♦ ♦ ChargeR's DC5R Blog ♦ ♦

[mugsee]

Yes they should be fine. They are a DOT approved radial, I could drive on the street with them if I felt like it.

That sounds like your about to take a challenge of sorts. Something along the lines of driving up to the next track day with them on...?

[Wlee2]

That sounds like your about to take a challenge of sorts. Something along the lines of driving up to the next track day with them on...?

only if it was dry though

[lukits01]

Liking the review of this tire
how hard was it to get heat into the rears?
did it take a few laps?

[what?]

What tyres is this on? I will probably be trialling a bit of tyre pressure differential to try and get the rear of the car to behave as I want it. I wasn't getting as much oversteer as I would have hoped with the staggered tyres.



Yes they should be fine. They are a DOT approved radial, I could drive onDo the street with them if I felt like it.

DOT aproved does not automatically mean ADR approved.
A fact that many drag racers have found out the hard way. Mickey Thompson make a tyre called "ET Street Drag Radials" these are D.O.T approved. Heaps of guys bolt these on and drive to the 1/4, race and drive home again. This is the selling point of these tyres: they are the pinacle in drag tyres before you get to a full slick, so you don't have to worry about changing wheels at the track. Heaps of guys do this every week, heaps of guys have been pulled over by Mr Plod, heaps of guys have been ok'd by mr Plod to. Though they are still illeagal as the do not meet adr 23 because they do not have a load rating.
Sorry for the lengthy reply, just trying to make you fully aware
Obviously this is not going to matter at Winton as it is a ASSA track, but places like Sandown and especially PI might be anal about it.
Ive sought clarification for myself from Hoosier in Melbourne, he is getting someone from Sydney to give me a call. I will let you know what they say.

[ChargeR]

That sounds like your about to take a challenge of sorts. Something along the lines of driving up to the next track day with them on...?

No thanks. That is 2 extra heat cycles on them. I need to get maximum life and grip out of them they are nearly the most expensive part on my car .

only if it was dry though

I think they could deal with damp. Standing water could be an issue though .

Liking the review of this tire
how hard was it to get heat into the rears?
did it take a few laps?

I will post a full review in the tyres thread after my next day but I didn't have any real issues getting some temp into the rears. The first few laps out the rear was sliding about a bit but beyond that they were fine. I think this is a factor of my driving style and setup though. Heaps of guys seem to run front/understeer biased setups and then complain that they can't get heat into their rear tyres.

DOT aproved does not automatically mean ADR approved.
A fact that many drag racers have found out the hard way. Mickey Thompson make a tyre called "ET Street Drag Radials" these are D.O.T approved. Heaps of guys bolt these on and drive to the 1/4, race and drive home again. This is the selling point of these tyres: they are the pinacle in drag tyres before you get to a full slick, so you don't have to worry about changing wheels at the track. Heaps of guys do this every week, heaps of guys have been pulled over by Mr Plod, heaps of guys have been ok'd by mr Plod to. Though they are still illeagal as the do not meet adr 23 because they do not have a load rating.
Sorry for the lengthy reply, just trying to make you fully aware
Obviously this is not going to matter at Winton as it is a ASSA track, but places like Sandown and especially PI might be anal about it.
Ive sought clarification for myself from Hoosier in Melbourne, he is getting someone from Sydney to give me a call. I will let you know what they say.

Thanks for the clarification. I hadn't looked up the exact ADR regulations and although I have driven the tyres on the street I won't be making a habit of it .

Let us know what the Hoosier guys say .

Also what gives you the impression that CAMS events will take issue with the tyres? Do you think that they will require a car running them to conform to the safety regulations for cars running slicks? I think that unlikely since they are still a radial DOT tyre and the main difference between them and an RE55s for example is the tread or lack thereof.

[what?]

Spoke to someone from Hoosier, i didnt quite get his name, i think it was mitch.
He didnt really seem to know what he was on about, ill pass on the info he gave me. He said that they are DOT approved and that DOT tyres can be used in Australia. He a said that CAMS do have a problem with them though as they have "some funnry rules"
Take from that what you will.
BTW congrats on the PB that is a awesome result at winton

[lukits01]

I will post a full review in the tyres thread after my next day but I didn't have any real issues getting some temp into the rears. The first few laps out the rear was sliding about a bit but beyond that they were fine. I think this is a factor of my driving style and setup though. Heaps of guys seem to run front/understeer biased setups and then complain that they can't get heat into their rear tyres.

would you recommend them for sprints or hill climbs?

[ChargeR]

Spoke to someone from Hoosier, i didnt quite get his name, i think it was mitch.
He didnt really seem to know what he was on about, ill pass on the info he gave me. He said that they are DOT approved and that DOT tyres can be used in Australia. He a said that CAMS do have a problem with them though as they have "some funnry rules"
Take from that what you will.
BTW congrats on the PB that is a awesome result at winton

I think from a quick look through the CAMS manual and the regs for various CAMS events that their main concern seems to be with maintaining parity in various classes. I have read some event regulations for classes for DOT tyres have a clause reading "no tyres marked 'for competition use only'". The Hoosiers have competition use only written on the side of them so this rule seems designed to specifically prohibit them. If I wanted to enter CAMS sprint events I would be more inclined to pick up some RE11s anyway.

Oh and thanks .

would you recommend them for sprints or hill climbs?

If you are doing hill climbs without much time to warm your tyres I think that the Hoosier A6 compound might be a better idea. How many laps, and how long is the track for your sprints? What format are your sprints run in? The R6 might be a better fit for sprints.

[T-BaGGeR]

What tyres is this on? I will probably be trialling a bit of tyre pressure differential to try and get the rear of the car to behave as I want it. I wasn't getting as much oversteer as I would have hoped with the staggered tyres.

R888. I was just playing around with different psi's and the higher pressures at do allow the rear to be happier which aids in rotation.

[DC5R]

Congrats on the new PB Tom~~~
u must be so so happy!!!

[DrTran]

Looks like you didn't have that much hard of a time to warm up those slicks.

Update 11: Winton Test and Tune - 8th of May 2009

Yesterday Didz, TeMp and I went up to Winton for a test and tune to see what times we could lay down. I had two main goals there, one to run on the Advan AD07s I used at Superlap to see whether they worked well on a track I was more familiar with. My second goal was to take my new Hoosiers for a test session to put a heat cycle on them before running a full day on them at the EXE track day in a fortnight. It was also an opportunity to check whether the tyres were going to rub horribly.

Conditions for the day were perfect, sunny and around 20 degrees. As a result there was a very healthy turnout of race cars, with half a dozen Porsche cup cars making the sessions particularly interesting. The first session out I decided to go out on the 255/235 Ad07s that I had driven up on. I hadn't checked my tyre pressures before the drive up and a quick check revealed them to be around 36 front with the rears down near 30 psi. This didn't seem ideal but I was too lazy to put any air in my tyres. The session went well though despite large amounts of traffic. Being passed by the fast Porsches and then being held up by some other street cars made it hard to get a completely clean lap. Results were the session were good though, I managed a 1:44.01 which is the fastest that I have ever gone at Winton on street tyres. On a fresher set of tyres and with less crappy driving I am confident that 43s or 42s wouldn't be out of the question. After this session the AD07s were done though with small chunks coming off them revealing canvas below and I still needed to drive home on them. It was time to move on to my big tyres.

I sat one session out while my car cooled a little and swapped over to my 275/245 Hoosier R6s. I set initial cold pressures to around 32psi at all four corners, which is a bit higher than what I would have previously used with RE55s. However Hoosier claim that the lightweight construction of the R6 rewards slightly higher pressures than a typical radial race tyre. The session went flawlessly with the tyres gripping quite well from the outset, none of the skatey feeling that I was expecting. There was a bit of traffic but I tried to gradually increase my pace until I was approaching the limit of my skill, all the while listening out for noises of rubbing or the tyres hitting where they shouldn't. On the last quick lap of the session I managed a 1:40.13 timed on AiM (Thanks mugsee), nearly 3 seconds quicker than my PB on RE55s. Saying I was pretty pleased would be putting it mildly.

After that lap I was caught up with some traffic and decided to do a bit of a cool down lap and next lap around the chequered flag was waved. After bringing the car off the track a quick inspection of the tyres in the pits revealed that the front left tyre had been rubbing slightly on the bracket/fenderliner where the bumper mounts to the front guard. That will be rectified before the next track day. No other issues, so I can confidently say that 275s work well on stock lightly modded DC5 guards. A quick check with my pressure guage revealed that the tyres had reached around 39-40 psi at all four corners which suggests that they were working okay but not quite fully up to temp.

In conclusion big tyres work. Whether they work better than slightly smaller tyres I don't know and I don't have the money to find out. I will stick with my massive tyres .

1st Session (AD07)
1:54.76
1:47.93
1:46.11
1:44.17
1:44.14
1:46.96
1:44.01
1:48.00
1:56.48
1:55.98
1:47.08


2nd Session (R6)
1:58.21
1:46.03
1:43.29
1:41.16
1:41.64
1:43.91
1:48.31
1:40.80
1:47.49
1:46.36
1:42.91
1:40.13

[ChargeR]

R888. I was just playing around with different psi's and the higher pressures at do allow the rear to be happier which aids in rotation.

Yeah I think that I will be running them a bit higher in the rear in the future to help get the car to turn.

Congrats on the new PB Tom~~~
u must be so so happy!!!

Thanks mate!

Looks like you didn't have that much hard of a time to warm up those slicks.

True story . Damn naysayers .

[ChargeR]

Update 12: EXE/Circuit Club at Winton - 23rd of May

Went up to Winton this past weekend with EXE/Circuit Club, it was an awesome day with plenty of track time and good organisation. It is always great to track with the EXE crowd and I will definitely be heading to more of their days in the future. This day was my first full day on my Hoosier R6s so I was a little nervous . First session out I took a passenger and the aim was to start warming up my tyres, which takes some time . Car felt good straight out of the box but I still need to play with tyre pressures or alignment to get the car turning in a little more crisply. Best time for the session was a 1:41.

Next session I went out by myself to try and set a decent time. Car still felt good and seemed faster with neater driving rather than throwing the car around which results in too much speed lost from sliding and my car just doesn't have the power to accelerate out well if I lose too much speed on corner entry. Managed to hit a 1:39 in this session which would turn out to be my fastest lap of the day. Pretty happy especially since I managed to edge ahead of Mugenbox23 for a little while . Only a little while though. Pressures coming off the track were 39 F, 38 R which felt pretty good, and is much higher than most would use with a radial race tyre. Next track day I may trial pressures around 34 all round to see how it feels, and conversely tyre pressures up above 40 to see how they go. Initial impressions suggest they are happiest in the high 30s though.

I lowered my front tyre pressures to 37 psi for the next session. It did not seem to have the desired effect of more front end grip resulting in a more neutral car, if anything the car understeered more. A few 1:40s but nothing close to my previous best of 1:39.78. The next session I lowered the pressures further and went out with mugsee riding shotgun in the hopes of him giving me some useful insight. He told me my driving was inconsistent. Oh well.

For the final session I pumped my front tyres back up to 39psi warmish in an attempt to get a little more front end grip. The car felt better as it did earlier in the day. Still not enough to get me back into the 1:39s though.

I have a few ideas on some changes to get a little more speed out of the car and myself in its current configuration:

• Try a little toe out at the rear to get the rear steering itself into the corners a little.
  
  
• Raise the rear of the car a touch to obtain slightly less negative camber, again to try and move the grip bias to the front.
  
  
• Add a little more front negative camber. Setting for this day was 4.6ish at the front, front toe was unknown. I don't have any conclusive tyre temp data because I didn't take it after coming directly off the track however looking at a few photos of my car suggests that the amount of body roll I am getting is significant.
  
  
• Improve my line through the sweeper (turn 5 on the map below), and just generally experiment with a few different lines throughout the track.

Here are my times for the day. I have included the times recorded using the in car AiM timer, kindly lent to me by Mugsee, for comparison. The times are generally very similar so the Winton "hand" timing is pretty accurate:

Natsoft (AiM)

Session 1
1:59.7200 (1:59.72)
1:43.6700 (1:43.66)
1:41.5800 (1:41.52)
1:41.3900 (1:41.43)
1:41.9700 (1:41.96)

Session 2
1:44.5300 (1:44.52)
1:45.3900 (1:45.35)
1:48.5100 (1:48.47)
1:43.2300 (1:43.18)
1:40.3900 (1:40.36)
1:39.7800 (1:39.79)
1:40.2000 (1:40.22)
1:59.1300 (1:59.22)

Session 3
1:43.4400 (1:43.64)
1:41.0900 (1:41.03)
1:40.3600 (1:40.38)
1:40.4900 (1:40.55)
1:40.6200 (1:40.57)
1:40.5300 (1:40.49)

Session 4
1:48.6000 (1:48.64)
1:42.7800 (1:42.81)
1:42.0600 (1:42.02)
1:42.1100 (1:42.15)
1:43.0600 (1:43.00)
2:14.6000 (2:14.59)

Session 5
1:47.8400 (1:47.86)
1:49.1300 (1:49.16)
1:42.7900 (1:42.78)
1:41.4200 (1:41.47)
1:40.6900 (1:40.68)
1:41.3800 (1:41.42)
1:40.0900 (1:40.14)


Pics (borrowed from Matt Mead. Check out his Flickr HERE)

[Didz]

Nice writeup guy, Really glad to see u break the 39's I told you u could do it!

He told me my driving was inconsistent. Oh well.

LOL I somewhat wish i asked more people to school me too! But i believe your wisdom helped me crack a second off my fresh pb from the first session.

Looking forward to see you get even faster guy.

[zeth_an]

Congrats on the PB Tom. 1.39xx is indeed impressive

Turn 5 is indeed a tricky one for me personally