Change of plan

[TVR_owner]

After spending the last few months with the Tuscan up for sale, I decided I would give it another chance. Status was I had the car down as something that did not do enough things well ...

So after a day at Oulton Park today on track with a car that still needs a few minor tweeks, I can report a new relationship has started....

No longer for sale!!

[YKB]

If you fall out with it again John you can always turn it into a new race care

[GT TVR]

Good man! I was wondering what you were going to do.
Think it's a wise decision: your car is very good, the steering was even better than mine (god knows why), you just need to sort the rear dampers/springs (which you probably already did).

and then a nice 4.5 maybe ...

what do you think of the spacers as proposed by Silverstone: http://www.pistonheads.com/xforums/topic.asp?h=0&a... sold my Tuscan due to poor handling! Fixed for £20!

[TVR_owner]

GT TVR said:

Good man! I was wondering what you were going to do.
Think it's a wise decision: your car is very good, the steering was even better than mine (god knows why), you just need to sort the rear dampers/springs (which you probably already did).

and then a nice 4.5 maybe ...

what do you think of the spacers as proposed by Silverstone: http://www.pistonheads.com/xforums/topic.asp?h=0&a... sold my Tuscan due to poor handling! Fixed for £20!

Spring length vs suspension travel is being looked at as we speak. I can lower the car but I also wnat to stay of the suspebsion bump stops.

Car will stay as a 4.0 Gerjo (its only done 9000 miles!).

Wheel spacers I have a firm view on. I have not spent £20, nor would I. Guess I would need to understand (from someone not trying to sell something) how increasing scrub radius can have such a radical effect on a car.

All ok with you I presume?

[GT TVR]

Yep, all is fine John. Looking forward to the end of the season...

Porsche club is visiting us at the end of Sept incl trackday at Charade. Should be fun. Ian&Jill and Mike&Sue are coming too that week.

Car needs to stretch it legs, hasn't run for 2 months. Will put on some decent rubber (R1R) at the end of the year, and some better brake pads. For the rest it's running brilliantly but it can sure use some extra oemph. Must say I haven't had any trouble with the bump stops.

Oh, and I need something with a nice V12 ... but then, who doesn't !

Edited by GT TVR on Thursday 5th August 18:23

[dvs_dave]

TVR_owner said:

Wheel spacers I have a firm view on. I have not spent £20, nor would I. Guess I would need to understand (from someone not trying to sell something) how increasing scrub radius can have such a radical effect on a car.

That's because the standard scrub radius is wrong. The spacers move it into the sweet spot. They do work....as many others will confirm.

[GT TVR]

dvs_dave said:

TVR_owner said:

Wheel spacers I have a firm view on. I have not spent £20, nor would I. Guess I would need to understand (from someone not trying to sell something) how increasing scrub radius can have such a radical effect on a car.

That's because the standard scrub radius is wrong. The spacers move it into the sweet spot. They do work....as many others will confirm.

could you explain how that works please? what is the scrub radius anyway? never heard of it.

[TVR_owner]

GT TVR said:

dvs_dave said:

TVR_owner said:

Wheel spacers I have a firm view on. I have not spent £20, nor would I. Guess I would need to understand (from someone not trying to sell something) how increasing scrub radius can have such a radical effect on a car.

That's because the standard scrub radius is wrong. The spacers move it into the sweet spot. They do work....as many others will confirm.

could you explain how that works please? what is the scrub radius anyway? never heard of it.

[VARLEYHYD]

TVR_owner said:

After spending the last few months with the Tuscan up for sale, I decided I would give it another chance. Status was I had the car down as something that did not do enough things well ...

So after a day at Oulton Park today on track with a car that still needs a few minor tweeks, I can report a new relationship has started....

No longer for sale!!

Good to see the car out on track, (well the back of it).

I am really pleased that you have stuck with it, and refined it to what it now is.


All the best, G

[dvs_dave]

Take the time to read the spacers thread and follow a couple of the links posted on it. It's all explained there.

[softtop]

There is probably a massive difference between the MK1 and the MkII. I am sure that most of the people who are noticing a real improvement are the MKI owners. The set up is much more nervous and this many people cannot all be thinking it feels better because they have spent a few ££

[TVR_owner]

softtop said:

There is probably a massive difference between the MK1 and the MkII. I am sure that most of the people who are noticing a real improvement are the MKI owners. The set up is much more nervous and this many people cannot all be thinking it feels better because they have spent a few ££

I have read the thread in some detail. There is a chap early on in the thread - Chad Speed, who discusses the results of the spacer and how it has made a difference in some areas but made handling worse in others. He mentions a chap by the name of Alan Staniforth who is greatly respected in the field of suspension/chassis tuning. Would be nice to hear what he had to say on the issue?

I guess the solution for the ultimate handing Tuscan would be so comprimised for road use that it would be a waste doing the work to persue that solution.

Has anyone done anything with revised castor and rack height on the MK I Tuscan? I did some work with both on a Sagaris, and the difference was night and day (for small money - but a bit more than the 30 squid solution )

[TVR_owner]

softtop said:

There is probably a massive difference between the MK1 and the MkII. I am sure that most of the people who are noticing a real improvement are the MKI owners. The set up is much more nervous and this many people cannot all be thinking it feels better because they have spent a few ££

Stuart,
I've not driven a Mk I with or without spacers. But... how many owners do you know that run their cars with a mix of tyres front to rear, maybe the wrong tyre pressures, possibly poorly set up geo, on cheap or worn shocks, possibly with a chassis that probably should have been rebushed years ago? They probably dont notice the difference, but within minutes they notice the spacers?? Maybe their is that much difference.

Good to catch up with you at Oulton, you missed a treat not being on track!!

[softtop]

TVR_owner said:

Has anyone done anything with revised castor and rack height on the MK I Tuscan? I did some work with both on a Sagaris, and the difference was night and day (for small money - but a bit more than the 30 squid solution )

I am sure I have read something on here a while ago. Half the battle is knowing what changes make the improvements and then being able to deliver the change in some form of easily fitted kit. Knowing that a car would need to be re set up is not an issue, it is to have the car altered in a manner that is easily procured.

Could you PM me about the rack height changes you made. I would like to look into this.

[TVR_owner]

softtop said:

TVR_owner said:

Has anyone done anything with revised castor and rack height on the MK I Tuscan? I did some work with both on a Sagaris, and the difference was night and day (for small money - but a bit more than the 30 squid solution )

I am sure I have read something on here a while ago. Half the battle is knowing what changes make the improvements and then being able to deliver the change in some form of easily fitted kit. Knowing that a car would need to be re set up is not an issue, it is to have the car altered in a manner that is easily procured.

Could you PM me about the rack height changes you made. I would like to look into this.

They were combined with Castor changes. Rack height revision was 4mm (up)to keep steering arms in the right place post castor revision. Not saying this would apply to the Mk I (or any other) Tuscan.

I agree with you about knowing what the cahnges are and then being able to buy them as a bolt on.

[GT TVR]

On my car (MKII S Tuscan) we changed the geo (mostly extra rear camber) and the castor and that made quite a difference (although it was already pretty good to begin with). The Nitrons/Eibachs did the rest. And soon be changing to 225 front tyres.
Must say I do wonder why 255 front tyres seems to work on the Sag but not on the Tuscan.

Don't know if any MKII owners are using the spacers?

Edited by GT TVR on Saturday 7th August 10:36

[softtop]

how is Caster altered and did you go more positive or move towards neutral?

[TVR_owner]

softtop said:

how is Caster altered and did you go more positive or move towards neutral?

Shims either side of top ball joint relocated/machined and from memory more positive but would need to do some thinking about what we did. The aim was to improve the turn in and reduce/remove the understeer.

[Basil Brush]

The setup looks to have evolved over the life of the Tuscan. The very early cars like mine on 18" wheels were awful. The Cerbera rack used was too narrow for the chassis, with the track rods running nowhere near parallel with the lower wishbone, due to the outer ball joint height. Couple that with overly soft springs and harsh shocks and it's not exactly the basis of a great handling car. I assume part of the transformation from fitting Nitrons etc is down to the firmer springs limiting the suspension movement, therefore reducing bump steer effects.

The rack was widened and, looking at the uprights, the upper ball joint mount was moved on later cars (2003 on?) which I guess was done to work better with the 18" rims? I would therefore assume the impact of the spacers would be reduced on the later Mk1s and Mk2s.

[Chad speed]

TVR_owner said:

softtop said:

There is probably a massive difference between the MK1 and the MkII. I am sure that most of the people who are noticing a real improvement are the MKI owners. The set up is much more nervous and this many people cannot all be thinking it feels better because they have spent a few ££

I have read the thread in some detail. There is a chap early on in the thread - Chad Speed, who discusses the results of the spacer and how it has made a difference in some areas but made handling worse in others. He mentions a chap by the name of Alan Staniforth who is greatly respected in the field of suspension/chassis tuning. Would be nice to hear what he had to say on the issue?

I guess the solution for the ultimate handing Tuscan would be so comprimised for road use that it would be a waste doing the work to persue that solution.

Has anyone done anything with revised castor and rack height on the MK I Tuscan? I did some work with both on a Sagaris, and the difference was night and day (for small money - but a bit more than the 30 squid solution )

I upset the guy selling the spacers by trying some Halfords cheapies first to see what difference it made, it seems I missed his posting about the spacers not working with 225/35/18 tyres. I would have bought some from him too if his response hadn't been so aggressive and rather lost interest in the thread. Have to applaud his salesmanship though, perfect targeted advertising for your business for free on PH.
Anyhow, for the spacer solution to work the kingpin inclination axis should coincide with the centre of the width of the tyre contact patch and the road. Change the rolling radius and the intersection of these points is lost. With the smaller rolling radius of my tyres I decided to try different thickness spacers 1mm, 3mm, then 4mm to see the difference - 3mm was still best. But my point remains the same, they may improve the 'feel' of the car with the recommended tyres but its surely just a patch and not getting to the route of the problem. My guess is that there is bump steer due to incorrect positioning of the inner steering arm joints (rack length)which can be improved by moving the rack location vertically. There are two ways to ascertain this: 1. Acurately draw the geometry of the front suspension and rack location. 2. Make a bump steer gauge and try it on the car.
I have used the latter method successfully in the past, as shown in Alan Stanniforth's book, and got to within 0.005" over 2" bump and 1" of droop.
The solution to rack location is likely to be relatively cheap so not worth the time and effort of a specialist company and I too simply don't have the time.
Its worth noting that getting the core geometry of the suspension right should come before adjustments to camber, toe and castor to suit personal preference (although target settings have to be used from the outset).
Don't get me wrong, I'm genuinely pleased the spacers improve Tuscan handling its just not, in my view, the final cure.