Wider Track 205

[EdCherry 34 1 Cars]

damper angles also come into why the cars were widened. when putting 300bhp through the front wheels grip is the ultimate priority, and a vertical and at 90 degrees to the road damper (ie upright) doesn't surfice!

 

Why is that then?

[petert 585]

1:11:5 with an 8v! 1sec diference with half the horsepower, I call that an ass whipping!

Your ecu is now password protected.

[Sandy 191]

Simply widening the track alone, will not make the car quicker overall necessarily. The major issue with the 205 and similar chassis, is getting a good combination of front end lateral grip, traction and steering behaviour. Rear grip is more than adequate in almost every case, with the right initial geometry and spring rates, if the damping is sorted (either by better wheel to damper movement ratio or costly high spec dampers). Getting the front end to steer, grip and put the power down well, requires a much broader look at the geometry than just widening it. You need to tackle the major flexibility issues with the standard subframe and body, revise the pick up locations and pivots for lowered ride height, to restore a sensible roll centre range, dial out the bump steer as much as possible and strengthen the arm design. Rally cars that have had these issues properly resolved are very rare indeed and most pull all over the road hideously, wasting grip and traction. A C2 Colin had in recently had over 40mm of toe change in compression! We have lots of friends running very compromised chassis, that declare them to be fine; but with all due respect to them, you really don't appreciate how much difference it makes to have a properly sorted chassis, until you've sampled one!

[Henry 1.9GTi 36]

I think my megane has a wider rear track. Still goes sideways

I went wider front on my 205 by doing the 309 wishbones and added some 15mm spacers. Runied it. Took the spacers off and the steering was sooooo much better.

 

All wider track does is reduce weight transfer which will give you more grip due to tyre non-liniarity. But cars have been designed around there standard track so all the geometry works (ish) at standard track width. You also need to think about the wheelbase to track ratio and how you want to car to perform in differnt types of corners.

 

All in all I would say theres alot more to be gained in other areas than making the tack slightly wider. For a rally car the dampers are working overtime so would imagine this is the best place to start!

[amusingadam 6 1 Cars]

so to ask a few points is it worth fitting 309 wishbones as i called my local factors today and 309 arms are 35+vat each where as 205 ones are 44+vat each and would you need to upgrade to 309 drive shafts in order to accommodate the new arms

[Cameron 16]

I love that someone compared a Deltawing to a 205!

 

The distribution of tyre load transfer is what gives you your handling balance and ultimately your peak level of grip. Having a lot of load transferred from inside to outside tyre on an axle reduces the total grip available at that axle due to tyre non-linearity witchcraft.

 

Load transferred = Roll Moment (i.e. a torque) / Track Width

 

So wider track = less load transfer = more grip. Hurrah!

 

In a nutshell, assuming no other changes:

Widening the front track means less load transfer, which means more front end grip and increased tendency to oversteer - pretty much what you want in a FWD track car.

Widening the rear means more rear end grip, and a tendency towards nice, safe, controllable understeer - exactly what you want in a Skoda Roomster.

Edited June 30, 2013 by Cameron