Active Diffs - Where's the loss of performance?

[ST205GT4]

Was just looking back at some of the stage times for rallies from 04-07 and there has been next to no change in the winning times over the same stages.

If active diffs were so great how come their loss has had minimal impact on speeds?

I realise there have been advances in some other areas in the meantime, but there wasn't even a huge drop off in speed in the year right after they were banned.

[Daniel]

I can't say as I don't know but remember how Loeb was going to fall from the top because he wasn't able to drive without active diffs :laugh:

[J4MIE]

I'm probably wrong but wasn't it only active centre diffs that were banned? So ront/rear still are?

[Daniel]

I'm probably wrong but wasn't it only active centre diffs that were banned? So ront/rear still are?
I think it's the other way around :)

*Edit* yup it is

http://www.rte.ie/sport/motorsport/2007/1108/steeringwheel.html

[ST205GT4]

Ha yeah he's really struggled since then!

[jonkka]

Basically the same performance is available from passive diffs. Active diffs just make testing much easier as those can be re-adjusted in a fraction of the time required by passive mechanical units. The performance gain on actual stages is dependent on how well the initial diff setup suits to the stage and road conditions plus active units can be adjusted on the fly. Theoretically, active car should have some performance advantage but praxis might prove that advantage to be very small.

[Zico]

I can't say as I don't know but remember how Loeb was going to fall from the top because he wasn't able to drive without active diffs :laugh:

Shhh.. (embarassed smiley) :D I believe I was one of those predicting that.. due to wrongly believing that the active centre diff was also included in the ban.

[OldF]

If I remember right, David Lapworth said in an interview that the active diffs are about 0,1 s / km faster than mechanical diffs. Not much but 0,1 * 350 km = 35 s.

[ST205GT4]

With all due respect to Lapworth's much greater knowledge of these things, the timesheets aren't backing up his claims!

[Dingardo]

he was probably right.. but improvements in tyres, handling and power would mean that disadvantage was negated.

[Finni]

2006 Sordo drove active Xsara in Catalunya and Corcica. Then he stepped in passive diff Xsara for Germany and did his most convincing drive in the year. There was hardly any difference.

[ST205GT4]

I expected someone to pipe up with Dinga's ideas. However I refuse to believe that within 3-4 months of Loeb stepping out of his active Xsara and into the passive one they had made sufficient advances in tyres or magical engine technology to mask the loss of "performance" from active diffs.

In fact I believe that Citroen actually had some of their suspension components banned by the FIA (http://www.kinetic.au.com/oldernews.html). So in fact they were going backwards at least in that area.

Did Michelin suddenly develop much better tyres in that timeframe? Or Citroen a much more powerful engine? Active diffs look a lot the Emperor's New Clothes to me...

[Zico]

I expected someone to pipe up with Dinga's ideas. However I refuse to believe that within 3-4 months of Loeb stepping out of his active Xsara and into the passive one they had made sufficient advances in tyres or magical engine technology to mask the loss of "performance" from active diffs.

In fact I believe that Citroen actually had some of their suspension components banned by the FIA (http://www.kinetic.au.com/oldernews.html). So in fact they were going backwards at least in that area.

Did Michelin suddenly develop much better tyres in that timeframe? Or Citroen a much more powerful engine? Active diffs look a lot the Emperor's New Clothes to me...


The advantage was so minimal, ie, 0.1 sec per km... you should not expect to see a difference on the time-sheets.

[Daniel]

I expected someone to pipe up with Dinga's ideas. However I refuse to believe that within 3-4 months of Loeb stepping out of his active Xsara and into the passive one they had made sufficient advances in tyres or magical engine technology to mask the loss of "performance" from active diffs.

In fact I believe that Citroen actually had some of their suspension components banned by the FIA (http://www.kinetic.au.com/oldernews.html). So in fact they were going backwards at least in that area.

Did Michelin suddenly develop much better tyres in that timeframe? Or Citroen a much more powerful engine? Active diffs look a lot the Emperor's New Clothes to me...
You're only the second person on this forum to ever mention Kinetic :) The second being me. Perhaps I'm looking too much into it but I do think Kinetic were one of the factors that made the Xsara totally unbeatable before the system was banned. Not the sole factor but a factor nonetheless.

[pentti]

Members here should remember my utmost hate for active diffs. Two reasons. Delay and too abrutvive for traction. Good sensitive drivers like Colin and Tommi were destroyed with these systems.They reacted before active diffs started to confuse. It's long story why active diffs came but basically it is just because mechanics forgot how to use the file!!