Improving steering at speed...

[cliftyhanger]

I now have fitted the poly bush and new steering shaft to my toledo, and replaced the ball joints that had any play. Steering seems much better, however, it still feels a bit light at speed.
I have read/heard that reducing the front drag strut/tie rod length can help? I believe there is no other way to change castor angles.

Front toe measures about 2mm toe in Wheel bearings have a tiny bit of "rock" in them, so all that is fine. Springs appear slightly lower than std, and that must reduce castor angle?

Pointers would be appreciated on this. I did the last RBRR and the steering feel was irritating. I would like to sort it now, so I have a year to fettle other stuff! (like find the new distributor springs I bought and now can't find )

[soe8m]

Shorten the front drag strut 15mm but an even better mod is use 2500 type bushes on that spot for better location when braking and fast corners. I adjust my front wheel bearings till just no play. Having a little play left is for uncertain mechanics.

Jeroen.

[Carledo]

I've come across this a few times with Toledos and have not yet had to resort to shorter tie bars (they are only drag struts if fitted BEHIND the axle line, a la T2000)

My cures are as follows:-

If you still have the original Toledo lower arms, poly bush the inner bushes, Chris Witor does the bushes. (DON'T do this if you have fitted Dolomite arms with the rose jointed inners)

Solid mount the rack.

Poly bush the rear subframe mounts.

Set the track to parallel, toe in is for crossplys!

Good luck, Steve

[gmsclassics]

Agree with Steve, no toe in, just run at parallel. You could try to find a steering rack with a 3.25 lock to lock rather than 3.75, but it will be heavier at low speeds. Find the hardest bushes you can and fit them to the front tie bars and do the the nuts up really tight. The standard ones are useless for precise steering. Altering caster and camber will have lots of other effects such as loss of self centering, faster turn in, all fine for the track but tiresome on the road.

Different brands of tyres will have different characteristics and tyre pressures at speed will also have an impact.

Geoff

[sprint95m]

This is a good question.

I don't have a definitive answer but do have some observations.
Not yet having tried shortened tie bars I can't comment on these, but can offer the following.......

Firstly make sure the front subframe's back mounting bushes are compressed.
I have yet to encounter a problem here but back in the days of the DSR it was considered something to check for,
if necessary the locating tube length can be reduced (with a grinder).
Use Dolomite style mounting for the front of the front subframe instead of the double cup Toledo arrangement.


Front spoiler, I fitted one to an early 1850 and it does make a noticeable improvement, especially in blustery weather.

Solid rack mounting, yes I will do that again.
Based on my experience of manual steering on the T2000 range I would go for a higher ratio pinion.
Sure it makes the steering heavier but the gain at speed is worth it.


Tyres, I am sure that these have a bearing here....
on the Sprint I ran in the 90s I had Uniroyal 175/70HR13 tyres (340 series?) and didn't appreciate
how good they were until I had to change them (because Uniroyal had discontinued the H rated version).
Tyre choice is incredibly subjective, the new owner of the T2500 I sold thought the Uniroyal tyres fitted were rubbish
(he also thought the manual steering was ridiculously heavy ).

Wheels, I have used Minator Minilight replicas (from Rimmers) and the increased track width again makes a difference.
On the subject on wheels a bigger diameter offers the option of lower profile tyres whilst retaining the rolling diameter, e.g.
http://www.willtheyfit.com/index.php?wi ... offset2=22
This is a route I intend using.



Ian.

[Carledo]

Agree with Steve, no toe in, just run at parallel. You could try to find a steering rack with a 3.25 lock to lock rather than 3.75, but it will be heavier at low speeds. Find the hardest bushes you can and fit them to the front tie bars and do the the nuts up really tight. The standard ones are useless for precise steering. Altering caster and camber will have lots of other effects such as loss of self centering, faster turn in, all fine for the track but tiresome on the road.

Different brands of tyres will have different characteristics and tyre pressures at speed will also have an impact.

Geoff

I agree with Geoff here as well, tyres and tyre pressures can have a big effect on roadholding! I just think it's best to get the more basic bits right before investigating esoteric things like tyres and pressures, which may turn out not to be needed once the geometry is correct. Though it has to be said, that if you run for any length of time with INcorrect geometry, this can and does sometimes have adverse effects on tyre wear patterns that will NOT self correct!

On the Carledo, I have altered SO much, spring rates, shockers, ride height, overall weight, weight distribution, camber, wheel offset, wheel diameter, wheel width, tyre profile, etc, etc, ad nauseam, yet somehow everything STILL works together very nicely. Maybe i'm just lucky!

Oddly, i'm still running my original 40+ year old rubber front tie bar bushes without discernible adverse effects! Though I HAVE changed out the rears to counter the massive axle tramp I was getting! It's pure laziness, I have some Superflex red bushes to fit, but since it works as it is, the job is low on the priority list!

It's also worth noting that rear suspension bushing and location can have an adverse effect on steering as well, by introducing rear wheel steering into the equation!

Steve

[Carledo]

Wheels, I have used Minator Minilight replicas (from Rimmers) and the increased track width again makes a difference.
On the subject on wheels a bigger diameter offers the option of lower profile tyres whilst retaining the rolling diameter, e.g.
http://www.willtheyfit.com/index.php?wi ... offset2=22
This is a route I intend using.
Ian.

Having just checked the link you posted above Ian, the new wheel and tyre parameters you posted are EXACTLY the wheel and tyre choice I have selected and bought for my Sprint project, purely on instinct! It's good to know my engineering instincts are still sharp, even if age is dulling my memory!

As a by product, using these wheels and tyres will allow you (as it has me) to fit even larger 256mm discs on a TJ conversion. If you want details of disc part numbers and which calipers and carriers to use for this, drop me a PM!

Steve

[cliftyhanger]

Part of my thinking about shoter tie-rods is that shorter springs will effectively reduce castor (the tie-rod will push the bottom of the upright further back)
The car was fitted with new dolomite lower arms about 30,000 hard miles ago, nothing to report there about play. Tie rod bushes are polybush or whatever it was, no play. Subframe bushes seem OK.

The feeling is that the steering just feels very light at speed (45mph+) and I think more castor may help. I will measure it at the weekend....
And on that note, does anybody have a definitive answer about how far to turn the wheels each way to measure castor? I have seen a few different figures mentioned. And what should the castor actually be??

Tyres currently Michelin e3b 185/55 15 on MGF wheels, but at 6 years old are developing sidewall cracks so about to be replaced. I have some montego 14" steelies somewhere, I could slip those on but need to check offset. Or I do have a newish set of 185/60 13's on 5.5J spitfire/GT6 wheels. Could be a cheap option, what with christmas on its way!

Deffo do not want heavier steering in town. The lady wife thinks parking is already a bit heavy...

Cheers all
Clive

[Carledo]

Part of my thinking about shoter tie-rods is that shorter springs will effectively reduce castor (the tie-rod will push the bottom of the upright further back)
The car was fitted with new dolomite lower arms about 30,000 hard miles ago, nothing to report there about play. Tie rod bushes are polybush or whatever it was, no play. Subframe bushes seem OK.

The feeling is that the steering just feels very light at speed (45mph+) and I think more castor may help. I will measure it at the weekend....
And on that note, does anybody have a definitive answer about how far to turn the wheels each way to measure castor? I have seen a few different figures mentioned. And what should the castor actually be??

Tyres currently Michelin e3b 185/55 15 on MGF wheels, but at 6 years old are developing sidewall cracks so about to be replaced. I have some montego 14" steelies somewhere, I could slip those on but need to check offset. Or I do have a newish set of 185/60 13's on 5.5J spitfire/GT6 wheels. Could be a cheap option, what with christmas on its way!

I'm not sure castor is a problem, if you consider the arc that the tie bar describes in service, then the rearmost point of the arc and therefore minimum caster occurs when the tie bar is horizontal and this is the "ideal" position, all others are necessary compromise forced by design criteria. Once the arm is above this critical horizontal point, caster will actually increase again.

According to my shop manual, castor angle is 2.25 degrees (+1 degree) at normal kerb condition or 2.75 degrees (+0.5 degrees) fully laden. This would seem to imply that castor INCREASES as the car drops, which is what my understanding suggests. The manual suggests 3 different positions when measuring, but it doesn't say what they are (at least what i've skimmed so far) and in any case, the value is the same at each test position!

I am running the same wheels with the same size tyres as you are and have lowered the front on ASP Gaz by somewhere in the region of 1.5" which has given me a soupcon of negative camber, added to which, I have removed a single shim from each top wishbone mount to further increase neggy camber. All my front end bushing is still rubber (more laziness, if it ain't broke....) but I have solid rack mounts (both of them) and my tracking is firmly on parallel. I am experiencing no vagueness in steering whatsoever on road or track, you yourself have, I believe, witnessed how well behaved the car is at Coombe! I can shove it through Folly at 80+ and hit a ton easily before braking for Quarry without fear. And it doesn't wander at all, right up to it's thoroughly illegal V-max of around 117mph!

I have had stock Toledos brought to me by concerned owners that were equally un-nerving at similarly low road speeds and the list above is what I did to cure them! And it worked - more than once!

I cant advise about the Montego wheels, but I believe the offset on the Spit/GT6 rims will be too great to work well on a Toledo.

Steve

[sprint95m]

Montego steel wheel fit better than Sprint alloys
(they were used as spare wheels on the MGF so are easy to find)


[/quote]




Ian.

[Carledo]

Montego steel wheel fit better than Sprint alloys
(they were used as spare wheels on the MGF so are easy to find)

Ian.
[/quote]

Ah! I didn't know that an MGF spare is a Montego steelie! I have an MGF steel spare as my Sprint spare wheel to go with the Minators!

Steve