Suspension Advice Please

[DeanB]

Not yet!

I have to wait for Mike at Tollbar to get back from Brands, so hopefully in a week or so

[Numbnutz]

Well I can't talk I got mine in July and did bugger all with them other than look at them.  I fitted them the other week, and with one thing an another I've not had time or chance to check the geo, and recently its done nothing but rain since so I can't fine tune the ride height or geo.

 

I'm contemplating going into the garage and having a faff right now - GF won't be happy ha ha.

 

I bet you are itching to get them fitted, and set up.  Have you decided on the geo etc yet?

[DeanB]

Mate I haven't thought for a second about the geo - I will let Michael take care of that. He set up my Formula Ford, my vx220 when I had nitrons fitted and the elise to date and they have all been bob on, for me at least.

Ride height wise I will probably just come down an inch or so, with a bit of rake. The nss aren't designed for really low ride height and I need to park in multi-stories.

[Dennis]

Well my budget has gone well out of the window, I am now replacing all the wheel bearing and fitting upgrade toe links, it should come back handling like a kart by the time I have finished.

 

Just on with the por15 this weekend

[Numbnutz]

A lot of ppl suggest 340 road (check seloc wiki for details, (http://wiki.seloc.org/a/Geo_Setups) or variations on it (such as higher ride height, slighlty less camber) as a starting point. But it really depends on your intended use and ability.

 

For example they built in understeer on the std S2 (mainly with 175 tyres and chassis) because a lot of people had problems loosing/controlling the back end with S1's (probably more so in the wet - although I accidentally got a 160 sideways on a roundabout on a test drive ha ha). So changing too far from std has its consequences.

 

My 46 nitrons are classed as TD/Race and the fronts are a bit shorter and run 5" springs and the best I could get was 117/127 unladen without loosing too much droop. A consequence of the lower ride height is affecting the toe (may need riser blocks on the steering rack to reduce bump steer, but only if you go much lower than std), and changing ride height will affect the camber (the more neg camber the better)- hence the need for a geo.

 

Any way, I finally got time and chance to take mine out with the nitron 46's and have a play and adjust the dampers. Quite a different ride to the oem softer sprung harder damped bilsteins. I chose 425/550 springs with helpers (as the Honda is a pro 25 kg heavier, and I wanted harder springs for track use, so compromises road feel).

 

Dampers ended up at fronts +3 from full soft, and rears 8 from full soft. (Although this may change as I use them more).

 

Slow speed potholes and bumps do jar quite more than oem, but higher speed comfort over bumps feels much better, much reduced body roll, and confidence inspiring on faster bends.

 

I noticed more over steer on tight roundabouts and some controlled rear slides when pushing more power exiting tighter corners that I will keep an eye on, there is more feedback with the firmier suspension but it's not fair to comment further until I get the geo done. Maybe I'm more confident or maybe the std rollbar and firmer springs is causing the drift.

 

Once I get chance to geo and use it I will report back if anyone is interested.

 

One thing I did notice was putting the gf's s-line A3 back up the drive after being out in the elise and it felt soft as hell ... hmmmm. Ha ha.

[DeanB]

Numbnutz I am pretty sure you should always adjust the dampers from full hard not full soft. As a general rule if you make one end harder than the other the harder end will slide more. Stiffening up the front relative to the back will induce a little more understeer, and conversely stiffening up the rear relative to the front will make the car a little more oversteery.

Racing drivers will tell you for a car to be really fast on the stopwatch the rear end needs to feel a little loose (so prob stiff at the rear) but for ordinary mortals like me a car set up that way is just too scary. To give you an idea when trying out different damper settings on my vx220 (with nitrons) I stiffened the rear a little and was amazed how well it turned in on slow and slow-medium corners but then I went through a couple of fast corners and shat myself.

Nowadays I am happy to live with a bit of understeer in the slower stuff and drive around it by trail braking and lifting off and so on.

At the moment, as I am still running old 175 fronts I also don't want to risk too much negative camber on the front as it can adversely affect braking performance - it is already too easy to lock the fronts in the wet.

[Numbnutz]

Yeah usually the damper settings are represented as negative numbers from full hard, they usually come from nitron at -10r (from full hard) and this is what the first test ride was done at on bumpy roads, and it was far too hard and jarring for my liking.

 

So, I turned them down in steps of 3 and then up in steps of 1, until I found something I liked for my road use.

 

But as the settings were closer to full soft, it was easier for me to work with and remember clicks from full soft. There are 22 clicks on 46's so if my maths are correct I'm currently preferring to run at : -

 

Front = -18r / -19r not sure which I prefer most out of the two yet.

Rear = -15r ~ -17r a lot more weight at the back, not had enough time to fine tune what I prefer - but may soften them a touch, but I do like the rear drift under power, probably won't do my rears any good though.

 

The reason I dropped down was because of the feeling of high speed bumps being too fast/bobbly, and low speed too crashy, but they felt great on smooth roads, but they are few and far between around here, especially after winter. There is still some fine tuning to go, and the above is more on ride / safety when pressing on and hitting a few bumps one after another is a little off putting if they are any firmer, and you end up bobbling around in your seat.

 

As for neg camber, I know what you mean about the 175's and braking, that's why I moved to exige rims and I'm on 205 AD08's at the front, and I quite like these, although I may try Avon zzr on my other set as I've lots of tread left on these at the mo. But once you know you camber, it's only a matter of removing shims to try a bit more neg, unless you want lots of neg and then you are into machining the arms or buying new ones which is another geo, and more suited to track use than road.

 

For me, I don't mind trying a few things to find what I prefer, and if I go the wrong way, I can put it back or go the other way.

 

But what I will say is I quite look forward to getting some more time to play out, but gf has booked up Sunday and Monday in advance :/

Also thought I'd share my findings as its good to debate, and may help others in similar situations.

[Numbnutz]

Incidentally, here are some 40/46 spring rate and other choices.

 

[jonnyfox]

Actually with the S2 at about 840kg that bump and rebound was great but at 800kg the bump and rebound felt too far apart. Ended up B10/R14 after a session with Track Group....then the alternator went, after we'd found the cause of the persistent oil leak, before the engine lunched.....Arrrr Happy Days lol.

 

Those dampers were bloody awesome. Benj has them back up for sale if anyone is interested, rebuilt to fit an S1. A little too soft for his car at 450/550. I'd of had them back but I've just purchased some brand new Lotus Motorsport jobbies.

[Numbnutz]

Thanks for the update Jonny, I'll add the extra info to the spreadsheet. Are these settings for track rather than road? Did you make a note of your different track and road settings?

 

Is that Benj as in Benja off exiges/seloc?

 

I'm bad enough trying to decide which settings I prefer for road use on one ways let alone 2 ways. Ha ha.

[jonnyfox]

The 46mm Ohlins were that good and the spring rates so at ease with the car I never botherd to change them be it track,road,wet or dry at either weight. I've spent a lot of time fiddling with 36mm two way dampers which wasn't an issue but the 46's are nigh on incredible.

 

It is that Ben but he thinks the softer spring rates are affecting and accelerating driveshaft issues. They just need harder springs but I fear panic mode has set in and he's originally a Nitron man.

[Numbnutz]

Accelerating drive shaft issues? Are his tripod bearings bottoming out by any chance?

[jonnyfox]

Dunno, I've never had a drive shaft issue to give it any thought or research time ;-)

[Dennis]

Mine is all on, just needs corner weighting/geo-ing

 

 

 

I hope the rose joints aren't too harsh....

[DeanB]

looking good Dennis