Harder springs/anti-roll bar etc for sprinting....??

[guitarguy]

Just done my first season of L7C Class1 sprinting as a total newbie.... Very pleased with my progress in just 5 sprints from the slowest of the slow to.... well,  not! . Always maintained I'm more interested in developing as a driver  rather than throwing money at the car... However, very obvious amidst a garage full  of Class 1 cars at Anglesey just how 'soft' my road spec Roadsport is.... (14" wheels and tyres, no adjustable platforms, high ride height, no widetrack, full screen rather than aero, no LSD, no full cage......). Very limited funds so looking to sharpen things up as best I can on a budget..... 

Very obvious in the action pics ...

a) how high I'm riding

b) how much the car is rolling into the corners (almost cocking the inside rear at times (squishy is how I best describe it from the driving seat).

*******

Have decided to stick with the 14" wheels next year as only just got a full quota of new 1a rubber (not ideal I know!), but am thinking about adjustable platforms to get a little lower, and stiffer springs and/or anti-roll bar.  (I think shock up grades will be beyond my immediate budget....)

Don't particularly want to go to full on race mode suspension wise as I drive to the events and use throughout the year (and can't afford it) , but a move in that direction is needed I feel... (wide track is something I may think about a little further down the line, and of course a change to 13's). This is really a stepping stone...

Any thoughts??  No idea whats on (or how to tell) but any thoughts on suitable poundage re springs would be good... (bog standard '05 Roadsport 1.6 120K). A simple job??

Cheers

 

 

[Simon.Rogers]

So long as they are standard and I guess they are.  Leave the springs alone.  They are matched to your dampers.

If you increase thesprings you should be increasing the valving in the damper and you can't.

Go for the adjustable platforms. Get the car lower and send me your email and I will send you Meteor's set up guide you can do at home for free with a tape measure.

 

[Alan Bowler]

Wot Simon says. I've chucked money at the car, and nothing made a bigger difference in speed events for me than slowly gaining experience/confidence. A good read here: http://www.lotus7.club/forum/techtalk/very-good-read-autocross-win-dennis-grant 

If you have the right tyres, then next on my shopping list would be adjustable platforms so you can flat floor it. It may ride a bit higher on 14" wheels.

Someone with more expertise than me can advise whether its more important to have level lower front wishbones as a starting point, or get the ride height lower. I had 14s previously, and it always looked alot higher than others. I've gone from hard springs back to standard, which seems to work for the hills and tight circuits.  

AB

 

[Mark Durrant]

I agree with Simon, keep the standard springs, fit adjustable platforms and set it up as per his instructions. However, if you still have the Avon ZV1's then replace these with Yoko A539's, they are available in 14", as the tyres on your car will be 4+ years old and they had zero grip on the day they were made, so even less now! The A539's are fine on the road and will be safer than your ditch hunters.

[6speedmanual]

Getting the front geometry right is more important than lowering for lowering sake.

Slightly taller ground clearance (14" wheels) less detrimental than having your roll centre all wrong. Level lower wishbones is your friend.

Peter

[6speedmanual]

Do you have a rear anti roll bar?

Peter

[6speedmanual]

Do you have a rear anti roll bar?

Peter

[guitarguy]

 

Thanks for the feedback people...

Take your point Simon. Yes will PM my email -  thanks for that.

************

Alan - agree totally!!! A great read btw (just dipped in so far!), thanks for the heads up!! And yes, a massive fan of improving my driving first and foremost - trust me, that I am working on too!!! I see this with guitarist's I teach  - I believe you need to earn the right to have good gear, a sort of right of passage! (But then again, you don't want anything completely rubbish holding you back once you've got the basics - like my old tyres at the start of this season - see below!).  Feel I've earned the right for a tiny tweak or two now .

*************

Mark - replaced the old ZV3's (discontinued now) but budget restraints meant I had to replace them two at a time - so had to go for the Avon equivalents (ZT5's) - equally as bad I imagine, but 1000 times better than the old 'hard as nails' 10 year old (!) examples I had on before!! And now that I have 4 tyres that do actually (sort of) work the car actually behaves predictably which helps massively!!! (Anglesey was my first 2 events with new rubber on each corner - I was up in the 95's points wise on the International (a massive improvement from where I started at Curbs 1) and was not last!!...

I wasn't aware A539's were available in the right profile as 14's (185/60 14's at the mo) but have just googled and saw some reference..... (I picked up an 'almost free' set of 13 A539's  via blatchat but have no rims as yet. They are quite old (6 or 7 years I think from memory) so personally I think I'm better with my new ZT5's for now....).

**************

Peter - no rear ARB. Do I need to fit one - will that help things?? Again, take your point re geometry.

How important is the Road or Race position of the rear 'trailing arms'/'tie bars' (? - sorry not sure of correct terminology). Nick Potter pointed out that mine were in the upper road position when he did my lowered floor. Any benefits to be gained there??

Thanks again all....

(PS.  May have have an offer of some platforms... so making some progress)

 

 

 

 

 

[Richard Price]

guitarguy,

What front ARB are you using?

The red bushed 5/8" front ARB works very well.

I ran in class 2 for 8 years, with standard springs and dampers, narrow track and a red front ARB, and enjoyedreasonable success.

Some may advise you to fit a rear ARB. I've tried with and without a rear bar, but have always gone back to running no rear ARB.

I'd put a "wanted" up for a set of adjustable platforms to fit to your existing dampers (that's what I did, and was offered a few sets).

Once you have the adjustable platforms, then you need to have a session with someone who knows how to check and adjust camber, toe, ride heights and cornerweights.

 

 

[6speedmanual]

As you have no LSD and you are already experiencing rear wheel lift or wheel spin on the inner wheel on turns a rear ARB will not help at all.

Setting the rear trailing arms to lower mounting hole will reduce roll-oversteer geometry changes and mean that the car should pull corning force (generate required slip angle) with less yaw angle.  Will help in left-right or right-left transitions.  It may help it feel as it it has a quicker turn in too.  Experiment with it.  It's such an easy change it's a classic for you to do a suck it and see and learn about the effect and feel.

5/8" bar is quite a stiff one but making the front of the car do the roll resistance will potentially keep the car more level and allow the load across the rear axle to stay more evenly shared between the rear wheels, improving grip and traction (reduce inner wheel spin).

Stiffening front ARB generally tends to increase understeer but you may be able to counter this with more negative camber, a sniff more castor (but not too much as it makes steering heavier) and maybe a sniff of toe-out to sharpen turn-in feel (if not actual total grip).

Going from 9/16 up to 5/8 is quite a big jump with 50% increase in torsional stiffness and therefore load shift across front of car.  But again this is an easy thing to have a play with.  What FARB do you have now? 

Have fun!

Peter

[Richard Price]

If the car is absolutely standard RoadSport, then it will have an orange bushed front ARB.

The orange bushes are 1/2", but the standard RoadSport ARB is actually 10mm, which has sleeves at the position of the rubber bushes to increase its diameter to suit the bushes. It's so soft it may as well not be there at all!

Whilst convention says that increasing front ARB stiffness will increase understeer, the opposite is true in this application! With the standard ARB, body roll is excessive, which causes camber change, which causes understeer. A stiffer ARB reduces roll, and reduces camber change due to roll, thus reducing understeer.

The 5/8" ARB is well proven to work well.

[6speedmanual]

Good feedback from RP.

Can you get a 5/8" farb?

It is circa 6x stiffer than the 10mm (3/8") mentioned to be the standard Roadsport spec. It will work the outside front tyre much harder but if you gain poise, responsiveness and better rear traction, all good. As above adj platforms should be high on your shopping list.

And an ADA camber/caster guage (what I call my ouijia board!)

Peter

[6speedmanual]

Here's a. nice one. About half price of new:

Very good accurate tool.

http://m.ebay.co.uk/itm/281486231439?nav=SEARCH

If you had the platforms I could do geometry and corner weight flat floor for you.

Peter

[Richard Price]

Peter,

The ADA style of camber guage is a little outdated now.

There are several digital spirit level apps available for smartphones that are easier to use.

Narrow track ARB's are available in :-

ARB diameter	Bush colour
10mm	Orange	Sleeved up to 1/2"
1/2"	Orange
5/8"	Red
18mm	Green
3/4"	Yellow

The Green and the yellow are VERY stiff!

The blue bushed 9/16" ARB is only available in wide track.

 

Mark,

Caterham are actually showing that they have 34 5/8" in stock (@ £44.40)

http://www.caterhamparts.co.uk/product.php?id_product=2675

You'll also need a couple of rubbers:-

http://www.caterhamparts.co.uk/product.php?id_product=3517

and it would be wise to replace the balls:-

http://www.caterhamparts.co.uk/product.php?id_product=3094

'can't remember if the studs that are required to attach the balls to the ARB are supplied or extra?

http://www.caterhamparts.co.uk/product.php?id_product=453

I'd try a "wanted" for an ARB complete with rubbers. As you'll never want to go back to your existing ARB, you can reuse the existing mounting brackets, and boots (unless the boots are split?)

http://www.caterhamparts.co.uk/product.php?id_product=447

 

If you fancy a trip my way, I can help with geometry checking and adjustment etc.

 

 

 

 

[6speedmanual]

The ADA is indeed a very old school piece of kit, however it offers the following advantages:

Cannot go out of calibration, requires no calibration.  Depends on gravitational pull for its cal. (perfect, unless you live somewhere where the earths gravitational pull is not in a downward direction!)

No batteries.

Robust

Very accurate. The cleverly designed curved scales allow reasonable resolution down to 1/8 degree. Much more accurate that spirit level "bubble" devices. More accurate that a badly set up electronic light beam or laser device.*

Can be deployed on a number of contact surfaces depending on application.

Very low cost.

Fits in briefcase or laptop bag.

Whilst there are many other pieces of kit out there the ADA still a very valid and strong contender.

* I once did a chassis set up with a "professional" who got in a terrible tangle over some camber settings on a rear axle, going so far as to state that the axle was bent! I used the ADA to demonstrate that his "Flat Floor" wasn't! and that the rear axle had equal camber on both ends...

Linky to ebay (as this new fangled BlatChat still does not allow me to create link from my mobile) http://www.ebay.co.uk/itm/Car-wheel-camber-castor-alignment-gauge-/281486231439?pt=LH_DefaultDomain_3&hash=item4189e3078f

Peter

[Richard Price]

Peter,

Granted. I agree, there is nothing wrong with the gauge

Mark,

I've got a flat floor to work on

 

[mikecocker]

Mark, I've got an orange and a red arb with rubbers which you're welcome to experiment with. You will need to put your own brackets on though, not a big job.

[guitarguy]

 

Thanks once again to all...

*******

Richard, it seems I'm running orange bushes and a 1/2" ARB - looks like 5/8 Red is the way forward then... that and adjustable platforms (had an offer of those already...)

Thanks for the parts links - appreciate that. As the balls are out of stock I'd probably have to re-use...

********

Peter, not actually experienced inside wheel lift from the driving seat - rather just photographic evidence of my car rolling somewhat more than everyone else in a couple of corners (and seemingly getting pretty close to lifting the wheel). Oh,  and I was having some instruction on a Javelin trackday at Angelsey in July and the instructor asked if I had a rear puncture - obviously felt a bit squirmy to him from the passenger seat. I don't know if that was his interpretation of excessive roll...)

Must admit I tend to favour 'old school' methods guys - not a massive fan of tech myself....  .

Do most sprinters run trailing arms in the lower position as a matter of course?... Is this an easy change?? (anything that might 'tighten things up a bit', in lay persons terms, feels a bit... sloppy).

Oh and thanks both of you for the offers re setting up the suspension.... appreciate that.

Looking at a front on pic of my car (haven't actually gone down to the garage and checked) lower wishbones look pretty flat. Does that mean I can't really lower the front then - with the 14's on...?

*********

Thanks for the offer Mike, appreciate that too. I think I'm happy to just commit to a red 5/8 ARB. Is that something you might be thinking of selling?

********

My focus is very much on driver improvement.....but having a few things to tinker with over the winter months ain't gonna hurt....  .  I'm not in a massive hurry to get this all sorted, so I'll put out a few feelers.... and come back re possible setting up help when I've got the bits sorted and on if that's OK.

 

[andrew mckay]

Very useful exchange of info. The club and forum never ceases to amaze me. I won't miss the replies now.