More Seveducation Please

[Paul Mason]

Chaps, should a 2001, S3, imperial car have a rear anti roll bar? If no, ignore the rest this query....

In the garage fettling etc today and removed rear wheels to check, clean & grease etc and I can't seem to find the rear ARB? I can see an upper trailing arm, A frame, De Dion into back of hub and a coil-over - but could have sworn my previous car had an ARB with a drop link to the rear of the hub (with a number of holes to adjust the ARB stiffness). Either I'm being blind, stupid or my current car doesn't have one (or an entirely different set up?)

Many thanks in advance

[Jonathan Kay]

Lots of us don't have one.

Happy Christmas

Jonathan

[Paul Mason]

Many thanks Jonathan, and Merry Christmas to you too. Was worried I have was missing something there!

[Wrightpayne]

Optional extra - some designs were known to fail.

Ian

[Paul Mason]

Many thanks Ian, so if they can go without, why do some have and others don't, what do they add? I didn't know I didn't have one and if I had been asked before today, I would have said I did? Theres no perceptible roll of looseness seemingly to the rear of my car (to be honest, could do with being a touch softer if anything I'd say?)

[Jonathan Kay]

... why do some have and others don't... 

Road v track, personal preference, accidents of history (!) and as part of the whole suspension set-up (which IMHO is one of the most interesting current 7 topics).

Jonathan

[Paul Mason]

I feel Jonathan that I need to go do some research to understand this better. I have a front ARB with orange ends on the bushes and don't know what that means either, so going to research some Google and past threads and resources on here to get myself up to speed. I have (what I believe to be) a decent and very adjustable suspension set up, which has been flat floored and camber and castor and toe all set and have a page of numbers in my history file, but don't know what any of it means!

[Jim 123]

Paul, a dumb question but have you managed to get a copy of the build manual? Just in case nobody has mentioned this to you.

[Paul Mason]

Now you mention it Jim, I actually think I have one wrapped carefully in the garage that came with 7 number 1 (as well as about 12 years of Low Flying in binders). So definitely not a dumb question as I haven't thought to re-read since 7 number 2 has come along, but think they'll be worth digging out.

 

Since asking the original question though, now thinking I need to better understand the impacts of ride height, bump and rebound settings (think my shocks are adjustable for both) camber, castor and toe settings. Think all are set on my car, just thinking I need to better understand why they have been set as they are? I think ultimately I will want to raise the ride height a smidge (the coke can on its side just squeezes under will the tin rubbing) and soften the ride a little too - need to understand what springs I've got on - so far all I know is they are Eibach and they're red. As you can tell......my Seveducation still has some way to go yet! Slowly slowly, catchie monkey

[Jonathan Kay]

Let me know if you want the Assembly Guide or Handbook for your current 7. 

Jonathan

[Paul Mason]

Will do Jonathan, appreciated. My last car was a 1995 and current is 2001 so guessing not a huge degree of difference (suffice that I do indeed have the last manual still).

[Paul McKenzie]

More rigid chassis from '96, much softer suspension (to make it available to a wider audience ).  Removable upper chassis tubes.

Usually no rear ARB, if there was one then centre mounted through the DD, then later mounted to the low buttress on the DD (inferior and susceptible to fractures)

Centre mounted handbrake on transmission tunnel.

So not many changes

 

 

 

[Paul Mason]

I'll have a look on the DeDion to see if there is anything but guessing not based on what I've seen and comments thus far. Yes, got a centrally mounted handbrake vs. under dash on previous car. Guessing I may need a later build manual after all

[Geoff Brown]

My 2000 1.6K Supersport had a rear ARB as standard though I do know that it was a 'removable option' when creating the specification.

[paul jacobs]

My current 1.6K 2000 academy chassis doesn't have the a/r bar, and I wouldn't want one either.  Around that time I used to run an HPC with a rear  a/r bar and played around with different settings, but in the end I just disconnected one end and effectively ran it in sprints and hillclimbs with only the front bar - the reason was that it made the car far too loose on the rear, really very slidey, more than was just fun and controllable.  I remember going into a tight (ish) left hander up a hill, quick but not stupidly so, and the rear end just whipped out, a bit like lift off oversteer, except I didn't lift off.  Having lightening responses in those day, naturally I caught it, *wink*but it did take me unawares, so after that I always left it disconnected.

I doubt having one will improve your car Paul.

[Paul Mason]

Thanks Paul, good to know that lots of people go without and to be honest, wouldn't want the rear of my car any more slidy, if anything I'd like to soften a touch, would rather be slightly slower and a little more compliant on the road

[7 wonders of the world]

Many of the academy guys after dropping the front ARB for a wet race find the handling better and leave it off therefore running with no ARB either end.

Adjustable ARB's both end are fine for racing particularly on slicks for fine tuning with tyre temps etc.

[Paul Mason]

My front anti roll bar has orange bushes (not sure if that means anything?) The front end has nitrons with an adjustment screw knob on the bottom and 225 lb springs. Rear is nitrons also though not sure what springs, think 180lbs? Think the springs are probably about right from what I have read so maybe softening the shocks is what I need to do. However, no idea which way to turn or the effect it could have, so will leave well alone until I have some money to go see an expert.

[Richard Price]

The colour of the ARB rubbers indicate the ARB diameter.

Orange = 1/2"

Blue = 9/16"

Red = 5/8"

Green = 18mm

Yellow = 3/4"

With 225lbs/in front,  180lbs/in rear, is a little stiff, and likely to make the back a little loose.

To soften your Nitrons, looking from the of the damper with the adjuster, turn anti clockwise.

[Paul Mason]

Thanks Richard, so the front ARB I have is the softest being the thinnest? With regards to the dampers, if I go anticlockwise (as it's at the bottom of the damper I'm guessing clockwise from below, anticlockwise from above) what will the effect be, just a little more compliance? If the springs are a little stiff, will softening the damping be noticeable or for the full effect will I need to soften the springs too?

[Richard Price]

If the car is narrow track, then there are two variants of ARB that use orange bushes. The standard Roadsport ARB was actually 10mm sleeved up to 1/2". It's very soft! There is then one that is all 1/2"

Widetrack start at 1/2".

Do your dampers have a single adjuster knob, or two? Either way, to soften, turn anti clockwise from underneath. However, the springs and dampers need to be matched to each other.

Softer damping is likely to give a more comfortable ride, but if it's under damper it's likely feel uncontrolled and bouncy.

I've been an advocate of standard springs and dampers for a long time, and feel that folks often run unnecessarily stiff springs, but, soft well controlled springs, give a good ride and offer good road holding through being compliant. Too stiff and you're likely to hop over undulation and loose grip. Standard rear springs are progressive, but around 130lbs/in at normal loads, so 180 is a little stiff.

[Paul Mason]

Hi Richard, believe it's wide tracked (description when bought) however don't know how to verify. Car came with a current suspension set up and a suspension geometry/corner weight set up sheet showing toe, camber etc. All a bit foreign to me to be honest. Car grips very well, though needs tyres to be warm (Kumho V70a's think AA heat rating though not sure whether that means hard, medium or soft to be honest). My reservation is that it can skip on a bumpy road and is lively when damp (appreciate it's never going to be planted by its nature and I need to adapt to that). Looking to back it off just a little as think it set more track orientated than road......don't want to lose its sharpness, just want to dial in a little more wriggle room with a slightly softer balance

[Ivaan]

If you want to play with the settings, for each corner just note the direction of turn and the number of clicks to the stop, then you can always return to the original settings.  You'll feel the range difference just bouncing the car in the garage.

My dampers have a huge range from very soft to rock hard, so it's a question of playing until you get a setting you like. Obviously, each side will need to be the same setting, but  I tend to keep the front a click or two lighter ( very light Bec )

Clive

[Paul Mason]

Thanks Clive, I'm going to have a look today to understand how they work......then doubtless will be back with more questions!

[paul jacobs]

Wasn't Chapmans principal to have soft springing and firm damping?  It's interesting that one should, ideally, set the springs to give the sort of ride required and then match dampers accordingly, rather than use the dampers to set the ride quality ie.  harder or softer, but in practice it is easier to use the damper settings than to go to the bother of having a load of different spring set ups.

Out of interest my ex=academy car has had the K series replace with a 1000cc R1 engine, placed right back against the scuttle, and although still using the standard radiator, one would expect ihe weight saving to be considerable, say around 80 kgs.  When I got the car it had atrocious bump steer and so, whilst trying different suspension settings to reduce this, I put a spare pair of 400lb springs that I last used on a hillclimb HPC with a boat anchor in the front.  I expected the ride to be rock hard and really uncomfortable, but in practice it has hardly changed, certainly not enough for me to bother putting the original springs back.  The bump steer has been almost completely eradicated by raising the rack btw, a solution well documented in the archives.