DJazidca

I'm currently running Goodyear F1 Supercars at the track (only 2 events so far). I have a separate set of Supercars for the street. One of my rear street tires took a nail to the shoulder and is not repairable.

Ultimately I want to move to an R compound race tire for the track. Would it make sense to convert my rear F1 Supercars back into street tires - and then run R compound tires at the rear and F1 Supercars on the front at track events for awhile? As soon as the front Supercars wear out, I would be running all R compund tires at the track.

Would running F1 supercars at the front and R compound tires at the rear cause any problems? Would I get any benefit from softer rear tires at the track?

Joy of 6

Would running F1 supercars at the front and R compound tires at the rear cause any problems? Would I get any benefit from softer rear tires at the track?[/QUOTE]

I know that someone smarter than me will fill in the details, but the short answer is No. Don't do it. You will have two different kinds of tread patterns and two diffrerent treadwear numbers. both will lead to unstable cornering. the front will slide and the rear will stick, so you will be "pushing" arount all corners. there is give with the street tires but none with the R's. It will snap spin if you loose it. You will be setting your self up for a big off and you can get hurt. So as I led off with, there are some smarter people who can give you more details.

kelp

Not to mention that posthumously you would also place highly in the Darwin Corvette Awards Book.

rasrboy

Please dont' do that!

95jersey

Very bad idea! Mixing R compound is one thing, but street and r compounds is a bad thing. You will basically get massive understeer and the car will probably handle worse than if you just stayed with street tires.

Timz06

Try putting the r's up front and let us know how she handles! I have tried this before for fun, and after one lap, pulled off into the pits. Don't do it! Just run one or the other.

VetteDrmr

As one that has run exactly one set of matched tires during my autox/DE experience, and mixed and matched according to my budgetary needs (currently running 275 seriesToyo RA-1s up front, 315 series V700 Victoracers in back), let me give you some real world experience.

First off, the car will not turn itself inside out, the engine will not explode, and death, destruction, and mayhem are not guaranteed to occur.

What will happen is your car will not be balanced, traction-wise. When you change tire width, compounds, or even just new tires to one end of the car, you will be adding grip to that end while not changing it at the other (duh!).

If you add R compound tires to the rears and keep your current tires up front, you will increase your rear grip, probably BY A TON. Therefore you'll experience understeer on corner exit much more so than before, because you'll have more traction at the rear, getting more power down earlier. Just like overcooking a corner entrance and understeering, you now can "overcook" a corner exit and slide the front tires. That means you have to drive the car.

Obviously, if you put new tires on the fronts and not on the rears the opposite will happen. You will be able to dive into the corners much deeper, and if you trail brake you'll get the rear to slide out from underneath you much easier. So, it's back to basics: brake in a straight line, turn in, and power out. Since you have more front grip, you will have the rear sliding a lot more if you try to push harder than you would have with street tires all around.

With all that said, running your C5 with fresh R compounds all around is an absolute blast!

HTH, and have a good one,
Mike

Diesel68

I agree with VetteDrmr. Mixing tires is not the end of the world, but you need to be careful of how it is done. I have mixed it up both ways with street tires and R's, and it is not too bad as long as you know what to expect.

I wouldn't worry much about having R's on the rear, as understeer can sometimes be a good thing. You just have to realize that the car is going to stick on corner exit and that you can over power the front tires. What I liked about that combo is that I am able to do some heavy trail braking and the car still stays under me.

I would be very careful to mount only R's on the front though. The rear will be touchy and you have to be very careful and deliberate with the power. Smooth inputs are a must. I wouldn't recommend it to someone still learning car control.

Get some Nitto 555R2's as your rear tires for replacements. It is a step up with out it completely throwing your balance off. It is also a great entry level R tire that will give you plenty of miles.

Independent1

^^I think another potential problem with putting the Rs on the front is that the rears may lock up first under hard braking due to less traction than the Rs, and that is not good.

Personally, I would not mix and match different types of tires. I would guess also that the optimum operating temperature of the tires is quite different with the R compounds doing better when they are hot versus the non-R rubber.

varkwso

I have done it on my Camaro - street and R's. I mix R's (or I mix street tire brands on axle pairs) all the time due to economics on my C5s. Brands, age, sizes and cord showing - I have done pretty much all of them.

It does make it more "exciting" to drive - but it is not the end of life as we know it. Others have stated the considerations. Be careful, drive the car and have fun.

I wish I had a new matched set of NT-01s, R6s, or Kumhos every weekend - will not happen - it is faster and more predictable.

sothpaw2

I have put Nitto RRRII R-comps (100 treadwear) on the back of my C4 and F1 Supercars on the front--both brand new. The handling was pretty good but as others have mentioned to you I was ultimately limited by what the fronts (supercars) could do.

The down side that nobody brought up specifically was that I burned up a set of rear pads in 2 days, 1 event, that were brand new. The fronts were hardly touched, maybe they wore 10%? The rears actually didn't make it completely thru the second day, I missed as session.

So your brake bias is going to be off and you can see why. I wasn't having any lockup problems or anything and the brakes were great. You will just have to change the pads often.

You might consider finding a used F1SC to replace the damaged one. I have 275-40-17's used in good shape and I sold a few rears this year, 295-35-18.

DJazidca

Very interesting insights. Thanks for the replies.

Jason

Good to know I'm not the only one that's had to scrounge for tires.

VetteDrmr

From personal experience ABS does a good job of keeping that under control. You lose braking capability on the front end as ABS engages, but the rears don't lock up.

Interesting point about having more brake pad wear on the rear with R compounds on that end of the car. Does show how much more braking you can get done from that end of the car before the fronts start sliding, but a good point to look out for.

Have a good one,
Mike