Track tyres??

[malcolm]

My second trackday this year was the Red Rose Anglesey event last weekend.  Really flying (after the track dried in the morning).  The vented Capri brakes/greenstuff pads are great and car feels really taught (uprated/lowered/polybushes,etc).

 

The limiting factor (apart from the driver) would now seem to be the standard Avon road tyres.  I'm running 15" MGF wheels.  Is there a softer 'semi-race' tyre I could go to for more grip.  I'm only doing 6k miles or so a year.  Or am I really looking at different set of rims for track use?

 

Still a few thousand miles until they need replacing, but it has got me thinking.....

 

Malcolm.

[JRCWeedon]

This is the second time I have attempted this post I can almost guarantee that when I do one of any length the system decides to dump it!!

As you might imagineI have a certain amount of experience over the years of sticky tyres.

Maxsport Intermediates - remoulds but do not let that put you off very sticky cheap (about £50) but limited in sizes. I use 195/55 x 15 but you can get their semi slick in 205 which is useless in the wet.

Avon CR6ZZ equally good but expensive about £110 each they do a 205/50 - look like truck tyres but grip wet or dry.

Yokohama AO32R harder rubber but good all round tyre in a good range of sizes.

Good Hunting

John

[clive]

Malc,

 

Brake hard, go slower into the corner, turn in later (it feels like far too late), and power on as you unwind the lock and you'll come out faster in a straight line and use all of the road... erm, or end up over shooting, one of the two!

 

Otherwise, buy F1 car... hehe!

 

As for tyres, the TR Register series has a set supplier I believe... why not ask one of those boys?

[malcolm]

Thanks for the advice chaps.  I'm quite sure my technique will continue to improve, and that this will help my lap times.

 

In the mean time I perceive the most obvious limitation of the car (for trackday use) to be tyres.  More grip under braking, and whilst "putting the power on as I unwind the lock" will help I'm sure.

 

Malcolm.

[stephen cooper]

Having borrowed a set of 32rs for anglesey myself, they were a massive improvement over my road going avons! However apparently they wont last long 2-3000 miles at a guess? especially with your v8 power!

[jemgee]

Stephen

 

Now I know why i was struggling to catch you - my 6 is on old Firestone 660 on the rear and the grip wasn't there until they were good and hot!

[stephen cooper]

Yep, don't think mine got hot enough either, should have ran lower pressures maybe. After a while I'd had enough of having to go flat out down the straights all the time, was much easier when the track was damp!

[MikeyTT]

If your looking for traction then the Yokohama 32Rs are pretty damn good. Don't know how they will last on the road as I only run with them on the track. They have massive amounts of grip on the track tho.

 

As a matter of interest are you running a rear anti roll bar? What poundage are your rear springs?

 

These two can have a massive difference on rear end grip. Certainly for track use.

 

For my Green and Yellow racer I was advised that 200lb rear springs are the way to go. And for those that saw me at Anglesey will know how quick and early I was on the power. I also don't run with a rear anti-roll bar, which helps the trction no end.

 

Thanks to a certain very fast yellow championship dominating driver and owner for that snippet of info  

[malcolm]

Thanks for the replies.  32Rs look like a good track tyre.  Anyone tried 21Rs?  Apparently they are almost as good for trackdays and have a longer road life?

 

Interesting questions.  I do still have the rear anti-roll bar (are you really suggesting I might remove it).  Also using 200lbs rear springs.  I'd be really interested to know what front springs you have.....

 

I have to keep the car practical for road use too, but with a low annual mileage I'm very tempted by such road/track tyres.  I'll check out the costs.

 

That certain yellow V8 is quick though isn't it!

 

Malcolm.

[Cinnobar]

Malcolm, I don't run with a rear A/R bar and it does help traction. I left it off after the rear suspension rebuild after I read about it on one of the Septic sites I subscribe to. I don't think many do though cos Simon at Robsport questioned it when I told him during the rebuild.

I'd really like to try a stronger front one but that will have to wait until the car comes back.

Using the suspension theory learnt after the years of being involved with cars I can't see that it does very much anyway especially if you run with poly bushes all round on the back. I suspect the whole back axle is running as a roll bar and thats a damn sight stiffer than a bit of half inch bar!

Jim

[andrewt]

The roll bar question gets very interesting very quickly. I don't run competition bushes on the back. Instead I have rose jointed the entire rear suspension. This means excellent location but no roll resistance due to fighting the bushes. This can be proven by removing the springs and shocks before picking up one end of the axle. It can be lifted through the entire travel at one side simply by taking the dead weight of the axle. (Jim is right in that the stiffer bushes act as a rear anti roll bar by transferring torsional loadings into the body end of the axle links.)

When the car went back on the road a month ago I briefly tried it without the rear bar. I found this was giving me loads of understeer in most conditions though it felt very stable at speed & rear traction was excellent. One option was to reduce the front anti roll bar to offset the difference, but my concern with this was ending up with too much body roll in the dry. For the moment I have put the rear bar back on and this has evened out the understeer, though it is still arguably a little too willing to slide either end in the wet!

The theoretical ideal is not to use a roll bar at either end and to adjust the spring & damper rates to get the ideal handling compromise, however this tends to lead to poor ride comfort. Most road cars use a softer spring for comfort and add roll bars to help whilst cornering. The idea being the roll bars have (very little or) no impact whilst both wheels ride a bump together. This should maintain a compromise between ride quality and handling. Most of the people on the forums will probably do well to keep this compromise, as the other option is most often best suited to outright track or competition cars.

Its always interesting to experiment though as different drivers react differently to the same settings and the driver having confidence in the car is one of the most important ingredients to rapid progress.

 

Have fun

Andy

[Guest ajttriumph]

I run falken tarmac rally tyres as my "wets" 205 50 15 on my 8 they are vey good and you will get 5000 or so with them, i have found that aqualplaning becomes an issue with wider tyres on the 8.

 

They are as good or slightly better than the A032R's in the wet but not as quite as good in the dry the big benefit being they are half the price, if you are flush with funds it is hard to go past A008R's as a (barely) road legal semi slick for the dry, diabolical in the wet though.

 

For hillclimbs & sprints i run 400lb front 250lb rear with sway bars.

 

For racing 500lb or 600lb front (depends on quality of surface) and 350 rear no rear bar.

 

Without adjustable shocks not much point going past the 300 front and 200 rear.

 

You are at the point of no return malcolm, the above 8 though still street registered can really only be driven for short distances before the hard ride becomes unbearable.