Rear camber

[rtg]

I'm setting the ride height on my S, and measured the rear camber: They are reading -3Deg & -0.98Deg. Reading the Steve Heath book they ask for +1.25Deg, but apart from shimming the trailing arm to hub with a wedge, am I correct that there's no other way of fixing the rear camber?

In general, what is the effect of a) having a negative camber, and b) having differing cambers? i.e. is this something that needs fixing or, not being a racing driver, I'm really not going to notice?

Thanks, Richard.

[rtg]

.. and I'll read the Suspension wiki to the bottom next time before I post! - good explanation of camber adjustment there. Cheers.

[GreenV8S]

If they're different from side to side either you've bent something, or the two sides have been shimmed differently, or you're measuring it wrong. How are you measuring it?

[phillpot]

I've not tried this but theory/logic would say to me if you can slot the holes where the pivot block bolts onto the trailing arm it would give a little adjustment?
Maybe even just rotating the block 180 degrees would make a difference if it is not perfectly symmetrical?




How did you get such accurate measurements?

I wonder how accurately they were made/set up from the factory?


In the "real world" of rumbling around a few A and B roads I doubt it will make a noticeable difference to handling, but could show up on tyre wear?

[Kitchski]

phillpot said:

Maybe even just rotating the block 180 degrees would make a difference if it is not perfectly symmetrical?

The mount isn't symmetrical sadly. You could try switching it with the other side, as even though they're all meant to be identical, this is TVR we're talking about.

phillpot said:

I wonder how accurately they were made/set up from the factory?

See above!

phillpot said:

In the "real world" of rumbling around a few A and B roads I doubt it will make a noticeable difference to handling, but could show up on tyre wear?

Yup I'd agree. In the real world 90% of drivers wouldn't notice. We get lots of cars in where the tracking and geo is miles out, and the owners are totally unaware! For the mileage your average S covers each year, I doubt tyre wear is a serious issue personally.

[Kitchski]

rtg said:

I'm setting the ride height on my S, and measured the rear camber: They are reading -3Deg & -0.98Deg. Reading the Steve Heath book they ask for +1.25Deg, but apart from shimming the trailing arm to hub with a wedge, am I correct that there's no other way of fixing the rear camber?

In general, what is the effect of a) having a negative camber, and b) having differing cambers? i.e. is this something that needs fixing or, not being a racing driver, I'm really not going to notice?

Thanks, Richard.

Just realised who you are (it's Rich from Southways!) Real world, you're not going to notice a difference IMO, but if you're unsure get it down to the Wheel Alignment Centre in Southampton (pre-book, he's busy). Quite used to seeing factory settings from TVR not matching up across the width of a car! It's very hard to measure it accurately, so there's a chance it's better than you think.

Fitted gear lever yet? Typically I've had two more enquiries on one now!

GreenV8S said:

If they're different from side to side either you've bent something, or the two sides have been shimmed differently, or you're measuring it wrong. How are you measuring it?

I can safely say his chassis' not bent Not sure what kind of shimming you're referring to though? The camber isn't adjustable on the back end, only the toe in/out. Slotting the holes on the inner toe adjuster could alter the camber, but only by a small amount as the outer bush won't allow it any great degree of movement.

To be fair, we get chassis' in where there is 8-10mm difference N/S to O/S in the height of the rear chassis beam relative to the chassis rails! I don't think I've ever seen an S chassis that is perfect to start with.

[phillpot]

Kitchski said:

Not sure what kind of shimming you're referring to though?

The idea is you put shims (washers) between the top or bottom bolts of the four holding the bearing carrier to the swinging arm to adjust camber (not impressed with the idea myself).


Posh version, retains 100% surface contact...... clicky

Kitchski said:

Slotting the holes on the inner toe adjuster could alter the camber, but only by a small amount as the outer bush won't allow it any great degree of movement.

I agree, you couldn't "go mad" but suspect it would flex enough to accommodate a degree or so?

Edited by phillpot on Saturday 14th May 18:25

[Kitchski]

phillpot said:

Kitchski said:

Not sure what kind of shimming you're referring to though?

The idea is you put shims (washers) between the top or bottom bolts of the four holding the bearing carrier to the swinging arm to adjust camber (not impressed with the idea myself).


Posh version, retains 100% surface contact...... clicky

Kitchski said:

Slotting the holes on the inner toe adjuster could alter the camber, but only by a small amount as the outer bush won't allow it any great degree of movement.

I agree, you couldn't "go mad" but suspect it would flex enough to accommodate a degree or so?

Edited by phillpot on Saturday 14th May 18:25

Yeah I'd heard of the camber correctors (agreed its not something I'd want on my car) but it sounded like it was being implied that there was a chance a standard adjustment was wrong, and I was just confused as you can't adjust the rear camber as standard. I might have got the wrong end of the stick though.

Slotting the holes might achieve something I guess. Haven't tried to be honest. Normally if the camber is excessive the ride height is too low, but I'm not sure Richard's is.

[phillpot]

Kitchski said:

Normally if the camber is excessive the ride height is too low, but I'm not sure Richard's is.

I think the 2 degree in-equality would concern me more?

[GreenV8S]

Mine was within a quarter of a degree of equal side to side, and that's what I'd expect from parts that were built on a jig. I don't know whether other cars are normally this close but I don't see why they shouldn't be. However, it would be very easy to get a false reading when measuring this, and since I don't know where the figures we've been given came from I don't assume they're accurate.

[phillpot]

For someone to quote 0.98 degees (as opposed to 1.0) I assumed they were using something pretty clever dicky?

[rtg]

Thanks for the replies -

I'm using two right angles to obtain a vertical reference line, aligning this up with the centre of the wheel and then using a vernier to measure the difference at the top and bottom of the alloy wheel. Nothing really flash, and I forgot to round up to 1Deg. I'm not trying to set up the ideal car, but interested in the process and double checking my attempts at setting up the shocks. The ride height was very low, so I've now adjusted this (170F,180R) and this has removed much of the discrepancy - I'll re-measure it next week. Tyre forces are (FR=250kg, FR=265kg, BL=230kg, BR=230kg) and so am happy with the results.

EXCEPT:

Rich, I was planning to take it over to Southampton wheel alignment centre after the ride height was set - it was riding ridiculously low. However, I took five minutes to inspect the FUEL HOSES (as you suggested). Every single pipe I can see is cracked and I've got some strange gloopy substance on the outside (I've posted pictures and full account on the facebook page).

It's now off the road and I'll replace the hoses (when I know what to replace them with!) and swap the gear lever at the same time as I've got to drop the exhaust.

Edited by rtg on Monday 16th May 10:30

[GreenV8S]

rtg said:

I'm using two right angles to obtain a vertical reference line, aligning this up with the centre of the wheel and then using a vernier to measure the difference at the top and bottom of the alloy wheel.

That method assumes the ground is flat and that the chassis is parallel to the ground - how did you establish that?

[rtg]

The measurements were on a brick driveway, which previously I've laid a long straight edge to check the levels. The chassis was leveled as part of the ride height adjustment and checked against the central runners. But I take your point - there's loads of sources of error in the measurement.