Discussion
Having fitted more sticky rubber I now find ( as predicted by the wise ones on here and elsewhere ) that because I can carry a lot more speed into and through corners I am getting a lot more body roll. I suspect this means that I am not always maintaining the ideal tyre footprint. I have Nitrons with their standard Spring rates. What do other people on here run. I don’t really want to bake a big step change all in one go, but advice gratefully received.
I moved up to 400lbs front and 300lbs rear. Still compliant enough on the road but combined with winding the Nitron adjusters up to their hardest setting, it stiffens the car up quite substantially.
You may have already done so but fitting shpubs droplinks and some new ARB bushes will significantly improve roll too. I have to say though, it feels much stiffer but when you see some photo's of your car cornering on a track/hillclimb it will still look like it's on its ear! I suspect you'd have to up the spring rates massively to make a big change and I can't believe road driving would be much fun after that.
You may have already done so but fitting shpubs droplinks and some new ARB bushes will significantly improve roll too. I have to say though, it feels much stiffer but when you see some photo's of your car cornering on a track/hillclimb it will still look like it's on its ear! I suspect you'd have to up the spring rates massively to make a big change and I can't believe road driving would be much fun after that.
Edited by GarryM on Monday 23 April 13:31
dnb said:
I would suggest an ARB upgrade if you can find one. Mine has 26mm front and 23mm rear ARBs and it doens't seem to roll at all. (But it does breaks the ARB mounts from time to time...)
Where can you buy such a ARB upgrade ? If you look at the ARB mounts they seem to be a bit flimsy, someone must have figured out a more sturdy replacement, any 1 ??
Interestingly Barretti discovered a kit car maker local to us, who seems to have pretty good credentials. Whilst glossing over the site I noticed that one of the cars used GAZ dampers, and they recommended 350/300 for track and 300/250 for the road. Sounds a bit similar ? Well in my mind there are 2 really significant differences, the car is only half the weight (500kg) and the dampers are mounted much more near the vertical (so nearly all of the 300lbs is acting against the travel - not just 75% of it!). 
I am firmly in the stronger/longer spring camp (possibly on my own?) and certainly not for macho / track only reasons - they give a far better ride IMHO - much less pogo'ing down the road.
More relevant to OP is that if you change the springs you may well need to change the valving... Joo has been doing this for yonks with his Nitron packages.
Dave
I am firmly in the stronger/longer spring camp (possibly on my own?) and certainly not for macho / track only reasons - they give a far better ride IMHO - much less pogo'ing down the road.
More relevant to OP is that if you change the springs you may well need to change the valving... Joo has been doing this for yonks with his Nitron packages.
Dave
You don't need to change Nitron valving unless you start going into much higher rates.
375to400lb front 300to325lb rears will work very nicely on road cars and just start again on adjustments.
£20 each is about the norm and I would stick with 9" springs to avoid too much pre-load.
Nitron use 325fr and 250rear
BTW you will probably find that increasing spring rates will increase service intervals because the damper doesn't have to work so hard and that goes for Ohlins as well.
375to400lb front 300to325lb rears will work very nicely on road cars and just start again on adjustments.
£20 each is about the norm and I would stick with 9" springs to avoid too much pre-load.
Nitron use 325fr and 250rear
BTW you will probably find that increasing spring rates will increase service intervals because the damper doesn't have to work so hard and that goes for Ohlins as well.
Edited by the gazman on Monday 23 April 15:08
Edited by the gazman on Monday 23 April 15:32
As with all things you dont have to change the valving, but it sure makes things a lot better .. if you're using a generic nitron damper valving you might want to speak to Guy about changing it if you go stiffer on springs .. i never vary spring rates more than 20% without valving changes.
You'd not know how well your tyres are working unless you got to a G circle and plotted the tyre temp gradient against circle diameter, from that you can deduce the overrall picture of how your tyre contact patch is changing with applied steering angle and roll .. the idea being to get the tyre working at it's optimum for all cornering situations ..
don't forget though that every time you optimise for cornering you may be harming traction or braking .. depends what you want from the car, your driving style and how grippy the surface is.
You'd not know how well your tyres are working unless you got to a G circle and plotted the tyre temp gradient against circle diameter, from that you can deduce the overrall picture of how your tyre contact patch is changing with applied steering angle and roll .. the idea being to get the tyre working at it's optimum for all cornering situations ..
don't forget though that every time you optimise for cornering you may be harming traction or braking .. depends what you want from the car, your driving style and how grippy the surface is.
the gazman said:
You don't need to change Nitron valving unless you start going into much higher rates.
375to400lb front 300to325lb rears will work very nicely on road cars and just start again on adjustments.
£20 each is about the norm and I would stick with 9" springs to avoid too much pre-load.
Nitron use 325fr and 250rear
BTW you will probably find that increasing spring rates will increase service intervals because the damper doesn't have to work so hard and that goes for Ohlins as well.
375to400lb front 300to325lb rears will work very nicely on road cars and just start again on adjustments.
£20 each is about the norm and I would stick with 9" springs to avoid too much pre-load.
Nitron use 325fr and 250rear
BTW you will probably find that increasing spring rates will increase service intervals because the damper doesn't have to work so hard and that goes for Ohlins as well.
I dont think his is a road car based on previous posts...
Happy to see you noting some of the benefits of higher spring rates
- surely its simple physics that applies to all dampers tho? Dave
Ok
I didn't realise that this was motorsport oriented, from my dyno testing and Nitron themselves, any more than 40% increase would entail moving the damper range up on the shim stack.
BTW I have never flinched from upping spring rates and run 400/325 springs as standard and more on the back of Cerbs with no problem.
I understand where Joo is comming from and suggest that springs, dampers and geometry have a part to play in all set-ups, hence the large range of differing geo settings I use but I do have to watch out on Nitron and Ohlins because they do run a narrower band of damping than Gaz and revalves may be neccessary.
I didn't realise that this was motorsport oriented, from my dyno testing and Nitron themselves, any more than 40% increase would entail moving the damper range up on the shim stack.
BTW I have never flinched from upping spring rates and run 400/325 springs as standard and more on the back of Cerbs with no problem.
I understand where Joo is comming from and suggest that springs, dampers and geometry have a part to play in all set-ups, hence the large range of differing geo settings I use but I do have to watch out on Nitron and Ohlins because they do run a narrower band of damping than Gaz and revalves may be neccessary.
Edited by the gazman on Monday 23 April 16:17
Garry, how old is the picture you are looking at ? You may have one prior that is pre Nitrons and almost certainly it is pre new drop links and roll bar bushes. Fair to say however that it still feels like the door mirror is only an inch off the road now I am running slicks.
When the Nitrons were serviced at the end of last year they said the valving would cope with going up “two levels” in the spring rating. Quite what that is I don’t know. Will call them tomorrow and ask.
Joo. Haven’t driven round in a circle and checked the temps but am fairly happy with them after a spirtied run up the hill. As it is currently set up I seem to have lots of turn in grip, plenty of grip under breaking but not a massive amount off the line. Got two comprehensive second places at the weekend with your new bushes fitted by the way.
If I can control the body roll a bit without compromising what I currently have that would be good. A concern about stiffer anti roll bars is that I keep hearing it can make wet handling an issue. Does the same apply with upping the spring rates.
The car by the way is a Hill climb tool on Hill climb days and a slightly stiff burble to the Pub Sunday lunchtime car on other days.
When the Nitrons were serviced at the end of last year they said the valving would cope with going up “two levels” in the spring rating. Quite what that is I don’t know. Will call them tomorrow and ask.
Joo. Haven’t driven round in a circle and checked the temps but am fairly happy with them after a spirtied run up the hill. As it is currently set up I seem to have lots of turn in grip, plenty of grip under breaking but not a massive amount off the line. Got two comprehensive second places at the weekend with your new bushes fitted by the way.
If I can control the body roll a bit without compromising what I currently have that would be good. A concern about stiffer anti roll bars is that I keep hearing it can make wet handling an issue. Does the same apply with upping the spring rates.
The car by the way is a Hill climb tool on Hill climb days and a slightly stiff burble to the Pub Sunday lunchtime car on other days.
First thing is that in the wet, you won't be running slicks and with reduced speed, roll isn't a problem. Yes reducing/removing arb is often done but equally the opportunity to do this can be very limited when sprinting. In the end, I keep my dry set up the same for the wet but run larger diameter super sticky cut slicks. May not be an optimum set up but it was beating Scoobies in the wet.
If you don't run high spring rates to match the slicks then you won't get the best out of them. Period. Are higher spring rates ideal for wet conditions? Probably not. Neither is negative camber. So ideally you need to change the springs and geometry. This isn't practical for most and so any setup is going to be a compromise. Personally I would go for a good dry setup and run with it. Sprinting in the wet is often more of a test of driver skill in applying the right foot more than anything else and this can more than make up for any compromises with the setup.
In other words, get it right for the dry and live with it for the wet but don't compromise one setting simply to reduce the compromise for the other. Also you can bet your bottom dollar it will rain when you are in the starting line on slicks so you'll have to get used to driving in less optimum setup and conditions! Happened so many times to me I've lost count! It even hailed once. No that was interesting.
If you don't run high spring rates to match the slicks then you won't get the best out of them. Period. Are higher spring rates ideal for wet conditions? Probably not. Neither is negative camber. So ideally you need to change the springs and geometry. This isn't practical for most and so any setup is going to be a compromise. Personally I would go for a good dry setup and run with it. Sprinting in the wet is often more of a test of driver skill in applying the right foot more than anything else and this can more than make up for any compromises with the setup.
In other words, get it right for the dry and live with it for the wet but don't compromise one setting simply to reduce the compromise for the other. Also you can bet your bottom dollar it will rain when you are in the starting line on slicks so you'll have to get used to driving in less optimum setup and conditions! Happened so many times to me I've lost count! It even hailed once. No that was interesting.
Sorry Steve - I meant my car. My point was that after upping spring rates by 20%, fitting rose jointed drop links etc etc, the car "felt" much stiffer but when I saw some photo's of my car on track it was still rolling badly and that was on SO3s and not the R888s I have now. TVRs seem to roll more than others unless you go up to the sort of spring rates shpub has. It's not a big problem tho' - stick a top driver in a 'rolling' Griff' and he/she'll still disppear into the distance!
steve-V8s said:
When the Nitrons were serviced at the end of last year they said the valving would cope with going up “two levels” in the spring rating. Quite what that is I don’t know. Will call them tomorrow and ask.
A concern about stiffer anti roll bars is that I keep hearing it can make wet handling an issue. Does the same apply with upping the spring rates.
Two levels up would be 50lb but 100lb would not cause any problem to standard valving, the question is "is that enough"? Its not really enough for track work but would be fine for road and you would notice 100lb difference.
On wet handling stonger ARB's are a lot less user friendly than springs IMHO, you don't get the feel in a lot of peoples opinion.
I recomend taking a few clicks off the dampers and toeing the front out a bit in the wet.
Steve : maybe it's time you sat down with a suspension person and discussed face to face what you want from your car and how you drive it .. the trouble with asking a forum is you get 10 opinions on how it should be done, none of which are directly applicable to you and your car but which may well work brilliantly onthat person's car and their style .. if you want to get on top you,ve got to get to grips (!) with your own style and adapt the car as close as possible to make the most of that, then change your style slightly to make up the difference .. just ask simon cole
Initially I have decided to go up 75lb all round and hope that is within the valving range. I prefer to make small incremental changes rather than bug jumps, also that allows me to put the Fronts on the rear, change just the rear springs and put them on the front. That way I will end up with 400 Front 325 rear.
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