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A/C making strange sound

Anyone know if wider tires would be 235/45-17

Anyone know if there is any advantage to this? Having more contact patch/surface area

Will this rub?

Thanks
:roll:
 

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maxwolfinger said:
http://www.imprezawrxsti.com/postnuke/modules.php?op=modload&name=PNphpBB2&file=viewtopic&t=3031
people have gone up to a 245/40-17
actually some else has 255/40/17 for the track without any probs.
 

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ya someone put on 255s. I will probably go back to 225/45 as its cheaper and im not going to be tracking anytime soon.. that and another 5mm of cushion, but i love the 245/40 combo and it worked / is working great.

Robert~
 

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Light Weight System Advice

NOt by much. Actually, from the sounds of it, our speedo is off by a couple miles per hour and it might make it more accurate. There was a spreadsheet floating around that would do the speedo calculation when you typed in your stock wheel/tire size and they new size. I put in the 235/45 combo and it only change it by 1 or 2 mph. I wouldn't worry about it.
 

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The speedo is about 4mph fast at normal speeds and 5mph fast once you get into track speeds (80mph+). The ECU knows the correct speed though, according to my GPS and PSI3 unit -- it is the speedometer that is lying.

The best deal I see on wheels seem to be the Rota SDR 17x7.5 at $650 a set, shipped (ET48, 18 lbs). I'm considering those for my track wheels (where I don't care so much about width). Another good deal are the new SSR Competition 17x8.5 (ET48, ~15.3 lbs) at about $1600/set which Tirerack should have in a month or two (which they say _do_ fit over the STi calipers, unlike the currect SSRs). I'm thinking about those for autocross wheels. Other choices include the Advan TCII (17x8.5, very light) at $2500 or the Fikse Profil 10 available in just about any size you want, but $3200 a set. I believe the Volk TE37 and CE28N fit as well, at slightly over $2000.

Going to 8 or 8.5 inch wheels should help a lot even without going wider on the tire. I would guess 235s should fit. One problem I'm seeing is that (1) going to a wider wheel would make tire clearance more critical, and (2) Hoosiers and Kumhos are probably wider than normal tires anyway -- so a good fitting Cooper doesn't necessarily mean a good fitting Hoosier. Let's see -- Ecsta 235/40, Victoracer 245/45 or 255/40, or Hoosier 245/40 ($$$). Not even counting the new race tires for next year, though it looks unlikely they'll make anything to fit our sizes right away anyway.

If anyone does find out what fits or doesn't, do tell. I'm trying to figure out the best way to determine this without buying a whole set of tires just to try it out.
 

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WRX_Mundi,

Sounds like you've done your homework on rims. Do you know for certain that the 48mm offset will not cause the tires to rub? I wouldn't think so but want to confirm before I drop $$$. Also, what's your opinion of the gc-6's at www.prodrive-usa.com? They look great and are forged like the SSR's. What is the PSI3 unit? I know the speedoff is off by exactly what you say. I'm surprised to see that the ECU knows what's going on. Thanks for any info.
 

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STIMPV1 said:
Sounds like you've done your homework on rims.
After finding out the prices for my very limited choices last June I really got into looking around for solutions.

Do you know for certain that the 48mm offset will not cause the tires to rub? I wouldn't think so but want to confirm before I drop $$$.
I have seen someone driving at the road track with the Rotas and they worked fine for him. I spoke to the person at subydude.com who also indicated the Rota SDRs in 17x7.5 will fit the STi. I have no idea what tire size these people are using though. The Prodrive link below indicates a 48mm offset for their 17x7.5 wheels which they claim fit the STi.

Same story with the Fikse wheels, where I was told 17x8.5 fit, and the same for the new 17x8.5 SSR Competitions -- nobody has indicated what tire size was used for the test. Also, I'm looking at changing out the springs and possibly struts, so fitment might get even harder. Found an interesting quote from Fred Puhn's handling book, where he says, "For best handling use a rim width at least as wide as the tire tread." And continues that even wider is better if possible, and effectively stiffens the sidewalls. The V700 tread width for 225/45-17 is 8.6", and even bigger for the Hoosiers, so going to the wider rim is probably a good thing if you're serious.

Also, what's your opinion of the gc-6's at www.prodrive-usa.com? They look great and are forged like the SSR's.
I haven't really looked at them. They do look attractive and the price isn't too bad though the SSR's should be a bit cheaper. The 17x8's use a ET43 offset -- is that going to work well? Don't know.

What is the PSI3 unit? I know the speedoff is off by exactly what you say. I'm surprised to see that the ECU knows what's going on. Thanks for any info.
The PSI3 SECS unit is made by PSI^3 Automotice Technology in England, and resold by a number of places in the States, including Quantum Racing. It plugs into the ODB-II port underneath the steering wheel, and then displays all kinds of info from the ECU. It's a breeze to install since there is just that one plug which includes power. Shows things like road speed, RPM, intake air temperature, coolant temperature, throttle percentage, boost, and so on. It will keep track of the peak value for some items, which is handy for speed (everyone always wants to know how fast you went, and this keeps you from having to look at the speedo or do all the calculations in your head (OK, so if I was at about 5000 rpm in 6th, that means I was doing...? mph).
 
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