Tail happy old Alfa Spiders
What causes an Alfa Spider S4 to be so tail happy and what can you do to improve things.
Before you imagine there is a chest of gold at the end of this rainbow... sorry I don't have the solution.
If anyone out there does then please save me.
But, for what its worth, here is the story so far.
Started this tortured trail with a 1991 Spider on old firestone 195/60/15's and standard running gear.
The back end was a little sloppy so the rear arm and trunnion bushes were replaced with new poly.
The end play was taken up by packing shims behind the trunnion pivot end plates. This sharpened the handling a little but only made it easier to get the rear to loose traction. Nice for drifting.
So time for new rubber... a few laps of the Nurburg car park soon showed the favorite for lighter cars to be TOYO T1-R's. But the T1-R does not come in 195/60/15. The choices were 195/55/15 or 205/55/15.
The 205/55/15 seemed the better option as the outer diameter is about the same as 195/60/15 - giving the speedo a chance of telling the truth. With 195/55/15's on the back the speedo is out by more than 12%, reading around 80mph when the sat-nav is at 70.
This introduced a nasty 'stepped' oversteer on both sizes, which I have yet to fix. Looks like the T1-R tyre walls are far too soft. The back end of the car can be wiggled sideways at least 3 inches each way! This doesn't show up much on normal roads. But on the track or with heavy cornering the back squats sideways causing oversteer and hitting rather than clipping the apex. So as soon as the T1's are paid their dues and done their miles it will be time for something a bit stronger - perhaps Bridgstone Potenza's...any suggestions ?
A recent spin round the Donington circuit gave the opportunity to try out another idea... It had been suggested that the roll of the car was causing too much load to be placed on the outer wheel and lifting the inner wheel. There is a stiffer front roll bar on the market that should help. But before that leap of cash, I followed another cheaper option... detach the rear roll bar ... and it may well have improved that oversteer a little. Of course, this did give some extra roll - So I guess next will be the stiffer front roll bar and tougher tyres. ...hope it works.
Hmmm. I am no Alfa expert (though I am sure many on here are), but given what you have already tried, perhaps it is a case of looking at suspension set up/geometry or better tyres. If your tail-slides are happening largly under load on 'spirited' or trackday driving, then you might want to invest in a set of Toyo R888's. Road legal enough to get you to and from the action and give you plenty of performance on track.
Years ago, when I was a member of the Alfa owners club they used to run driver training days at the old Oran Park circuit in Sydney. The instructors would take great delight in showing just how tail happy the spiders were. The second neatest trick was demonstrated during a threshold braking / pump braking exercise around some tightening cones to show the technique for countering understeer. Basically, you entered the cones a little too fast to induce some howling understeer, then pumped the brakes quickly to slow down and make the corner.
Invariably, the spiders would ALL spin out repeatedly, much to the amusement of spectators. The problem is (unfortunately) the nature of the beast. They are not really track cars as the "flexy flyer" chassis just isn't up to the task like the equivalent GTV. A heavy Alfetta is faster around a track simply because it's better behaved.
The best trick, of course, was to be howling around the track on the tail of an Alfetta or an Alfasud and back off at an inopportune moment, resulting in a flat spin into the centre of the track. Scary. Exhilarating too. It's just the car, enjoy it for what it is (a chick magnet, a lovely thing to look at, a brisk classic roadster, not a racer).