.O.T? Don't really see the point of dragging one post up from 2011 ...Quote:
Originally Posted by BDA Cosworth
It is a valid question... i prefer questions from ass licking, they taste better...Quote:
Originally Posted by BDA Cosworth
Are you talking 4WD, 2RWD or 2FWD, with or without handbrake. So many ways correction could be done. A driver also has a pedal to the right... Pedal to the metal often makes good corrections.Quote:
Originally Posted by Lundefaret
Turn in later with wider line, is theoretically very good idea.Quote:
Originally Posted by Lundefaret
Try doing that on gravel, when all the loose gravel is on the outside of the corner, and you will either go off or loose a lot of time with wheelspin.
On tarmac it could work better, unless someone before you has cut and brought gravel and dirt to the outside, then the result is the same as on gravel.
It is actually the complete opposite. It has to do with how much or little sideways forces You want acting at Your cars/tires at certain points of a turn.Quote:
Originally Posted by COD
The Loeb-remedy for tarmac stages with dirt/low friction on the mid apex is to go in deeper, make more of the directional change earlier, and then straighten the line over the low friction area so to start acceleration earlier. This is when acceleration is wanted, and huge cuts prohibited.
The same goes for gravel and snow, just watch Ogier, Loeb, Mäkkinen, Mikkelsen (on the first 1,5 days of this years Rally Sweden were he drove brilliantly), and so on.
My point was that Warmbolds blogg entry was very interesting, but that one needs to be certain what is the driver, and what is the car.
If You have an older rallycar with no adjustments, You have to adjust your self to the car, and this ability is a lot more worth than being able to adjust the car to one self.
This is because You can run the car closer to the theoretically perfect setting, and because of tire wear, changes in grip levels etc, the stage will vary in many parameters.
Going up trough gokarts etc, whit a focus on making the kart perfect for the driver, is not how to become the next Loeb or Ogier or Mäkinen or Röhrl. ;)
Hi Anthony, I would love to hear your thoughts about this video, "Behind the Scenes at M-Sport" (a nice '2011' turbo at 12:32). https://www.youtube.com/watch?v=FYbMk50awO0
Hi Tom, I watched it with interest. They speak about rebuilds etc. Nothing special for me there. I would have liked more info from the gearbox man... I noted from the damper man that the smaller spring is indeed a helper spring and not a tender. Therefore it seems M-Sport is still using a linear spring suspension system. From 10:32 the ride height adjuster was interesting. He says the driver resets it inside the car..."obviously when he is stopped (with a smile)..." The 2004 Focus had a ride height adjuster which was driven by a pump and controlled by buttons on the steering wheel. I understand that nowadays it's supposed to be manual so I wonder how you reset it from inside the car (straight forward question). Maybe they handle a manual hydraulic pump somehow. The turbo part was interesting as well. 155.000rpm, 1.000°c, 70L/sec, 1.000km before rebuild, 2.000km on test car...Quote:
Originally Posted by tomhlord
All in all a cool video!
Attached(hopefully) some pictures, in the picture from the trunk you can see the adjuster unit. It's the black tube by witch turning you hydraulically adjust the ride height. Basically you just turn a piston that increases or decreases the spring bottom. Rules prohibit adjusting when driving so that's why the adjuster is situated in the trunk and in the engine compartment on the fiestas.Quote:
Originally Posted by Antony Warmbold
Yeah, we want part two ASAP. The assembly of the car.
Yes, they use linear spring. Small one is helper. Sometimes on tarmac they use additional, very stiff tender, so then 3 springs in total.Quote:
Originally Posted by Antony Warmbold
Ride height adjusting canister allows lifting the car two times. Then needs to be charged which is done during the service. It is operated manualy - by hand.
Turbo figures sound rather typical, so nothing special.
But I also agree that it's pretty interesting movie.
Thanks a lot for your input! I see the ARB (purple rod) as well! It did not pass inside the trunk on the 2004 Focus.Quote:
Originally Posted by AMSS
I think on the 2004 Focus the ride height control system had an amplitude of around 30mm (gravel). Are they getting similar figures today?Quote:
Originally Posted by br21
Hello Antony, regarding the springs. I would think that a progressive spring set up would be helpful getting one over the treshold, but still maintaning a stiff a spring as possible, what do You think about that?
The tarmac tender, what is the mission for this?
Hi Lundefaret,Quote:
Originally Posted by Lundefaret
Please clarify "getting one over the treshold".
Do you mean "one" --> the driver?
"Threshold" ?
Thanks,
Hello Antony, tanks for taking the time :)Quote:
Originally Posted by Antony Warmbold
One= the driver
Threshold: The point that must be exceeded to begin producing a given effect or result or to elicit a response.
I am talking about the threshold of the suspension set up, wich You must exceed to get in to the "working area", "scope" (need a good word ;) of the suspension.
The most common mistake regarding threshold is to put it to high during testing, because You know the road by heart etc, and can push more/put more load in the suspension, but then be surprised when the car dont turn at all on the first stage of the rally proper.
Using a two spring system (or a progressive spring) where one is softer should in my mind lower the initial threshold, making it easier to reach the threshold proper.
This would come with a downside, and that is that it will take a little longer to reach the maximum of the suspension, and that it will lead too a little more (as much as the softer spring/part of the spring will allow) movement in the car, wich has both upsides and downsides.
What do You think about this?
About the tender: Is that a bump stop off sorts?
Yes, in recent versions of Fiestas - WRC, S2000 and R5 rear ARB is going inside the trunk of the car. Only difference is in R5 it's solid rod, in WRC/S2k it was pipe (with hole inside). Also in R5 you have two possitions to adjust ARB blade.
I don't remember exactly, but that adjustable suspension should be around 30mm also in recent cars.
Tender spring is very rare, way more often progressive spring is used, but not in case of Reiger/M-Sport combination. Sometimes they use very hard tender on tarmac, but only in specific situations and not with all drivers. It has very small working range and is working only when main spring is fully loaded - so under braking or on long corner.
"One= the driver"
--> ok!
"Threshold: The point that must be exceeded to begin producing a given effect or result or to elicit a response.
I am talking about the threshold of the suspension set up, wich You must exceed to get in to the "working area", "scope" (need a good word of the suspension."
--> ok, got it thanks.
"The most common mistake regarding threshold is to put it to high during testing, because You know the road by heart etc, and can push more/put more load in the suspension, but then be surprised when the car dont turn at all on the first stage of the rally proper."
--> ok.
"Using a two spring system (or a progressive spring) where one is softer should in my mind lower the initial threshold, making it easier to reach the threshold proper.
This would come with a downside, and that is that it will take a little longer to reach the maximum of the suspension, and that it will lead too a little more (as much as the softer spring/part of the spring will allow) movement in the car, wich has both upsides and downsides.
What do You think about this?"
--> I see what you are saying. I can only speak as a driver with a driver's point of view. Let's say I'd sit in a new car for the first time. The engineer in charge of the test would tell me "...yeah we put our development driver's settings in...have a go and we take it from there..."
From that point on I will just drive up and down at rally speed and look for improving the stage time (If I am specifically testing for that) ; look for improving the handling - confidence aspect ; test for behavior on jumps, bumps, cuts, braking, etc. Then there is the whole game of testing with specific tires after a tire regulation change for example.
So when I test I am not thinking about "...is my setting allowing me to reach the threshold?" In my viewpoint this is something an engineer worries about.
I am thinking "is my setup allowing me to go faster than my reference time and do I feel good about the car?"
Because at the end of the day if an engineer puts a ridiculously soft spring and damper on my rally car I will be sitting on the bump stop when leaning on my tires in first corner and result will be immediate loss of grip and/or spinning. Or if it's a jump we'll both loose our teeth on it. So I'll tell the engineer "something is wrong I cant do any speed in corners". but this sort of scenario never happens. My dad has stories about this from seventies but it's not happening since a long time in professional teams.
On the 2004 Focus I never ventured far from the factory driver's setups because their theoretical setup was very good, totally driveable. I had a 4N softer spring on rear with a very thin ARB because I wanted more grip on the rear (understeering car) because I had precise notes and I knew exactly where to go and hence could go more aggressively in corners and more grip on rear suited my driving style. I also had harder low speed settings on dampers because I felt the car better. Then we ran slightly modified Markko Martin spec diff maps and all the geometry / ride height was standard.
When you speak about drivers having a wrong setup for the rally; from my experience what I saw was a tendency for drivers to go softer and softer with dampers...because yes when you know the test stage by heart and anticipate every aspect of the road you can indeed improve the time by going softer and looking for traction. In the rally however, you are on 350km of stages recceed twice at 70kph in an airport rental car so your rally car will for sure feel like a lazy donkey which "is out of balance" and "bumps through on the rocks" with your airpump suspension which feels like you are on a 30ft sailboat in middle of Atlantic.
About the progressive springs I have always believed there was a reason why Tommi Makinen won 4 championships in a row, apart from his skills. I heard him speak about how his car (mistu) had "the perfect balance between suspension and transmission". When he started in our Mazda's we had progressive springs and he went on to Mitsubish eventually with our engineer who took that knowledge over there.
Unfortunately I never had a chance to test them on my cars so that's about all I can tell you about that.
My personal belief is that Ford sticks to linear because they are convinced their damper does the job. Maybe they tried progressives and it did not work better.
All I know is that for MAZDA, finding the right springs meant lots and lots of custom orders from EIBACH with different specs of ramps etc before finding the ones that worked. Also Ingvar Carlsson and Timo Salonen had a real knack for testing those.
So who knows, maybe they are right.
"About the tender: Is that a bump stop off sorts?"
-->here is explanation of tender: http://wrcbehindthestages.blogspot.n...prings-co.html
The bump stop is something else which prevents damper damage on heavy impacts.
I hope all this makes sense to you!
Regards,
Anyone got a WRC wheel alignment printout, gravel/tarmac anything will do.
Would be interesting to see and to compare with RSRBR.
This is my car's geometry for Monte Carlo 2003 (2002 Focus WRC)Quote:
Originally Posted by SubaruNorway
Typical M-Sport, they don't care about castor.
Also rear toe-in is quite big, which is interesting.
Anybody know what was max wheelbase and track allowed for Focus then?
BTW. Current cars geo settings I wrote some days ago in other thread - tech stuff
I also noticed the difference between left and right front castor and found it interesting. If I'm not mistaken the rear toe-in makes the car more understeering, right? That would fit with what Antony wrote about his preferred car behavior. I have seen several asphalt setups and in some there was rear toe-out used. However that was with fully mechanical S2000 cars while Focus WRC 02 was fully active car.
I think that for 2-litre WRC cars there was same rule for wheelbase as for recent cars which means stock value +/- 1%. That would mean 2615 mm +/- 26,15 mm in case of Focus. I'm not sure though. I have no idea about track limit.
i would say a little bit different,with toe in at rear, you make the car not to oversteer.Quote:
Originally Posted by Mirek
toe in at rear gives the advantage of having a car that goes on straights in 150 Km/h without crawling. Makes the driver more confident not having to compensate with steering all the time.
Toe in in rear usually makes car more stable - less overstear, like all above said. Usually in non-active cars most people use some smaller toe-in, but that really depends on driver.
So if max wheelbase allowed was 2641mm they had still some way to make car "longer" - more stable, etc.
From what I noticed MSport never really paid attention to castor and all cars from them which I saw had different castor on both sides. Still castor around 8 is nothing special, but don't know the construction of its suspension too good.
Thanks guys about the toe-in at rear. I actually meant it like You said (less oversteer, more longitudinal stability) just wrote it incorrect.
Hi and happy new year guys! (and girls)
I have made a special video for all motorsport fans! You can call it my new year contribution.
http://youtu.be/Vhwm1sjKV6I
Hi everyone !
If you'd like to get a view some of the co-driver's many jobs, here's a video about it :
http://youtu.be/P9rje-aPNi0
Cheers,
Antony
Found and signed up to this forum as a consequence of your blog Antony. Please keep the posts coming, some absolutely fascintating reading on your blog!
Thanks! you made my day !!Quote:
Originally Posted by tbtstt
Did a little piece of comparison between Tänak and Ogier on my blog
http://wrcbehindthestages.blogspot.f...-vs-tanak.html
Cheers,
Thanks a lot. Actually Tänak didnt have a real go at this powerstage, he said he tried to add some more pace but that was it. But yeah I also noticed on sweden onboards that Tänak loses a lot in the twisty slow sections compared to Ogier and on the fast parts he doesnt lose time or is even faster than Ogier. And i agree that it is down to confidence and experience, which Tänak hasnt got a lot at the moment because of the recent incidents. We will see what he can do with the new upgraded Fiesta, he has said that it will suit him more.
It is a rare privilege to watch such fast driving on such a rough and technical stage. Ogier literally "ran over" it. In such cases one can see the real difference why some drivers have more "luck" avoiding troubles than others.
I tried the calculator with the Polo RX values (http://www.volkswagen-motorsport.com...php?id=823&L=1), 0-100 km/h = 2,1s and 1300 kg. Got an odd result, 825 PS.:confused:
well 850N of torque is huge so hell...why not !!!Quote:
Originally Posted by OldF
Hello Antony,
I read all your topic and it is absolutely fantastic.
Not sure if you still provide support to rally fans but I want to try to ask you a question about something that really confuse me and it seems that no one actually knows.
The hot question is about steering lock ratios of modern wrc cars and its applications on driving and on setups.
Fiesta/focus wrc specs on M-sport site says: "Steering: Power-assisted high-ratio (12:1) rack and pinion. One and a half turns lock to lock."
From onboard cams I noticed that most of the wrc cars actually have 540° of steering wheel rotation but some seems to have only about 360° or little more (It's not easy to retreive it from onboards) So, Is it adjustable? The other part of the question is about rotation angle of wheels. 12:1 ratio means that the wheels can be phisically turned a total of 45° from lock to lock.
I tend to think that it is a low value for a car that is frequently sideways, most of street derived cars have about 60° of wheels rotation and I think that an high value (even if not always used during driving) can help you to recover the car in the case of sudden loss of grip or if you exceed on slip angles... Is even this adjustable on WRC cars?
I would like to ask you if you can confirm the m-sport values and (if they are actually adjustable) what steering/wheels lock values were you running on different rallies or surfaces conditions.
Thank you :)
Hiya Jack, 360° on a wrc car - I have never seen. But one and half turn sounds right for all the cars I've driven. I have never heard a driver or a tech speaking of or wanting to change the ratio or adjusting it - but anything is possible to do if you really need to. My feeling is if someone would make the steering more direct it would make the car more difficult to drive. I am unable to answer about the rotation angle of the wheels, sorry. But I can say that whatever angle they turn to, it always felt like plenty. A proper gravel driver will use speed, throttle and brake to make the car turn with as little big steering inputs as possible; maximum traction is attained with the front wheels straight. If you see a good driver coming around a corner with full opposite lock it's probably because he accidentally put the rear wheels in the loose and lost the rear. Hope this helps a bit with your questions!
Dear Jack, the reason why WRC cars have low steering rotation (i.e. very large turning radius) is IMO in driveshaft joints limitation. When front wheels are powered, especially with huge torque You need to keep the angle rather low, otherwise driveshaft brakes. I give an example from cheap rally car with stock steering - You can take commom old Honda Civic VTi with 170 Hp 1.6 engine with very low torque. The stock steering allows so high angle of the driveshaft joint that with LSD it is very easy to break the driveshaft just by pushing full throtle on first gear in full turn.
That's also why You can see very high steering angles possible with RWD cars - there are no driveshafts in front. Simple as that.
Anyway the turning radius limitation is more of an issue on asphalt than on gravel. It means some corners You need to take with handbrake because otherwise You have to reverse.
PS The driveshaft joint extreme angles are kind of limitation also for suspension travel. With McPherson struts the more travel the higher angle of the driveshaft joints.
Thank you for your replies, maybe I tought that it was more important than it actually is!I supposed 360° after watching this clip of Mekee from 2017 Sweden https://www.youtube.com/watch?v=C2-eRLOu26E when he turn the wheel exacly 360 degrees recovering the car from a snow bank, but maybe it is just a coincidence, I'm sure that during mexico rally he was using 450 degrees (saw him crearly at lock position during his "car park tour" on the last stage). :)Quote:
Hiya Jack, 360° on a wrc car - I have never seen. But one and half turn sounds right for all the cars I've driven.
Very interesting theory, I read a similar supposition here https://forums.nasioc.com/forums/sho...d.php?t=707665Quote:
Dear Jack, the reason why WRC cars have low steering rotation (i.e. very large turning radius) is IMO in driveshaft joints limitation.
but the only solution seems to be contacting Prodrive :D
I also read an interesting article about braking from redbull site https://www.redbull.com/gb-en/jari-m...art-of-braking
I think that the section "The Loeb effect" could be an interesting topic about how he changed the driving and braking techniques :)