I bought a set of 255x40x17 Toyo RA1. I will be mounting them on my car for daily driving and occasional track use. I was reading that you need to run between -2.5 and -5.0 camber if not you will get uneven tread wear. My car gets between 200-300 miles per month so tread life should not matter. Anyone running these tires that can give some advice on the alignment? Would running -3.5 upfront and -2.5 out back be a good setup? Will I need special camber bolts for the rear to get to -2.5?

 

Within practical limits, more negative camber will give you more grip at that end of the car. Optimum camber to give a neutral handling car will depend on the spring rates and sway bars used. The stiffness of the suspension bushings will also have an effect.

If you are using higher-than-stock spring rates with a similar front/rear rate ratio to stock plus the stock swaybars, you need a lot more negative camber in the front. To get roughly neutral handing, you need about -3 in the front and -0.5 in the back. This is a very rough estimate. Personally, I wouldn't go beyond -3 in the front for any street-driven car.

If you post more info about your suspension, you'll probably get better advice.

I use the same RA1s. Great tires on a (at least) 9 inch rim.

 

I just re-read your post. Your comment about uneven tread wear with <-2.5 degrees front only applies to track-only driving. It will also depend on what rim you are using. Narrower rim -> more rollover -> more outside shoulder wear.

If you run -2 and above, you will noticibly more wear on the inside shoulders with street use.

 

I am using a 17x10 rim. I have megan coilovers with 10k spring up front and 8k spring out back. I also have a hotchkiss swaybar.

 

Why did you decide to go 255?

 

i could have gone with wider but from what i have seen the 275x40 doesn't seem like a good fit since its to tall.

 

I've gone through several sets of 255/40 RA-1s. I have some for sale in my sig!

According to Toyo, the RA-1s like a minumum of 3.0 degrees of negative camber. Whether that is practical for you is a different story. I haven't found too much uneven wear from driving on the street from this much camber (I run 3.0 up front). Toe, IMO, will kill your tires faster than anything else.

As far as your rear camber, you will probably need some crash bolts to get to -2.5 degrees. I run 3.0 up front and 1.2 rear.

BTW, get some bigger rubber with a 17x10 wheels! 255 is freakin' tiny. 295/40!!! Roll and pull your fenders.

 

Question? What tire pressure are you running?

 

right now I am just running 35psi all around. that is another good question. what is a good starting point psi when I get to the track? I will be doing autox this weekend.

so far the grip on the tires without a alignment is amazing. way better than the falken rt615 I had on.

 

anyone got an estimate life of these tires on tyhe street?

they are not gonna last as long as a set of rt-615's right????

 

I went from the stock advans to the RT-615s (255s) and I absolutely hated the 615s. I wouldn't even consider them as a track tire. I'm currently back on Advans for the track but my next set of tires will be RA1s. I'm hoping they will feel as good as the ADVANS do.

 

Don't count on it. The RA1's may be stickier than the Advans but the feel won't be as good. The have a softer sidewall. If you want the grip of an RA1 with a stiffer sidewall look into the NT01.

 

..double post

 

I dont know that I agree with that. At less air pressure the RA1 feels better than the Advan. Nitto and Toyo are two halves of the same company and the carcass construction is DSOC II in both. About the only difference is tread that I am familiar with. My 275/40's at 32psi are pretty incredible compared to the stock advans or even my 275/35-18 street tires.

 

I had stock size RA1s on stock wheels with -3 camber. The inner shoulder was nearly gone in about 2K miles. That's way too much camber for street driving with an R compound tire. If you drive for any amount of time on the highway the inside edge of the tire will be so hot that it will almost burn you, while the outside edge will be just warm. Toyo's camber recommendations are for competition use.

Also, my experience switching from Advans to RA1s was that grip was much better with the RA1s, but turn in response was much worse. When I saw that I was burning out my RA1s on the street, I dialed back the alignment and got PS2s for the street. They feel similar to the RA1s but with less ultimate grip (much better ride than the Advans though).