Nick Jackson (2) Posted March 7, 2010 Share Posted March 7, 2010 This is affecting both front tyres. I had the local tyre shop set the tracking and alignment before the RBRR in October by reference to the Haynes manual and their experience of the wheels and tyres on the PI. I'm running 15" Minilites from Tech Del with 195/60 tyres. Is there way to work out the best theoretical settings (e.g. toe-in, camber etc.) for the big saloon?Thanks. Link to comment Share on other sites More sharing options...
JohnD Posted March 7, 2010 Share Posted March 7, 2010 Nick,Wear on inside edge can mean excess negative camber, +/- a tracking error, but mainly the first.But you have got yourself into this!15" wheels on a Spitfire? 50 profile tyres would restore the rolling diameter (see: http://www.mintylamb.co.uk/?page=tyre.htm) but even the 60s have grossly shorter side walls than the original cross plies. Such short sidewalls have to be MUCH stiffer, so they tolerate camber change badly in comparison with crossplies or taller radials. Such stiff sidewalls lift the tread off the road when camber goes more than a fractionof a degree away from neutral, and the tyre rides on the shoulder. Triumph suapension changes camber a LOT! Review the camber, and the tracking, and then fit stiffer springs, to reduces suspension movement.JohnPS Ooops! NOT a Spitfire! The 2.5Pi also had 13" wheels, but a MacPherson strut front end. MacP always tends positive in compression so the argument still applies! J. Link to comment Share on other sites More sharing options...
Lord Sorbington Posted March 7, 2010 Share Posted March 7, 2010 My intial reaction is that you may need a little more toe in? Bear in mind that wider tyres and wheels with a different offset may cause more splaying out of the wheels when moving than the standard tracking figure allows for. Trouble is that I'm not sure adjustments you make now will affect the wear pattern of the existing tyres?Obviously, things like worn drag strut bushes, inner and outer track rod ends etc. will have an effect too. The position of the tyre in relation to the rest of the suspension (due to wheel offset) may also be a factor?I don't think you can really have a lot of negative camber on the front of these cars. By accident rather than design mine has no shims between the hubs and struts and hence has a little more negative camber than normal but it's covered many thousands of miles like this and tyre wear has always been even. Link to comment Share on other sites More sharing options...
dazzer Posted March 7, 2010 Share Posted March 7, 2010 Hi NickTracking is best set parallel, you can do this yourself by carefully measuring inside rim to rim front and inside rim to rim rear of the front wheels. No fancy tracking gauges required.As for camber you actually add shims on the lower securing bolts to increase negative camber. What you need is a camber gauge to check what the actual reading is. I've added shims to increase my negative camber but I am running 175/70 14s to keep the rolling circumference pretty close to the standard 80 profile 13 inch tyres. John D is right 50 profiles are way off the original rolling circumference check out http://www.miata.net/garage/tirecalc.html to compare compatible tyre sizes to the original 80 profile 13" set up.CheersDarren Link to comment Share on other sites More sharing options...
Lord Sorbington Posted March 7, 2010 Share Posted March 7, 2010 570 wrote:Hi NickAs for camber you actually add shims on the lower securing bolts to increase negative camber. What you need is a camber gauge to check what the actual reading is. CheersDarrenInteresting, I'll have to have a closer look for shims when I get the car back.I have noticed a little bit more negative camber and significantly better handling since the lower suspension arm bushes and ball joints were renewed. Either way, it doesn't seem to be significant froma tyre wear point of view.Out of curiosity, why do you say that tracking is best set parallel? The book suggests 1.6mm of toe in and I'd have thought that wider tyres and offsets which widen the track would have required this to be increased if anything? Link to comment Share on other sites More sharing options...
Nick Jackson (2) Posted March 7, 2010 Author Share Posted March 7, 2010 I don't think my wheel/tyre setup is unusual so others must have solved this problem and it just a question of working out the correct settings. I'll do a bit more asking around and see what I come up with.ThanksNick Link to comment Share on other sites More sharing options...
dazzer Posted March 7, 2010 Share Posted March 7, 2010 HiMost modern applications run parallel and working in BL franchise for many years everything was set to parallel as a matter of course.Always works well if the track rod ends, suspension bushes etc are in good order. Shouldn't be any need for the tracking to be set toe in to allow for the take up of play as the vehicle moves forward.CheersDarren Link to comment Share on other sites More sharing options...
Raider Posted March 8, 2010 Share Posted March 8, 2010 Having worked for Michelin for 17 years our advice was always to set as close to parrallel as the manufacturer's figures would allow.In rare occasions we might set something else but that would be with a technical manager's input on something out of the ordinary Link to comment Share on other sites More sharing options...
kenv8pi Posted March 8, 2010 Share Posted March 8, 2010 HI Nick I run a pi with 205 55 15 had the same thing mess around with the tracking for a long time. It depends on how low you have set the front end? I have 205-400 progressive with koni ajustable sat just off the bump stops about 5mm I have set mine to 3mm toe in which seems to work. and the tie bar bushes on the chassis end need to be the very hard polybush to help stop the wheels spreding under (heavy) braking which will ware the tyres aswell if you have power steering you will find the tyres will ware out quicker. Hope this mite help Ken 8) Link to comment Share on other sites More sharing options...
Lord Sorbington Posted March 10, 2010 Share Posted March 10, 2010 1521 wrote:HI Nick . and the tie bar bushes on the chassis end need to be the very hard polybush to help stop the wheels spreding under (heavy) braking which will ware the tyres aswell Ken 8)Yes, if you ever watch your car while it's on the brake rollers at MOT time you'll see just how much those bushes compress. Link to comment Share on other sites More sharing options...
GreenV8Machine Posted April 29, 2010 Share Posted April 29, 2010 Im just about to wang a stag anti roll bar on my 2000 seeing as though I cant get a witor extra fat one, with reinforced drag struts, polybushed, new hubs, stubs and bearings. So after that im going to get it all set up. I take it I'm sticking some washers between the lower pair of damper strut mounting holes and the vertical link for negative camber, correcto? Link to comment Share on other sites More sharing options...
Richard B Posted April 29, 2010 Share Posted April 29, 2010 GT6_User_and_Abuser wrote:I take it I'm sticking some washers between the lower pair of damper strut mounting holes and the vertical link for negative camber, correcto? Be warned, they are 10 thou shims, not washers. ;) Link to comment Share on other sites More sharing options...
CRAJ Posted April 29, 2010 Share Posted April 29, 2010 Richard_B wrote:Be warned, they are 10 thou shims, not washers. ;)And very easily lost when dismantling , if you dont realise they are there.Not that easy to get back in either when you are struggling with the weight of the front hub, disc, caliper etc.Colin. Link to comment Share on other sites More sharing options...
dazzer Posted April 29, 2010 Share Posted April 29, 2010 The washers vary.I believe 1 x 0.010 washer per side is standard. I bought a tray of assorted stainless steel shims and currently have .045 per side.Bring on the negative camber!Cheersdarren Link to comment Share on other sites More sharing options...
GreenV8Machine Posted April 29, 2010 Share Posted April 29, 2010 sorry, "round, holed thin pieces of steel resembling a thin washer" ;)there was none in there when i removed the strut, ill get some more Link to comment Share on other sites More sharing options...
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