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Spring rates on striker?
INDY BIRD - 15/6/12 at 10:47 AM

Hi all

Just wondering what spring rates are being used on a sec raw striker, front and back,

I called martin at raw and wrote them all down , lost the damm bit of paper ,

So just checking before I ring him again and pester him,

Thanks

[Edited on 15/6/12 by INDY BIRD]

loggyboy - 15/6/12 at 12:29 PM

I seem to recall mine are 280 front 200 rear...

INDY BIRD - 15/6/12 at 12:54 PM

Thanks for that as I have 180 rears and 225 fronts which I think is ok for road but not sure about track?

Thanks

Dopdog - 15/6/12 at 02:13 PM

I think i run 250 front and 200-210 rear

INDY BIRD - 15/6/12 at 02:22 PM

So Mine seem a little soft then?
Thanks all

Dopdog - 15/6/12 at 02:25 PM

have you got those wheels on yet? photos

loggyboy - 15/6/12 at 02:27 PM

Bareing in mind mine are for Zetec engine with full cage.

FatChapChipChop - 15/6/12 at 02:50 PM

225lb front, 180lb rear is "standard" .. For track, you could well do with 300+200 ...

Regards

FatChapChipChop - 15/6/12 at 02:50 PM

I meant 250, not 300 ..

loggyboy - 15/6/12 at 02:54 PM

Beginning to think Im recalling mine incorrectly!

INDY BIRD - 15/6/12 at 03:18 PM

Upright mods being done as we speak, so should be good by tommo, only reduced the hole down by 6 mm to get clearance,

Fitted shortened springs and had to just bend a fraction the mandrake arm on the calipers,

Also a small trim of the outer end of the bottom a arm, ie one below the calipers, and should be good to go, no mods for rod ends required etc,

Tommo will be dee day,

I'll take some pics in a mo and post later of mods on chassis from prev post,

Thanks and I'll have to get some new springs then?

Sean

Dopdog - 15/6/12 at 03:48 PM

I have a set of raw spec track day springs 325 front and 225 rear

ps
not fitted but in the shed

[Edited on 15/6/12 by Dopdog]

Dopdog - 15/6/12 at 03:54 PM

Just thinking on this people seem to go too hard on the springs for track days. remember the suspension is supposed to move, its the shock that does the work as well.

when I had the hard springs on it felt good I was used to it. Once I put on the softer springs and had the car set-up at Procomp I have never looked back.

Just a thought.

bi22le - 15/6/12 at 05:44 PM

I have 300 front, 180 rear at the moment.

bi22le - 15/6/12 at 05:47 PM

quote:
Originally posted by Dopdog
Just thinking on this people seem to go too hard on the springs for track days. remember the suspension is supposed to move, its the shock that does the work as well.

when I had the hard springs on it felt good I was used to it. Once I put on the softer springs and had the car set-up at Procomp I have never looked back.

Just a thought.


Hmm i may have a softer pair of springs. Maybe 225. I wonder if that is too soft?

procomp - 15/6/12 at 06:09 PM

Hi

Just to try and give you guys a bit off help.
What you have to remember is that at the front end with the inboard setup you need to know EXACTLY what the Dampers are doing in compression and rebound. You can't go making choices on the springs if you have no idea what the Dampers are giving in compression and rebound.
Also remember that all the spring poundage's that RAW hand out for track use are from cars that have raced with totally different suspension setups ARB's ( manufactured by me ) and Dampers that have been valved to work in that application not just Off the shelf items.

Cheers Matt

INDY BIRD - 15/6/12 at 08:33 PM

InterestIng matt that's put a spanner in my works, more to think about ongoing then I think I'll put it on track an see how bad it is and what needs to happen,

Thanks for all your input,

Sean

JB - 16/6/12 at 08:53 AM

quote:
Originally posted by Dopdog
Just thinking on this people seem to go too hard on the springs for track days. remember the suspension is supposed to move, its the shock that does the work as well.

when I had the hard springs on it felt good I was used to it. Once I put on the softer springs and had the car set-up at Procomp I have never looked back.

Just a thought.



I tend to agree. All other things being equal (note this phase!) you want the softest springs you can get away with so the suspension does not hit the bump stops or ground excessively in critical parts of the road or track. As race tracks are generally smoother than the road (all other things being equal) you could argue that you run softer springs on a smooth race track than a road full of potholes and bumps......

I have a 900kg car and I run wheel rates of 210lbs front and 220lbs rear, (with 70mm of bump travel) but it does have a rearward weight bias.

INDY BIRD - 16/6/12 at 09:00 AM

Maybe it's run the softer spring and invest in a anti roll bar to negate any body roll on track?

Especially on the wet I suppose you would want it softer to grip more?

Thanks again

phelpsa - 16/6/12 at 09:10 AM

quote:
Originally posted by JB
quote:
Originally posted by Dopdog
Just thinking on this people seem to go too hard on the springs for track days. remember the suspension is supposed to move, its the shock that does the work as well.

when I had the hard springs on it felt good I was used to it. Once I put on the softer springs and had the car set-up at Procomp I have never looked back.

Just a thought.



I tend to agree. All other things being equal (note this phase!) you want the softest springs you can get away with so the suspension does not hit the bump stops or ground excessively in critical parts of the road or track. As race tracks are generally smoother than the road (all other things being equal) you could argue that you run softer springs on a smooth race track than a road full of potholes and bumps......

I have a 900kg car and I run wheel rates of 210lbs front and 220lbs rear, (with 70mm of bump travel) but it does have a rearward weight bias.


I'm not sure I would agree with this.

You need to keep the tyre's contact patch in full contact with the ground for as much time as possible A lot of sevens suffer with poor suspension geometry and high CoM which makes this difficult, hence the need to keep a reasonable stiffness in the corner springs / ARBs.

Also, the softer the springs, the more time you spend in transients. On circuits this is a definite disadvantage.

phelpsa - 16/6/12 at 09:13 AM

quote:
Originally posted by INDY BIRD
Maybe it's run the softer spring and invest in a anti roll bar to negate any body roll on track?

Especially on the wet I suppose you would want it softer to grip more?

Thanks again


Eeeeeeeeeexactly. Find baseline springs for as soft as you want to run (wet/bumpy surfaces), then add adjustable ARBs front and rear to get the balance right at other times.

It's worked for decades in everything from karting to F1!

You still need to work out what spring rates you need though Best way is to work out your wheel frequencies, then you can compare with cars with other suspension arrangements.

JB - 16/6/12 at 09:40 AM

quote:
Originally posted by phelpsa
quote:
Originally posted by JB
quote:
Originally posted by Dopdog
Just thinking on this people seem to go too hard on the springs for track days. remember the suspension is supposed to move, its the shock that does the work as well.

when I had the hard springs on it felt good I was used to it. Once I put on the softer springs and had the car set-up at Procomp I have never looked back.

Just a thought.



I tend to agree. All other things being equal (note this phase!) you want the softest springs you can get away with so the suspension does not hit the bump stops or ground excessively in critical parts of the road or track. As race tracks are generally smoother than the road (all other things being equal) you could argue that you run softer springs on a smooth race track than a road full of potholes and bumps......

I have a 900kg car and I run wheel rates of 210lbs front and 220lbs rear, (with 70mm of bump travel) but it does have a rearward weight bias.


I'm not sure I would agree with this.

You need to keep the tyre's contact patch in full contact with the ground for as much time as possible A lot of sevens suffer with poor suspension geometry and high CoM which makes this difficult, hence the need to keep a reasonable stiffness in the corner springs / ARBs.

Also, the softer the springs, the more time you spend in transients. On circuits this is a definite disadvantage.



I did make quite a point of saying "All other things being equal" and obviously on these type of cars other factors come into play.


My way of doing suspension is to let the springs deal with the bumps, ARB`s deal with the bends and dampers deal with the transients. Maybe an over simplification........but a reasonable starting point.

phelpsa - 16/6/12 at 10:03 AM

quote:
Originally posted by JB


I did make quite a point of saying "All other things being equal" and obviously on these type of cars other factors come into play.


My way of doing suspension is to let the springs deal with the bumps, ARB`s deal with the bends and dampers deal with the transients. Maybe an over simplification........but a reasonable starting point.


As you say, that is a massive over simplification. It all has to works as a package in each of those situations.

Saying 'everyone else is running far to stiff springs' is all well and good if you understand the requirements of each specific car and application.

[Edited on 16-6-12 by phelpsa]

rost - 16/6/12 at 10:14 AM

I'm running 225 on the front and 180 on the rear. It does give more roll on the track, I think a striker can get away with that. I did install an ARB this winter but I haven't tried it on the track yet. What would be gained by going for heavier springs? Is it just to reduce roll?

phelpsa - 16/6/12 at 10:49 AM

quote:
Originally posted by rost
I'm running 225 on the front and 180 on the rear. It does give more roll on the track, I think a striker can get away with that. I did install an ARB this winter but I haven't tried it on the track yet. What would be gained by going for heavier springs? Is it just to reduce roll?


Heavier springs will reduce roll and pitch, an ARB will just reduce roll. Whether anything would be gained depends on where you feel the gain is! A bit of pitch is generally a good thing with seven derived cars as it reduces the tendancy to lock up when you first hit the brakes (an area where some transient can help), hence the fashion is to run quite soft springs and a pretty heavy ARB on the front.

Dopdog - 16/6/12 at 08:37 PM

its all gone a bit too complicated for me

phelpsa - 16/6/12 at 10:36 PM

quote:
Originally posted by Dopdog
its all gone a bit too complicated for me


MORE BOOST!

andypg - 17/6/12 at 02:52 PM

I'm using spax with 180lb springs.They are too soft for my lardy 16st arse.I've just collapsed the right rear,because they keep hitting the bump stops.I'm thinking of changing shocks and springs,but not sure what to and which rating....Any sugestions?

Dopdog - 17/6/12 at 02:52 PM

Ah I understand stand now