Litton Corse build with 2.0l Lancia 8v TC

[Strat Fan]

Hello Paul,

As John says it is extra caster you require for the self centering on the steering. If you have already set the bump steer with the caster as it is set now then you could disconnect the swing bolt where it attaches to the TCA and wind it in say 3 full turns, the thread is a 2mm pitch & every 2 full turns will add approx 1 degree of caster so this would increase the caster to approx 6 degrees. This way after the test you can wind the swing bolt back to where you are now safe in the knowledge that you don't need to reset the bumpsteer. Quite often a new ball joint has a reasonable amount of stiction which can hinderthe self centering, once the ball joint loses its "newness" then things will free up, not helpful for IVA but something I have witnessed in the past which could be worth mentioning to the examiner on the retest.
If you have 1 degree of toe in then this could possibly affect the self centering too, 10minutes is a better starting point for the front axle.
With regards to the rear settings, the set up John has posted is very agressive on the rear (the front is fine), the rear toe is marginally more than I would start with & the rear camber is way more than I would look for on a road car.

Good luck with the retest!

[john]

With regards to the rear settings, the set up John has posted is very agressive on the rear (the front is fine), the rear toe is marginally more than I would start with & the rear camber is way more than I would look for on a road car.

Good luck with the retest!

Yes. More than I would want too in an ideal world, but a work in progress. Definitely more than Paul would want on A Stradale style on what size rear tyre?

[Strat Fan]

Yes. More than I would want too in an ideal world, but a work in progress. Definitely more than Paul would want on A Stradale style on what size rear tyre?

I think the Corse "S" cars did run quite aggressive rear toe settings so these would probably be fine, it's the camber that is not ideal & I appreciate that this is out of your control currently on Frederics car.
A strut type suspension system offers less camber gain in bump than the equivalent double wishbone set up so it is common to see more static negative camber on strut equipped track based cars to help compensate for the increased roll generated where the cornering loads & grip are greater but this wouldn't be suitable to a road car where the car spends substantially more time heading in a straight line.

[turbonutter]

I think the Corse "S" cars did run quite aggressive rear toe settings so these would probably be fine, it's the camber that is not ideal & I appreciate that this is out of your control currently on Frederics car.
A strut type suspension system offers less camber gain in bump than the equivalent double wishbone set up so it is common to see more static negative camber on strut equipped track based cars to help compensate for the increased roll generated where the cornering loads & grip are greater but this wouldn't be suitable to a road car where the car spends substantially more time heading in a straight line.

The corse settings recommended by Steve greenwood for the S are on my website http://m.turbonutter.net/site/mobile...etwork=fw#1022

The I settings are there as well, but not sure who gave me those.

My S ran a touch more toe and 7 deg front castor....

[MichaelEustace]

Some video from the IVA test day: https://www.facebook.com/michael.eus...02876717517852

Car unloaded outside the Norwich test centre:





During the test, the headlights were found to be pointing down too much, so we adjusted the headlamps themselves, which ran out of adjustment so we just lengthened the arms on the headlamp opening mechanism - hence why they're not quite flush in the closed position shown below. We'll sort this once the car has passed IVA.


The other Stratos that has previously been through the test centre...


...which was on the Norwich test centre's Very Cool Wall.

[hollytree]

Hello Paul,

As John says it is extra caster you require for the self centering on the steering. If you have already set the bump steer with the caster as it is set now then you could disconnect the swing bolt where it attaches to the TCA and wind it in say 3 full turns, the thread is a 2mm pitch & every 2 full turns will add approx 1 degree of caster so this would increase the caster to approx 6 degrees. This way after the test you can wind the swing bolt back to where you are now safe in the knowledge that you don't need to reset the bumpsteer. Quite often a new ball joint has a reasonable amount of stiction which can hinderthe self centering, once the ball joint loses its "newness" then things will free up, not helpful for IVA but something I have witnessed in the past which could be worth mentioning to the examiner on the retest.
If you have 1 degree of toe in then this could possibly affect the self centering too, 10minutes is a better starting point for the front axle.
With regards to the rear settings, the set up John has posted is very agressive on the rear (the front is fine), the rear toe is marginally more than I would start with & the rear camber is way more than I would look for on a road car.

Good luck with the retest!

Corse I
I got some front damper mount plates made to drop the top mount by 1" as the front trailing arm was only about 1/4" from the chassis rail and on bump was hitting it. If I jacked the spring collars then I had no droop. Now I have about 2" bumps and 1'1/2" droop and it feels good.
I have just had it set on one of those new fangled laser jigs.
I have got all the settings pretty close to those in the Corse I build manual, however:-

I started with caster FL 2"35' FR 3"31'
To increase these towards the Corse I suggestion of 3"-5" the trailing arms had to be wound out to lengthen them and now both L&R are 4"30' BUT the lower rear wishbone arms are now very much to the rear of the little tunnel they sit in just in front of the bulkhead.

Lengthening the trailing arms to increase caster does not tie up with what Craig says above when he says "wind it in", which implies shortening the trailing arm.

Am I doing something wrong?
Am I missing something?

[Strat Fan]

Corse I
I got some front damper mount plates made to drop the top mount by 1" as the front trailing arm was only about 1/4" from the chassis rail and on bump was hitting it. If I jacked the spring collars then I had no droop. Now I have about 2" bumps and 1'1/2" droop and it feels good.
I have just had it set on one of those new fangled laser jigs.
I have got all the settings pretty close to those in the Corse I build manual, however:-

I started with caster FL 2"35' FR 3"31'
To increase these towards the Corse I suggestion of 3"-5" the trailing arms had to be wound out to lengthen them and now both L&R are 4"30' BUT the lower rear wishbone arms are now very much to the rear of the little tunnel they sit in just in front of the bulkhead.

Lengthening the trailing arms to increase caster does not tie up with what Craig says above when he says "wind it in", which implies shortening the trailing arm.

Am I doing something wrong?
Am I missing something?

Extending the front trailing links reduces the castor unless your upright was already leaning forwards (negative castor) rather than backwards (positive castor).
From what you describe then it sounds like your Track Control Arm is leaning back too far and that the top ball joint is actually farther forwards than the lower ball joint?
The image below was pulled from the www for the image but some of the text is relevant as well, just disregard the bit about power steering.

[hollytree]

Craig
Thanks
That is what is "visually" looks like, but how can that happen?
There is no adjustment in the top ball joint position.
If I had to lengthen the trailing arm to increase caster, should the machine be recording it a Negative caster?

PS when do you want me to drive down

[hollytree]

I have just gone and wound the trailing arms in so the bottom wishbone arms are now towards the front of the tunnel.
Looking down on the top ball joint the bottom joint is now in front - positive caster.
Amazing how only a couple of inches of adjustment makes such a difference.
More annoyed the machine did not pick up Negative!

[hollytree]

I have just gone and wound the trailing arms in so the bottom wishbone arms are now towards the front of the tunnel.
Looking down on the top ball joint the bottom joint is now in front - positive caster.
Amazing how only a couple of inches of adjustment makes such a difference.
More annoyed the machine did not pick up Negative!

Well that all worked out well.
Just been up and down the dual carriageway at 90kph (I think my gauges are KPH ahem!)
All feels good.
I must have been on negative camber. I will have a word with the man on the fancy machine tomorrow