R300 springs

[tezza]

I have a nice new R300 and have decided to uprate the springs as they seem too soft for country lanes as the car does seemed to wallow over bumps and gets close to grounding(should have got stiffer springs to begin with I here you say!) Still as this is my first Caterham I have nothing to compare to so I went for standard. Anyway question is what poundage are the standard springs and what would be best for fast runs down country lanes?

I would like a spring that was as stiff as possible but not so much as to cause the car to be thrown off line if I was to incounted bumps etc, not too worried about it being too hard at slow speed as (I am guessing here) they would work better as the speed increased.

For some info the car is running the new 15" wheels and the driver is 75kg and sump clearance is normal ie 75/80mm

thanks terry

 

[c21vhpd]

Tezza,

 

My tuppence worth. When I got my 21 it had 400lb front springs and was pretty much rock solid - roll was non-existant. But those bumpy country lanes were undriveable as the front of the car basically took off on every twig, pebble and catseye. I was limited to 50mph on roads I could happily do at 65 in the tin-top.

 

So I put the original 150lb springs back in and I can now do the lanes at Xmph where X is a big a number as you care to make it, but cornering has become a bit more 2CV like. On the se7ens.net tour in Finland I played a bit with Hoopy doing some slaloming and he was able to weave about 25% faster than me. Of course, his 7 has less upper body weight than the 21, but even so, I felt a bit like a preganant hippo in comparison.

 

Miraz has, I think, 275lb springs on his limo stretch 7, and those felt just about perfect, and I'm going to try ones the same - again the 21 is heavier than the SV, but Geoff is substantially, ahmmm, more sturdily constructed than I am , so I'm hoping 275lbs will give a good compromise between bumpy road speed and wallowing round corners.

 

Honda Passion Orange, 640kg , and proud of it 😬

[Peter Carmichael]

250lb/in fronts have worked very well on my widetrack car. Works for road use, trackdays and sprints. The rears are fine on the progressive springs. A fat front ARB (18mm, you may have this already) works well and it is a good idea to match the rear for roll stiffness. If you have radius arm rear suspension, the balance between over/under steer is very sensitive to rear ride height.

[tezza]

thanks for info, but it seems to be the back that wallows the most so was going to uprate all round(or did you mean 250lb front and rear, yes you guessed it I am clueless) How do you find the car on B roads, does it get thrown off line alot with this set up or is this the best average to go for?

terry

[scooby dooby doo]

The rears will be much softer. something around 150 I'd guess.

 

If the rear is wallowing then that would be an ARB problem, unless it is VERY softly sprung. presumably the R300 has one 🤔

 

HOOPY Membership Number 4136 R706KGU

[Miraz]

I've just changed to 250lb fronts in an attempt to reduce low speed understeer in the wet - I haven't really had a chance to push the new setup yet - maybe this weekend.

 

Miraz

[c21vhpd]

I have 200lb (average) progressive rate rears (and have had 200lb constant rates on) and they seem fine for wallowyness. ARB's front and rear are the orange ones (I know you're not supoosed to refer to them as such, but being a typical 21 owner I go by the pretty colours ).

 

Of course, I do have a boot and hence a bit more weight out back, but it can't be that much...

 

Honda Passion Orange, 640kg , and proud of it 😬

[paul jacobs]

It may be worth while speaking to Len Unwin, see the Freestyle Motorsport Advert in LF. If I remember rightly, for racing he used to say that you could go up to around 400lbs on the front, but don't for goodness sake think about stiffening the back end up, this will promote wildly exciting oversteer if you do. Then again, it could be worth a try, if you find life boring.......

 

Red 245bhp Vauxhall powered 21-Now sold, back in the fold with my new 1600K Seven