R888 vs Dunlop DZ03G
Discussion
You guys. Pressure is IRRELEVANT. Temperature is where it's at 
What I means is this. The pressure guy will say my tires work best at 30 psi. Great everyone goes and sets theirs to 30 psi.
Now turn up at Silverstone for morning quali with an ambient temp of 9 degrees and see how you go! Your tires which were fine at 30 psi at Rockingham on a nice balmy day of 24 degrees are now way too cold and sliding all over the place.
To set tires correctly you must measure the temp in 3 positions (outside, middle, inner) on each tire and try by adjusting pressure to normalize it across all 3 readings and all 4 tires and to do that you need to know what the optimum tire temp is for your tires. So if Dunlop say for the Dirreza that you get optimum grip level at 40 Degress C then that is what you're aiming for on each tire.
For a 245 Direzza on an 18 inch rim a "good" hot pressure is 32 front 34 to 36 rear but when I ran that on said Silverstone day with 9 degrees ambient and damp in the air I was all over the place because the tires were still to cold so we had to up them a lot to get the heat in them.
What I means is this. The pressure guy will say my tires work best at 30 psi. Great everyone goes and sets theirs to 30 psi.
Now turn up at Silverstone for morning quali with an ambient temp of 9 degrees and see how you go! Your tires which were fine at 30 psi at Rockingham on a nice balmy day of 24 degrees are now way too cold and sliding all over the place.
To set tires correctly you must measure the temp in 3 positions (outside, middle, inner) on each tire and try by adjusting pressure to normalize it across all 3 readings and all 4 tires and to do that you need to know what the optimum tire temp is for your tires. So if Dunlop say for the Dirreza that you get optimum grip level at 40 Degress C then that is what you're aiming for on each tire.
For a 245 Direzza on an 18 inch rim a "good" hot pressure is 32 front 34 to 36 rear but when I ran that on said Silverstone day with 9 degrees ambient and damp in the air I was all over the place because the tires were still to cold so we had to up them a lot to get the heat in them.
Soul Reaver said:
You guys. Pressure is IRRELEVANT. Temperature is where it's at
What I means is this. The pressure guy will say my tires work best at 30 psi. Great everyone goes and sets theirs to 30 psi.
Now turn up at Silverstone for morning quali with an ambient temp of 9 degrees and see how you go! Your tires which were fine at 30 psi at Rockingham on a nice balmy day of 24 degrees are now way too cold and sliding all over the place.
To set tires correctly you must measure the temp in 3 positions (outside, middle, inner) on each tire and try by adjusting pressure to normalize it across all 3 readings and all 4 tires and to do that you need to know what the optimum tire temp is for your tires. So if Dunlop say for the Dirreza that you get optimum grip level at 40 Degress C then that is what you're aiming for on each tire.
For a 245 Direzza on an 18 inch rim a "good" hot pressure is 32 front 34 to 36 rear but when I ran that on said Silverstone day with 9 degrees ambient and damp in the air I was all over the place because the tires were still to cold so we had to up them a lot to get the heat in them.
Interesting. What I means is this. The pressure guy will say my tires work best at 30 psi. Great everyone goes and sets theirs to 30 psi.
Now turn up at Silverstone for morning quali with an ambient temp of 9 degrees and see how you go! Your tires which were fine at 30 psi at Rockingham on a nice balmy day of 24 degrees are now way too cold and sliding all over the place.
To set tires correctly you must measure the temp in 3 positions (outside, middle, inner) on each tire and try by adjusting pressure to normalize it across all 3 readings and all 4 tires and to do that you need to know what the optimum tire temp is for your tires. So if Dunlop say for the Dirreza that you get optimum grip level at 40 Degress C then that is what you're aiming for on each tire.
For a 245 Direzza on an 18 inch rim a "good" hot pressure is 32 front 34 to 36 rear but when I ran that on said Silverstone day with 9 degrees ambient and damp in the air I was all over the place because the tires were still to cold so we had to up them a lot to get the heat in them.
I was always told to set the pressures so that when you have done your stint, back in the paddock they should be at a certain pressure (30/32 for the Clio btw). This means that depending on the type of circuit, track temp, ambiant temp etc you adjust your cold pressure to suit and tweak as required. Is this not the case? And I need to buy a heat sensor?
As an aside, I use the Direzza on the Clio in the wet and whilst they may take longer to warm up, when they are up to temperature they are pretty good. I lost 15s around Donnington GP (2:12 lap) after a hammering of rain.
Thurbs said:
nteresting.
I was always told to set the pressures so that when you have done your stint, back in the paddock they should be at a certain pressure (30/32 for the Clio btw). This means that depending on the type of circuit, track temp, ambient temp etc you adjust your cold pressure to suit and tweak as required. Is this not the case? And I need to buy a heat sensor?
As an aside, I use the Direzza on the Clio in the wet and whilst they may take longer to warm up, when they are up to temperature they are pretty good. I lost 15s around Donnington GP (2:12 lap) after a hammering of rain.
Yes as was I I was always told to set the pressures so that when you have done your stint, back in the paddock they should be at a certain pressure (30/32 for the Clio btw). This means that depending on the type of circuit, track temp, ambient temp etc you adjust your cold pressure to suit and tweak as required. Is this not the case? And I need to buy a heat sensor?
As an aside, I use the Direzza on the Clio in the wet and whilst they may take longer to warm up, when they are up to temperature they are pretty good. I lost 15s around Donnington GP (2:12 lap) after a hammering of rain.
However pressure is only the medium for getting your tire to the right temperature. Pressure in of itself is not the be all and end all of tire setup. It is a tool used to get the right heat in them. Why do you think F1 use blankets? Yes, because they know their tires temp operating window and they want the tire to be in that window as soon as they fit it and not have to wait for it to heat up. They also know from all the data they have what pressure to set the tire too to maintain it at that temp.
Lot's of things are affecting your tires temps and pressures
1. Suspension setup, camber, toe etc
2. Weight of car
3. Grip levels of the track
4. Track temp
5. Ambient temp
6. Using air or nitrogen
7. Size
8. How worn they are (how many heat cycles)
9. Driving style
So yes you do need a tire temp probe to set them up correctly and you also need to know from the manufacturer what the optimum grip window is in temp terms. You could also get a durometer which will tell you how soft they are too once in that window.
So to set them correctly
1. Know the optimum temp window
2. Write down the track temp
3. Write down the ambient temp
4. Write down the humidity
5. Set your base cold pressures to what you think is about right
6. Go out and test to heat them up
7. Come in and measure the inside, middle and outside edge of all 4 tires starting with the rears. Write this all down
8. Check your HOT pressures and write this down too
It's best if you have two people to do this, one to measure the temps while the other does the pressures as when you come off track they will start to cool rapidly so you need to do it fast (ish)
9. Now you have some data and you can start to adjust and fine tune to get your tires into what the manufacturer told you was their optimum window and also what feels right to you and your driving style.
10. Once you have that you have the holy grail setup for that track and that days temps. So next time you run on a day with those ambient and track temps you will have a much better idea of what hot pressure you need to be around to achieve optimum grip and you should also know that your fronts rise from cold by about 6 psi and your rears by 4 psi etc so you will also be better equipped to set your cold pressures.
11. Remember if you're running a lot of camber your inside edge will always be a lot hotter than the outside edge and it will be difficult to balance that across the tire.
I hope all that makes sense.
Soul Reaver said:
Yes as was I However pressure is only the medium for getting your tire to the right temperature. Pressure in of itself is not the be all and end all of tire setup. It is a tool used to get the right heat in them.
Why do you think F1 use blankets? Yes, because they know their tires temp operating window and they want the tire to be in that window as soon as they fit it and not have to wait for it to heat up. They also know from all the data they have what pressure to set the tire too to maintain it at that temp.
Lot's of things are affecting your tires temps and pressures
1. Suspension setup, camber, toe etc
2. Weight of car
3. Grip levels of the track
4. Track temp
5. Ambient temp
6. Using air or nitrogen
7. Size
8. How worn they are (how many heat cycles)
9. Driving style
So yes you do need a tire temp probe to set them up correctly and you also need to know from the manufacturer what the optimum grip window is in temp terms. You could also get a durometer which will tell you how soft they are too once in that window.
So to set them correctly
1. Know the optimum temp window
2. Write down the track temp
3. Write down the ambient temp
4. Write down the humidity
5. Set your base cold pressures to what you think is about right
6. Go out and test to heat them up
7. Come in and measure the inside, middle and outside edge of all 4 tires starting with the rears. Write this all down
8. Check your HOT pressures and write this down too
It's best if you have two people to do this, one to measure the temps while the other does the pressures as when you come off track they will start to cool rapidly so you need to do it fast (ish)
9. Now you have some data and you can start to adjust and fine tune to get your tires into what the manufacturer told you was their optimum window and also what feels right to you and your driving style.
10. Once you have that you have the holy grail setup for that track and that days temps. So next time you run on a day with those ambient and track temps you will have a much better idea of what hot pressure you need to be around to achieve optimum grip and you should also know that your fronts rise from cold by about 6 psi and your rears by 4 psi etc so you will also be better equipped to set your cold pressures.
11. Remember if you're running a lot of camber your inside edge will always be a lot hotter than the outside edge and it will be difficult to balance that across the tire.
I hope all that makes sense.
Thanks, I will give it a go over the winter. However pressure is only the medium for getting your tire to the right temperature. Pressure in of itself is not the be all and end all of tire setup. It is a tool used to get the right heat in them. Why do you think F1 use blankets? Yes, because they know their tires temp operating window and they want the tire to be in that window as soon as they fit it and not have to wait for it to heat up. They also know from all the data they have what pressure to set the tire too to maintain it at that temp.
Lot's of things are affecting your tires temps and pressures
1. Suspension setup, camber, toe etc
2. Weight of car
3. Grip levels of the track
4. Track temp
5. Ambient temp
6. Using air or nitrogen
7. Size
8. How worn they are (how many heat cycles)
9. Driving style
So yes you do need a tire temp probe to set them up correctly and you also need to know from the manufacturer what the optimum grip window is in temp terms. You could also get a durometer which will tell you how soft they are too once in that window.
So to set them correctly
1. Know the optimum temp window
2. Write down the track temp
3. Write down the ambient temp
4. Write down the humidity
5. Set your base cold pressures to what you think is about right
6. Go out and test to heat them up
7. Come in and measure the inside, middle and outside edge of all 4 tires starting with the rears. Write this all down
8. Check your HOT pressures and write this down too
It's best if you have two people to do this, one to measure the temps while the other does the pressures as when you come off track they will start to cool rapidly so you need to do it fast (ish)
9. Now you have some data and you can start to adjust and fine tune to get your tires into what the manufacturer told you was their optimum window and also what feels right to you and your driving style.
10. Once you have that you have the holy grail setup for that track and that days temps. So next time you run on a day with those ambient and track temps you will have a much better idea of what hot pressure you need to be around to achieve optimum grip and you should also know that your fronts rise from cold by about 6 psi and your rears by 4 psi etc so you will also be better equipped to set your cold pressures.
11. Remember if you're running a lot of camber your inside edge will always be a lot hotter than the outside edge and it will be difficult to balance that across the tire.
I hope all that makes sense.
Guys bit of an update on this debate, the MSA have spoken with their 2016 tyre listing making for this debate for some a moot point sadly. The Dunlops are now list 1C, R888 still showing on 1B.
https://www.msauk.org/assets/2016tyrelists1abc.pdf
https://www.msauk.org/assets/2016tyrelists1abc.pdf
Soul Reaver said:
Is there a logical reason whys clubs are not allowed to use slicks? Slicks are cheaper, better wearing and better performance so I just don't see the logic of racers having to use what are essentially road tires for racing?
The reasons that slicks are not used in many club series are variously because:1. They are not cheaper in the long run. Especially as there often becomes an imperative to have new sets at each meeting for optimum performance. Ask the PCGB racers how much costs went up when they switched to slicks.
2. Increased strain on suspension and braking components due to high braking and cornering forces = increased cost again. See my PCGB comments above.
3. Time is often an issue in club meeting with down time between races kept to a minimum. If a race is declared "wet" just before the start because of a sudden shower then you have to give racers the chance to change from slicks to wets and this costs time within crowded programmes and may have an adverse impact on the races at the end of the day. With List 1 b tyres mandated the race can legimatedly go ahead without delay.
andy97 said:
The reasons that slicks are not used in many club series are variously because:
1. They are not cheaper in the long run. Especially as there often becomes an imperative to have new sets at each meeting for optimum performance. Ask the PCGB racers how much costs went up when they switched to slicks.
2. Increased strain on suspension and braking components due to high braking and cornering forces = increased cost again. See my PCGB comments above.
3. Time is often an issue in club meeting with down time between races kept to a minimum. If a race is declared "wet" just before the start because of a sudden shower then you have to give racers the chance to change from slicks to wets and this costs time within crowded programmes and may have an adverse impact on the races at the end of the day. With List 1 b tyres mandated the race can legimatedly go ahead without delay.
Ok fair enough Andy but my Direzza's last 1 race of an hour and 1 quali session of 30 mins and they cost a grand a set. Are they worn out then no but are they good enough to do that again not really so I change them or at the very least the fronts. Fair enough point on the wet race thing but then again my Direzza's are not good enough to race in the wet and struggle in the damp to be honest.1. They are not cheaper in the long run. Especially as there often becomes an imperative to have new sets at each meeting for optimum performance. Ask the PCGB racers how much costs went up when they switched to slicks.
2. Increased strain on suspension and braking components due to high braking and cornering forces = increased cost again. See my PCGB comments above.
3. Time is often an issue in club meeting with down time between races kept to a minimum. If a race is declared "wet" just before the start because of a sudden shower then you have to give racers the chance to change from slicks to wets and this costs time within crowded programmes and may have an adverse impact on the races at the end of the day. With List 1 b tyres mandated the race can legimatedly go ahead without delay.
Interesting about wear rates.
I have used Yoko 48s and Toyo 888s on a variety of FWD race cars inc a Super Production ex works Toyota as well as on an old 924S race car and they usually last at least 4-6 race meetings, each meeting consisting of a 30 min practice and a 40 min race.
I have used Direzzas on 3 x half track days on an E36 M3 race car and they look like brand new with masses of tread left. I suspect the rears would last 4 meetings and the front more. The Direzzas are probably the best (least bad) of the list 1B tyres in the wet.
Maybe I'm not using the tyres hard enough and thats why Im slow, Lol.
I have used Yoko 48s and Toyo 888s on a variety of FWD race cars inc a Super Production ex works Toyota as well as on an old 924S race car and they usually last at least 4-6 race meetings, each meeting consisting of a 30 min practice and a 40 min race.
I have used Direzzas on 3 x half track days on an E36 M3 race car and they look like brand new with masses of tread left. I suspect the rears would last 4 meetings and the front more. The Direzzas are probably the best (least bad) of the list 1B tyres in the wet.
Maybe I'm not using the tyres hard enough and thats why Im slow, Lol.
ISTR the guy who won the PCGB Championship when they first went to slicks spent £16K on tyres. I was in the same class and it was realistic in previous years to win class 2 on 2 sets of tyres at a price of about £1,600 total. Lap times went down by 3 seconds on middle length circuits and as much as 5 to 6 seconds at Silverstone with the corresponding increase in wear and tear on the vehicles.
Slicks have no place in amateur club motorsport IMHO.
Slicks have no place in amateur club motorsport IMHO.
16 grand!! Strewth ill stick to the Rezzaz then ha.
Andy I could at a push get two races and quali session out of mine but then they really would be done for. I am running quite a lot of camber on the Audi both front and rear and some toe on the rear to heat them a bit so maybe they are scrubbing a bit more than normal. Ill run a set on some test days and see how long I can get out of it before it's canvas.
Andy I could at a push get two races and quali session out of mine but then they really would be done for. I am running quite a lot of camber on the Audi both front and rear and some toe on the rear to heat them a bit so maybe they are scrubbing a bit more than normal. Ill run a set on some test days and see how long I can get out of it before it's canvas.
andy97 said:
Interesting about wear rates.
I have used Yoko 48s and Toyo 888s on a variety of FWD race cars inc a Super Production ex works Toyota as well as on an old 924S race car and they usually last at least 4-6 race meetings, each meeting consisting of a 30 min practice and a 40 min race.
I have used Direzzas on 3 x half track days on an E36 M3 race car and they look like brand new with masses of tread left. I suspect the rears would last 4 meetings and the front more. The Direzzas are probably the best (least bad) of the list 1B tyres in the wet.
Maybe I'm not using the tyres hard enough and thats why Im slow, Lol.
Interesting Andy, I've found the dunlops to be awful in the wet compared with the toyo 888s. I have used Yoko 48s and Toyo 888s on a variety of FWD race cars inc a Super Production ex works Toyota as well as on an old 924S race car and they usually last at least 4-6 race meetings, each meeting consisting of a 30 min practice and a 40 min race.
I have used Direzzas on 3 x half track days on an E36 M3 race car and they look like brand new with masses of tread left. I suspect the rears would last 4 meetings and the front more. The Direzzas are probably the best (least bad) of the list 1B tyres in the wet.
Maybe I'm not using the tyres hard enough and thats why Im slow, Lol.
Your point about how many race a set of tyres last really comes down to how competitive the championship is. if all the cars are very closely matched and the championship is close, drivers suddenly find the need to use a new set of tyres every race. I was involved in championship battle last year with very little between the rival cars, and I got through 3 sets of dunlops in 4 races, the other races were all on Pirelli wets.
If you're out there racing on a race by race basis and just happy to beat the guys you qualify near then the tyres will obviously last much longer.
I found this in relation to R888. I don't know who wrote it.
SET UP ADVICE FOR THE TOYO PROXES R888
What I would like to do is to offer some advice on tyre temperatures and pressures and how to achieve the best from our tyres when taking part in either trackdays or racing.
The R888 has a semi race construction (very stiff) and a race tread compound. The optimum tread temperature range is between 85C and 95C measured using a probe type pyrometer, and ideally a maximum difference across the tread of 9C. The maximum hot pressure we recommend is 40psi. Camber angles up to 5 degrees are permissible but the final setting will depend on tread temperatures. It is advisable to have as much positive castor as practical as castor induces a beneficial camber change during cornering. I recommend that the tyres be put through a heat cycle before hard use, this will scrub them in and remove any mold release agent.
The pressures you use will initially depend on the weight of the car, too little pressure on a heavy car can lead to over deflection of the tyre and subsequent failure.
Below are some basic settings:
VEHICLE WEIGHT COLD PRESSURE HOT PRESSURE:
Very Light < 800kg
COLD
17 - 22 psi
HOT
22 - 29 psi
Light 800kg - 1000kg
COLD
20 - 26 psi
HOT
24 - 32 psi
Heavy 1000kg - 1400kg
COLD
23 - 27 psi
HOT
28 - 40 psi
Very Heavy > 1400kg
COLD
27 - 35 psi
HOT
37 - 40 psi
As a tyre gets hotter the pressure increases, this is due to the moisture in the air. The cold pressure you set to achieve a desired hot pressure will depend on the conditions on the day i.e. ambient and track temperature, wet or dry. If the day/track is cold you will need to start with a higher cold pressure as the tyre will not get as hot therefore the pressure increase will not be so great.
Hot pressures must be balanced side to side. Once the tyres have cooled you will find that you will have a difference in pressure side to side, if you have been racing on a right hand track you will find the offside pressures will usually be higher than the nearside.
Changing hot inflation pressures by small amounts can be used to fine tune handling.
Reduce Oversteer Reduce rear pressures or increase front pressures
Increase Oversteer Increase rear pressures or reduce front pressures
Reduce Understeer Reduce front pressures or increase rear pressures
Increase Understeer Increase front pressures or reduce rear pressures
Achieving the required tread temperatures will depend again on the conditions on the day i.e. ambient and track temperature, wet or dry.
You often here competitors saying “My tyres started to go of towards the end of the race”, this is usually due to the tread getting to hot.
The tread temperatures are constantly changing through out a race, hotter when cornering and cooler when on the straights and cooling even more when you are slowing to come into the pits. Therefore the temps you record in the pits will be lower than those during the race. So if you record temperatures within the range given above the probability is the temps will be too high during the race.
Increasing your tyre pressures will cause your tread temperatures to increase, more pressure stiffens the tyre’s casing which results in the tread having to do more work resulting in the tread getting hotter. Lowering your pressures will cause them to decrease.
Inevitably changing one thing will affect other things, the whole set up of your car is a compromise between anything that is adjustable.
SET UP ADVICE FOR THE TOYO PROXES R888
What I would like to do is to offer some advice on tyre temperatures and pressures and how to achieve the best from our tyres when taking part in either trackdays or racing.
The R888 has a semi race construction (very stiff) and a race tread compound. The optimum tread temperature range is between 85C and 95C measured using a probe type pyrometer, and ideally a maximum difference across the tread of 9C. The maximum hot pressure we recommend is 40psi. Camber angles up to 5 degrees are permissible but the final setting will depend on tread temperatures. It is advisable to have as much positive castor as practical as castor induces a beneficial camber change during cornering. I recommend that the tyres be put through a heat cycle before hard use, this will scrub them in and remove any mold release agent.
The pressures you use will initially depend on the weight of the car, too little pressure on a heavy car can lead to over deflection of the tyre and subsequent failure.
Below are some basic settings:
VEHICLE WEIGHT COLD PRESSURE HOT PRESSURE:
Very Light < 800kg
COLD
17 - 22 psi
HOT
22 - 29 psi
Light 800kg - 1000kg
COLD
20 - 26 psi
HOT
24 - 32 psi
Heavy 1000kg - 1400kg
COLD
23 - 27 psi
HOT
28 - 40 psi
Very Heavy > 1400kg
COLD
27 - 35 psi
HOT
37 - 40 psi
As a tyre gets hotter the pressure increases, this is due to the moisture in the air. The cold pressure you set to achieve a desired hot pressure will depend on the conditions on the day i.e. ambient and track temperature, wet or dry. If the day/track is cold you will need to start with a higher cold pressure as the tyre will not get as hot therefore the pressure increase will not be so great.
Hot pressures must be balanced side to side. Once the tyres have cooled you will find that you will have a difference in pressure side to side, if you have been racing on a right hand track you will find the offside pressures will usually be higher than the nearside.
Changing hot inflation pressures by small amounts can be used to fine tune handling.
Reduce Oversteer Reduce rear pressures or increase front pressures
Increase Oversteer Increase rear pressures or reduce front pressures
Reduce Understeer Reduce front pressures or increase rear pressures
Increase Understeer Increase front pressures or reduce rear pressures
Achieving the required tread temperatures will depend again on the conditions on the day i.e. ambient and track temperature, wet or dry.
You often here competitors saying “My tyres started to go of towards the end of the race”, this is usually due to the tread getting to hot.
The tread temperatures are constantly changing through out a race, hotter when cornering and cooler when on the straights and cooling even more when you are slowing to come into the pits. Therefore the temps you record in the pits will be lower than those during the race. So if you record temperatures within the range given above the probability is the temps will be too high during the race.
Increasing your tyre pressures will cause your tread temperatures to increase, more pressure stiffens the tyre’s casing which results in the tread having to do more work resulting in the tread getting hotter. Lowering your pressures will cause them to decrease.
Inevitably changing one thing will affect other things, the whole set up of your car is a compromise between anything that is adjustable.
Edited by Soul Reaver on Wednesday 7th October 10:58
I would very much appreciate your opinions on the following tyres and my usage for them.
I have this year been Hillclimbing [and one sprint] a 996 turbo with some decent success.
I have used Kumho V70’s this year but for next they have been moved to list 1C.
The list 1A and 1B tyres that come up tops are the following:
Dunlop DZ03G
Pirelli P Zero Trofeo R
Toyo R888R
Michelin Pilot sport Cup 2
I require the softest Tyres that can switch on ASAP. For all you track days users, a tyre that is not really ideal for many hard laps, more one that would overheat after a few laps if you know what I mean.
Cheers
I have this year been Hillclimbing [and one sprint] a 996 turbo with some decent success.
I have used Kumho V70’s this year but for next they have been moved to list 1C.
The list 1A and 1B tyres that come up tops are the following:
Dunlop DZ03G
Pirelli P Zero Trofeo R
Toyo R888R
Michelin Pilot sport Cup 2
I require the softest Tyres that can switch on ASAP. For all you track days users, a tyre that is not really ideal for many hard laps, more one that would overheat after a few laps if you know what I mean.
Cheers
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