Spring rates

[uvii]

Just fitted some new bits to the Atom. This included 2 way, remote reservoir  Nitrons. We had problems getting the set-up right at Silverstone, and think lower spring rates may help.

What springs are people using for Atom 2 300.

[Monza]

Of course it's higher price, but why didn't you go for 3 way dampers ? it's what needs the Atom because it has no anti-roll bars. The new 500 of course has them and it'll be asap an option on other Atoms.
180/60 or 70 Front and little bit more on rear.

[uvii]

I'm having rollbars made. Agree it needs them.

[Monza]

ahh ok. Good, but as you know, in this case what we use on the Atom is perhaps not the good spring for you.

[Atom120]

[quote="uvii"]
I'm having rollbars made. Agree it needs them.
[/quote]

Front and rear? If so, I'm interested - very interested!

Where're you planning on mounting them, and any idea of cost?

[uvii]

No idea at this stage. Its just the car, in reality, is a bit of a handful (when pushing on). Silverstone was a bit of a disappointment as I had real trouble trusting the car. On "track" settings i.e. quite firm, you just couldn't get the power down. Then when everything was softened off, the car seemed to skip round corners. I think a lot of the adjustability is lost with the stock springs as they are dominating the handling.

So, new spring sets coming in and another test session. We'll swap a couple of sets over at the track and see where we are.

Was hoping to get the car back for a bit of road arsing about. But it went back with my mech.

[Atom120]

Have you got standard factory spring rates at the moment? If so, I guess you're going to try going harder on springs - will be interesting to see what you find. Harder springs will obviously reduce the amount of roll, but if you're having problems getting the power down, harder springs could exacerbate the traction problem.

I'd be really interested to see if you can come up with a tidy way of packaging anti-roll bars, as they'd open up a huge range of different setup options!

[uvii]

Softer springs actually. But we'll buy in a number of different rates and try them out. Roll bars shouldn't be a problem, just need to get them done.

[Atom120]

Fantastic - not really heard of many, if any, people trying softer springs.

Going softer on the rear especially makes a lot of sense - should transfer less weight dynamically to the outside rear, reducing oversteer while improving traction and compliance over bumps and kerbs. I'm concerned it'll just induce too much roll and instability - though I've never tried it.

Ideal solution would be softer on springs, and then use the bars to help control the roll - please keep us updated with how you get on!

[uvii]

Im pretty lucky as one of my mechs is ex F1 suspension specialist. He wasn't there at Silverstone, but he'll come next time.

[wasp]

[quote="uvii"]
Softer springs actually. But we'll buy in a number of different rates and try them out. Roll bars shouldn't be a problem, just need to get them done.
[/quote]

I know it's been a while but how did you get on with your modifications to the springs? Did you find a set up that worked for you? I was also interested if you had tried the anti-rollbars you were contemplating?

Cheers,

Stu

[FlyingTrotter]

Uvii's car is up for sale - see post in relevant section or PH - I believe he feels he got as far down the road as he could - saw him at Snetterton on his last outing and I'm pretty sure he didn't go the roll bar route

[wasp]

Oh ok, thanks for that. 

I was thinking that as he seemed to be pretty switched on with track machinery, it would be interesting to know how he felt the changes that he had made had affected the handling of the car, particularly the Nitron shocks.

He had a few interesting ideas which would have made a significant difference to the handling.

Cheers,

Stu

[Mr.Woolery]

What I did on my car (US Atom 2):
-Removed the helper springs all around
-Changed to DP's bellcranks/pushrods
-Installed Brammo's "race" springs on the rear only, leaving the stock softer springs up front
-Inverted the front shocks (Konis) leaving the rears alone (interference prevents inverting the rears)
-Upsized the rear wheels/tires to 275/45/17
-Aligned the car

I still have to track test it, but so far these changes have garnered immense handling improvements in street conditions.  No hard data points, but subjectively the car limits feel equal on the street to what they used to feel like on the track.

[uvii]

Atom is now sold.

The Nitrons/Palatov Bellcranks made a big difference, but just moved me on to the next problem. The car was much better through the faster corners, but I came to the conclusion I probably needed bigger wheels/tyres; which would have needed bigger uprights/bearings/... It didn't make sense. I have my eye on a couple of proper race cars and I think I just need to accept that, for what I want, I need a 100% track car. I've been out in a Juno and its a completely different league and I feared the Atom would just instil bad habits. That's not to say they aren't great fun...