Hello from Antony Warmbold

[Rallyper]

Yeah, we want part two ASAP. The assembly of the car.

[br21]

Hi Tom, I watched it with interest. They speak about rebuilds etc. Nothing special for me there. I would have liked more info from the gearbox man... I noted from the damper man that the smaller spring is indeed a helper spring and not a tender. Therefore it seems M-Sport is still using a linear spring suspension system. From 10:32 the ride height adjuster was interesting. He says the driver resets it inside the car..."obviously when he is stopped (with a smile)..." The 2004 Focus had a ride height adjuster which was driven by a pump and controlled by buttons on the steering wheel. I understand that nowadays it's supposed to be manual so I wonder how you reset it from inside the car (straight forward question). Maybe they handle a manual hydraulic pump somehow. The turbo part was interesting as well. 155.000rpm, 1.000°c, 70L/sec, 1.000km before rebuild, 2.000km on test car...

All in all a cool video!

Yes, they use linear spring. Small one is helper. Sometimes on tarmac they use additional, very stiff tender, so then 3 springs in total.
Ride height adjusting canister allows lifting the car two times. Then needs to be charged which is done during the service. It is operated manualy - by hand.
Turbo figures sound rather typical, so nothing special.
But I also agree that it's pretty interesting movie.

[Antony Warmbold]

Attached(hopefully) some pictures, in the picture from the trunk you can see the adjuster unit. It's the black tube by witch turning you hydraulically adjust the ride height. Basically you just turn a piston that increases or decreases the spring bottom. Rules prohibit adjusting when driving so that's why the adjuster is situated in the trunk and in the engine compartment on the fiestas.

Thanks a lot for your input! I see the ARB (purple rod) as well! It did not pass inside the trunk on the 2004 Focus.

[Antony Warmbold]

Yes, they use linear spring. Small one is helper. Sometimes on tarmac they use additional, very stiff tender, so then 3 springs in total.
Ride height adjusting canister allows lifting the car two times. Then needs to be charged which is done during the service. It is operated manualy - by hand.
Turbo figures sound rather typical, so nothing special.
But I also agree that it's pretty interesting movie.

I think on the 2004 Focus the ride height control system had an amplitude of around 30mm (gravel). Are they getting similar figures today?

[Lundefaret]

Hello Antony, regarding the springs. I would think that a progressive spring set up would be helpful getting one over the treshold, but still maintaning a stiff a spring as possible, what do You think about that?
The tarmac tender, what is the mission for this?

[Antony Warmbold]

Hello Antony, regarding the springs. I would think that a progressive spring set up would be helpful getting one over the treshold, but still maintaning a stiff a spring as possible, what do You think about that?
The tarmac tender, what is the mission for this?

Hi Lundefaret,

Please clarify "getting one over the treshold".
Do you mean "one" --> the driver?
"Threshold" ?

Thanks,

[Lundefaret]

Hi Lundefaret,

Please clarify "getting one over the treshold".
Do you mean "one" --> the driver?
"Threshold" ?

Thanks,

Hello Antony, tanks for taking the time

One= the driver

Threshold: The point that must be exceeded to begin producing a given effect or result or to elicit a response.

I am talking about the threshold of the suspension set up, wich You must exceed to get in to the "working area", "scope" (need a good word of the suspension.

The most common mistake regarding threshold is to put it to high during testing, because You know the road by heart etc, and can push more/put more load in the suspension, but then be surprised when the car dont turn at all on the first stage of the rally proper.

Using a two spring system (or a progressive spring) where one is softer should in my mind lower the initial threshold, making it easier to reach the threshold proper.
This would come with a downside, and that is that it will take a little longer to reach the maximum of the suspension, and that it will lead too a little more (as much as the softer spring/part of the spring will allow) movement in the car, wich has both upsides and downsides.

What do You think about this?

About the tender: Is that a bump stop off sorts?

[br21]

Yes, in recent versions of Fiestas - WRC, S2000 and R5 rear ARB is going inside the trunk of the car. Only difference is in R5 it's solid rod, in WRC/S2k it was pipe (with hole inside). Also in R5 you have two possitions to adjust ARB blade.
I don't remember exactly, but that adjustable suspension should be around 30mm also in recent cars.
Tender spring is very rare, way more often progressive spring is used, but not in case of Reiger/M-Sport combination. Sometimes they use very hard tender on tarmac, but only in specific situations and not with all drivers. It has very small working range and is working only when main spring is fully loaded - so under braking or on long corner.

[Antony Warmbold]

"One= the driver"

--> ok!

"Threshold: The point that must be exceeded to begin producing a given effect or result or to elicit a response.

I am talking about the threshold of the suspension set up, wich You must exceed to get in to the "working area", "scope" (need a good word of the suspension."

--> ok, got it thanks.

"The most common mistake regarding threshold is to put it to high during testing, because You know the road by heart etc, and can push more/put more load in the suspension, but then be surprised when the car dont turn at all on the first stage of the rally proper."

--> ok.

"Using a two spring system (or a progressive spring) where one is softer should in my mind lower the initial threshold, making it easier to reach the threshold proper.
This would come with a downside, and that is that it will take a little longer to reach the maximum of the suspension, and that it will lead too a little more (as much as the softer spring/part of the spring will allow) movement in the car, wich has both upsides and downsides.

What do You think about this?"

--> I see what you are saying. I can only speak as a driver with a driver's point of view. Let's say I'd sit in a new car for the first time. The engineer in charge of the test would tell me "...yeah we put our development driver's settings in...have a go and we take it from there..."

From that point on I will just drive up and down at rally speed and look for improving the stage time (If I am specifically testing for that) ; look for improving the handling - confidence aspect ; test for behavior on jumps, bumps, cuts, braking, etc. Then there is the whole game of testing with specific tires after a tire regulation change for example.

So when I test I am not thinking about "...is my setting allowing me to reach the threshold?" In my viewpoint this is something an engineer worries about.

I am thinking "is my setup allowing me to go faster than my reference time and do I feel good about the car?"

Because at the end of the day if an engineer puts a ridiculously soft spring and damper on my rally car I will be sitting on the bump stop when leaning on my tires in first corner and result will be immediate loss of grip and/or spinning. Or if it's a jump we'll both loose our teeth on it. So I'll tell the engineer "something is wrong I cant do any speed in corners". but this sort of scenario never happens. My dad has stories about this from seventies but it's not happening since a long time in professional teams.

On the 2004 Focus I never ventured far from the factory driver's setups because their theoretical setup was very good, totally driveable. I had a 4N softer spring on rear with a very thin ARB because I wanted more grip on the rear (understeering car) because I had precise notes and I knew exactly where to go and hence could go more aggressively in corners and more grip on rear suited my driving style. I also had harder low speed settings on dampers because I felt the car better. Then we ran slightly modified Markko Martin spec diff maps and all the geometry / ride height was standard.

When you speak about drivers having a wrong setup for the rally; from my experience what I saw was a tendency for drivers to go softer and softer with dampers...because yes when you know the test stage by heart and anticipate every aspect of the road you can indeed improve the time by going softer and looking for traction. In the rally however, you are on 350km of stages recceed twice at 70kph in an airport rental car so your rally car will for sure feel like a lazy donkey which "is out of balance" and "bumps through on the rocks" with your airpump suspension which feels like you are on a 30ft sailboat in middle of Atlantic.

About the progressive springs I have always believed there was a reason why Tommi Makinen won 4 championships in a row, apart from his skills. I heard him speak about how his car (mistu) had "the perfect balance between suspension and transmission". When he started in our Mazda's we had progressive springs and he went on to Mitsubish eventually with our engineer who took that knowledge over there.

Unfortunately I never had a chance to test them on my cars so that's about all I can tell you about that.

My personal belief is that Ford sticks to linear because they are convinced their damper does the job. Maybe they tried progressives and it did not work better.

All I know is that for MAZDA, finding the right springs meant lots and lots of custom orders from EIBACH with different specs of ramps etc before finding the ones that worked. Also Ingvar Carlsson and Timo Salonen had a real knack for testing those.

So who knows, maybe they are right.



"About the tender: Is that a bump stop off sorts?"

-->here is explanation of tender: http://wrcbehindthestages.blogspot.n...prings-co.html

The bump stop is something else which prevents damper damage on heavy impacts.

I hope all this makes sense to you!

Regards,

[SubaruNorway]

Anyone got a WRC wheel alignment printout, gravel/tarmac anything will do.

Would be interesting to see and to compare with RSRBR.