Griff steering on uneven roads

Griff steering on uneven roads

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Discussion

BlueArsedFly

Original Poster:

51 posts

213 months

Wednesday 16th July 2014
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I've only just got back in the Griff after a long, long layoff and getting used to it again. When driving on uneven roads, especially if the camber on the left hand side is worse than towards the middle of the road or if it's bumpy, I get a lot of kickback through the steering, to the extend I have to slow right down to stop leaving the road or hitting an oncoming car. Is this normal or should I be looking at getting the geometry or something else looked at? It's a non-PAS one if that makes any difference, and standard wheels etc


ncs

3,972 posts

281 months

Wednesday 16th July 2014
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Get it checked, as this shouldn't be the case, you might have to spend a couple of quid getting it sorted but its money well spent.

My wifes got a Z4 Coupe which is a fantastic car but the run flat tyres give the same effect, bit scary at times isn't itbiggrin

Nicknerd

chj

763 posts

212 months

Wednesday 16th July 2014
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Definitely not normal. It could be something simple such a geometry, but I'd get the whole suspension, bushes and steering set-up checked for peace of mind if it's as bad as it sounds.

BlueArsedFly

Original Poster:

51 posts

213 months

Wednesday 16th July 2014
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Any recommended garage? I'm in North Oxfordshire

Cheers

phillpot

17,105 posts

182 months

Wednesday 16th July 2014
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Guglielmi in Daventry?


Not used myself but they get their fair share of recommendations on PH scratchchin

Barreti

6,680 posts

236 months

Wednesday 16th July 2014
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Before you start worrying about geometry, tell us about what connects you to the ground.
What wheels and tyres are you wearing front and back.
What wheels and what sizes
What tyres
What pressures
How old
Do you know what shocks are fitted and how old they are.

Lets see if anything on that list scares the hell out of us and if not then get it down to someone like Steve Guglielmi - who I highly recommend by the way and will be visiting again myself when I fit the Nitron shocks I've just got my hands on.

bluezeeland

1,965 posts

158 months

Wednesday 16th July 2014
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Barreti said:
Before you start worrying about geometry, tell us about what connects you to the ground.
What wheels and tyres are you wearing front and back.
What wheels and what sizes
What tyres
What pressures
How old
Do you know what shocks are fitted and how old they are.

Lets see if anything on that list scares the hell out of us and if not then get it down to someone like Steve Guglielmi - who I highly recommend by the way and will be visiting again myself when I fit the Nitron shocks I've just got my hands on.
Think thats a solid piece of advise ! Would even go as far as checking the bushes for wear....

Goes to show TVR' do like an 'outing', once in a while...



BlueArsedFly

Original Poster:

51 posts

213 months

Wednesday 16th July 2014
quotequote all
TVR 15" wheels at the front, with Falken Ziex, 225/50R15, tyres about 5-6 years old
TVR 16" wheels at the back with Bridgestone S-02 245/45Z16, tyres 2 weeks old (that's what the MoT garage put on in their wisdom, I've already read on here that the sidewalls are too stiff for the Griff, but too late now).

Not sure about the dampers, I know they're aftermarket adjustable ones, but they've been on the car since I got it around 7 or 8 years ago, so probably getting on for around 10 years old. Not sure about the springs, again as long as I've had the car.

Also not sure about tyre pressures - the car was only MoT'ed 2 weeks ago, they fitted the rear tyres and would have hoped they inflated the tyre pressures appropriately - will check tomorrow.

And yes, I'm an adrenaline junkie, but the handling at the minute on anything but smooth roads, even in a straight line is terrifying, and worse when accelerating hard. The car also suffers from snap oversteer under acceleration, which I can rarely catch (have a local airfield to practice these antics on), so would like to make that a bit more progressive if possible

GlynMo

1,140 posts

248 months

Thursday 17th July 2014
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BlueArsedFly said:
(that's what the MoT garage put on in their wisdom, I've already read on here that the sidewalls are too stiff for the Griff, but too late now).
My guess is that the first problem is that the garage have over-inflated the tyres - they usually do.

FlipFlopGriff

7,144 posts

246 months

Thursday 17th July 2014
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Agreed. Drop the rears to 24/25 and see how it drives. Next you shoud look at replacing the fronts as they will be getting hard now.
Fronts should be 205/55/15 not 225 as these were fitted on PAS cars.
FFG

V8 GRF

7,294 posts

209 months

Thursday 17th July 2014
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BlueArsedFly said:
TVR 15" wheels at the front, with Falken Ziex, 225/50R15, tyres about 5-6 years old
TVR 16" wheels at the back with Bridgestone S-02 245/45Z16, tyres 2 weeks old (that's what the MoT garage put on in their wisdom, I've already read on here that the sidewalls are too stiff for the Griff, but too late now).

Not sure about the dampers, I know they're aftermarket adjustable ones, but they've been on the car since I got it around 7 or 8 years ago, so probably getting on for around 10 years old. Not sure about the springs, again as long as I've had the car.

Also not sure about tyre pressures - the car was only MoT'ed 2 weeks ago, they fitted the rear tyres and would have hoped they inflated the tyre pressures appropriately - will check tomorrow.

And yes, I'm an adrenaline junkie, but the handling at the minute on anything but smooth roads, even in a straight line is terrifying, and worse when accelerating hard. The car also suffers from snap oversteer under acceleration, which I can rarely catch (have a local airfield to practice these antics on), so would like to make that a bit more progressive if possible
Firstly, I'd lay odds the tyres are inflated to too high a pressure, non TVR specialist garages & tyre fitting places always seem to inflate tyres to 30 + PSI and that makes the handling evil. If that is the case then I'm sure reducing the pressures to the 24/26 suggested above will help.

It also sounds like there's potential for an unbalancing of grip front to rear there. A properly sorted Griffith shouldn't have snap oversteer in a straight line in dry conditions.

They stopped making SO2s in 2011 iirc and I'll lay odds they may well be older so there's a chance they've gone hard, especially as the recommended life of a tyre (used or not) depending who you believe is between 6 and 8 years, those are likely to be 4 years old and I'd check how old they really are when you check the pressures. How they've been stored will have affected them as well. So you've potentially got hard tyres front and back.

There were a lot of posts a few years back of people encountering the differing grip levels front to back that you're encountering with different makes of tyre on either the front or back axles and SO2s on the other.

I'd also suggest that your dampers may well be in need of a rebuild. I have Nitrons on my car and they need a refresh every 5 years or so and the difference when they're returned is a revelation.

FFMan

410 posts

248 months

Thursday 17th July 2014
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mine used to do this on old front tyres - changed them for some decent ones and it went completely.

BlueArsedFly

Original Poster:

51 posts

213 months

Thursday 17th July 2014
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Just checked pressures - 30 in the fronts and 40 in the rears! Dropped these to 23/25, hopefully will get a chance later tonight to go out and see if there's any improvement in the handling. Am I right in thinking the suspension would have been working too hard with such high pressures and couldn't cope on the rough roads?

Actually quite amazed the garage just stuffed so much air into the tyres.

I'll likely drop the front tyre size down to 205 when I get the chance but keep 245 on the rears. I'm hoping this will give less front grip relative to the back and give me more feedback about how much grip I have and can temper the throttle accordingly?

bluezeeland

1,965 posts

158 months

Thursday 17th July 2014
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BlueArsedFly said:
Actually quite amazed the garage just stuffed so much air into the tyres.
I'm not ! some of these so-called 'mechanics' can barely speak, let alone listen !

Too high a pressures, to much torque (wheel nuts are a particular favourite) wrong oils, wrong type of greases, the list goes on and on...........moral; check, check and check 'em !

please report outcome !

Frank

FlipFlopGriff

7,144 posts

246 months

Thursday 17th July 2014
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At 40 I'd think you'd be near the limit of the tyre. They usually put them aroudn 30 as this is a fairly standard pressure but for normal cars.
30 front is way too high - 24-25 would be normal.
FFG

stevesprint

1,114 posts

178 months

Thursday 17th July 2014
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40 psi, you must have been bouncing down the road like a football. Glad to hear you've identified the problem.
Good Luck
Steve

BlueArsedFly

Original Poster:

51 posts

213 months

Friday 18th July 2014
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Thanks very much for the advice on here. Took the same roads as last time and absolutely no dramas, the car was a joy to drive.

BlueArsedFly

Original Poster:

51 posts

213 months

Friday 18th July 2014
quotequote all
stevesprint said:
40 psi, you must have been bouncing down the road like a football. Glad to hear you've identified the problem.
Good Luck
Steve
Yes I was - when I drove home having picked the car up from the garage, I remember accelerating hard in 3rd on a straight, hit a few bumps and was all over the place, fighting the steering to stay out of the ditch and oncoming traffic. I struggled to keep up with 1.0 Micras on the twisty stuff it was so bad. The car felt very crashy in ride too, but tonight with the lower pressures it was a different car, so much better, much more confidence inspiring. Very happy now, thanks all.