Tony

The KA was lowered by 25mm. As a result the camber position rested at -45 rather than the proscribed -18' . The wheel off-set and camber position resulted the tyre wear seen..... As Mat suggested the front toe would if measured also be incorrect, so the owner could blindly assume the wear was 100% due to the toe, the likes of Crap-fit would adjust the toe belaying the real reason 'Camber'. wim says: Be very wise, lowering the cars suspension is never without consequence. The benefits are massive but you should seek guidance prior to the modification..... wim can provide this!

Yes

Interesting, the COG and polar yaw seem dependant of the high powered car, and obviously the suspension/coil rate, so i wonder how in development can you manufacture the overall package. The maths needed to calculate the suspension, frame rigidity, angular inertia, roll centre, seems endless so i do wonder Mat how you have concluded this? i assume it's by driven example

That 'sneaking preference' invites questions... why the unsure smiley?

thats power over, drift is continues sideways slide...a fishtail doesnt constitute a drift a good vid here showing Drift, and the driver imputs....(jane may like one of the cars me thinks) Drift vid Nice video..... would have been even better if it was the 'Driffty'... Any pictures of your Driffty would be appreciated Mat! I am looking forward to setting the Driffty but i am still baffled with the rear tyre size. As you said the power belays traction despite the 255mm tyre width but could this cosmetic look retract the overall Drift?

KPI (King Pin Inclination) AKA SJI (Steering Joint Inclination) SAI (Steering Axis Inclination) owns one of the most important areas Geometrically on your car but is often dismissed due to it's complexity.... With luck this post will develop an understanding and questions are invited. The Kingpin position is perpendicular to the vertical viewed from the front of the car, the inclination in measurement decreases figuratively as the inclination is increased, so a position of 12 degrees holds less than a figure of 10 degrees this means the inclination is more inclined mechanically but lower figuratively, it's important that you can image this! So what?: The Kingpin deserves respect since it controls every area within the steering axis it truly is the (Kingpin)... Geometrically! Purpose: The KPI forms the lower pivotal axis positioning the Castor trail (Mechanical) also inviting the activation of the TOOT (Toe Out On Turns) during a turn, but we have some dynamics to consider... Since the Castor trail is established then the KPI is left to react during compression of the suspension, this is known as the Camber curve, calculating the curve is dependant of the length of the suspension compression and the length of the wishbone this realises the curve positions (one for the mechanical engineers) Example: Front:- Camber compression on (loaded) -1 degree 10' Camber compression off (unloaded) +10', this is the Camber curve. So how come with independent suspension can the car still drive straight if one wheel hits a bump loading the Camber curve since the conical force generated by the Camber position would insist that the car will violently pull toward the negative direction? Solution: All cars follow the same principle by design... Imagine the car like a Sandwich upper and lower decks... The upper deck rests it weight on the Kingpins and since the positions are linked through the steering rack then the inclination commands the opportunity to be at rest and equal, a natural equilibrium. Deviation by the driver in straight line travel off-sets the equilibrium by declining/inclining the KPI, in essence the inner KPI is lifted holding more weight than the outer KPI, again since they are both linked through the steering rack the drivers deviation is replied by the KPI returning the steering position retaining the natural balance resting on the inclination. To the bump: The production of independent suspension suggests that the Camber will indeed 'Curve' attenuating it's force, so how is this belayed?..... The hero is the KPI.. Positions: Assume the static front camber position of -30' and a KPI position of 9 degrees, during a compressive load the curve could position the camber at -1 degree adding conical force but the KPI due to the pivotal position will incline suspending an independent reaction involving the vehicles weight pushing back down on the Kingpin belaying the conical force offered by the camber curve, the reactive position of the KPI would be 8 degrees 30' this is more inclined. You try it?: You can witness the KPI in action... simply turn the front wheels from side to side, you will see the car rise as you go from lock to lock, this is solely due to the Kingpin inclining. Chassis dynamics is complicated but not impossible to understand or indeed develop, grasp the reasons why one particular angle is there then you are well on your way to develop your own theory.... My biggest criticism with technicians is that they only realize the positions not the forces... in reality most desires or complaints are born through the recognition of the forces!

wim is designed to help and educate in the Geometry field, so from these images can anyone suggest why these front tyres have worn in this fashion and what angle was responsible?

The machine in action........ now at about 400lbs pressure The flexibility of the wheel is amazing to watch, no wonder alloys flat-spot There is a preemptive skill needed to operate this machine but since the wheel was scrap before any attempt to straighten it then the slight possibility of it cracking seems to be worth the attempt. Cost: £50-£80 depending on wheel size and level of damage, in the event the wheel cracks then the cost is £0 regardless of duration wim says: I like this machine, it gives the owner a second chance to recover the wheel after hitting one of the Councils compulsory pot holes. Commercially there is a very big market for this service and i forecast it would be possible with good advertising to expand this through the postal service.

What amazes me it the fact that very few tyres actually blow out now days, so the RFT benefit is minimal in absolute requirement and that the RFT if punctured cannot be repaired. So the Female 'need to get home' safety concept is flawed because if the Rave had conventional tyres on then if punctured the owner could just run on it flat... ok this would destroy the tyre but what the hey the RFT would also be scrap?

I know you are wise around the Geometry machine so how would you set a RWD car specifically for Drift

explore it .....?? how exactly Geometrically and mechanical... Experienced drivers should be able to command specific handling desires... If you talk in Drift then you must be aware of the environment..... and develop it.... So are there any takers on this topic?

Doe's your Dad like cats

Big in the World and here in the UK... Does anyone want to explore this area?

when were these tyres introduced ? Not sure for the Rave.... 06 seems reasonable since no shop at the moment is equipped to deal with the tyres.... and seemingly no Dealership!.... what a mess!

but you cant take your son to your test, what would you do ? bit unfair on disabled and weak drivers, and has no reflection on there driving ability Never though of that.....Able bodied blindness..... wim wants to expand any avenue you can think of to assist this area....Good work bazza!

The Rave4 has one of the new concept RFT (run flat tyres) and it's gone very wrong.... Since the 4X4 tyre has such a high tyre aspect ratio the tyre needs to be heavily armored.... Problem is the manufacture Bridgestone has made the tyre so armored that no centre can remove it from the rim So a new (trade) directive has been released: 'all customers should be directed to the Dealership so the entire assembly can be replaced'..... So in effect all Rave4 owners will need the tyre and wheel replaced as a single unit. wim says: Utter pants, no evolution should suggest such constraints in tyre make or replacement restrictions... I noted in the internal mail no suggestion was mentioned if the customer will also need to pay for the wheel as well as the tyre

Now that's top information wim style.... Thank You Mat!..... and it saved me hours on goooogle

Setting a Starlet next week for a wim member who also needs a Panhard rod fitted and set.... this i have never done, the member is aware if this fact so..... this weekend i will swat-up but it would help if anyone here has experience of the set-up of the Panhard.... Any doe's or dont's i need to be aware of?

A concealed button that you need to press each time the driver's door is closed....if not....then after 2 mins the alarm starts to cut the fuel and the lights flash / horn sounds and the car comes to a halt! I sometimes forget to press the button and have errrrm, suffered some3 embarrasment as a result! You forget......nah!... distracted methinks... This is a valid question so don't think I'm taking the Mickey.... If you have the carjack fitted is this displayed as a warning on the car?... like a sticker or something?

Mark played pass the turbo and i just passed out What do they put in Ryabina these days carjack immobilizer what's that

On yeh.... party at mine 8pm..... don't be late

Seemingly the selling point with RFT is the 'blow out' fear factor?.... To tell the customer that 'even if' a tyre blows out the car will be in perfect control 'Sells', in addition there is the 'Lady sale'.... She is the one who has a puncture on a dark lane on her own..... With the RFT there is not need to stop... Both examples seem convincing to the uneducated... Another point, the sale of 'Stop Sticks' to the police would drop methinks

Mark i just noticed you're 101..... Congratulations

More and more cars today don't carry a spare tyre.... BMW, MCC and so on.... For some the reason is space, for others the reason is the development of the run-flat tyre belaying the need for a spare..... and it's cost effective .... Whatever the model of car the driver needs clear indications that the tyre is deflating, some use an electronic internal bladder, others use the ABS ring rate by reading an increased RPM on the deflated tyre. Clear benefits are safety since you have a visual warning of a problem. The down side is the tyres are very expensive and if punctured are scrap. So back to the conventional tyre....... Innocently you drive and get a puncture, the handling is affected and you pull over and fit the spare... most tyres by comparison to the RFT are cheap and can be repaired... But there is a problem. Modern cars perform so well that a punctured tyre is almost undetectable... You have no visual warning on the dash and can assume all is well until.... This Nissan driver was on the Motorway with no indication from the car anything was wrong, until he looked in the mirror and saw smoke belching from the rear....... In panic he hit the brakes and spun the car into a ditch. As you can see the resulting spin almost turned the tyre inside out.... So maybe the RFT is better but cost is an issue... Or is the old school spare tyre an an aware driver better.

In your particular case the reason for the vibration has been 1+2 since the GSP9700 solved the problem... Tyre manufacturing does vary in results according to the make of tyre.. The cheaper tyre tends to require more compensation... The reason i intend to explain in full as a wim knowledge topic very soon.