Tony Posted April 5, 2007 Report Share Posted April 5, 2007 So far so good.. I feel the historic failures of the IS200 Geometrically will dissipate with the IS250 but!!! This babe... With 4k on the clock needed wim attention The complaint was a "Dead zone" at the steering centre.... concerning enough for the owner to visit wim.... Our findings were only toe related and i will report back as soon as the owner tests the new positions. Quote Link to comment Share on other sites More sharing options...
Tango Posted April 5, 2007 Report Share Posted April 5, 2007 So far so good.. I feel the historic failures of the IS200 Geometrically will dissipate with the IS250 but!!!This babe... With 4k on the clock needed wim attention The complaint was a "Dead zone" at the steering centre.... concerning enough for the owner to visit wim.... Our findings were only toe related and i will report back as soon as the owner tests the new positions. Well at least he came to you instead of his local stealership, although I assume it's still under warranty?? Must admit mine changed totally after the WIM toe adjustment, although as we lowered it as well it was difficult to attribute the change just to the initial adjustment. Quote Link to comment Share on other sites More sharing options...
Tony Posted April 5, 2007 Author Report Share Posted April 5, 2007 Indeed.. I actually contacted the customer and explained the corrections will be very small shall we continue? He said yes! The reason is that the chassis is so new no real analysis is available weather the correction will correct the complaint. I did pull your file and some interesting similarities were evident, i await the customer feed-back to conclude our calibration analysis. Quote Link to comment Share on other sites More sharing options...
TK Chan Posted April 6, 2007 Report Share Posted April 6, 2007 Indeed.. I actually contacted the customer and explained the corrections will be very small shall we continue? He said yes! The reason is that the chassis is so new no real analysis is available weather the correction will correct the complaint. I did pull your file and some interesting similarities were evident, i await the customer feed-back to conclude our calibration analysis. Thanks Tony for bringing this to our attention. My IS 250 has only logged 1600 km so far as it is for casual ride. Does this mean the problem has not surfaced yet? To be honest, I do not fully comprehend this problem of "Dead Zone" and how will it behave in action. Could you elaborate a bit more. It does not seem to attract any similar report either from the US or the other Lexus IS2 clubs. Quote Link to comment Share on other sites More sharing options...
Tony Posted April 6, 2007 Author Report Share Posted April 6, 2007 Indeed.. I actually contacted the customer and explained the corrections will be very small shall we continue? He said yes! The reason is that the chassis is so new no real analysis is available weather the correction will correct the complaint. I did pull your file and some interesting similarities were evident, i await the customer feed-back to conclude our calibration analysis. Thanks Tony for bringing this to our attention. My IS 250 has only logged 1600 km so far as it is for casual ride. Does this mean the problem has not surfaced yet? :rolleyes_anim: To be honest, I do not fully comprehend this problem of "Dead Zone" and how will it behave in action. Could you elaborate a bit more. It does not seem to attract any similar report either from the US or the other Lexus IS2 clubs. Remember this is an observation not a criticism of the IS250. The complaint "dead zone" is when the steering is dead ahead but has no feeling... Almost detached from the road making the driver feel nervous. The toe positions can increase or decrease the lateral compression of the steering rack from the tyres rolling resistance if set incorrectly... Example the IS250 has the steering arms in front of the wheels centre pivotal point, so if the toe is statically set positive then the rolling resistance will act laterally on the tyre suggesting a zero toe. Add to this the type of drive (push= RWD pull=FWD) then the toe will need to be adjusted... In addition to add complication the tyres width will deserve more consideration because the wider contact patch adds resistance.... So a simple +1mm (static) may indeed need +3mm to retain a feel-able steering at the "dead zone". The conclusion is being investigated. Quote Link to comment Share on other sites More sharing options...
Tango Posted April 6, 2007 Report Share Posted April 6, 2007 I took a hard look at the Bridgestone Potenzas that were on the original 17" rims on my car. Considering they were only on for 5000 miles I was surprised how much the inners on both front tyres had worn in comparison to the outer edge. Thinking back, we lowered the car on those rims and tyres...Tony, do you have the record of how many miles the car had done on the factory settings, i.e. at the time you initially measured the set-up? Quote Link to comment Share on other sites More sharing options...
Tony Posted April 6, 2007 Author Report Share Posted April 6, 2007 I took a hard look at the Bridgestone Potenzas that were on the original 17" rims on my car. Considering they were only on for 5000 miles I was surprised how much the inners on both front tyres had worn in comparison to the outer edge. Thinking back, we lowered the car on those rims and tyres...Tony, do you have the record of how many miles the car had done on the factory settings, i.e. at the time you initially measured the set-up? Yes. I should have the mileage and tread depths to 100th of millimetre from your first visit. Quote Link to comment Share on other sites More sharing options...
Tony Posted April 11, 2007 Author Report Share Posted April 11, 2007 Here is the owners report back to wim ...................................................... Tony - thanks for your help last week. I promised you an email when I had driven the car for a few days, to report on any changes noticed. I think I can safely say that the steering problems have been corrected. The central vagueness and the tendency to drift gently to the right have gone. The steering centres readily and the car holds a straight line "hands off" in a way that it would not do previously. It's amazing that such small adjustments should make so much difference. Best wishes ......................................................... I am very pleased for the owner but also worried for owners since the correction was so small yet so detectable to the driver.. To my knowledge the IS250 has EPS and centre weighting on the steering, seemingly this was not central generating the distress. Quote Link to comment Share on other sites More sharing options...
TK Chan Posted April 13, 2007 Report Share Posted April 13, 2007 Here is the owners report back to wim...................................................... Tony - thanks for your help last week. I promised you an email when I had driven the car for a few days, to report on any changes noticed. I think I can safely say that the steering problems have been corrected. The central vagueness and the tendency to drift gently to the right have gone. The steering centres readily and the car holds a straight line "hands off" in a way that it would not do previously. It's amazing that such small adjustments should make so much difference. Best wishes ......................................................... I am very pleased for the owner but also worried for owners since the correction was so small yet so detectable to the driver.. To my knowledge the IS250 has EPS and centre weighting on the steering, seemingly this was not central generating the distress. Tony, Thanks for your insight. I am quite surprised that such an issue could surface so soon with such a new car. From the picture of your customer's IS 250 it is a stock deluxe package with everything pretty much standard from the factory. I presume there is no modification to its configuration. If this "dead zone" phenomenon is a manufacturing defect, then there should be a lot of owners/drivers experiencing the issue already. I don't know if I have read enough of the forum messages to notice that such issue has ever been discussed. Another scenario could be that your customer's IS250 might just be a bad copy out of the manufacturing batch. BTW, have you driven the car before the problem was corrected and how did it feel? Was the problem easily detectable by the average driver? As I have changed the stock wheels and going to have the chassis lowered, I will lose factory warranty for those components. That is indeed a concern if any related manufacturing defect is detected subsequently. TK Quote Link to comment Share on other sites More sharing options...
Tony Posted April 13, 2007 Author Report Share Posted April 13, 2007 Most times i don't drive the car first for two reasons.. 1: It could be in a dangerous condition (see horror of the week posts) 2: The data measured is all i need to know how a car drives. Saying that though when i measured this IS250 i was unhappy to set the small amounts without the owners consent because i was not convinced the calibration would solve the problem... It did! I don't think this particular complaint will become an IS250 nemesis since it's the first of it's type.. to my knowledge but if it reoccures again we now know what the criminal is. Quote Link to comment Share on other sites More sharing options...
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