Has anyone tried...

[After_Shock]

Thats the thing hows their a risk!? It makes no sense at all, if theirs more grip its going to protect things more, as I said the engines have exactly the same rev limit regardless of tyres.

F1 engines are amongst the highest strung in the world but use probably the stickiest tyres in the world and if that theory is true why are they not all running around on £75 Falkens to protect their engines? (major exageration I know).

[Wobbly Dave]

I never actually said engine and even so it has nothing to do with the rev limit, in my mind.

It is not just that bit that has to deal with the power. What's right for me may not apply to others.

[After_Shock]

The C70 was almost identical to the spec your running now so that was on the edge aswell however that ran slicks for a good while without a problem, ive tried looking at it from a few angles and I still cant see how it would push anything over the edge or put anything at risk!

[pyrotechnictigger]

The theory is sound. Once the engine pushes over the grip level of the tyre, the grip is releases as a function of spin. Acts like a safety valve. If the tyres dont spin, the drive train as a whole is under max possible load. The more torque the engine generates, the more load on the drive train. Whether its enough to break anything is a different matter, but it is theoretically sound. If not spelt correctly

Thats my 100th post BTW

[After_Shock]

Well done on the 100th!

True but as you say how could that damage the car and if the car is that fragile that it could be caused to break simply because of tyres they shouldnt be tuned to that level.

But what happens when the car has less grippy tyres on and constant wheelspin is happening, that will put more stress on the components than actually having the grip?

[pyrotechnictigger]

Nah because the engine is running free with much less load.

[After_Shock]

First time ive heard of grip being a bad thing, starting to see were your coming from but if things are that fragile the cars shouldnt be running so close to the limit, personally if it was that close I think it would break either way as eventually less grippy tyres will get grip and increase the load.

Also whats the point in having the power if you cant actually use it as with that theory having the grip to get the power down the car will get damaged.

[Ross9]

Theory is that in the lower gears where the torque forces are stronger on the car the tyres slip and let it dissapate, higher gears the force on the shafts etc is less at the same rpm and boost so it dsoesnt matter that its gripping now.

I read Daves original post as he was saying the engine could break as it was tuned to the "edge" and the tyres gripping and increasing load woul dbreak it. Which I fin dhighly doubtful

I think what he actually meant was that the power output of his car is enough to warp a shaft, break a cv etc if the tyres gripped. Which can happen, but I would be surprised if it were to occur.

I'm pretty sure the T4 will be fine and dandy.

Ross

[JUDGENINJA]

I asked the same question to a tyre specialist after I ask to price up a set of slicks for my two spares in preparation of Avon Park earlier this year. The response I got from him was "DON'T DO IT, you'll damage your car" ...
This made me curious to find out why...

Basically the interpretation I made was :
the engine transfers all it's power to the clutch...
which then transfers power to the gearbox...
which then transfers the power to the driveshafts...
which then transfers power the wheels.
In return the increased grip level of a slick tyre would transfer alot of the stresses back up the drivetrain system

Which component actually gives way first would be down in the lap of the gods, but which ever weak link your car has it would find it.

I wouldn't say don't do it, but if you do beware of the possible consequences it may cause....

[Ross9]

Yeah, sound theory, exactly the way I see it. reckon al will be fine at jacqs spec though.

Only semi-slicks as well, full slicks are cheating, if its not road legal then its a competition car, which is a whole different ball game and not comparable.

Ross

[Wobbly Dave]

All I was trying to say was that it was important to know where the limits are. I was trying to point out that increasing the traction puts additional load on the transmission and engine. It has to. Newton says so! As to whether you approach the braking load of those components is another thing. I was just erring on the side of caution.

If you will allow me a small degree of latitude...
It is the same for any modification. Jamie's T4 engine went bang when he put NOS on it. Hamish bent rods on Adam's ex-850R.

If Hamish and Judge's tyre expert have said similar things - then I think there maybe something to bear in mind. That's all!

[madness]

hey! i only bent 1 rod

as i mentioned to ross i am using toyo r888's now which are road legal and i have found them really good. but- it needs to be a hot day. on a semi warm/cold day normal road tyres are better.

i dont think @ the spec any of our cars have anything would go apart from a driveshaft - they are the known weak point and i have spares in the shed !!!

[Ross9]

Lol, well they didn't make much difference to my latest run up the 1/4 mile i must say, managed pretty much the same as last time i was there, thankfully no loss of drive shafts clutch or gearbox noted. looks like even though the car is more powerful, it has still reached the threshold of its current spec and will take an almighty shove to get it past 14.2 and 2.3 secs 60ft.
thanks for the replies though folks.

jacq.

[madness]

ross, when they were doing the 24 hr s60 touring races they had to tape in the car 2 spare driveshafts , as all spares had to be carried and reliability on them was questionable to say the least !!!!!!!!!!!
we have had a few go on standard cars in the workshop , hence my preperation with the spares.