Tested these at a recent 2 day track event.

1. Kumho Ecsta MX Tires: I acquired a set of replacements for my daily driver azenis. Curious as I am, I decided to leave my track wheels and r compounds at home, and give the new Kumho a go.

It was hot at streets of willow this weekend - temps on Saturday were 94 - 95 F and in the high 80's low 90's on Sunday.

My initial impressions are: the tire has great grip. I ran sessions with passengers all day long, and the tires stayed consistent throughout - for those of you that are familiar with the streets of willow, you'll remember that it's very tight track. You're either turning, or braking or turning or braking - so it's very hard on the brakes and especially on the tires in my case since I don't have an LSD and all the turns have camber changes and undulations throughout.

The tires come up to temp fairly quickly: 3/4 through the 1st lap they felt good, and 1/2 way through the 2nd lap they were "on." I fell as if the kumho compound is softer than the azenis compound.

The temps that I used over the weekend varied with the conditions.

On Sunday (the hotter day) I started with 40 psi front HOT and 38 psi rear HOT - I was getting too much wear on the center section of the tread and dropped to 38 front HOT and 36 rear HOT. The drop in pressures worked in getting more even wear across the tire, but I didn't have enough time left on Sunday.

On Saturday (the cooler day) I started with Sunday’s HOT pressures of 38/36 but felt that was a little low on account of the cooler ambient temps and experienced some (very minor) sidewall rollover - I up'd the pressures incrementally by 1 psi after a series of outlaps and got the tires working a little better.

Overall, I'd say in extreme heat (95 F or more) the mx's probably work best (for me) somewhere around 38 psi HOT. This will vary with cars of different race weights - my car at close to 3000 lbs will require different pressures than a 2400lbs civic.

Conclusion: the azenis has met its match! The MX is a viable alternative to the azenis for road course use - auto-x people may wish to stay with the azenis as (I feel) it comes up to temperature sooner and is therefore "on" that much sooner.

That said, the MX felt more consistent (even in the high ambient temps) than the azenis and offered the same (if not more) absolute dry grip - this is what impressed me the most.

The only downside, however, is the amount of wear (which leads me to believe the mx is a softer compound than the azenis) - the mx's wore more in 2 days at the track than the azenis - how this will factor over the long run for someone who uses the mx consistently at the track, I don't know - but for the price and performance, I think it's a worthwhile trade-off.

Random Tangents:
Cobalt SPEC VR are still some of the best pads I've used.

My brake pedal feel still sucks (even after replacing m/c, brake lines, and lots of bleeding) - maybe I'll get a pimpy AP Racing dual m/c setup like RR98ITR.

I like ATE fluid

This & That: Radical West was there and they're starting a radical racing school

Lastly, saw my 1st U.S. Elise - gorgeous car. Interior is cool, and my 6'2" frame fit perfectly. The seats are awesome, fixed back and felt very supportive; the steering wheel was tiny and 3 spoke. The dash and gague cluster were intelligently, and intuativly designed - all the gauges were clearly visible and easy to read. Rear visibility was good, and the engine note was nice.

Couple disappointments, though: no trunk space at all - seriously zero. Brakes were a little underwhelming looking and didn't seem to jive with the car's overall "race" bred design. I was expecting big 2 piece floating rotors all around and 4 pots - not tiny disks and single piston calipers. The gear shift felt a little vague - unlike the s2000 which is crisp and direct; lastly, the price tag - 50k is a lot. Then again, I'm splitting hairs - the Elise is one of the coolest cars to ever grace these shores.




Modified by bb6h22a at 2:42 PM 8/31/2004

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bb6h22a &raquo;</TD></TR><TR><TD CLASS="quote">On Saturday (the cooler day) I started with Sunday’s HOT pressures </TD></TR></TABLE>The MX's are so fast you can travel through time!

GREAT SCOT! 1.21 GIGAWATTS!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bb6h22a &raquo;</TD></TR><TR><TD CLASS="quote">I was expecting big 2 piece floating rotors all around and 4 pots - not tiny disks and single piston calipers. </TD></TR></TABLE>

Its only slowing down 2,000 lbs

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bb6h22a &raquo;</TD></TR><TR><TD CLASS="quote">This & That: Radical West was there and they're starting a radical racing school </TD></TR></TABLE>

Whoa... more info?

Radicals = :superbling:

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TeamSlowdotOrg &raquo;</TD></TR><TR><TD CLASS="quote">The MX's are so fast you can travel through time!

GREAT SCOT! 1.21 GIGAWATTS!</TD></TR></TABLE>

No no... the MXs are so mega tiiiiiiiiiiiiiite and hot , that they stay hot for 24 hours.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">

Its only slowing down 2,000 lbs
</TD></TR></TABLE>

I know, I know but you know what I was getting at. Again, I concede that I'm splitting hairs.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Whoa... more info?

Radicals = :superbling:</TD></TR></TABLE>

The school is a 2day program @ 2000 bucks. (NASA, POC and SCCA accreditation to come sometime in Oct of this year). I was told that you get in excess of 500 actual track miles in the radical and tires, gas & all your racing gear is included. Your personal liability, should you stuff the car, is the first 5000 - so if you write the car off, you're out 5000 on top of your 2000 entry fee.

The rental program is 1200 / day and includes tires, gas, racing gear, track support etc - it's an arrive & drive deal - pretty cool, considering how much fun those cars are.

 

Very interesting. I've run MX's for a couple events now at the big track at WSIR and at Buttonwillow. My last set was Azenis sports, so I have that for comparison.

Some thoughts:
- I got the MX's to chunk. My Azenis's didn't do that as much.
- I had to run much higher pressures with the MX's to prevent rollover. I'm talking 50 psi range. I have maybe ~1.5 degrees of negative camber on a DC2.
- I agree that the MX's are softer. I definitely had more wear with them.
- I like the MX's on the street better. Quieter, softer ride, probably better in the rain (although I have yet to test that). I like the Azenis's better on the track. Stiffer sidewall, better steering response, but they do get greasy and the MX's don't do that. However, with the better wear on the track, I can tolerate a little sliding around. I'm cheap, so I'd rather have the tread life. I'm going back to them.

My .02.

 

OT: I daily drive my mx's in the rain (oregon) and they are fantastic. An azeni just doesn't compare in the rain, and for a daily driver tire in oregon that should be your first decision

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fidracer &raquo;</TD></TR><TR><TD CLASS="quote"> Quieter, </TD></TR></TABLE>

Definitely... Azenis sound like mud tires.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">softer ride,</TD></TR></TABLE>

Yep.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">probably better in the rain (although I have yet to test that).</TD></TR></TABLE>

Shaved MXs are scary in the rain. Much scarier than Azenis at the same tread depth. I never had a hint of hydroplaning with the Azenis.

 

I recently came up with a delimma between a taller 225 MX or the 215 Azenis... I was wondering if the extra width would be worth it on my 2700lb mule... hearing that the MX have less track-treadlife is news to me, but I guess its because the Azenis get "greasy" and stop wearing down as much???

 

I was unimpressed. Yes, they were very grippy and responded better to prolonged use at higher temps, but the SOFT sidewalls and the quick wear was alarming. Especially the sidewall roll. The air pressure necessary to reduce the sidewall roll was ridiculous. In turn, the steering response and 'feel' was much lower than I would have liked. The sidewall rollover definitely did not inspire ANY confidence to push hard. The alternative, upping the pressures tremendously, saw the tire wear worsen quickly.

I'll stick with Falkens.

 

I'm currently using a set of 245/40/17 MXs on 17x8" wheels on my WRX for daily driving, STX autocross and the occasional track event. I've got around 10k miles of street driving, probably 110 autocross runs out of them as it stands right now. They're getting close to 2/32" tread depth now. The rain performance leaves something to be desired at this point since things can get a bit scary. Much better when I removed the toe-out I had at the rear, now at zero-toe all around. They're noisy, but the sidewall stiffness isn't THAT bad. I use 42-45psi cold up front and 39-40 in the rear. Granted, I have -2.6 camber up front so that keeps the shoulders alive. Up front, I was using 37 psi cold for track and as I was actually seeing more pressure creep in the rear, so I dropped those down to 32psi cold.

On my earlier set of 225/50/16 MXs on stock 6.5" wide wheels, I ran 45-47psi cold up front and 52-55psi rear for autox to make the car rotate with stock suspension, -1.2 camber up front. On track I used 40/40psi to make the rear end calm down a bit, I was getting a bit more roll on the rear tires at that pressure.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hatch2k &raquo;</TD></TR><TR><TD CLASS="quote">I recently came up with a delimma between a taller 225 MX or the 215 Azenis... I was wondering if the extra width would be worth it on my 2700lb mule...</TD></TR></TABLE>
Azenis are wider than their rated width.

205/50-15s are around 219mm wide. Not sure exactly how wide the 215/45-16s are, but they're supposed to be a little bit wider than the 205s . . .

 

The 225/50/16 MX is 236mm wide... it's pretty damn fat.

 

Straight from Falken: http://www.falkentire.com/tires_rt215_sizes.htm