el_gencer Posted September 26, 2007 Report Share Posted September 26, 2007 Hi peeps can anyone offer me some advice. My problem is as the topic tile suggests is that my car doesn't feel as planted as it once did. I have tein type flex coilovers installed and the doc kindly did a full geometry on the car in May this year. After that the difference was noticable by huge margin, the car felt solid as rock. At the moment the car feels a little on edge like the backend is soft and wants to step out (there are no knocking sounds). It doesn't step out it just feels like its going to and can be a little disconcerting at times. I had new tyres install a couple of weeks ago and have been checking the psi levels and all is fine, and there are no visible defects with them. I've had a quick look under the car at the coilovers and there is nothing leaking from them and everything looks good thats attached to them. I even got a freind to drive my car last night, but he couldn't feel anything wrong. He did say he couldn't really comment as he's not driven it much. I'm begining to think its all in my head. Quote Link to comment Share on other sites More sharing options...
Tony Posted September 26, 2007 Report Share Posted September 26, 2007 Welcome to wim.... How many miles have you done since the calibration? Quote Link to comment Share on other sites More sharing options...
el_gencer Posted September 26, 2007 Author Report Share Posted September 26, 2007 Hi Tony, thanks for the welcome. I'd say roughly around 2 - 2.5k in total. Quote Link to comment Share on other sites More sharing options...
Tony Posted September 26, 2007 Report Share Posted September 26, 2007 Only you would know if the handling feels different.... I assume the dampening hasn't been changed? If not then the car will need to go on the Geometry rig if only to remove the chassis from the equation. Quote Link to comment Share on other sites More sharing options...
el_gencer Posted September 26, 2007 Author Report Share Posted September 26, 2007 Nope dampening is the same as its always been (i dont tend to use the edfc). I think the best way to describe it is skittish. I have driven over loads of sleeping policemen though. Could these knock the geometry out slightly ? My friend reckons its because i'm not used to the new tyres, the last set were toyo proxies t1-r the new set i'm on are falkens. To me it just feels like the rear end isn't sitting right. Quote Link to comment Share on other sites More sharing options...
Tony Posted September 26, 2007 Report Share Posted September 26, 2007 Nope dampening is the same as its always been (i dont tend to use the edfc). I think the best way to describe it is skittish. I have driven over loads of sleeping policemen though. Could these knock the geometry out slightly ? My friend reckons its because i'm not used to the new tyres, the last set were toyo proxies t1-r the new set i'm on are falkens. To me it just feels like the rear end isn't sitting right. You need to look back and think "when" did things change.... Was it after the tyres were fitted? Quote Link to comment Share on other sites More sharing options...
jon Posted September 26, 2007 Report Share Posted September 26, 2007 FK452s or ZE512s? Quote Link to comment Share on other sites More sharing options...
Tony Posted September 26, 2007 Report Share Posted September 26, 2007 FK452s or ZE512s? Is the T1-r reinforced? Quote Link to comment Share on other sites More sharing options...
jon Posted September 26, 2007 Report Share Posted September 26, 2007 It's quite a soft sidewall afaik but banded steel. Quote Link to comment Share on other sites More sharing options...
el_gencer Posted September 27, 2007 Author Report Share Posted September 27, 2007 They are the ZE512s. I believe they are a harder compound than the toyos. Quote Link to comment Share on other sites More sharing options...
Tony Posted September 27, 2007 Report Share Posted September 27, 2007 They are the ZE512s. I believe they are a harder compound than the toyos. But are they reinforced?.... If not the flexibility in the tyre sidewall will be quite detectable to the driver. Quote Link to comment Share on other sites More sharing options...
jon Posted September 27, 2007 Report Share Posted September 27, 2007 http://www.tyrereviews.co.uk/Tyre/Falken/ZE512.htm makes for interesting reading Quote Link to comment Share on other sites More sharing options...
Mark H. Posted September 27, 2007 Report Share Posted September 27, 2007 I have these on my MR2, i also saw them on a 1969 5L Mustang i was parked next to yesterday as well. I actually need to replace the rears now as they are only a mm or 2 from 1.6 minimum, but one has continuously lost air faster than others and its noticeably flatter again at the moment both looking at and feeling through driving. The car noticably lifts up when its at higher pressure. The cars suspension is pretty rigid though, the whole car will stay stiff but wobble on the 50/55 profile tyres if you put your foot on an rock it abit. I need to find somewhere to fit some more (a full set from camskill is just under £200 not fitted for 4) and have a geometry check as i haven't had one done yet since i have owned it. Hopefully it is not the rear alloy that is letting air escape. Would you use 205/50 or just stick with 195/55 if you were using the standard rev 3 15's Jon? Regarding the person on your site with the IS, are these not known to have extreme inner tyre wear if not suitably set geometrically. That is hardly the tyres fault. I take it the rears are bald in the middle, that sounds like his tyres were overinflated, and the handling of the car seems to change alot with a 6psi shift on the Mr2 so perhaps they were set too high for the weight load. It sounds like that person needs to have his geometry checked and chack what would be the best tyre pressures for his vehicle. To the original poster, perhaps it would be worth changing your tyres psi and going for a short journeyto test. Changing the pressure up or down may help if the sidewalls have a diffferent resistance to the last ones you had, if you find it improves then keep a check on how evenly they wear and take it from there. Also is the weight index number high enough, and would the run out lines change the cars stability at the rear as well as at the front? Quote Link to comment Share on other sites More sharing options...
jon Posted September 28, 2007 Report Share Posted September 28, 2007 Mark, Depends how you like the balance. I tracked with 195/225 and didn't like it at all, but i can't stand a car that understeers. I think most people go for the 205 now unless it's an unmodified rev1. Quote Link to comment Share on other sites More sharing options...
el_gencer Posted September 28, 2007 Author Report Share Posted September 28, 2007 They are the ZE512s. I believe they are a harder compound than the toyos. But are they reinforced?.... If not the flexibility in the tyre sidewall will be quite detectable to the driver. Looks like they aren't reinforced for the 215/45. http://www.falkentire.com/ziex512_sizes.html Would this be what i'm feeling ? the difference betten a tyre that was reinforced and now a tyre that isnt ? Quote Link to comment Share on other sites More sharing options...
Mark H. Posted September 28, 2007 Report Share Posted September 28, 2007 Mark, Depends how you like the balance. I tracked with 195/225 and didn't like it at all, but i can't stand a car that understeers. I think most people go for the 205 now unless it's an unmodified rev1. Does the speedo take its speed from the gearbox/rear wheels, and 205's wont upset the abs at all? 205/50's actually have a smaller rolling radius than the standard ones iirc. Quote Link to comment Share on other sites More sharing options...
jon Posted September 28, 2007 Report Share Posted September 28, 2007 IIRC the speed is taken from the gearbox. You can double check on imoc but i think 205/50 will be fine with the abs, i don't know as i don't have abs on the turbo but the abs on my old NA didn't mind going to 215/35 18 all round (no stagger) Quote Link to comment Share on other sites More sharing options...
Tony Posted September 28, 2007 Report Share Posted September 28, 2007 They are the ZE512s. I believe they are a harder compound than the toyos. But are they reinforced?.... If not the flexibility in the tyre sidewall will be quite detectable to the driver. Looks like they aren't reinforced for the 215/45. http://www.falkentire.com/ziex512_sizes.html Would this be what i'm feeling ? the difference betten a tyre that was reinforced and now a tyre that isnt ? Yep.... Tyre pneumatic slip angle is very sloppy compared to a reinforced tyre sidewall...... Almost as if the wheel is floating in the rim as you corner. Quote Link to comment Share on other sites More sharing options...
Mark H. Posted September 29, 2007 Report Share Posted September 29, 2007 IIRC the speed is taken from the gearbox. You can double check on imoc but i think 205/50 will be fine with the abs, i don't know as i don't have abs on the turbo but the abs on my old NA didn't mind going to 215/35 18 all round (no stagger) I might go for the slightly wider ones next time then, not sure whether to change them all at the same time or not as they have a couple of mm left on the front. Need to find somewhere to do the geometry as well. Quote Link to comment Share on other sites More sharing options...
el_gencer Posted September 30, 2007 Author Report Share Posted September 30, 2007 They are the ZE512s. I believe they are a harder compound than the toyos. But are they reinforced?.... If not the flexibility in the tyre sidewall will be quite detectable to the driver. Looks like they aren't reinforced for the 215/45. http://www.falkentire.com/ziex512_sizes.html Would this be what i'm feeling ? the difference betten a tyre that was reinforced and now a tyre that isnt ? Yep.... Tyre pneumatic slip angle is very sloppy compared to a reinforced tyre sidewall...... Almost as if the wheel is floating in the rim as you corner. That would explain everything then. I really didn't think a tyre would make that much difference. Guess you learn something new every day. My mind can rest, suppose all i have to do is just get used it. Hopefully the arb's (when i get round to buying them) will help the matter a little. Thanks el_gencer Quote Link to comment Share on other sites More sharing options...
Tony Posted September 30, 2007 Report Share Posted September 30, 2007 They are the ZE512s. I believe they are a harder compound than the toyos. But are they reinforced?.... If not the flexibility in the tyre sidewall will be quite detectable to the driver. Looks like they aren't reinforced for the 215/45. http://www.falkentire.com/ziex512_sizes.html Would this be what i'm feeling ? the difference betten a tyre that was reinforced and now a tyre that isnt ? Yep.... Tyre pneumatic slip angle is very sloppy compared to a reinforced tyre sidewall...... Almost as if the wheel is floating in the rim as you corner. That would explain everything then. I really didn't think a tyre would make that much difference. Guess you learn something new every day. My mind can rest, suppose all i have to do is just get used it. Hopefully the arb's (when i get round to buying them) will help the matter a little. Thanks el_gencer They will reduce the roll but not the loose feeling.... Up the tyre pressure to 35psi, this will lower the slip angle. Quote Link to comment Share on other sites More sharing options...
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