Hello from Antony Warmbold

[Antony Warmbold]

Write something about suspension, tire pressures maybe? Basically a "How to set up a WRC car"

Hi,
It's pretty big subject. If you want we can talk on the forum. Anybody who has specific questions I can try to answer.

Tire pressures usually hovered anywhere between 1.8 bar and 2.2 bar cold at the stage start. Depending on which surface and which tires you had. I was starting stages in Catalunya with 1.8bar cold and if I remember correctly at the stage end it was not unusual to see the pressures at 2.5bar. That was with mousse. Today they might do a little different.
We put the same pressures front and rear.
On rough gravel rally I was a bit afraid to start stages with 1.8bar. So I started with 2.0 for a bit more safety in the first few kms. It's easy to knock a tire off the rim when it's got low pressure. it happened a few times to me, usually on the rear and usually when you hit banks or things like that. So either you watch out for them in the beginning or you don't care. It's a risk worth thinking about.
i had always been thinking that maybe it would have been a good idea to use a specific gas instead of air in the tires.

[SubaruNorway]

They must be using nitrogen now since it doesn't expand when it gets hot like air?
Nokian supply some new tires to where i work with that anyway, i think it's only been on winter tires.

I've always wondered how the steering feels like, is it lighter than in a roadcar?

[Antony Warmbold]

Yes, from what I have heard Nitrogen behaves more steady than air when it gets hot. I asked the tire man in the team about it once and he told me they were just using air. I would not be surprised if somebody uses nitrogen nowadays, if allowed by regulations, as it would in my opinion really help on hard surfaces.

The steering, mainly, has another ratio, which makes it more direct. So you turn quite a bit less the wheel than on a standard car. This is really useful. As far as the power steering is concerned, it depends from car to car. On the corolla wrc it was very light, to a point where you could not feel the road so well. I did not like it very much and I always thought you ended up steering too much just to look for feeling the grip.
on the focus the steering felt much better. I thought the feeling for the road was just enough. The Mini felt just right as well.
You can get this difference from road cars as well, some have more light feeling than others. It's important that the engineers get it just right, with help from driver's feedback, so you can feel the road and the grip.
Compared to a road car, I would say that it depends on the road car, but on the rally car you don't feel every rock on the road as you do in a road car. i would say the steering feels more robust than a road car. If you drive a rally car in ruts, for example, you don't get bothered at all.

This "getting it just right" also applies for the brake pedal. The skoda wrc that I tested once gave me absolutely no feeling whatsoever from the brake pedal. it felt like you were pumping air and it was very difficult to judge how much to push on the pedal. That car must have been extremely difficult to drive in slippery conditions as far as braking is concerned. In my opinion everything in a rally car has to be optimized that it gives as much feedback as possible from the road and the grip to the driver. So steering and brake pedal are VERY important for grip feeling.

That is why in my opinion a new team who wants to develop a car must, at all costs, hire drivers with experience from TOP cars as they are the only ones who know from experience how good a car can be and should be.

[Antony Warmbold]

Yes, from what I have heard Nitrogen behaves more steady than air when it gets hot. I asked the tire man in the team about it once and he told me they were just using air. I would not be surprised if somebody uses nitrogen nowadays, if allowed by regulations, as it would in my opinion really help on hard surfaces.

The steering, mainly, has another ratio, which makes it more direct. So you turn quite a bit less the wheel than on a standard car. This is really useful. As far as the power steering is concerned, it depends from car to car. On the corolla wrc it was very light, to a point where you could not feel the road so well. I did not like it very much and I always thought you ended up steering too much just to look for feeling the grip.
on the focus the steering felt much better. I thought the feeling for the road was just enough. The Mini felt just right as well.
You can get this difference from road cars as well, some have more light feeling than others. It's important that the engineers get it just right, with help from driver's feedback, so you can feel the road and the grip.
Compared to a road car, I would say that it depends on the road car, but on the rally car you don't feel every rock on the road as you do in a road car. i would say the steering feels more robust than a road car. If you drive a rally car in ruts, for example, you don't get bothered at all.

This "getting it just right" also applies for the brake pedal. The skoda wrc that I tested once gave me absolutely no feeling whatsoever from the brake pedal. it felt like you were pumping air and it was very difficult to judge how much to push on the pedal. That car must have been extremely difficult to drive in slippery conditions as far as braking is concerned. In my opinion everything in a rally car has to be optimized that it gives as much feedback as possible from the road and the grip to the driver. So steering and brake pedal are VERY important for grip feeling.

That is why in my opinion a new team who wants to develop a car must, at all costs, hire drivers with experience from TOP cars as they are the only ones who know from experience how good a car can be and should be.

[Barreis]

What's new about you and the mini project?

[Antony Warmbold]

What's new about you and the mini project?

To be honest, I would need support from whoever wants to be part of that adventure, to help make it happen.

[Tomi]

A little off topic, but you Antony might know, did Mazda Rally Team (Europe) have any collaboration with Mikael Sundströms Muurala Motors in the past? I was just thinking becaus he did build good cars as well.

[OldF]

Antony, how did you evaluate the braking points and grip?

What kind of damper adjustment did you use for different surface and roads (fast/slow bump/compression and fast/slow rebound)?

What kind of camber and caster adjustments for different surface and roads?

Btw, have you been reading “Driving style evolution” thread? Would be nice to read some comments from you about that topic.

[Antony Warmbold]

A little off topic, but you Antony might know, did Mazda Rally Team (Europe) have any collaboration with Mikael Sundströms Muurala Motors in the past? I was just thinking becaus he did build good cars as well.

I don't know of any specific collaboration.

[Antony Warmbold]

Antony, how did you evaluate the braking points and grip?

What kind of damper adjustment did you use for different surface and roads (fast/slow bump/compression and fast/slow rebound)?

What kind of camber and caster adjustments for different surface and roads?

Btw, have you been reading “Driving style evolution” thread? Would be nice to read some comments from you about that topic.

I evaluate the braking points with my gut. The moment that I start the 1st stage of the rally, on gravel for example, I already feel the amount of slip under my tires as I accelerate. This gives me an idea for braking distance. Then very soon in the stage I purposely went past what I imagined was a braking point, just to see. Many times it turned out there was more grip than expected so I just pushed the limit until a few corners later I got it and continued like that. So basically I had to scare myself a bit right at the start to find where the edge was. I found that, if I did not do that, I easily fell into a false rhythm.

I am in Finland now and I don't have any spec sheets so it's hard to give an answer for geometry specs.

As far as I know there was different specs of dampers used for different events. I don't know if my dampers were systematically the same as the factory cars but I know that I had settings that were harder than the recommended settings. Because I was looking for stability and re-activity from this car which was very difficult to get.
Those shocks were very, very soft. I could change 5 or 6 clicks on them and not feel a darn thing. Completely different from the Ohlins in the Corolla wrc where 3 damper clicks changed the car behavior radically.
It literally took something like 8 clicks on the focus before you started feeling the shocks were even there and so, if I remember correctly, I sometimes had settings that were 10 or 12 clicks harder than some, which was almost half of the total clicks you could play with.

There was 3 settings on the dampers. High / low speed compression and rebound with a single speed. I had never heard of fast rebound yet at the time. I don't remember specifics in terms of the high and low compression, all I can tell you is that I changed them around until I had something I judged was stable enough. The rebound was very open on rallies like Sweden because you wanted the wheel to follow the ground as much as possible. Although If there were jumps like in Finland you had to keep the rear rebound somewhat closed because otherwise the spring was too eager to kick the car's behind up in the air on take-off, which would result in a nose dive and a nasty landing.

On gravel the usual springs were linear with 30 kg on front and 25 kg on rear.

In 2005, before Neste Rally, I got to test the car for a few hours in Finland, and I was invited to try springs that Mikko had liked which were 30/21. basically softer on rear but same on front. This changed the car balance a lot and made it more under-steering. I was then able to drive much more aggressive and not lose the rear in endless slides. It suited me and the times were systematically quicker with this other balance.

I think somebody mentioned how a car needs to be under-steering, to be safe to drive, on the drivingstyle thread. That is true, as far as I am concerned.

It comes to a point where you have to attack and be SO aggressive and fast into corners that it is impossible to keep a neutral car or over-steering car on the road. You must set it up so the rear is "lazy to come out" and then when you push hard enough it will be just fine. If you try different setups and change the car balance like from 30/27 to 30/21 you will notice the huge differences in stage times and driveability.