KumHo Ecsta V730
 

Has anyone run these on the track yet?

Any idea how they compare to the V720 and other 200 TW tires - RS4, RT660, ZIII, RE-71R, A052?
Pricing is very nice too - $600 for a set of 255 square.

https://www.tirerack.com/tires/tires...30XL&tab=Sizes

They have a nice tread profile, with very large outer blocks that look like they should hold firm under cornering with minimal squirm. Minimal void space too. It looks like an NT-01 with deeper grooves for water evacuation.

https://cimg8.ibsrv.net/gimg/www.s2k...821c8ddd72.png

NT-01 for comparison below:
https://cimg6.ibsrv.net/gimg/www.s2k...b0f12b33b0.png

Kumho are trash, worst tire there is, sticky for first 1000 miles then they turn into ice cubes , cup2, re-71 and advan are king but the hancook last the longest

I have them, my personal impressions, it's like the 660 and RS4 had a child. It has the endurance of the RS4 with almost as much grip as the 660. It likes low pressures, I ran it 27psi hot.

Ran them this past weekend at Streets of Willow. Running them again at Buttonwillow for the first time this week. Been reading more on pressures, yes, definitely seems like it wants lower pressures. I was running it at 33 hot and still managed to beat my PB at SOWS-CCW by 2.5 seconds (when i was on NT-01s in slightly warmer weather).

Will definitely be running lower pressures this weekend. It seems that the super stiff sidewalls like you to have lower pressures to be able to use the whole contact patch, and so that you can get more heat into them.

Great tire, under-rated tire. Awesome for lapping on track. Price is great too. $651 for a set of 4x 255 ($162 ea). Compared to A-052 which is $1052 for a set of 4x 255 ($263 ea).

It's like a grippier NT-01 with slightly peakier break away characteristics. I managed to finally break sub-2:00 at buttonwillow on the last lap of the first session (got 11 laps in total - 13 if including warm up and cool down laps). The V730 kept getting faster and faster through out the session (complete opposite of the A-052 where the tire was done after the first 2 hot laps - still felt good, but was slow). I checked my temps after the first session and had 31 PSI hot. I dropped the pressures more, per slowcrash's recommendations to run 27-28 hot - thanks (GRM also had the same recs), and the grip improved. I was able to set a few more sub-2 laps in the subsequent 2 sessions. They are super consistent for a whole 25 minute hotlapping session.
Wear rate look awesome. They start out with 8.3/32nds worth of tread. After two track days at 3 sessions each, i've only just worn away the other grooves. I'll try to get some pictures up later.

Now to the not so great stuff.
They do take a while to get up to temp. Including the initial warm up lap, I'd say another 2 hot laps at about 8/10ths to really get some heat into them. This was in 50-60F ambient, so likely much better in summer. The other bit is that they are a bit peaky and have sharper break-away characteristics - reminded me of the Dunlop Direzza ZII (haven't driven the Z-III yet). They aren't as grippy as an A-052, and likely are a few tenths off of the RT660.


Some other info, super super stiff side walls. I was running -3.5 camber and at 27 hot PSI, I was barely touching to little triangle on the side walls. I could definitely dial down the camber, which is actually a good thing. These tires will work great on camber limited cars. I'm looking forward to running these in warmer weather. I bet they'll wake up even more and will hold up well for the whole session. I'd say that this is my new go to tire.

For reference, I tried the A-052 in a smaller size (245) and was not impressed with them, especially for the cost - I only got 9 hot sessions out of them (3 session x 3 track days) before they were toast. My previous go to tires were 100TW tires - NT-01 and Toyo RA-1

GRM recently did a comparison test to the A-052 on a civic hatch.
https://grassrootsmotorsports.com/ar...hang-yokohama/

TL;DR summary
Pros

• Excellent price
• Consistent grip for a whole 11+ laps (25+ minute sessions)
• Stiff side walls, can run less camber
• Great wear rate so far
• Grippier and faster than NT-01 and RA-1

Cons

• Peaky grip
• Sharper break-away characteristics, no audible feedback
• Needs heat and takes time to get up to operating temp
• Not as grippy as A-052 and likely a few tenths slower than RT660

Any more (long term) updates on these to share? Just picked up a set and heading out to buttonwillow this weekend.

First track day since covid, wish me luck!

Kid #2 was born at the end of January. Car has been sitting on a battery tender since that December buttonwillow track weekend - hasn't moved since. Realistically, I probably won't make it back to the track until 2023...

Main thing for this tire - lower pressures when hot. 27PSI hot, try starting out at 25PSI cool (right before you head out on track for the first session). Adjust accordingly from there. Definitely don't run higher than 29PSI hot.

Also, not sure if I already stated it, but you can run far less camber with these tires. I think 3.0 is likely sufficient. The 3.5 that I had to run with A052s and other tires is too much for this tire.

Read your reply a little late but thanks anyway. I ended up running about 30psi hot but definitely could've gone lower. It was my first time to buttonwillow so it was more about learning the track than anything else. Tires were fairly new as well (~200 mi) so they weren't properly broken in yet. Grip was consistent once they got up to temp. Hopefully will get to attend one or two more events before the year is up.

Congrats on baby #2! My last child was born during the start of the pandemic (June 2020) and yesterday was my first track day since so I understand priorities change. #dadlife