Hi,

Just want to pick your brain to do a quick sanity check.

I run on 255/335 or 265/335 18" tires depending of the availability and it happened so what I got a set of 335 toyo RA1s rears for next season.
Other tires I have in reserve are new fronts 265 kumho v700, and used 255 toyo r888 with 50% tread left. My previous tires were v700 kumhos, fronts are shot and have to be replaced, rears are half way shot.

question is - what r-comps are safe enough to mix? I suppose kumho v70a compound will probably melt first compared to toyo RA1, what about R888?
as essentially logical way now is to mount used r888 combined with current used v700 in rear, get them all corded, then apparently put on new v700 fronts with RA1 in rear.

my fronts get corded faster than rears, probably due to too much car throwing at auto-x, so it is quite problematic to estimate exact tire wear rate. i would generally prefer to have stickier tires in front but I do not want to get into situation when one axle will melt while other is only getting warmed up. have anybody here tried to do such a stunt with those brands? how do RA1 and V700 tires feel in a mix?

Or should I stop this non-sense and just sell v700 and get complete RA1 tires setup with 245 fronts instead despite of loosing extra grip compared to 265 tires and try to compensae that with different sway bars setup? Or perhaps put on new V700 fronts with 50% done v700 rears, wait for them all to cord, then buy new RA1 fronts and put them on with rear RA1 toyos? or do I just overthink this entire scheme as none of that really matters and all those tires have such similar grip that none of those brands permutations would be even noticable?

 

Not wise to mix R-Comps. I have run mixed before and each tire warms up different, has different grip levels and different feel. You can mix to just practice but you will be unable to get realistic times. I ran Hoosier R6 rears and BFG R1's front. The Hoosiers of course felt better, biggest problem was the transient response of the front and rear felt detached and not cohesive so it didn't inspire confidence. I ran them as they both had a day left on them and the front Hoosiers had already been corded so I threw the R1's on to finish them off.

 

I see. That makes sense definitely, I am just wondering if overall similarity of those DOT r-comps I have will minimize traction diffs, or not.

So let`s forget about Kumhos as they have totally different compound. What about running 255/35 R888 Toyos in front with 335/30 RA1 Toyos in rear?
Do they also behave differently to degree that makes them unsable together?

 

I would not recommend mixing the compounds.

 

I wonder if new RA1 tires have same compound s R888 tires or not. I get conflicting info about this. Old ones were different, but what about new ones?
I just asked tiresdirect,net who sold me those RA1s and Tim McMillin says R888 and RA1 have some compound of rubber. Go figure.

I assume that nitto nt01 and toyo R888 are same, so they can be mixed safely, right?

 

I was told by my tire dealer that the RA1's and NT01's are the same compound, and he is a racer himself. I personally wouldn't mix brands especially for the track.

 

NT-01 and R888 are basically the same compound with different tread/carcass..Nt-01 better bang for the buck but less sizes available...

 

it is all about what site has a current discount sales on what tires, that is why it comes to matching this sh$t afterwards... if one pays full retail on a complete set none of that would be an issue...

 

so current working theory is that nitto NT01, Toyo RA1 and R888 are essentially using same exact rubber? that would be quite convenient if that`s true.

 

According to my tire dealer that is not true. The 888's heat cycle out before cording whereas the NT01's and the RA1's don't lose traction all the way to the cords. That is why the NT01's are considered a better value.

 

You have to be careful but it can work well.

In my GT3 I had the problem that my rears were heating up much faster than my fronts. I switched to a softer compound in the same tire for the front and the front/rear heating was much more even.

The primary concern is that the two tyres you choose will be at whatever the optimal temp is for each tire at the same times. I now run R888's in GG compound for the rear and DZ03 in R1 compound (medium) for the front. Both heat up at approximately the same rate, which I can control with more/less right foot. However, each has different grip characteristics and for this reason I would try to keep front and rear tires as similar as possible (with a slightly softer compound in the front).

 

same=ng

 

yea, same compound.