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-   -   Kumho Victoracers V700 (https://www.rx7club.com/race-car-tech-103/kumho-victoracers-v700-379313/)

jose-rs1 12-22-04 08:10 AM

Kumho Victoracers V700
 
Full Tread, Heat Cycled or Shaved?
Which one is best for road racing?

Umrswimr 12-22-04 08:11 AM

Road racing? I would say shaved. You can heat cycle them yourself for free.

macdaddy 12-22-04 09:45 AM

agree - shaved. heat cycle them yourself.

My personal experience with the V700s is that they are good for autocross, but get greasy after 3-4 hard laps on a road course. The 710's (now that they supposedly have the delamination problem fixed) would probably be a better choice.

Pricier, but long-lasting (sticky down to the cords) are the Toyo Proxes RA-1s - would also get them shaved and heat cycle them yourself. Don't know about availability in the DR, though - I get mine here in the states from Appalachian Race Tire. If we cross paths at the race track, they mount them for free. If not, they will UPS them to me. http://www.racetire.com/

jose-rs1 12-22-04 12:03 PM

How do you HEAT CYCLE them?
for our racing series we are only allowed 700's, any kind.

SHAVED are the same tires and compound, you just don't have to break them in. RIGHT?
HEAT CYCLE are to last longer. with he same grip as regulars.

edmcguirk 12-22-04 12:31 PM

I think the theory is that there are many different length "long chain molecules" in a tire that has not been through a heat cycle. Bringing the tires up to operating temperatures and then allowing them to cool for at least 24 hours will break the molecules that are too long and cross-link the molecules that are too short.

But anyway, the tires are a little too soft until they have had a heat cycle and they will wear out immediately if you run them hard.

Similar story for shaving. The rubber can shed heat more easily if it is thinner so the tread blocks won't squirm as much. Theoretically a tire will last longer if it is thinner to start with (never worked for me though). And the thinner tread will also grip a bit better.

On the other hand, you want full tread depth if you are going to run in the rain. And in general, you really need experience to take full advantage of these tweeks.

I'm cheap and my skill level puts me just a little ahead of the middle of the pack. I buy full tread non heat cycled tires. I put some miles on the street to do my own heat cycle and I don't really drive at the skill level to take full advantage of a shaved tire. I prefer getting a few extra weekends out of a full tread depth tire.

but that's just me
ed

DamonB 12-22-04 12:56 PM

Full tread is fine for autox. For road race duty the tire should be shaved or it will overheat. When overheated the tire becomes a little greasy and also wears much faster.

I heat cycle my V700's and always feel grip go away before the tread does.

jose-rs1 12-23-04 07:40 PM

so the best choice, is to buy SHAVED and HEAT CYCLED
or just SHAVED and HEAT CYCLED them yourself.

how long should these tires last? any ideas that can help.

macdaddy 12-23-04 08:50 PM

Depends on how hard you drive (or overdrive) the tires, how much negative camber you're running, the track surface, etc. I would guess if you are racing sprints (20-30 minutes), with about an hour of track time (practice, qualifying, and racing) per race, you ought to be able to get at least 6 or 8 races (or the equivilent testing time) out of them. YMMV - check with the guys in your series with similar cars and see what their experience is.

redrotorR1 12-24-04 11:25 AM


Originally Posted by jose-rs1
so the best choice, is to buy SHAVED and HEAT CYCLED
or just SHAVED and HEAT CYCLED them yourself.

how long should these tires last? any ideas that can help.

You're talking about a difference of $15/tire. $60 to shave the tires. $60 to heat cycle them. The Victoracer V700 can be run at full tread without chunking issues. I've done it several times .... however, the tire is fastest on its first few laps. After enough heat builds up, the tires get greasy and your laptimes will fall off. Shaved tires will be less affected by the problem; however the lifetime of the tires will be less. Keep in mind, most tires will be noncompetitive well before the tread depth gets worn out.

John Magnuson 12-29-04 01:27 PM

I used to run the Victoracer V700 at track days with good results. However, I have now switched to the Toyo RA1 tires because I find they last at least twice as long. I do believe that the Victoracers where a little bit stickier. I run both tires full tread. If you're competing professionally and winning is imporant you'll need to get them shaved.

-John


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