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Bad geometry from new


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I think many of us know about the poor manufacturer's geometry setup on the Lexus IS.......are there any other manufacturers and models whose initial geom is bad?

 

Yep recent example has been the Mazda MX5... 3000 miles on the clock and the handling was so poor the customer feel the need to have the car checked..... i did and ten angles needed correcting.... needless to say the report and bill is going back to Mazda.....

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I've heard that BMW'S and Mercs are bad as to set them up properly you have to have weights set out on each seat or alternatively take the family with you and keep them inside the car when the geom is being carried out.

 

Introduce the family to WIM on your next visit.

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I've heard that BMW'S and Mercs are bad as to set them up properly you have to have weights set out on each seat or alternatively take the family with you and keep them inside the car when the geom is being carried out.

 

Introduce the family to WIM on your next visit.

Actually your analogy is very true.. BMW MERC AUDI.... all need to be loaded and carry a full fuel tank.... even the rad has to be checked and topped up?.... 'pants' is'nt it!

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tony, have you ever done a peugeot 206? the ride height has to be set to a certain level,

 

i found that 8x56lb weights and 3 trolley jacks in the boot plus 1 56lb weight in each front foot well gets the height down to the right level.

 

oh and they quite good realy realy lowered.

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  • 3 months later...

I think many of us know about the poor manufacturer's geometry setup on the Lexus IS.......are there any other manufacturers and models whose initial geom is bad?

 

Yep recent example has been the Mazda MX5... 3000 miles on the clock and the handling was so poor the customer feel the need to have the car checked..... i did and ten angles needed correcting.... needless to say the report and bill is going back to Mazda.....

 

That was me!! and yes Mazda did a letter and a copy of the bill, in return i got the cost fully refunded and a letter in return full of remorse!! we have now just ordered another MX5 mk3 for the misses and just to see if Mazda have sorted this problem it will be booked in with tony the day we pick it up to see it things have improved , if not another letter and bill will be sent to Mazda !!! apart from that we love the car ! lol

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I think many of us know about the poor manufacturer's geometry setup on the Lexus IS.......are there any other manufacturers and models whose initial geom is bad?

 

Yep recent example has been the Mazda MX5... 3000 miles on the clock and the handling was so poor the customer feel the need to have the car checked..... i did and ten angles needed correcting.... needless to say the report and bill is going back to Mazda.....

 

That was me!! and yes Mazda did a letter and a copy of the bill, in return i got the cost fully refunded and a letter in return full of remorse!! we have now just ordered another MX5 mk3 for the misses and just to see if Mazda have sorted this problem it will be booked in with tony the day we pick it up to see it things have improved , if not another letter and bill will be sent to Mazda !!! apart from that we love the car ! lol

 

that seems very fair of mazda

dont think lexus would be the same :mellow:

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I think many of us know about the poor manufacturer's geometry setup on the Lexus IS.......are there any other manufacturers and models whose initial geom is bad?

 

Yep recent example has been the Mazda MX5... 3000 miles on the clock and the handling was so poor the customer feel the need to have the car checked..... i did and ten angles needed correcting.... needless to say the report and bill is going back to Mazda.....

 

That was me!! and yes Mazda did a letter and a copy of the bill, in return i got the cost fully refunded and a letter in return full of remorse!! we have now just ordered another MX5 mk3 for the misses and just to see if Mazda have sorted this problem it will be booked in with tony the day we pick it up to see it things have improved , if not another letter and bill will be sent to Mazda !!! apart from that we love the car ! lol

 

that seems very fair of mazda

dont think lexus would be the same :mellow:

Problem with the Lexus is that the data is incorrect, whereas with the Mazda the positions are incorrect... their error cannot be disputed.

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Ever done a Civic Type R. I swear i've +ve camber at the front, perhaps i'm just used to my 2.6 degrees -ve on the mr2.

 

Looks shocking though.

The type R has a conservative -30' camber...... and you deffo have more -ve camber mate :mellow:

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Good news is i've the camber adjustment bolts in the rear today and i'll do the front soon. I'll be back soon, just got to put the rest of the car back together one i've bought some shallow sockets.

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Good news is i've the camber adjustment bolts in the rear today and i'll do the front soon. I'll be back soon, just got to put the rest of the car back together one i've bought some shallow sockets.

Excellent news... i cannot wait to set the front... you will not believe the difference!

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Hey, i like the front :mellow:

 

You're right though, the car needs to be a little more balanced towards neutrality rather than trying to spit me off the road at any high speed corner.

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Hey, i like the front :mellow:

 

You're right though, the car needs to be a little more balanced towards neutrality rather than trying to spit me off the road at any high speed corner.

 

High speed track....Front -1 40' camber.....long castor. Rear -2 10' camber (toe we can play with) allowing slight corner out/on oversteer :unsure:

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We need to discuss (read argue) this, clearly we're shooting at different ends of the car for camber.

 

Worse case, i try it my way and your way and report back :rolleyes:

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We need to discuss (read argue) this, clearly we're shooting at different ends of the car for camber.

 

Worse case, i try it my way and your way and report back :rolleyes:

 

Argument is visible theory nothing wrong with that...

 

What is your end goal toward the handling of the car... we know it's fast track.... very light, and you seem to enjoy much over steer... most times this balance would detract overall speed since the over position generates a 'lift off' corner out, are we in agreement on this!

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My goal is indeed the fastest possible time from the driver and car, however my driving style allows me to play with the backend more than the average it would seem resulting in a slight oversteer bias being faster than a slightl understeer car (which to be fair, i struggle with).

 

The current high camber front, low rear gives me a front i'm very happy with and a low speed balance i can deal with. It's the higher speed balance i'm more concerned with taiming, and while I agree the FR balance needs to be addressed i fear your proposed figures will result in more understeer than i can take.

 

Don't forget, the rev2+ SW20 is a very understeering chassis by default despite what people think.

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My goal is indeed the fastest possible time from the driver and car, however my driving style allows me to play with the backend more than the average it would seem resulting in a slight oversteer bias being faster than a slightl understeer car (which to be fair, i struggle with).

 

The current high camber front, low rear gives me a front i'm very happy with and a low speed balance i can deal with. It's the higher speed balance i'm more concerned with taiming, and while I agree the FR balance needs to be addressed i fear your proposed figures will result in more understeer than i can take.

 

Don't forget, the rev2+ SW20 is a very understeering chassis by default despite what people think.

Your aspirations go against the grain geometrically (i like that) .... my natural positions 'as displayed' is probably to protect the novice.... most drivers could/would not want such an over-steer position as yours.

 

Personally i would like to test the camber/castor/camber positions in a more balanced format, then release the toe for development... what area within the corner is the magic moment..... example.. transfer/brake/over/roll/ off.... if you were to explore a particular area what area would that be?

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Why develop toe over camber? Don't get me wrong, i'll gladly offer my car and feedback to any WIM designed setup, i'd just like to know why.

 

My basic understanding would indicate there's more raw grip to be gained from nailing camber than there there is toe, where as toe can be used to effect the behavior of the vehicle in transient (ie turn in) situations.

 

As for my magic moment in the cornering procedure, I like a car nailed in the transient 'brake to turn-in', the rest i can catch. Still, i look forward to having slightly less rear on power on.

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Why develop toe over camber? Don't get me wrong, i'll gladly offer my car and feedback to any WIM designed setup, i'd just like to know why.

 

My basic understanding would indicate there's more raw grip to be gained from nailing camber than there there is toe, where as toe can be used to effect the behavior of the vehicle in transient (ie turn in) situations.

 

As for my magic moment in the cornering procedure, I like a car nailed in the transient 'brake to turn-in', the rest i can catch. Still, i look forward to having slightly less rear on power on.

 

Compressive camber belays slip angel and tightens the car... The camber curve during transfer amplifies security but in your case only at the front due to the front/rear camber disparity (low rear) This invites over-steer in particular i feel corner out..... this must retract track speed.

 

A balance of camber positions combined with a long castor would introduce a consistent drive.. then add front toe in for turn in and rear toe out for over-steer in gradual testable increments subject to driver feed-back.

 

Raw grip if taken literal is nothing more than superglue, balance -ve- power is the key.

 

In truth you cannot own a 'brake turn in' if the rear owns 80% ability to rotate around the front, since the front is so well planted.... the car wants to spin..... catch nothing you will need to lift off! this then is not fast track, but fast thinking?

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Vauxhall Monaros! They all wear the front inner edges of the tyres. Not really got to the bottom of it yet though. They normally check out OK but still wear the tyres. My current thereoy is that there is more movement in the suspension than Holden/vauxhall allowed for in the toe set up.

 

Interestingly, the VXR models which feature firmer suspension seem to suffer less?

 

On mine i rather unscientifically increased toe in slightly and that seemed to sort it.

 

Really ought to get to the bottom of it though, well at least when i have been fully educated!

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Vauxhall Monaros! They all wear the front inner edges of the tyres. Not really got to the bottom of it yet though. They normally check out OK but still wear the tyres. My current thereoy is that there is more movement in the suspension than Holden/vauxhall allowed for in the toe set up.

 

Interestingly, the VXR models which feature firmer suspension seem to suffer less?

 

On mine i rather unscientifically increased toe in slightly and that seemed to sort it.

 

Really ought to get to the bottom of it though, well at least when i have been fully educated!

 

Positions offered by the manufacturer are nothing more than suggestions!... excepting something is wrong then self-analyzing a solution is nothing more than healthy (good for you).... chassis dynamics even in the raw needs much dynamic thought.

 

An area i drum into students is do not look at the colors or the numbers displayed, look at the forces displayed?

 

Every position represents a static force, then a dynamic force... all angles swap their forces dynamically to induce some form of stability.... if you loss one force what! is the dynamic consequence? often the reply is :unsure: .... so there is a real need to understand exactly what each angle represents before you can theorise dynamic Geometry with accuracy...

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