white06si
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What base tire pressures run good on a track for a 06 Si?
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notyper
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Short tight track? Long one? Stock suspension/alignment? Inexperienced driver?
I'm assuming you are probably relatively new to track days and your car is relatively stock. If so, start at 34-35 psi cold in the front, and 36-37 psi rear. You'll want them around 40 psi hot and then adjust to suit.
SC
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white06si
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Long track 2.4 miles with HFP suspension and upgraded brakes. I am a semi-experience driver. Why more psi at rear?
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notyper
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You don't work the tires as hard at the rear on a FWD car, so they aren't going to heat up as much.
Since you have the HFP suspension I'm assuming you also have a professional alignment done? If so, you can drop the pressures a little bit all around (1-2 psi). One of the big concerns with a FWD car (stock suspension and alignment) is that you're going to roll the sidewalls over and torch the tires in tighter corners. Higher pressure helps prevent that. But with a better suspension and alignment (more camber ideally) this is less of an issue and you can run a lower pressure. Just be sure to check them after the first session to see where they are hot.
The real key will be to play with the pressures over time and check tire wear in the process. If you find you're rolling the fronts onto the sidewalls too much you may want more pressure.
SC
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white06si
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SC
This is good info. Yes I have had an alignment and I do have about -1 camber ft and in the rear. Last time I was at the track I had stock susp. and the ft. tires were rolling and my instructor, who runs a Mini, told me to lower ft. tire pressures. I didn't think that was right. So you say run the rears a bit higher than the fronts? Won't the run cooler?
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notyper
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In an ideal world lower tire pressures (within reason) will generate more grip as long as you have a good alignment and aren't rolling the sidewalls.
Even with a good alignment and suspension the fronts are still going to get a lot hotter, so your hot pressures will be higher up front after you start running.
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white06si
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SC
Thanks for your help. I run this weekend and let you know how it works out.
KD
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white06si
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SC
It was about 70 degrees and humid. The pressure that worked good for me were 35f 32r. The rear were not getting very hot, they are just there for the ride.
KD
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white06si
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SC
It was about 70 degrees and humid. The pressure that worked good for me were 35f 32r. The rear were not getting very hot, they are just there for the ride.
KD
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notyper
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Glad you had a good time.
SC
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white06si
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SC
I am thinking about race tires. I was told to look for 15'' wheels to fit that vehicle so tires will be less expensive. Do you have any experience on this?
KD
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typer_801
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Very popular with the autocross crowd to go with the smallest wheel diameter possible. Lower rotational mass, less unsprung weight. Also lots of good tire choices in the 15" at least with Hoosiers (i.e. 245/50/15) Can stay with a near stock diameter or go smaller for improved gearing (i.e. 275/35/15). Tires appear to be $40 cheaper each in the smaller diameter sizes (still cost ~$250 each).
Only real concern is the 15in wheels clearing the calipers. Will need to research and confirm whatever you'll buy will fit, it'll be close.
white06si wrote:
SC
I am thinking about race tires. I was told to look for 15'' wheels to fit that vehicle so tires will be less expensive. Do you have any experience on this?
KD
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RyanDL
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white06si wrote:
SC
I am thinking about race tires. I was told to look for 15'' wheels to fit that vehicle so tires will be less expensive. Do you have any experience on this?
KD
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The 16" wheels from the earlier RSX-S models would be the smallest wheel you can fit -- the brake setups are the same. That said, any compatible 16" wheel should fit.
Race tires offer lots more grip, but don't offer much in the way of progressive breakaway or letting you know they're about to let go. This isn't as much of a big deal on a FF car since recovering from problems is simpler. Rest assured, race tires aren't cheap, wear quickly, and shouldn't be daily driven (rain is a big no-no, as are cool temps). Grip isn't there unless they're warm, either.
Honestly, I'd try a very grippy street tire rather than a dedicated race tire, unless you really want to have a set of dedicated track wheels.
Ryan
Last edited by RyanDL on 01-25-2012 15:24
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typer_801
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16's are a sure thing, but a handful of 15's will fit. Check out this thread on the club RSX board, The RSX-S have the same 11.8 calipers as the Si and here's a set of wheels which clears them.
RyanDL wrote:
The 16" wheels from the earlier RSX-S models would be the smallest wheel you can fit -- the brake setups are the same. That said, any compatible 16" wheel should fit.
Ryan
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notyper
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Dunlop Direzza Star Specs. The Hankook RS-3s have a little more grip, but the Star Specs have great grip, terrific wet performance (at least when they have tread) and they wear very well. I've put three track days, a drag strip session and lots of other abuse on these on my S2000 and they've been terrific.
They're also pretty cheap. The only downside is that they have a bit of a hum at freeway speeds, but its a small price to pay.
I'd also choose to stick with 16" wheels. Finding good sizes of 15" tires is pretty tough. In fact, it's getting hard to find good sized 16" tires these days - I can no longer get 245/45/16 for my S2000 so I moved up to 17" wheels.
I would try to shoehorn a 245/40/17 on your car if I could, but that's a pretty tight fit on stock wheels. If you 16", you're probably going to have to use a 225/50/16.
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typer_801
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If you're going with 17's , used TL wheels from the prior gen cars work too. They're 17x8, so you pick up an important 1 inch of width and probably reasonably plentiful, but not horribly light.
Old Evo VII wheels also are 17x8 and fit as do RX-8 wheels.
And with 16's the old FD3 RX-7 16x8 wheels fit too. Very affordable and light too (~15 lbs a piece), but tire choices are limited as Sean pointed out.
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RyanDL
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I'll toss the Kumho XS into the mix. They are stickier in the dry than either the Star Specs or Hankooks, though a bit dicey in the rain. I have 1 full track day, a season of auto-x, and plenty of hard street driving on them and they still have ~50% tread life.
Ryan
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notyper
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You know I'd never considered the MX Ryan. They didn't do as well as you might like in the Tire Rack test and I've never seen anyone running them in competitive Time Attack cars.
But I went back and looked and they seem alright for the dry as you stated. They're a little cheaper than the Dunlops. Lighter too, but that's probably because they run about 10-20% less tread depth new. They also offer some more of the hard to find sizes.
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intune
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Grassroots Motorsports did a nice comparison and write-up that you might find helpful:
http://grassrootsmotorsports.com/articles/top-tires/
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white06si
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Wow this is really good info. Thanks to everyone replying. I have another question, what track brake pads should be used? I have had 2 sets of EBC Yellowstuff, both have pitted and melted. I also have slotted rotors. The rears are ok but they don't get that hot since about 80-90% of the braking is at the front.
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notyper
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I'm a big fan of Carbotech Panther Plus for a street/track car. They will squeal on the street but aren't too hard on rotors. As you get faster these may not be enough pad, but for someone who is just out having fun they work very well. Also use a good fluid like Motul.
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white06si
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I need a more aggessive pad. Hawks maybe good but I hear they are very hard on rotors. I also used ATE Super Blue this time and it worked great. I had no brake fade or spongy pedal, which I have had in the past.
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notyper
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Well, in my experience EBC stuff is pretty mediocre, and that's being kind IMO.
I can run the PantherPlus on a 500 whp S2000 without any issues as long as I take a breather lap every 4-5 laps. That's with stock rotors/calipers/lines and Motul RBF600.
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white06si
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SC
Do you have any pitting of the pads? Are they easy on your rotors? I was told EBC are good, but they aren't. The track I drive on is 2.4 miles with very hard braking. I may give these a try. How long do they last. The EBC were worn 50% in 2 days about 200 miles.
KD
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notyper
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They don't pit or groove the rotors. They do wear the rotors faster than stock though. I typically will get 4-5 track days and 10k+ street miles before I need to replace pads. At that point the front rotors are usually getting thin too.
SC
Last edited by notyper on 01-27-2012 18:59
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white06si
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SC
I looks like Carbotech doesn't make the PantherPlus anymore and they are the XP6. Where did you buy yours?
KD
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notyper
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I've got a few sets lying around the shop.
SC
Last edited by notyper on 01-31-2012 00:33
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RyanDL
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white06si wrote:
SC
I looks like Carbotech doesn't make the PantherPlus anymore and they are the XP6. Where did you buy yours?
KD
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I'm using the XP8 on my S2000, but I've always been a fan of the Panther+. I think the XP8 is the direct replacement. I've never been able to get either the Panther+ or XP8 to fade and they seem to have endless grip.
In my experience, EBC pads were garbage.
Ryan
Last edited by RyanDL on 01-31-2012 10:00
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white06si
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Ryan,
I agree with you about EBC. That is why I want something else that works well by others with experience in this. How are the XP8 cold? Can you drive to the track with stopping power cold?
kd
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white06si
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SC,
Are these new, if so how much and how can I get in contact with you?
kd
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