Toyo RA-1 : 205/255 or 235/275?

[DONYMO]

I will be buying Toyo RA-1 tires for my SSR-Competition wheels soon. I am debating which tire sizes to use. Has anyone tried 205/40-17 fronts with 255/40-17 rears (instead of 235 front and 275 rear)?

The reason I am leaning toward the 205 / 255 combo is weight. The RA-1 fronts, in the 205/40-17 size, are 5 pounds lighter PER TIRE than the 235's. Also, when using the 255 rear instead of the 275 rear, I will save 3.1 pounds per tire.

I am thinking that having a total of 16.2 lbs less unsprung weight will be more advantageous than having 1 inch wider fronts and 0.7 inch wider rears.

So...if you have tried the 205 front / 255 rear combo, let me know your thoughts on how they performed. My concern is that the car may push too much (with 205 fronts) when cornering (i.e. I will lose too much front grip in relation to the rears).

Thanks!

 

[sjs]

I can't answer your question but I understand your logic. The difference in unsprung weight may not make a huge difference either, but I'd still start with the narrower tires assuming they are a good fit for the wheel widths.

Have you raced on RA-1s? I use them on the 510 when running vintage events that don't allow the full race tires. Personally I like the way they work, but they seem to have an evil reputation at the limits and other drivers are always surprised at how easily and controllably my car is drifted through corners on them. I suspect a properly controlled suspension is a big factor.

 

[Peter Mills]

Donymo:
Last year I tried RA-1's 235/40/17F and 275/35/18R. Absolutely love them tires. I had mine shaved to 4/32 and I still have rubber left for this year. I do have some rubbing at full lock, but I can live with that. 205/40/17 is too narrow for front, don't use that size.

 

[nsxtasy]

Hi Don,

I have heard great things about the RA-1, which is why I'm in the process of switching over to them from the A032R for my track events.

I disagree with Peter about the 205/40-17 for the front, and think that should work fine; after all, that's the same treadwidth as the stock size 205/50-15 that I've been using on the track with excellent results.

One other consideration that you did not mention - I'm pretty sure you will find that you can fit a set of the 205 and 235 tires inside the car to take them to the track, and I doubt that you can do this with the 235 and 275. Also, the 235 will rub, as Peter noted.

As you have obviously recognized, you can make a case either way - and I'm quite confident that any differences between the two will be minimal. So take your pick, and try them out.

See you at the track this weekend. (Let me know if you would like me to show you all the tricks about fitting the tires in the car.)

 

[DONYMO]

Ken...I would be using 255 rears (rear wheels are 9.5" wide) with the 205's. Do larger rears with the 205 present any problems vs the stock setup?

 

[Andrie Hartanto]

For the SSR comp, I recommend using 205 front and 255 rear. This is the better size to fit the size rims you have. You will get broader temperature distribution and easier to maintain the tire pressure you want.

 

[nsxtasy]

Ken...I would be using 255 rears (rear wheels are 9.5" wide) with the 205's. Do larger rears with the 205 present any problems vs the stock setup?

Not that I can think of - it should be fine, I would think...

 

[Andrie Hartanto]

205/255 are fine. I used to run them back in the days.

Ken,

you got to try toyo RA1. It is a much better tire than A032R. Last longer, grip better, more consistent and more resistant to heat.

 

[docjohn]

Hey there Don,I'm running the ssr comps and 235/17 275/17 combo.I have no problems other than some front rub.My springs are zanardis.My take on this topic is that iether way you will have fun.I did not do any scientific study before choosing tire sizes I just went with the widest that would fit.I like this tire for its durability and consistancy.Plus I didnt care about ultimate performance since I don't compete and we're talking about hpde's not races.So I did'nt get too technical with the physics of tire size vs rim width.I got the 7 in fronts and 9.5 rears from tire rack.Quite honestly the comps are light enough that I feel a difference in the cars braking and accel vs my blitz wheels with 265/35/17 so3 which are also heavy tires.

 

[DONYMO]

Thanks for all the replies!
I am going to go with the 205/255 combo.

Take care!
Don

 

[sjs]

How embarrassing. My earlier comments about the RA-1 being unforgiving should have been for the A032R, which is what I run on the 510 for vintage events. People keep telling me to try the RA-1 but last time I needed tires there was no stock nationwide in my size. Man, been too long since I raced if I can't even remember what tires I run!

Speaking of which, why am I doing this rather than working in the garage?