Wet set up help

[Tony Whitley]

Looks and good in the wet? CR500.

[oldbutnotslow]

HeMan,

Its hard to look " *smokin*cool *smokin*" when you are being dragged back from a track incident with your car in bits on the back of the recovery truck!

Not to mention that you are then going to have to get back home and have your pride and joy recovered as well. Then there is the excess that you will have to fund IF you have trackday insurance for the event if not then the full cost of the repairs.

I take 3 sets of tyres. Slicks, AO21's and full race wets as it can be dry one moment mildly moist the next and pi$$ing down moments later with a river running across the track.

But its up to you!

[Mucus72]

@ Charles, enjoyed your video hugely, would happily watch the whole race...

 

@Pendennis I definitely have a LSD - AP Suretrac one accordign to previous owner. I know that when up on jack, if I rotate one wheel by hand, the other rotates in the same direction.

 

@ OBNS and Jez - your help is just what I am after, really appreciate your comments, I now have castor, camber, toe out, rake, different types of ARB and tyre pressures to think about! (need to go on Wikipedia!)

 

Before this thread I was just getting in my car, driving to a track, trying to be good, then driving back home. Its only the terrible driving that I did in the wet that got all of these new thoughts started for me!

 

So, a few more questions. I have a wide track by default SV, its 2003, and I have been on Caterham's website looking at ARBs. I don't really understand? There are different widths and different colours. Its not clear what is what?

[Mucus72]

Apologies, by widths of ARBs I mean diameters. I have a 2003 SV...

[Birkin S3 ZA.]

Mucus72 you need to learn to drive like this in the rain fast reflexes are a must and big ba..s

 

Chris.

 

[Mankee]

Quoting HeMan: 

I did Bedford a month or so back in the dry and although I am no expert, I would add that although too much right foot might be the cause, not enough opposite lock quick enough may have been the difference between hero and zero (or 180, but you know what I mean) in some cases.

 

You mentioned running 2 year old rubber, do people think the age is important? Mine has the Avons on (maybe the original set from the factory in 2006 if the previous owner was gentle) and although I am hankering for a set of A048s, at Bedford in the dry at least, they seem fine. I must admit an ulterior motive though, I am at Spa in a few weeks and it may well rain, so would investing in new rubber (A048) be worthwhile or should we assume if it rains, grip will be comical whatever and just use it as an opportunity for a rear-out laugh (and some learning)?

Going slightly off-topic of the original subject, but are you there on 9th/10th October? If so, see you there! I bought some A021Rs last week. I couldn't care less about what they look like, especially being massive 70 profiles, but gave them a beating at Hethel and they are very good tyres, even in the dry. Needless to say, they will be coming with me to Spa. At £52.50 a corner, I don't mind if it turns out dry and I destroy them over the 2 days, although I will have some dry weather wheels and tyres with me as well.

[HeMan]

Yeah, apologies if I have hijacked the tread a little!

 

Yes, although only the 9th.

 

I was going for the 60 profiles (thats what I have currently), why did you get 70s? Should I?

 

Unfortunatley I am driving the 7 there and my wife will be in the passenger seat, so I have to put all my money in one set. The A021Rs seem to be the way to go (too be honest I have enough fun on the ZV3s in the dry and these will be better than those, so it is the wet performance that concerns me the most). Where did you get them for £52.50, I havn't found them less than £93 (or £95 fitted)?

 

Edited by - HeMan on 16 Sep 2013 17:43:24

[Birkin S3 ZA.]

At our first round earlier this year my first qualifying was in the rain,

Before we started I was given some advice from one of our best drivers, he told me to keep my left foot on the brake pedal through the corners.

And if I felt the rear wheels spin jab the brakes to keep control and stop the car spinning.

If you just come of the throttle it takes to long for the wheels and motor to slow down to road speed, the brake will slow it all down faster and keep the car stable.

I never got to try as qualifying was red flagged after three laps ☹️

Maybe I will get to try it one day.

[Mankee]

George Polley (http://www.polleymotorsport.co.uk/) back national stock rods, who use 185/70R13 A021Rs as a control tyre, hence the low price. I rang them less than a fortnight ago to confirm the price and they charge £12.50 for delivery of four tyres. I would have gone for 60 profiles if it wasn't for the rather large price difference. Well pleased with them for bang-for-buck.

[HeMan]

Ahh, I need 14s, but still, it seems a lot more (£40 per corner) for an extra inch!

[Jonathan Kay]

When I click on the A021-R "Add to Cart" button I get an error returned. (Safari, OS X.) There isn't a pull-down menu for sizes as there is for other tyres. Does it work for others?

 

Thanks

 

Jonathan

 

Edited by - Jonathan Kay on 16 Sep 2013 20:01:56

[HeMan]

This is what Steve said to me earlier:

 

"Apologies for the website, it's not quite ready yet!

 

185/60R14 AO21R = £77.50 + VAT each"

[Mankee]

You need to call them up, JK.

[Jonathan Kay]

Thanks

 

Jonathan

[oldbutnotslow]

Marcus

I have been on Caterham's website looking at ARBs. I don't really understand? There are different widths and different colours. Its not clear what is what?

The colours refer to the mounting bobbins that are in the brackets that are bolted to the chassis just behind the radiator.

 

The colours reflect the thickness and thus the stiffness of the ARB

 

The stupid thing is that they are a mixture of imperial and metric measurements (not to be confused with an imperial or metric chassis)

So here we go

1/2" Orange

9/16" - Blue

5/8" - Red

3/4" Yellow

18mm Green

 

There are thinner ones than the orange but I am not sure if they were only for the early s3 chassis.

 

Ive never seen a yellow bar on a car. I cant imagine what it would be like to drive

 

Some years ago stiffer was considered better but the perceived wisdom is now tending toward a softer front end hence me saying that orange is a good starting point.

Lets be clear, its not as simple as just bolting a different ARB on an bobs your uncle. There are a whole raft of things that can affect the dynamic of the cars handling. For example, the profile of the tyres on your 7. Take a 15" rim running a 45 section cr500 tyre and compare this to say a 13" rim running a 60 profile AO21 tyre. The car would handle differently in each case and would require different suspension set up's to maximise the handling for both.

 

Sorry --- I know that this isn't really going to help you which is why a seven specialist in your neck of the woods will be able to look at a number of variables and should be able to help you to get the best out of the car always remembering that its a compromise at best particularly if you don't intend to change the set-up for different tracks and for wet and dry running on each track.

 

Edited by - oldbutnotslow on 16 Sep 2013 20:59:08

[irrotational]

Just to come back on one point - for my own benefit!

 

When coming back off the throttle after inducing power-oversteer, I assume/believe you have to react pretty quickly - but not completely snap off the throttle?

 

I have had a couple of VERY slow speed spins where I believe I came off the throttle too quickly, the rear goes very light, and it just keeps on spinning round.

 

Is that possible/correct?