Tuning shocks (Nitrons) on the track

[GarryM]

I’m at Donington tomorrow and will be playing with the settings on my new Nitrons. A bit late in the day but I thought I’d ask for advice on tuning. Until the other day, I was quite happy with the idea that winding up the shocks at one end of the car relative to the other would gradually reduce the grip at that end, i.e. if understeering soften the front or harden the rear and the opposite if oversteering.

A comment from someone who knows a lot more about this than me turned that idea on its head. He suggested that as Nitrons only have one adjuster it has to adjust bump and rebound at the same time only it has a far far bigger impact on the rebound than the bump. Consequently, he suggested, if the car is understeering you should increase the “stiffness” so that the rebound is increased keeping the front of the car down on the track. Similarly, if the rear is a bit loose, increase the rear setting.

I can see what he means and I suppose I'll find out tomorrow but are there any offers of advice from anyone?

[joospeed]

he's right .. if you soften it off you'll get more understeer .. I run the S full stiff on the front.

if you run it soft you generate turn-in understeer and half the corner is over before the tyre recovers, you'll never hit the apex and your corner is ruined .. wind it stiff, take advantage of the extra bite on turn in, if the front then starts to wash out at least you've got the car pointing somewhere near the apex so you haven't completely ruined the whole corner.

see you tomorrow

[starmist]

Migth get up to spectate if Steve Guigliami (whatever) finishes setting up my Nitrons in time!

It will be interesting to find out what he sets them to for fast road / occasional track action / fat bastard Jonny-No-mates driver

[GarryM]

Thanks Julian. Perhaps with the rain that's forecast it might not be the best idea to push it quite so hard but we'll see

Starmist - if it's any help I've settled on 11 on the front and 15 on the rear (both set from hard). I've got some very bumpy roads where I live though otherwise I would set it a bit stiffer all round.

[m12_nathan]

The bump ebound is a fixed ratio though? Certainly on the Noble running full stiff at the front gave loads less mechanical grip, and therefore more understeer than running 8 clicks from full hard. Proven on an airfield with Andrew Walsh doing setup excercises to get the max mechanical grip from each end of the car.

[joospeed]

ah but they're different beasts .. certainly on all the nitroned tvrs i've driven you need the front wound up to get the best turn-in. do noble run particualrly heavy springs and an even more aggressive rebound to bump ratio? i think what you're seeing here is that a noble isn't a tvr ...

[m12_nathan]

I was running 500Lb front and 650Lb rear, not sure how that compares, I've never heard of running the front stiffer to get rid of understeer even on cars with a similar configuration eg Caterhams.

[joospeed]

it depends what you're stiffening tho .. and what springs and dampers and roll resistance you have.

your springs are about twice as stiff as we run on the tvrs.

[m12_nathan]

I've worked it out, a Noble isn't a TVR

Seriously you must be running some very soft springs indeed! do TVR's have anti roll bars?

I was getting this body roll on the spring settings I mentioned:



Nitron were suggesting perhaps going another 100Lb harder all round (as it was a road car, not a track only car).

[chimhunter]

Anyone know of a website with basic details of how to set up adjustable dampers for a track? Now that I've got mine and I've got Snetterton coming up I could do with some advice before I make it oversteer city.

Rob

[HarryW]

My simple mind only stretches to this very broad brush understanding of shocks, springs and body roll when cornering.
It goes something like......Intial turn in body roll is controlled by the shocks (good quality ones really help apparently). The eventual maximum body postion in a sustained corner is determined by the spring rate (+roll bar = wheel rate). Obviously the weight of the overall car has quiet a bearing on that too .
So if if rolls on turn in stiffen the shocks up, if you find it wollowing/leaning heavily once in the corner you need stronger springs.
Don't forget my intial disclaimer and I'll add IMHO as well to cover the flamings .

Harry

[GarryM]

m12_nathan said:

I've worked it out, a Noble isn't a TVR Seriously you must be running some very soft springs indeed! do TVR's have anti roll bars?

325lb front and 250lb rear, ARBs front and rear. Doesn't feel too soft on the road but not yet been on track with this set up.

[starmist]

You've got Nitron's standard setup. I went for +25lbs all round, for a slightly more track biased rating. I might see you at Donington tomorrow, and I can let you know what Steve does.