ALFAGTV6.COM

Photographic evidence has been unearthed revealing that under certain circumstances, 116 GTV6s (and mine in particular) have been known to hang the arse!

http://www.digitalrealism.com.au/ssa308 ... /index.htm

See shots 5912 to 5917 for the results of an oversteer slide through turn one at Morgan Park (a 3rd gear sweeper ) which needed to be swiftly dealt with before a 2nd gear hairpin at turn two. Amazingly, we hit the apex and nothing else!

Very nice photography also.

Of course, this was an anomoly as a result of over-driving and normal programming (ie understeer) resumed on the next lap! If only I had some shots of the wet laps later in the day - that was drift central!

GTV27 wrote: Amazingly, we hit the apex and nothing else!

Ha, I'll have to steal this comment and use it myself!

Bah! Lies!
Clearly the Torana had overheated and dumped it's coolant (tap water) all over the track. Every other car managed to miss it but the rear boots of the Alfa aquaplaned over the wet spot ( ) and adopted the "I'm a drift car too" attitude.

yea of little faith - no outside assistance required, was purely down to 'bad' driving... I LIKE driving badly - makes for good photos too!

But this raises a bit of a mystery for me - why does my car understeer on race tyres (205/55 14 Toyo RA1 on 14x6.5 twinspark wheels EP+30) but is nicely balanced on my road tyres (205/45 17 Michelin pilot preceda pp2 on 17x7.5 wheels ep+35)? And when I mean understeer, it is anything from a subtle widening of the line under power to a complete front end loss where you can wind the wheel around and NOTHING happens depending on how restrained I am on the throttle after turn-in.

Obviously the road tyres are a lot slower than the race tyres (couple of seconds a lap on a 2km circuit, which is an eternity), but the car is soo much nicer to drive on the road tyres, that I'm beyond caring about the time lost.

Its like driving on a slightly greasy track and the car can be drifted around and is really responsive to wheel and throttle - unlike the race tyres which grip and grip and then just stop turning and then I'm running wide, missing apexes, having to get out of the throttle and getting angry (understeer is evil )

Anyway, if anybody has any ideas, I'm all ears (well, given this is a written medium, all eyes )

With the race tires you are underpowered, you cannot break traction with power and when you try you only make the car push the front wheels. It's also easier to heat the front wheels then the rear so you mey be overheating the fronts but the rear ones are nicely warmed to opti-temp.
Street tires does not vary the grip to the same amount as the race ones so you dos not overheat as much, also the weight transfer is smaller with less traction so the braking heats the tires more evenly.

Capito?

GTV27 wrote: Its like driving on a slightly greasy track and the car can be drifted around and is really responsive to wheel and throttle - unlike the race tyres which grip and grip and then just stop turning and then I'm running wide, missing apexes, having to get out of the throttle and getting angry (understeer is evil )

Anyway, if anybody has any ideas, I'm all ears (well, given this is a written medium, all eyes )

I am no expert so I'll state the obvious: street tires are engineered to be forgiving, hence they give plenty of warning before breaking away. Track tires are for maximum grip at the expense of giving any warning. That's why professional racers get the big bucks, they can balance on that fine edge between grip and breakaway.

MALDI wrote:I am no expert so I'll state the obvious: street tires are engineered to be forgiving, hence they give plenty of warning before breaking away. Track tires are for maximum grip at the expense of giving any warning. That's why professional racers get the big bucks, they can balance on that fine edge between grip and breakaway.

Well, race tires that doesn't give you any feedback arn't going to get any use. No-one would buy them!

Race tires give plenty of feedback, once you learn to listen. Going back to street tires is quite interesting, while the race tires give you feedback in a kind of conversational fashion the street tires is like a hysterical person in a state of shock (all screamiing an not really helping at all). But it's still fun to scare the other guys I share the commute route with, they are getting a bit blasé now though. They have stopped trying to "brake" from the passenger seat (just punching a hole in the air with their feet) going into roundabouts and doens't scream like little girls when the rear step out.

Mats great to read you drive like a proper Alfa driver.... I was starting to get a bit worried there.

At a track day I couldn't really give a you know what about ultimate lap time as I know Ferrari are not going to phone me to take over from Kimi for the last few races. Hence road tyres are my prefered choice and my wallet agrees with me.

I enjoy the almost neutral balance you get along with the 'hysterical screaming' and hearing passengers ask 'Do the brakes still work ?' It's all for the fun of driving.

Side line,my favourite chirp from a passenger was 'I never knew a road car could corner that fast.'

And that was in my BMW 525TDS Touring...

thanks for the feedback - plenty to think about there.

I think if I tune my balance for the race tyres (ie dial in more oversteer), it will be too unforgiving on road tyres (and more to the point, on the road). Yet more compromises....

I'm glad to hear I'm not the only one who likes sliding around on road tyres - better for my wallet too .

Mats wrote:And that was in my BMW 525TDS Touring...

hehehe, I've had this one drifting (love those off-road tyres) just don't tell my wife!

Jason,

I dont think the explanation is just a simple comparison between race and road tyres. The reason I say this is because I have had the same type of handling issues with my 3 litre GTV6 using only road tyres. Unpredictable undertseer. Almost like tramlining straight ahead. The more the LSD gripped the rear, the faster I would plough straight ahead.

I changed brands of tyres from Fulda to Yokohama and reset the front end with half the camber I had before. It absolutely transformed the car. It now handles very well with plenty of feedback all round.

Now this suggest to me that the geometry is very sensitive to specific tyre characteristics and makes it all the harder to make a road car into a track car if you want the ultimate performance in both instances-I think your situation is suffering from that problem.

To carry this a bit further, should you settle on a tire choice BEFORE you start tweaking your suspension? Or at least expect to make changes (perhaps some major) each time you change to a new brand or model of tire?

(For the sake of discussion let's call minor changes things like alignment and tire pressure, and major changes thinks like spring rates and roll bars.)

Minor, as long as we are not talking about going from Le Crap to El Fantastico or vice versa.

Lucky we have only one type of semi slick here Bridgestone RE55 so you just work on minor changes ie tyre pressure. One thing nice about semi is that understeer is very controllable as you just back off slightly and you got grip again. On road tyres with same set up I have found if you back off slightly the back suddenly shoots out never to be caught again. Road tyres scare me on the track. technically speaking if you have done your braking and you are accelarating to the apex(or just past apex) then you should eliminate most uncontrollable situations(or ploughing straight ahead) . Easier said than done.