camber issues

[N9TE]

Hey all.

I'm looking for some advice from some gurus. The inner edges of my rear tires are wearing faster than the rest of the tire. Probably in the neighboohood of 3x faster than the rest of the tire. I didn't think the rear (or fronts for that matter) could be adjusted for camber.

You'll have to go slow for me, using Peugeot terms for parts as I'm going over the factory manuals and parts fiche. My guess is that I've got some worn bushings. At least that what I got by doing a good search of the Peugeot-L newsgroup. The fronts are adjustable by some voodoo called "strut bending" where the engine is unbolted and the engine cradle is bent to adjust the camber.

Any advice would be appreciated.

[august]

The fronts are adjustable by some voodoo called "strut bending" where the engine is unbolted and the engine cradle is bent to adjust the camber.

baaaaaaaaahahahah are you joking?

i wish i could help on the rear camber issue. it's always been the front of the car that has the camber wear thing going on. i dont understand how the rear camber can really change all that much. is the cross member bending into a U?

maybe you should take that 6 woofer sub box out of your trunk!

we should get victor on this one, i'd be curious to see what he has to say.

[N9TE]

Seriout. Bruce Ashment sezs so here. (Using Google cache as vectorbd.com is spitting back 403s (permission forbidden) today.

Ya, an area where Victor would know more about somthing than just about anybody would be 505 suspensions I would guess.

[Bean]

Rear Camber is usually fixed by replacing the cross member isolation block bushings at each end of the cross member. (Told that they have a heavy duty taxi version or something that should be used.) Failing that - you can take it to a frame shop to tweak that rear cross member. From what I was told they put it on a frame machine, chain down the ends and jack up the centre and it cambers out the wheels.

Another method is to shim the rear bearing housings (where they mount to the trailing arms) to get rid of the camber.

The part about tweaking the front crossmember is just retarded - it's thick cast part - not something conducive to bending. (And even if it did bend - it'd hardly affect camber!) 505 Turbo's have some decent camber built in the front struts and if your getting worn inner edges at the front you usually just need a touch more toe in to even up wear... (But check your spring perches to see that they're not starting to rust out.)

Rabin

[SSB]

Ahhhhhhhhhhhhhhh, ok. Inside tyre wear? Welcome to Club Peugeot (or Club any IRS). Barring any control arm issues, which would allow the tire to shift and depending on which (or how many) bushings have failed could cause all sorts of odd wear patterns...................inside tyre wear is normal. While exagerated by how much weight is carried in the trunk the car normally has quite a bit of negative camber (I don't remember the rear numbers off hand but the front was -3 degrees). I have 225/60 - 15's and as such always wears to the inside. If one were to use the 205/60 - 15 it would show less wear and less still if it had the 195/60 - 15. To me is all good as when the car is leaned over in the corners that out side tyre is sitting very well into the pavement (watch video of Runoffs). I've also taken to rotating the tyres from side to side (necessating removing them from the wheels so that they continue to rotate the same direction). But tyres are to me sacrificial lambs and are destined to die a tortured death anyway.

However, speaking of shifting, those Taxi Cab bushings prevent exactly that. The standard (i.e. softer) bushing allows the entire rear cross member to shift. The informed source told me that (and I'm not exactly clear as to why) the side loading caused toe-in on the outside wheel resulting in good old (safe) understeer. The harder bushings redused the shifting of the crossmember and made for a more tail happy responce. But wait, there's more. I found cracks in the tub (wheel opening housing and floor) repetely after installing them. and the cracks again allowed toe-in. So we had to weld the tub twice while it was a race car ('88 & '89). Caviet em tor (sp?). So why did the taxi's use them?? To increase the pay load in the trunk. Did they crack also? I doubt the taxi's ever raced around corners very fast (probably run into a few curbs, though).

Lets see now...... bending things??. It's already got more than enought negative camber. Mine was bent (by virtue of jumping over a bed) and had a little more caster than others (and still does). Positive caster is a really good thing but I would imagine the that varible power steering assist thingy would not like it at all.

So, wearing out the inside of the tyres ??? Drive around corners faster would be my advise. Toe-out the front end and buy low wear rated tyres and drive like hell. Or...................toe-in the front end and buy the smallest, hardest tyres and have no fun at all.

[Bean]

So this begs the questions Victor - what was your race alignment specs?

I'm all for sacrificing tires in the name of outrageous handling - but I would always just have the standard wheel alignment done, so I've never really played with a "race" set up.

I'd be curious to hear what you ran at the track, and then compare it to what we run stock.

Rabin

[SSB]

So this begs the question

Well, as a showroom stocker we are pretty limited to what we can do. That being said, Peugeot already gives one all that you can use anyway...............with one exceptional area. And this expectional area has side affects. Toe. I believe specs call for toe-in on the front. Thats wonderful as it causes the front tyres to drive toward each other. It also causes the inside tyres to not be turning into the corner as much as the outside tyer. The effect is good old safe understeer (keeps yer grandmother alive).

Now, for those with heart beats somewhat elavated from comotose (with all due respect to yer grandmother) toe-out changes everything. Hold your hands, palm down, in front of you and point them slightly toward each other (just a couple of degrees). Now turn them left and right as if they were connected. The inside hand is pointing straight while the outside hand is tuned in. Now hold your hands pointed away and turn them as if they were connected. The inside hand is turned further into the turn than the outside. Which would you rather have going into the corner ?? Assuming the obvious answer, what about wearing ther inside of the tyre? And what about having the wheel shake inyour hands between 30-40 mph? Ah, there's the rub. Not only are you wearing the tyre on the inside because it's toed-out, it's shaking the steering wheel as well because the tyres are trying to drive away from each other and the rubber bushings snap them back into place. But ya know what?.......................................It's ok by me 'cause as soon as you turn into the first corner you'll get a very eger response to turn.

Now look at the attached picture then the previous one.

[Bean]

Ah yes - makes total sense!

Now to get specific - was there an amount of toe out that you used for the track? I'm thinking this would make a HUGE difference to slalom racing as well - but I'm curious where the line is before you have too much toe out.

I remember doing a steering rack swap then drving it to an alignment and I experienced Toe out at the extreme. It was a fight to keep it straight - but it definitely turned in eagerly!

Thanks Victor!

Rabin

[SSB]

I'm curious where the line is before you have too much toe out.

Rabin

Race track is differant then auto-X. At least as far as making adjustments. We had 1/2 hour practice, then 1/2 hour qualifying, before the 1/2 hour race. Using a pyrometer we would make tyre pressure adjustments according to tempretures (outside, middle and in). Then toe-out would would only be changed if the course had a long straightaway. 1/2" was nominal and 1" max (front wheel drive cars would be differant as the wheels close up the toe-out under acceleration). With as much rubber as Red had and the earlier style front suspension pieces the tyres moved forward and back nearly as much as they move up and down so it really wasn't very scientific. If I need more top end speed, I'd take reduce the out-out. If Red was "plowing" hard somewhere, he'd get more toe.

With Auto-X it would be trail and error over a long period and then even then you'd have to look at the track layout carfully. You can buy Dunlap gauges or you can use string to check the toe. Either way I don't think you'd go over 1". Affecting the toe-out is by either turning both tie-rod ends equally or (the fast way) is to turn one. The upside to turning one is the you can see the toe-out by how off centre the steering wheel is.

Bottom line is that it doesn't really change how hard the car can corner, but it does change how it turns into the corner.

[august]

to back up a bit. if anyone finds a source where we can find the taxi cab cross member mounts would you let us all know? i've looked a bit without luck.

victor: thank you much for all the info!

[Bean]

Brian Holm maybe? I know Mike Aube spoke of using nothing but taxi bushings on his repairs - so he might have a good source... Might need to pose the question on Peugeot-L list to see where people get them...

Rabin