Kumho Ecsta V70A feedback
 

I am planning on possibly entering the local time attack in a few months and need to decide on a tire. My car is a full street car with only suspension modifications so its heavy and the stock '99 LS1 doesn't make much power, but initial testing has shown that the car is quite fast on hoosier R6's as-is. I don't want to run on a 285 street tire so I'm forced to run modified class. Unfortunately hoosiers are not allowed in modified class so I need a minimum 50 treadwear tire. I'm trying to get as close to the grip as the hoosier R6 as possible. I think the tire to get is the Kumho V70A with a 305 all the way around and shaved. Any feedback is appreciated. I'm way outclassed on paper but looking at the most recent lap times in modified rwd my car is faster as long as the tires are not too far off the hoosiers.
thanks in advance!
-V

Rasrboy is the Kumho expert, hopefully he will chime in.

Anyone have any info on these or suggestions for other tires? I have had a hard time finding any help in terms of what tire to run. It's getting close and I need to make a purchase soon.

thanks,
-V

The Hoosier A6 is the first choice...

Now you said Hoosiers are not allowed......my second choice would be Kumho V710......

If they don't let you run those......then the Kumho you mentioned wouldn't be too bad.

Kumho
 

We run KUMHO tires on ALL our school cars (14) and on our race cars (4) and find them very predictable and stable. There are many other brands out there, and you will find different oppinions from people that know and don't know anything about tires. The bottom line is you have to choose a tire that works well and doesn't hurt your pocket book. The KUMHO V70A will work and last for many runs. Using the same size all around you might have to turn your traction control off, and make sure to run the proper tire pressures. :thumbs:

The V70 is a good ol workhorse of a tire and with proper care and feeding can work out well for you in this situation... Although it will never match the grip of a V710 or a Hooter it is a nice predictable tire that likes to run at a nice consistant slip angle of around 6%

I would say the most important thing to note about the V70 is the fall off from the "magic lap" to right afterwards :eek: IOW, all the KUMHOs have always had the "MAGIC" lap in them for qualifying and you have to NAIL it perfectly or lose it forever because after the second HOT full on lap that's it! It's gone and the tire will never be as fast again! With the V710 it falls off maybe 1 or 2% and stays there forever regardless of heatcycling...

With the V70 it will fall off horribly right after the magic lap maybe 3% + and not come back to within that 1% + or - window until it cools COMPLETELY off and cycles and best to let it sit for 24hr

If you keep pounding on it green it just gets greasier...

Also use a pyro for temps AND look carefully at wear and how the contact is made with track surface to get proper pressures these tires can fool you...

They are great tires and I believe there's still a couple track records here and there around the country held by those ol V70 skins maybe even in your neck of the woods... Can you say Thunderhill...?? :thumbs:

~s

Thanks for the input guys. I only have experience with the R6's on my C5. I've run the toyos (which are legal) on my race car for years, but those are heavy and lack grip substantially compared to even well used hoosiers. The corvette I've ran it at t-hill once a few months ago and on used R6's I was turning 2min flat over the top at t-hill. Thats north of 3400lbs. Stock FRC with brakes, suspension, and tires. Stock power. If I pushed a little harder (it was a track day with very restricted passing and very slow drivers) sub 2 min was no problem. I have recently added headers for a very noticable power gain. I estimate that with fresh A compounds and open track I can run easy mid 1:50's over the top and low 1:50's with bypass. That is what tells me I may have a decent chance at doing well at the time attack.
Anyhow, what pressures are recommended with the V700/70A. I need to rip off my fast lap in less than 5 laps as I'm sure there will be traffic after that. The hoosiers I've found like extremely low cold pressures.
thanks,
-V

I'll preface this with I've not run on the v700's but I've never heard good things about them.

I have run on, RA-1's, R888's, NT-01's, and They all have their perks. I'd lean to the NT-01's since they have a lot in vette sizing, but if you can snag some used (or shaved) RA-1's thats another good bet. 888's are great tires as well, but I'm not sure about their sizing.

Last year at my local track, the street FWD winner was a 1999 FRC with Z06 shocks, sways, and 275's all the way around. I think it made 342 on a dyno dynamics the day before. The car right behind him was a nearly race prepared e36 m3 that lost by .5 seconds :)

I would start at 25psi front, 23psi rear COLD and you should reach optimum HOT pressures of 34psi at 180 degrees.

SBW please chime in, you've got as much information since we have both been long time KUMHO sponsored. :cheers:

Thanks for the pressure recommendations. I'll give them a shot. Unfortunately, I will have no previous testing with these. I plan on mounting them at the track and other than the morning practice I won't have any previous time on them. Only 3 sessions I believe to make them stick.
I've searched around some more and it seems that everyone seems to like running the toyos or nittos. I'll give it another day or so for some more feedback. I wish the kumho guy would add some info. I've done everything I can to conatct him. Only problem I see is that tire rack shows just a few tires left.

Hey Henry!!

How you doin? I thought that was you! I think those pressure ring a bell in my brain and are about spot on except we always used N20 so not sure how that plays out with air from the compressor...?

Trackboss,

what sizes are you running? I have some new V700's in 17" & 18" in Corvette sizes in the raceshop leftover...

PM me with your preference and I'll look around to see what I can do for you... :thumbs:

I also have a bunch of shaved and unshaved Toyo RA1's:thumbs:

in hoosiers I run a 295/315 combo. The kumhos I just went ahead and ordered. 305 all the way around. Wheels are all 18"

Just stumbled across this thread, SGSVETTE (Henry) and Naykid (SBW) are dead on with your requested info. Scotty has a ton more time on these tires than I and so does Henry I am sure. Take their advise as they have been LONG TIME Kumho drivers & friends and they know these tires. I race & work around V710's mostly so when you are ready to hook even more, that's your tire if you choose to.

SIDNEY004- I do know a few things being in the business but by no means am I an expert. :willy: Thanks though! :D

I try to keep out of tire discussions in general, because Kumho is not a supporting vender here. Trust me, I tried to get them to get on here but that BUDGET word came up! :toetap: Plus, I don't want to wear out my welcome as a member myself and break the forum rules. Sorry & I hope you understand.:thumbs:

You & others are welcome to PM me if you have any questions and I will try to answer your questions off the forum or I will find someone that can. :thumbs:

Aaron :cheers:

I sent you a couple pm/email a few days ago with no response. Like I said, I bought the tires and requested more shaving than normal. I plan on only running a few laps at a time. Any reason I should start a little higher pressure? How quickly do they come in? Also, I have no time to heat cycle. I will have one practice in the morning with them then straight to competition so I really have to nail it from the beginning if I want to get the most out of them.
If anything these are about $400 less a set than the toyo, nitto, yokohama that seem to be the most popular tire for the class.
thanks,
-V

V700
 

Track Boss,

I ran the V700 at Thunderhill, then the A6's in similar conditions.
The A6's were 4.5 seconds faster, fwiw.

JRL

Good info, thanks. How many heat cycles were on the kumhos when you ran them there and shaved or no?

The kumhos were shaved and used for a couple of track days, maybe 6-8 heat cycles.

JRL

How many heat cycles on the hoosiers?

V700
 

The hoosiers were bought used as takeoffs, after someone ran them at the 2008 SCCA runoffs in Topeka. Then I put about 6-7 heat cycles on them. My car is a stock 2003 Z06. I ran 2:01.0 on the A6 and 2:05.5 on the V700, about 65 degrees weather both days. at Thill. The kumho got a little slippery during long runs, 20-25 minute run groups.
I'm running NASA TT this year. Good luck at Buttonwillow.

JRL

A little disappointing to hear they were that much slower than used up hoosiers.
If you are going to sears next week I'll be there in TT. Saturday was full. I'm sure nasa has cramed as many entries as possible so getting a clean lap will be a challenge. If you are attending we can talk more about the kumhos then.
thanks,
-V