After destroying way too many road tyres on track ( and having a sphincter clenching spin ) I've finally decided to bite the bullet and go for a set of proper track tyres.
I've budgeted for either 888's, Yoko A048's or Kumho V70a's. Obviously the Toyo's seem to be the tyre of choice for most, But has anyone an opinion or experience of the Yoko or Kumho products? Also how do the above fare in the wet compared to a road tyre?
I have a mildly baffled sump, But the thought of all the extra grip afforded by a decent track tyre fills me with dread. Are the cornering forces so much more with the above tyres fitted that i should have cause for concern?
Apologies if this has been covered a million times before. I'm just trying to justify the huge outlay on rubber.
888's, A048's or V70a's. What's your choice?
or Bridgestone RE070'sMicared wrote:After destroying way too many road tyres on track ( and having a sphincter clenching spin ) I've finally decided to bite the bullet and go for a set of proper track tyres.
I've budgeted for either 888's, Yoko A048's or Kumho V70a's. Obviously the Toyo's seem to be the tyre of choice for most, But has anyone an opinion or experience of the Yoko or Kumho products? Also how do the above fare in the wet compared to a road tyre?
I have a mildly baffled sump, But the thought of all the extra grip afforded by a decent track tyre fills me with dread. Are the cornering forces so much more with the above tyres fitted that i should have cause for concern?
Apologies if this has been covered a million times before. I'm just trying to justify the huge outlay on rubber.
I prefer A048's to 888 personally but the RE070's are a good (and cheaper) choice. Not tired the V70's yet.
And yes - R rated tyres grip a lot more.
Not tried the Kumho's.
I have tried Yokos a couple of times but not from new and found them to be quite hard and lacking early grip. 888s were grippy quite soon but can overheat and go off and be almost destroyed quite quickly. So decided that 888s were the ones to use for sprints and Yokos for track days.
That was early opinions but then, after chatting with Alan Meaker it quickly became apparent that it's not just a case of sticking on a set of tyres but actually monitoring what's going on. You need to check for a consistent temp. across the tread and adjust the pressure and camber settings accordingly. That way you'll get the best grip and maximum life from a set of expensive track rubber.
But of course, the tyres are only a part of what's going on. There's the suspension adjustment and arb settings, geometry, etc., etc.,
www. camskill
I have tried Yokos a couple of times but not from new and found them to be quite hard and lacking early grip. 888s were grippy quite soon but can overheat and go off and be almost destroyed quite quickly. So decided that 888s were the ones to use for sprints and Yokos for track days.
That was early opinions but then, after chatting with Alan Meaker it quickly became apparent that it's not just a case of sticking on a set of tyres but actually monitoring what's going on. You need to check for a consistent temp. across the tread and adjust the pressure and camber settings accordingly. That way you'll get the best grip and maximum life from a set of expensive track rubber.
But of course, the tyres are only a part of what's going on. There's the suspension adjustment and arb settings, geometry, etc., etc.,
www. camskill
After my Mallory big end failure I have a firm plan for future trackdays, some of it specific to the scoob, some quite general.
NB Mallory has the longest corner in UK motorsport, Gerrards. If you're at all prone to surge then that's where you'll find it. Longer and faster than Coram at Snett, Clearways at Brands or Chris curve at Cadwell. [in the past I've 'got away' with running slicks on a scoob with no baffled sump at Snett, but maybe I was lucky on that one occasion]
First point is to prepare the car beforehand. For my road-biased STi6 on RE070s that means a baffled sump, a Cosworth baffle plate (not absolutely sure that adds anything over the sump, but Paul at Zen thinks it does), breathers routed to catch-tank, fresh good oil and oil pressure gauge (amongst other gauges). Fuel supply may get a full swirl pot setup, not 100% sure on that one yet.
Next is to be aware of where you're likely to find surge and to drive the first hot laps with a passenger watching the gauge. Or have logging and come straight back in after one hot lap to look at the log, but even that could be too late. You're looking for a subtle change to a normally stable value over the duration of a corner, not something you see in a quick glance at the gauge. Be aware of how heavily damped the gauge/sensor is, as that will mask the amplitude of the pressure change.
Finally, don't ignore warnings signs. Easing back slightly on the one suspect corner may be the difference between a healthy engine and a broken one.
Andy
NB Mallory has the longest corner in UK motorsport, Gerrards. If you're at all prone to surge then that's where you'll find it. Longer and faster than Coram at Snett, Clearways at Brands or Chris curve at Cadwell. [in the past I've 'got away' with running slicks on a scoob with no baffled sump at Snett, but maybe I was lucky on that one occasion]
First point is to prepare the car beforehand. For my road-biased STi6 on RE070s that means a baffled sump, a Cosworth baffle plate (not absolutely sure that adds anything over the sump, but Paul at Zen thinks it does), breathers routed to catch-tank, fresh good oil and oil pressure gauge (amongst other gauges). Fuel supply may get a full swirl pot setup, not 100% sure on that one yet.
Next is to be aware of where you're likely to find surge and to drive the first hot laps with a passenger watching the gauge. Or have logging and come straight back in after one hot lap to look at the log, but even that could be too late. You're looking for a subtle change to a normally stable value over the duration of a corner, not something you see in a quick glance at the gauge. Be aware of how heavily damped the gauge/sensor is, as that will mask the amplitude of the pressure change.
Finally, don't ignore warnings signs. Easing back slightly on the one suspect corner may be the difference between a healthy engine and a broken one.
Andy
It's a difficult one to answer properly John. My guess would be to get the sump properly baffled first (I'm guessing that pipe in the top feed is some kind of feed for the pump?) If that is the pick up, it looks like you'd get pronounced surge in corners if the corner angle or extent of duration was severe enough. Can you get anyone to modify that one for you?
Truth be to be told John, your car is already capable of a 1'21" in the right hands. The prevention of oil surge is the correct protection for your car and the most sensible 'next step' as that is the cars achilles heel. Once that is cracked I would go and get some proper one to one coaching and plenty of seat time. Someone will have a used set of tyres of the description you want and the difference in cost between new and used will pay for the sump work
Truth be to be told John, your car is already capable of a 1'21" in the right hands. The prevention of oil surge is the correct protection for your car and the most sensible 'next step' as that is the cars achilles heel. Once that is cracked I would go and get some proper one to one coaching and plenty of seat time. Someone will have a used set of tyres of the description you want and the difference in cost between new and used will pay for the sump work
Stuart - the pickup goes in the middle of the sump (not shown on this pic - although the hole is). The pipe top right is a drain back and largely irrelevant to how well it will cope under cornering G.
What that sump really needs is some way of keeping a stack of oil around the pickup but short of cutting out the two tin layers in there and fixing a proper group N baffle system, (or selling that and buying a baffled sump) the best you can do is keep the oil level right, use good quality new oil, make sure you have a proper catch can set up and keep a sharp eye on the oil pressure drop around bomb hole to coram exit.
I saw pressure starting to dip coming out of the bombhole and decreasing all the way around coram in march until I got the proper baffles sorted.
The lack of an oil catch can is going to be a big engine killer for you - when going around that corner, the oil in the heads is all going to be flowing straight out of the lh cylinder head into the breather system and straight back into the air charge lowering the octane of the fuel massively and making it det. If oil surge doesnt kill the big ends, then that will cause det and kill pistons, rings, rods and/or big ends. Ideally I would set the catch can to drain back to the sump so as to keep it a closed (fit and forget) system. 3 inlets to the tank from both heads and crank, then vent and drain. RCM make a good one - not cheap but it does a very good and worthwhile job.
Yes, I use a pyrometer. Very worthwhile measuring temps on all 4 wheels at inner, middle and outer. Varying tyre pressures is the main outcome of the measurements as setting camber trackside can be a little hit and miss. I aim to get the 888's in their operating window temps wise and try and even the temp across the tread. This has led to running pressures on the 888's completely different to some/most other people. They seem to be working ok for me
You will need to come in on a flying lap to get a good measurement of temps and pressures so help will be needed in the pits (good job for James I reckon)
What that sump really needs is some way of keeping a stack of oil around the pickup but short of cutting out the two tin layers in there and fixing a proper group N baffle system, (or selling that and buying a baffled sump) the best you can do is keep the oil level right, use good quality new oil, make sure you have a proper catch can set up and keep a sharp eye on the oil pressure drop around bomb hole to coram exit.
I saw pressure starting to dip coming out of the bombhole and decreasing all the way around coram in march until I got the proper baffles sorted.
The lack of an oil catch can is going to be a big engine killer for you - when going around that corner, the oil in the heads is all going to be flowing straight out of the lh cylinder head into the breather system and straight back into the air charge lowering the octane of the fuel massively and making it det. If oil surge doesnt kill the big ends, then that will cause det and kill pistons, rings, rods and/or big ends. Ideally I would set the catch can to drain back to the sump so as to keep it a closed (fit and forget) system. 3 inlets to the tank from both heads and crank, then vent and drain. RCM make a good one - not cheap but it does a very good and worthwhile job.
Yes, I use a pyrometer. Very worthwhile measuring temps on all 4 wheels at inner, middle and outer. Varying tyre pressures is the main outcome of the measurements as setting camber trackside can be a little hit and miss. I aim to get the 888's in their operating window temps wise and try and even the temp across the tread. This has led to running pressures on the 888's completely different to some/most other people. They seem to be working ok for me
You will need to come in on a flying lap to get a good measurement of temps and pressures so help will be needed in the pits (good job for James I reckon)