Rally Cars tech stuff

[Rallyper]

Hi
Some points regarding bodyshell and wheel geometry.
A stiffer bodyshell is almost always an advantage, in general the stiffer bodyshell the softer and more precise all wheel setups will be and also alot more sensible to fine adjustments. It`s almost impossible or very difficult to use the chassis softness as an advantage. Think of it: how can you adjust the chassis stiffness.

For sure. I didn´t mean stiffer bodyshell would be bad. Just that in very slushy conditions you really can tell what a stiff suspension can do to the handling, when as i RMC, you have tyres that are not apropriate to the weather conditions...

[br21]

for some years now M-Sport cars were designed with more body roll than other cars. it's because of mounting points of the suspension, but also because of softer springs, dampers, etc.

[AMSS]

True, but after NORF pre event test last year they visibly stiffened the setup on the cars based on drivers demands, and the results were instantly better as well..

[makinen_fan]

for some years now M-Sport cars were designed with more body roll than other cars. it's because of mounting points of the suspension, but also because of softer springs, dampers, etc.

I think suspension mounting points would have to be more associate with body pitch than roll. Body roll is controlled by spring rate, ride height and antiroll bars. But the pitch has a lot to do also with suspension geometry and anti-dive characteristics induced in wheel kinematics (i.e. wheel moving backwards/forwards as it moves up/down).

Also I am not sure if this was the case with Focus vs C4. I remember C4 being softer generally than the Focus, especially diving under breaking.

[Plan9]

Have M-Sport developed a Fiesta R5+? If so, what is the main its main point of difference from the R5?

[Mirek]

Have M-Sport developed a Fiesta R5+? If so, what is the main its main point of difference from the R5?

What it shall be? There is 3 years long homologation cycle for R5 cars. They can not come with some big changes in such short time period. If You speak about FIA events...

[stefanvv]

There is R5+ already for British championship I presume, Wilson junior tested it last year on some event. Probably he meant that, yes it is developed, but I have no idea will be used by someone. Concerning differences, I think it had bigger restrictor and 6 speed gearbox AFAIR.

[br21]

R5+ is something similar to S2400, I mean planned for promotion/national events, etc. R5+ kit contains bigger turbo, bigger restrictor, etc. M-Sport plan to have conversion kits available for customers, but AFAIK those kits are not ready yet.

[Juha_Koo]

True, but after NORF pre event test last year they visibly stiffened the setup on the cars based on drivers demands, and the results were instantly better as well..

I'm really waiting for Mexico (and especially Portugal) to see Mikko's speed on gravel... Interesting to see whether he'll use the new stiffer setups or go back to his old ones.

Focus was supersoft, I remember one corner combination over crest and through a dip in certain testroad. In 2010 Focus bottomed basically every time (the plastic/carbon fibre piece behind front wheel arc was destroyed during the day) through that corner/dip. A year later Fiesta seemed to be a bit harder as it didn't bottom out on any of the runs I spectated there. Corner here in 1:58: http://www.youtube.com/watch?v=VWTIxREKX-M#t=119 (usually the line was a bit more from inside). Compare with Focus: http://juhake.kapsi.fi/JML_Day2/album/ 6th and 7th picture.

[Mirek]

There is R5+ already for British championship I presume, Wilson junior tested it last year on some event. Probably he meant that, yes it is developed, but I have no idea will be used by someone. Concerning differences, I think it had bigger restrictor and 6 speed gearbox AFAIR.

R5+ is something similar to S2400, I mean planned for promotion/national events, etc. R5+ kit contains bigger turbo, bigger restrictor, etc. M-Sport plan to have conversion kits available for customers, but AFAIK those kits are not ready yet.

Thanks You both.