Wet set up help

[Mucus72]

Hi all,

So I know Im an OK driver, in fact fine in the dry, but still no Ayrton Senna. I was lapping Mallory in a 56 second metronomic way a few weeks ago (my car is a circs 150 bhp rover K).

 

I then went to Bedford this Monday and it was raining cats and dogs, pretty much all day, and a bit of oil on track (Nissan GTR black flagged).

 

I would like a few of you who know about car set up to have a look at my video at the bottom of this post. Out of the hours of track time I had I still span 12 times. Now I will admit to "going for it" all day long, and I wanted to gain more skill and oversteer car control, as this was my first time on a wet track and I was very conscious of the MASSIVE run-off pretty much everywhere. So I was fooling around a fair bit, but my god it was a NIGHTMARE...

 

I have a LSD, Yoko A021R 185/60/14 little 6 inch wide tyres front and rear, and was running 16 psi in all of them. The previous owner had removed the rear ARB, and although I have never replaced it to pass comment on the differences, in the dry I appreciate the roll and grip seat of the pants movement I get, so wasn't planning on replacing.

 

And the car behaviour, well forgive some bad driving, but to be honest it would ALWAYS turn in well (I have never had an understeer problem unless deliberately provoking), lots of front end grip and always had an oversteer tendency. Literally just farting on the throttle post-apex would provoke the tail.

 

I still cant believe how little grip I had, 3 days later Im still thinking about it.

 

So help if you can regarding either car set up suggestions or is it simply my driving or the fact that ALL Caterhams are rubbish in the wet when trying to press on?

 

 

 

[ChrisC]

I second that 😬

[ChrisC]

I was also there, but I had side order of understeer to go with my oversteer. I have CR500s and still have the rear ARB fitted.

 

I am the "Not my spin" in the vid, but this was the end result of a lockup under braking (and a lack of talent).

[Willie.]

Try lifting your foot sooner, you're keeping your toe in it and spinning up the wheels. Nearer the end you're lighter on the throttle. Try lifting as soon as it goes, spinning the wheels is like lifting the handbrake.

 

Just my 2p...but I couldn't drive nails into butter

[Mucus72]

What about tyre pressures? Should I have gone much higher to try and get some heat into them? They were clap cold all day. Would re-fitting the rear ARB help?

[Jason Plato]

most of your spins are power oversteer on exit, you are applying too much throttle for the grip levels and then you are failing to apply sufficient opposite lock quickly enough and balance of throttle .

 

no changes to the car are going to over come a heavy right foot and a lack of correction

 

 

[Shad]

What Dave said.

 

The slides you didn't want to initiate were just from too much throttle too early. The spins were because you didn't get off the gas earlier enough, as well as (in some cases) not applying enough opposite lock. I don't think this is really about car set up, yet.

 

Take a look at my vid from last year:

 

You should be able to hear me give it a prod of throttle on entry or near the apex, then get out of it almost completely once the car has started to slide. I only reintroduce the throttle when the car has settled into its slide, so I can hold the angle (or increase it ). Finally, don't be afraid to let the steering wheel slip through your fingers if it's a big slide. You'll find it less frantic, but remember to wind the lock off as you recover the slide.

 

Keep practising, it's lots of fun

[elie boone]

As Dave said, but for your feeling you could put a slight higher pressure in the front tyres relative to the rears, it will introduce understeer making you to lift early'er and hopefully not to understeer off the track 😳

[rj]

Quoting Mucus72: 

the fact that ALL Caterhams are rubbish in the wet when trying to press on?

 

 

 

Hmmm

 

 

Not very far off...

[Klunk]

When you get it right it's noticeable that, not only are you more progressive, but you are almost in a straight line when you apply the throttle. Unless you want to practice drifting (and who doesn't - it's fun ) you need to follow the rule Jackie Stewart told Capt. Slow - never put your foot down on the throttle until you know you don't have to take it off again.

 

On the subject of tyre pressures, you may find that more in the rear would mean the tyres can clear the water better. However, I agree that the fronts should be higher to counteract the oversteer. Adding a rear anti-rollbar will only worsen the oversteer unless you stiffen the front one at the same time, which makes it a bit pointless.

 

Regards,

Giles

[Mucus72]

This is all really great info for me, and gives me lots to think about as I'm learning. Really appreciate all of your help!! I think I thought I had to keep my toe in as my fear that backing off would induce more oversteer. What you are all saying makes sense though. God help me, lets hope I'm better this weekend. I have a a bunch of laps driving in an Atom at MIRA on Sunday!!

[Superwhite R283]

Great info/video guys

[Harry No Sheds Flatters]

I agree with Dave J in that most of the spins were caused by being too agressive with the throttle before you have exited the corner. A smooth driving style is required when driving in the wet and you need to feed the power in gradually. One spin was caused by lift off oversteer as you entered the corner too quickly.

[Z3MCJez]

A few pointers from me.

 

1) Light hands. In the corners that you are taking without spinning, you have a nearly fixed steering wheel. You're not letting the car feed back to you at all. You can't make aggressive movements in the wet if the car is not under control, but no corner has uniform grip - how are you working out where the grip is? Try holding the wheel with only your fingers.

 

2) As noted above, most of your spins are too much loud pedal coming out of the corners. That is a feel thing. You need to practice having something other than full throttle.

 

3) There are some spins that are from removal of drive to the rear wheels. To be quick in the wet, you actually need to use the rear wheels to keep the car stable. The car will drive through the corners much more quickly when you're on the power. It's a bit scary sometimes to get on the power when your running out towards the edge of the circuit (but not too hard!) You can practice this at Bedford! (Note: this is an advanced skill)

 

4) I think the balance of your car isn't quite right. There are some "half-spins" where the front comes back around. That suggests the front is too stiff. In the wet I would remove the front roll bar. That will make your power spins worse, so more care needed with the loud pedal.

 

How old are the tyres, is the last question. Old tyres can be hidden in the dry, but won't perform well in the wet. You need the edges. I'd also take the pressures way up. At the end of the session, in the wet, I'd be looking for 24psi. In the dry different drivers prefer different pressures. I prefer 20psi, but I know others that I race with would find this too soft. It also means that I'm slow on the first couple of laps as the tyres are still not up to pressure. Although that doesn't explain my woeful starts!

 

Jez

[Guest]

As many others have said, its power oversteer so be more gentle with your right foot. Also you need to speed up your hands a little and don't just give it opposite lock and stay there, give it as little opposite as you can as quickly as you can without unbalancing the car, if that doesn't catch it, have another go. Last thing, you are trail braking some corners a little (more than you should for those corners or the wet) and not heal toeing the last change before the corner, so the car is a little unbalanced as you enter the corner, great if you want to have some oversteer fun, but you will never get max apex speed unless the car is flat and balanced as you enter the corner.

[oldbutnotslow]

I agree that most of your spins are as a result of too much power too early.

You may also want to consider keeping the car in a higher gear when going into and through the corner in the wet ie 3rd instead of 2nd.

 

I would second the comments re tyre pressures ( 20 to 24 is a massive difference in % terms) and particularly the age of the tyre.

They may be AO21's but if they are old and rock hard they will still be nightmare.

Also run with the minimum amount of fuel as this will help by not adding to the pendulum effect.

 

What size front ARB are you using and what rake are you running?

Remember that whatever you do at one end has the opposite effect at the other.

So increasing front end grip will make the car overseer.

but to be honest it would ALWAYS turn in well (I have never had an understeer problem unless deliberately provoking), lots of front end grip and always had an oversteer tendency. Literally just farting on the throttle post-apex would provoke the tail.

This sounds as if your suspension set up could also be a problem.

Oversteer may be fun but it wont give you the fastest lap overall and it will show up far more in the wet. You need a balance.

10 to 15mm of rake with an orange front ARB or red at most and connect the rear ARB on the first hole closest to the end of the arms as a start.

or if you dont have a rear ARB try disconnecting the front ARB (wet only)

Check your front end camber 1.5 degrees neg is a good starting point and have a look at the castor as well. (check where the washers are on the lower wishbone) 2-2-2 is a mid point. You can move them to give more or less castor

If you have adjustable platforms consider getting the car corner weighted for you.

Lastly have your tracking checked. Try having it set parallel to begin with.

 

You can mess about to find the best setting for you but always remember that its only ever a best compromise.

 

 

 

[Mucus72]

Some answers to some of your questions...

 

The tyres are 2 years old and have done a few track days and about 2000 miles.

 

My tyre pressures are 16psi all round when cold, so that's a big difference to what you are suggesting, as high as 24 psi.

 

The front ARB is orange, no rear.

 

And now you have all got me really interested so I will have a play around in the garage and have a look at some other settings over the weekend.

 

However, the majority rule, and I agree with most of you - it's me and lack of skill (at this stage!) more than car set up, and I will learn from your advice. In fact I'm less scared now of a wet track day and may deliberately book another in miserable October to have another try with my new found "education" on here. I love BlatChat, thanks all!!

[Z3MCJez]

In the dry, 16PSI all round cold will lead to imbalances when hot (maybe 18 fronts, 22 rear, depending on circuit and how hard you push it). Tyre pressures should always be set hot for a circuit (it's how you use them). On the road the temp differences (and therefore pressure differences) are much smaller.

 

I missed the always oversteer when you fart on the throttle. I think you need to check rake, or as OBNS suggests, get it properly corner-weighted with a base setting.

 

As a reference, and I run track-only with AO48s, 140bhp and race suspension (Sigmax specification, which is Supersport spec with different tyres) I have:

 

1) Max castor - all washers are behind the wishbone

2) Neg 3 degrees camber

3) Some toe-out - about 0.5degrees out

4) c. 15mm rake

5) 20PSI hot all round; (23/25 in wet)

 

I change the roll bar settings for every circuit, but would start with something like:

 

1) Orange front; 2nd softest attachment at the rear (+2), where 0 is disconnected and +4 is stiffest setting

2) Blue front; +3 at rear

3) Wet - no front; 0 or +1 at rear

 

My startpoint will depend on the circuit. At Bedford I'd start stiff, as the track is smooth. At Combe, opposite. In context, when we raced at Cadwell at the weekend I did one race on 1) and one race on 2). Neither was really right, but I didn't get enough time in testing on Friday, 'cos of the rain, to realise this (At that point, I would have left the front on orange, stiffened the rear a little and reduced the rake, by lowering the rear a mm or 2).

 

BUT, TAKE NOTE - I'VE NEVER USED AO21s. And this would be a horrible car to drive on the road (too stiff, too low, would tramline and would constantly want to run me off the road - which is desirable on track, but less so on a country road).

 

Jez

[DougBaker]

Find somewhere to drive the car where you can safely lose control with nobody around.

 

I have done a couple of the Carlimits Activity days at North Weald in the past and for £50 you get a full day of playing with nobody following you if you spin. So no need to be anything other than sideways, it is great fun

 

There is one left in October ( I am going to this one ) and another in November this year. here should you be tempted.

 

 

[Grubbster]

One other observation - you appear to be taking the 'dry' line through the corners, not sure about Bedford but on many circuits the traditional line is very slippery in the wet so a wider line might find a bit more grip.

[Pendennis]

Yes, as your day progressed your helping the car to oversteer, but early in the video it clearly shows the car is tail happy with the inside wheel easily spinning up, thus you do not have an LSD. Turn in oversteer which you have could be caused by many reasons, but I suspect you have too much rake.

Your car looks a real handful to drive and would benefit from a proper setup

 

Cheers

Ian

[CharlesElliott]

Whilst the front camera view is pretty bad, here's me going from 10th to 3rd in a race. The throttle position is on the dash so it gives some sense as to how I exit from the corners.

 

Edited by - CharlesElliott on 13 Sep 2013 22:16:41

[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)?

[oldbutnotslow]

He Man

Firstly Spa is always wet

Secondly it is NO place to try sideways antics.

Its a massive track with some of the most demanding corners you will ever encounter on track. Many of the corners are seriously off camber and down hill.

I've see cars seriously damaged more times that I care to count even being driven by very experienced drivers so put any thought of "sideways action" right out of your mind.

 

Sorry --- lecture over.

 

6 years is the accepted normal life of a tyre so you are over that now regardless of tread depth remaining.

AO48's are fantastic in the dry but need serious care when wet. You only have to look at the amount of groves to realise that there isn't much to move standing water.

 

Frankly I would suggest AO21's. Almost as much grip but great in the wet.

 

Enjoy Spa--- Its the best track that you will ever drive!!

[HeMan]

I am not sure if I should be terrified or not!?

 

You see the problem with the A021s, and I can’t stress enough just how significant this point is; they don't have as cool a tread pattern as the A048!

 

I take it the ZZR falls in to the too cool to be good in the wet too?

 

But if it’s going to be wet, and it sounds like it will be, I guess something new will help out whatever it is...