lt4 fd

It wont be autocrossed terribly often maybe once a month would be average starting out, but I want to be able to drive it on the street on weekends that are nice. My choices are the 315 nitto drag all 4 corners or the 285/40/17 kumho ecsta mx all 4 corners. they are both streetable and sticky and inexpensive which is great, but im upgrading the motor and will have 3.73 gears and 360-380 rwhp and 360rwtq and I want to hook in first from a punch atleast. Now the kumho will last longer I think and be a better tire to drive on but will it handle that much power in first? Also has anyone had much experience with the drag radial at an auto-x event?

LT4Firehawk

I'm guessing you have 11" wheels all around?? Otherwise, if you have 9-10", I'd recommend staying with 275/40s all around and using Nitto 555R IIs. I use these on my 17x9 Firehawk rims for street/roadcourse use and they are great. I'll probably get about 10K miles out of them before I retire them to track only use. As to the 315 555Rs, I don't autox, but I've used them a lot on the roadcourse and they are excellent there as long as they are on an 11" wheel.

LT4Firehawk

Oh yeah, as for traction. With 311rwhp with the stock 3.42s, the 275 555R IIs hook up great. The 555Rs that I have on 17x11s hook up even better, I can cut 2.0 60' times with them doing a 4000rpm clutch drop.

lt4 fd

sweet, well can anyone else answer my question about the kumhos?

O-taka

the cheap ecstas are not so good, but they are cheap.
first season autox should be on street tires anyway

LT4Firehawk

He's not talking about the cheap Kumhos. The Kumho MX is supposed to be about equivalent to the Goodyear Supercar tires. Many of the Z06 owners were switching to these when their Supercar tires wore out, and were very happy with them. The consensus seemed to be that they had slightly less dry traction (say 95%), but had much better wet traction, treadwear and a lot less ride noise. If it helps any, I debated a lot between the MX and the 555R IIs for the Firehawk. I finally decided that I'd live with the shorter treadlife for improved dry grip. Of course I've had a lot of experience with the 555R/RIIs and am a big fan of them. Also, I've heard so many good things about the MX that I'll be putting them on the wife's RSX Type S in the next month or so.

JimMueller

I have Kuhmo MX 285/40/17's on my car. My previous sets of tires were, in order:

[Dry/Wet/Handling opinion, 1 being best]
[4/4/4] Kumho Ecsta MX 285/40/17
[3/2/3] Bridgestone Pole Position S-03 265/40/17
[1/3/1] Bridgestone Pole Position S-02 275/40/17
[5/1/5] Michelin Pilot Sport 275/40/17
[2/5/2] Michelin Pilot SX MXX3

I too narrowed my picks down to the Nitto 555 & the Ecsta MX when I puchased a few months ago. I felt the R2 & Drag Radial would have too short of tire life, and the regular 555 I heard was noisier than the MX. Had the S-03 been available in a wider treadwidth, I would have stuck with it.

I had 400rwhp at the wheels with my previous engine. The MX's would break lose for about 1-2 seconds on a 1-2 power shift at redline, but not any other powershift

lt4 fd

wow 400 rwhp, how was traction in first... do you think they would handle 370 rwhp or so? That right there would seal the deal...

JimMueller

Well, this is a street tire, not a drag tire. You can't dump them at high RPM's and expect to get traction. You need to slip the clutch off-idle and keep the rear tires on the verge of slip - 5-10% slip is theoretically optimal. Not sure how you measure that in the real world.

Slipping the clutch from a stop from about 1500RPM works for me at autox. A little tire spin, but only briefly. Once traction is gained, they don't start to spin again in the same gear. It's not going to rip right to redline with you still on the starting line

lt4 fd

OH yeah im not talking about a launch i mean your going 25 and nail it in first, will they just light up or stay planted... also did you have the older mx's since they were a lil softer and had a 220 treadwear rating and the new ones I would get would have the 340 treadwear rating.... could be missinformed but just checking.

LT4Firehawk

You're looking at the wrong treadwear rating somewhere. Both Tirerack and Kumhousa.com show the MX as a 220 AA/A rating.

lt4 fd

Oh alright nm then, how would they compare with the slightly more expensive KDW?

LT4Firehawk

Don't have any personal experience, but the user ratings on Tirerack are exactly the same for the two of them. I'd go with the Kumho as they are less expensive.