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Re: modern rally cars
Dave Eaton wrote:
> well for the rally geeks in the world, nz has just hosted it's round of the fia
> world rally championship. as usual i did the rally-geek thing, although having
> to get back to work from holiday meant that i missed 2 days of it. fwiw, subaru
> 1st (erickson), ford 2nd (sainz) and 3rd (juha kk) and mitsibushi 4th (burns).
> i got talking with a chappie from the mitsibushi team who was a little
> underemployed (due to tommi makkinen rolling out on the 1st day). he had some
> interesting things to say on the modern rally cars.
> 1) weight distribution is as much a problem today as it was in the group 'b'
> quattro. most of the modern wrc cars are about 50:40 f:r distribution which
> isn't ideal. a lot of effort is undertaken to try and move the engine mass
> back behind the front axle line, although with the regulations stating that the
> crank can only be moved 20mm from original, most teams tip the mill backwards
> (towards the firewall) to improve things. other thing is to try and get the
> weight down low.
> 2) speed on the special stage (significantly faster now than the group 'b'
> cars) is mostly due to improvements in suspensions and transmissions. remote
> dampers (mostly bilstein) allows quick cooling of the shocks and very
> sophisitcated valving and differing rebound rates etc account for the rest. no
> rocket science because, although more science is becoming involved, it is still
> a matter of extensive testing and trial and error.
> 3) transmissions are still developing rapidly. ford have debuted the 1st
> sequential gearchange and toyota will follow bu the end of the month. these
> units are being provided by xtrac and will allow clutchless gearchanges (engine
> ignition is cut for the instant of the change) in about 1/500 of a second (yes
> thats right) via either a paddle, joystick or convential fore 'n aft lever.
> while f1 gearchanges happen in about 1/1000th of a second, thats still pretty
> 4) active diffs are getting more sophisticated all the time. surprisingly a
> lot of centre diffs are still fixed ratios with active front and rear diffs
> tied to acceleration sensors on each wheel. software control is becoming more
> sophisiticated all the time. didn't get much information on this side of
> things because of the intensive development all the teams are undertaking.
> 5) all the engines are much the same. anti-lag systems mean that their 300+hp
> is more usable than the 450+hp of the group b cars. work going on with
> scavenge systems and low friction, as well as ways of improving torque and
> final coment. these cars are fast. picture a car on a rock hard road covered
> with small gravel (aka marbles) going flat out on the straights in 6th gear at
> 200 kph! these guys are totally committed and are having to drive flat out on
> every special stage. brings back fond memories of 1985-6 for me. the end
> result after 3 days of special stages had subaru 13 sceonds in front of ford
> with the other ford 6 seconds further back. that close.
> '95 rs2
> '90 ur-q
You think you are a rally-geek ?
I go from New Jersy here in US on my anual rally trip to England
during our Thanksgiving. I start in Chester spectating the RAC rally and
following it around Northern England. I get service passes and watch
service. Than I visit preparation shops and purchase parts for my Celica
GT4 rally car (Clubman GrA). Than I take at least 3 days of one on one
rally schools. This year I hope to learn from Mark Higgins and his family
at Forest Experience rally school. This year I also hope to purchase a
rally transmission (not XTrack but a modifyed Toyota unit).
I like visiting England. Majority of race and rally parts and cars are