Solution to overheating tyres and brakes

[davekmoore]

Blimey, thanks for all this assistance!

The cooldown lap is good advice. Might be less fun though.

The car probably fails to comply with any class other than Open and I'm not looking to win anything anyway so I don't think it matters what other modifications it gets including whatever size or type of wheels and tyres.

It has RDA rotors, green pads, SS braided lines and race fluid. This all works fine but just has that groaning noise at the front when used lightly at the end of a 10 lap session. Is this just normal?

The concept of more brake heat being caused by more grip from better tyres worries me and I wonder how much this can be improved by more brake cooling - and how to do it? Or should I just go round the corners quicker and use less brakes ?

It seems no-one wants to buy the 17s so I may as well keep them for the road as they work great for that. When the tyres are stuffed I'll just buy cheaper ones than the Yokos (that won't be difficult!).

I want to drive to the track, sometimes with a passenger. The car will not be trailered. There won't be a wheel trailer. There won't be a support vehicle. So there's no room for a second set of wheels. All I want to do is arrive and put more pressure in the tyres that are already on the car. It doesn't matter if the track tyre and wheel combination is noisy or uncomfortable as I have no plans to drive more than 3 hours to a track. So, if I go for, say, 15x8s, what would be a decent tyre as a compromise to not actually wear out on the way to the track and give decent grip at the track?

[Apu]

I'm kind of in the same situation as you Dave. I was running street tyres the whole time and wasn't going very fast as they weren't the most confidence inspiring tyres!

I did have the option of a second set of wheels but chose to sell them off, so right now I run Kumho KU36 (used to run KU31) and that's dropped my Wakefield times from 1:22 to 1:18. I know now that I can go faster again and am targeting another 2 sec drop with the KU36s. They are "cheap" on a 15".

I run 205/50/15 as it's the max my 15x6.5 wheels can take...and I think that's enough for the street/sports tyre combo. That's already about 3% larger circumference, and I therefore didn't want to go to a 215 or 225 tyre.

[sailaholic]

225/45/15 from tire rack on 15x9 6ul.

Sent from my GT-I9100 using Tapatalk 2

[Hjt]

Your brakes seem fine, I would say the tyres are the concern.

I have done 20 lap sessions with stock rotors rubber lines and hawk hp+ pads with no brake fade. Tyres got really hot however (clutch did too).

[manga_blue]

Firstly, I'd keep using your existing tyres until they're stuffed. You're still gaining track experience. It's actually faster and easier to pick up your skills on slippery tyres. At that point you make a choice between dedicated competition r-specs and high performance street s-specs. For a stock SE I'd go with s-specs. The best combo would be 15x7 rims with 205/50R15 Dunlop Star Specs or Kumho KU36. The Dunlops are only a second per lap slower than r-specs at Winton in the dry and faster in the wet. The Kumhos are slightly slower than Dunlops but a lot cheaper. When you've worn those out you should be driving at a level where you can seriously contemplate r-specs.

Next, there have been problems with variable quality with RDA rotors. Give them a close inspection looking for signs of surface glazing and radial cracks, particularly on the outside facing surfaces ... something like this:


Finally, you can go to brake pads better suited to track work while still using street tyres. Track pads tolerate much more heat build-up than road pads which enables you to brake more smoothly and progressively. So they actually help you save your street tyres at the track. Hawk HP+ are one of the brands that work well both cold on the street and hot on the track.

[Zcootz]

FTFY???? What does that stand for ?

http://lmgtfy.com/?q=FTFY

Dann

lol, funny how the first item on the google search shows two definitions for the acronym. I'll make sure I run all my questions past you first Dann in the future to make sure they are acceptable to put up on the forum

[NitroDann]

Only one, and the one in bold, makes any sense in context.

Also i was having a laugh mate, No offense intended.

Dann

[Zcootz]

Only one, and the one in bold, makes any sense in context.

Also i was having a laugh mate, No offense intended.

Dann

Sorry dude, I took it the wrong way....

[Charlie Brown]

manga_blue's advice is the best you'll find.

I'm guessing your "Green" pads are EBC Green Stuff which are a road pad not a road/track pad.
Jump past the Red Stuff as they also are a road pad and use the Yellow's if you want to stay with EBC or try Hawk HP+ or Carbotech XP8 for a combined road/track pad.

[davekmoore]

Firstly, I'd keep using your existing tyres until they're stuffed. You're still gaining track experience. It's actually faster and easier to pick up your skills on slippery tyres. At that point you make a choice between dedicated competition r-specs and high performance street s-specs. For a stock SE I'd go with s-specs. The best combo would be 15x7 rims with 205/50R15 Dunlop Star Specs or Kumho KU36. The Dunlops are only a second per lap slower than r-specs at Winton in the dry and faster in the wet. The Kumhos are slightly slower than Dunlops but a lot cheaper. When you've worn those out you should be driving at a level where you can seriously contemplate r-specs.
Next, there have been problems with variable quality with RDA rotors. Give them a close inspection looking for signs of surface glazing and radial cracks, particularly on the outside facing surfaces ... something like this:
Finally, you can go to brake pads better suited to track work while still using street tyres. Track pads tolerate much more heat build-up than road pads which enables you to brake more smoothly and progressively. So they actually help you save your street tyres at the track. Hawk HP+ are one of the brands that work well both cold on the street and hot on the track.

Thanks for all that.

The car isn't stock. It has 174rwhp hence it's a bit of a handful in the twisty bits not just for me but also for Craig who instructed me at Winton. The challenge is to try to keep some boost on while keeping it pointed roughly at the next corner. So given that I have a spare set of 17 inch wheels, maybe I just get some KU36s thrown on them for the track and, as you say, wear out the Yokos on the road, then wear out the Kumhos on a mixture of the road and the track, then get more serious with some 15s?

No damage on the rotors.

There's also been a suggestion of going for yellow pads for the track.

Your thoughts?

[davekmoore]

Anyone got any thoughts on brake cooling? Ducts? Something else?

[rossint]

One of the guys I race with bought an SE last year, the cars standard except for R888's and a seat and harness, he had problems finding brake pads that would work on the track. He tried HP+ and I think HP blue as well but neither worked that well, I think he ended up going with Project Mu's and is happy with them. Mallala where we race is particularly hard on brakes.

[Muzdaman]

The best combo would be 15x7 rims with 205/50R15

Curious why you would suggest 15x7.

A 205/50R15 will be faster on an x8 over a x7.

Surely at his hp levels a 15x8 or even a 15x9 with 225/45R15 would be well worth considering?

[manga_blue]

Curious why you would suggest 15x7.
A 205/50R15 will be faster on an x8 over a x7.
Surely at his hp levels a 15x8 or even a 15x9 with 225/45R15 would be well worth considering?

Both Toyo and Kumho recommend a standard rim width of 6.5" for 205/50R15 r-specs, with Toyo specifying a max of 7.5" There's just no benefit in taking a track tyre beyond its recommended fitting range, unless you're the guy selling these wheels. Seriously, track days are filling up with overshod MX5s at the moment and some of them handle like barges. Guran's pulling higher Gs on 185/60s with 5.5 rims than most of the guys on 225s.

When he said "sorted SE" I didn't realise he meant 174hp sorted. It puts him a a very borderline area between street/track pads vs race pads and r-specs vs s-specs.

So given that I have a spare set of 17 inch wheels, maybe I just get some KU36s thrown on them for the track and, as you say, wear out the Yokos on the road, then wear out the Kumhos on a mixture of the road and the track, then get more serious with some 15s?

Sounds like a plan.

At the end of the day it really comes down to a decision about whether you want to stay with the convenience and low cost of a daily driver or step up to a more specialised track set-up. The daily driver set-up means you need to drive within the capability of the car, which is still a good approach for the first season. The track set-up would mean at least changing wheels and pads before meetings (and seats and harnesses). R-specs with good tread are drivable on the streets, just don't get caught in a downpour on the Hume coming home.

It would be worth trolling through posts about pads by Charlie Brown, Hellmun and CT on this forum to get the best informed opinions on track pads for those power levels.

[davekmoore]

Thanks manga_blue

Yes, I want to stay with a DD.

Would you give any different advice if the 174hp you mention is actually 174rwkW aka 233rwhp? 17x7s with 205/40s still ok?