Straight line stability

[nicbowman]

Hi All, Happy New Year and all that jazz.

I am just getting to enjoy my 4.3, but I am amazed at the lack of straight line stability. I have set the geometry at 0.5 degree camber and 4mm of toe in, which has improved it a bit. But, surely there is a cure?? Anyone know of a cast iron remedy?

Nic

Thanks for replies. The tyres are new and 24psi (Bridgestones). All suspension components look good, no wheel play, no oil leaks from dampers, etc. In general the handling is fine. There is some slight play in the rack centre. Maybe tramlining is normal. I will have a look at the rose jointed drop links. Ta Nic

>> Edited by nicbowman on Tuesday 3rd January 09:10

[griffter]

Mine's OK on a flat surface, but tramlines very easily. I think that's the way they should be (or at least the way they were originally).

[Guillotine]

usually its the Rake of the car causing this.

you should have a drop of 1/2 inch back to front, back higher. otherwise air gets underneath.
measure outrigger corners (easiest) obviously same L to R.

camber shouldn't be a prob, but 1 degree is normal setting, i think.

a slitter helps too, but not essential under 90mph.

andy

welcome aboard.

[Ballistic Banana]

Welcome

I have standard suspension on my Griff but have jsut added Steve Heaths rose Jointed Drop links www.tvrextras.co.uk and boy do they make a difference, especially with the tramlining.

BB

[GreenV8S]

Is that geometry the same front and rear?

Are the tyre pressures correct?

Are all the dampers working correctly?

Are all the bushes and steering joints in good order?

[Hoover.]

Had mine sideways at 80 in the wet....


Fine now..... learnt how to drive LOL

[N&L]

Regarding the effect of the splitter, mine was fitted in what appeared to be the wrong place and the wrong way round. The effect was to make the front light at around 90. I removed it (or to be exact it removed itself on a speed hump) and that improved things.

I have also subsequently fitted the Steve Heath rose ARB links front and back and they make a difference.

[richb]

nicbowman said:

I am amazed at the lack of straight line stability.

What sort of speed does this amazment occur at? Rich...

[tvr4ever]

Ballistic Banana said:

Welcome I have standard suspension on my Griff but have jsut added Steve Heaths rose Jointed Drop links www.tvrextras.co.uk and boy do they make a difference, especially with the tramlining. BB

I just ordered a set of droplinks (front and rear) for my car, can't wait to get them. I read so many positive reactions about them, they seem to be a must have item.

Fred

[GarryM]

Fitting rose jointed drop links to mine didn't make a great difference to tramlining (funny how we experience different results but I guess that's because tramlining can be influenced by many things). I had Bridgstone SO3s and since changing them (for ToyoR888s) the tramlining has all but gone. Must say, I was aware of the tramlining before but just got used to it. It is nicer without it! BTW, I used to run the SO3s at 21 psi fr/23 psi rr (rather than your 24 all round). You might find this helps a little.

[richb]

nicbowman said:

I am amazed at the lack of straight line stability.

I have had mine at 150 and it feels perfectly stable, that's why I asked what speed you are talking about? I had the geometry set by Racing Green on their laser set-up bed gizmo and I was surprised by how much it improved the feel, I also have the splitter. IMO it shouldn't be unstable so it sounds as though you need a set-up doing, bear in mind that the Griff suspension is fully adjustable on all 4 corners so it can easily get out of alignment over the years. Rich...

[nicbowman]

Hi, I can notice some instability at 70mph, hardly dangerous speeds! I may just need to get the feel for it, I tend to keep one hand on the gearknob, as when I push the loud pedal I need to change gear suprisingly quickly! Nic

[Ballistic Banana]

tvr4ever said:

Ballistic Banana said: Welcome I have standard suspension on my Griff but have jsut added Steve Heaths rose Jointed Drop links www.tvrextras.co.uk and boy do they make a difference, especially with the tramlining. BB I just ordered a set of droplinks (front and rear) for my car, can't wait to get them. I read so many positive reactions about them, they seem to be a must have item. Fred

[threadhijack]
Fred as well as the great info steve has on his site and the instructions you get theres somemore pics etc on http://thegriffithpages.com

[/threadhijack]

[Guillotine]

nicbowman said:

Hi, I can notice some instability at 70mph, hardly dangerous speeds! I may just need to get the feel for it, I tend to keep one hand on the gearknob, as when I push the loud pedal I need to change gear suprisingly quickly! Nic

Nic,

if you can "feel" it, its wrong.
check it in and get it checked! not expensive to put the gear on and check it!
mine has no probs at 170+
andy

just noticed your in Cambs! take it to castletvr and ask Micheal caine to spin it round the block...
he'll tell you if its OK within 500m VERY

>> Edited by Guillotine on Tuesday 3rd January 17:00

[steve-v8s]

Found mine was all over the place on anything other than a perfectly smooth surface. A close look underneath revealed that one of the rear dampers was weeping. Replaced them with Nitrons and it immediately felt much much nicer. Then I took it along for alignment which made it better still. I have to say however that it still feels less planted than the daily workhorse which is a 530 Beemer.

[nicbowman]

Cheers all. I think a drive to Castle TVR sounds sensible. When the salt dries off a bit!
Nic

[heightswitch]

Nic.
when I first bought mine I thought the same. Before you listen to the Bling Bling brigade and spend a fortune just consider your driving.

Griffs are light on the trigger and you get the best with a light grip on the wheel. I found that I was (in the early days) just a little too cautious of the power and my grip on the wheel was causing a certain amount of overcorrection, espetially the torque feeding back on lift off after a squirt on the throttle.

The car won't feel as refined as a 993 if thats what you had previously but you will feel more in charge of the car the more used to it you get.

Neil.

[richb]

heightswitch said:

Before you listen to the Bling Bling brigade and spend a fortune just consider your driving.

Fair comment but it shouldn't feel unstable at 70.

[nicbowman]

I am probably just over reacting to a new car, I like to get them fully sussed mechanically. I used to sprint a Scimitar and it was even worse at tramlining, but on a track it was awesome (odd thing to say about a Scimitar, but they can go fast, 35.8 seconds around Curborough). I will do some driving and see if I get used to it. The oddest thing is how good modern family cars are, for stability comparisons.

Nic

[bjwoods]

check tyre pressures, suspension geometry's can be way out, noticed a vast improvement..
As its a 4.3 it's quite old, when were the dampers last checked changed. again new ones gave me a vast improvment...
If it's slightly damp, any loose surface, even painted lines too much throttle to abruptly, will/can make it wiggle, lots of torque/pretty light car (relative any porsche, etc)

edite to add - do you 'know' what you are doing setting up the car...
even if you do, check all the above, and get it set to it's correct/original settings to give you a base line.

B

>> Edited by bjwoods on Thursday 5th January 10:41