Hankook Z214

I am running Hankook Z214 C71s on my 99 Neon FSP car (Konis XX high-rate springs, etc.). In many ways I have found these superior to the Kumho V710s. They wear better and transitions (offsets, slaloms, etc.) are crisper, but they do not seem to corner quite as well. I am thinking this is a tire pressure issue. With my V710s, I would run 28 PSI up front and 42 PSI in the rear for best results (I would wear the INSIDE of my front tires even with just -2.0 camber up front). Last year, my best results with the Hankook's were with 35 PSI up front and 42 PSI in the rear. Below 32 PSI up front, the tires made a sound like they were flat in hard corners. No matter what tire pressure I run upfront, I continue to wear the inside of the front tires. The car is only autocrossed and is trailered to events.

What tire pressures are you running?

Those are very unusual pressures for an FF-layout car, are you sure you don't have the front and rear mixed up? Or does the Neon normally understeer horribly and you're overinflating the rear to correct it?

I'm on Star Specs but I run 41.5psi front 27.5psi rear (cold). This is just enough to keep the car from running on any of the sidewall in corners, as determined with the shoe polish test. So basically I'm maximizing grip on both ends and not trying to adjust the handling balance with tire pressures. Those pressures also happen to be in the exact same proportion as the front/rear weight balance.

In reply to GameboyRMH:

R tire setups are very different than ST tire setups, With most street driven tires you want to run high pressures for more traction as it stiffens the sidewall. R tires have no such sidewall concerns. With a fair amount of negative camber, there should not be much sidewall rollover, even at 25 PSI.

Lower pressures on an R-tire usually result in more traction to a point. To get the rear to come around on a FWD SP car, one usually runs very little, if any, negative camber in the rear and either low-enough pressure to get the tire to rollover or high enough pressure to reduce the contact patch. Low pressures are supposed to make the care rotate in a more manageable fashion. I like the quicker breakaway of higher pressures.

In short, street tire pressure setups tend to be the opposite of R tires.

The inside tire wear could be from running toe-out. I run slightly toe-out for better initial turn-in response. That setting comes at a price in tire wear.

Have you check the toe setting from rear to see if something has changed?

A common band-aid is 'flip' the tires on the rims so the worn inside is now on the outside. Mark the tires and rims both inside and out and remount on the marks to avoid balancing again.

I ran my first event on my Z214s last month. Between the pyrometer and checking rollover wear, I was running 31/29 psi on a 240sx. I still need some more events under the belt to really good a good average, but lower pressures seemed to work well on them.

In reply to trucke:

Running 1/8 toe out up front which probably explains the inside wear. I was more concerned with using as much of my contact patch as I can.

Seems like a lot of pressure for r comps.

In reply to sachilles:

I would run my V710s at 28 up front. Doing so on the Hankooks made the tire feel "flat." Bringing to 34/35 PSI made the car feel better and cut about .5 off my time on a 45 second course. Rears can be run very high or very low to get the car to rotates. With zero camber in the rear, low pressure causes the tires to roll over a bit and the car will rotate. Running very high pressure in the rear results is a smaller contact patch. Most of hour courses are fairly tight so the ability of the car to rotate quickly is advantageous. A few of our lots have rough sand paper-like surfaces so a smaller contact patch works their as well.

The Quaiffe LSD allows me to apply power through corners. However, unless I can make the rear rotate, the car will still understeer at speed. Using my setup, my car will rotate under power almost (but not quite) like a neutral RWD car.

I've been running Z214's ( C51 ) on track ( 2100# CRX) and the recommended hot pressures and the Tire Rack Hankook guru suggested that for my car cold pressures in the vicinity of 28# and to aim for hot pressures of 32 - 34 psi ...

slightly different compound and different usage but maybe a ballpark beginning figure for you

I've got the same C71's on my Sentra, and I'm running very similar tire pressures that you are - 36 front, 42 rear.

Tire pressure balance is subject to the suspension set up. A stiffer roll couple in the rear is essential to FWD handling. This should be done with the suspension, not the tires. Tire do have a certain "spring" rating which depends on the tire construction and somewhat to air pressure. Using that theory, higher pressure would be beneficial.

You are describing a scrubbing sound. Diagnosing the sound over the internet is tough. Scrubbing is usually an indication of the tire pressure not getting enough contact. They feel flat because you have more contact patch. You are feeling more precision when they are over inflated, but it doesn't mean you are getting more grip. My personal suggestion is to lower the front to 20-25 and lower the rear to 35.

Having 42 psi in rear r comps on a front driver is giving you rear slip, but ultimately making you slower. It's compensating for something

With more grip in the front, your rear will come around easier. Your issue is lack of grip in the front, not too much grip in the back, if that makes sense.

I've been in your same boat. It's nice to have that precise feeling, but sometimes the dead feeling is faster. Are you taking tire temps?

In reply to wbjones:

I am running my fronts at 35 PSI (when up to temperature). That is not much different than suggested and my car is heavier than yours (about 2550#)

In reply to jstein77: Seems be optimal for my setup as well.

In reply to sachilles:

The sound it makes when the pressures are around 28 psi sounds as if someone was rolling up a rubber mat in front of my car. Literally like flapping rubber. My times also were quicker running the higher pressures, but that might be from my subconsciously pushing the car harder with the "more confident" feeling.

Think about it this way. If you mark your tires on the outer edge(shoe polish/tire crayon etc), you'll know if your tire is rolling over. Given it's an R-comp, it likely isn't rolling over at the lowest pressure you've run.

In my experience, that sound comes from tires that are heat cycled out and don't have grip, or tires that have folded over on the sidewall and don't have grip, or tires that just don't have grip. Bottom line is the sound is from not having grip, that would be a fair assumption?

Lack of grip comes from lack of contact patch, or lack of tackyiness from the rubber. New unshaved tires will feel vague to an extent.

Running softer pressures will reduce the feel, but should net with better forward traction, braking and turning, at the expense of feel.

You can't discount feel, so you being comfortable is important, but I think if you soften things up, you'd be happier once you get use to it.

Based on your symptoms in the original post. If you want to maintain your current pressures, move your front camber closer to -1.25 and see if that moves the wear closer to the center of the middle of the tire.

Again, I've been in your shoes. I loved the feel of certain setup, and felt like I could thread a needle with the car, but the times just didn't back it up.

In reply to sachilles:

My Hankooks have about 24 40 second runs and made that noise from day when with pressures below 30 PSI or so.

The last 4 only were run at 35 up front and my times on that day I did it (were much better almost a full second) with the higher pressures. I am not saying what you are saying is incorrect. Tires were new last year when this happened. They were not heat cycled out.

At one point I had the front camber down to -1.75. Maybe I will try it at -1.50 or 1.25. It could just be a mental block with me.

I like this thread. At this point my only question is whether tire temp is being checked across the surface of the tire. I think that would be a helpful diagnostic aid in this situation.

In reply to Vigo:

That will be done on 4/13/13 (my first event). It did observe by touch (last year) that the outside third was noticeably cooler than the inside third. Unscientific for sure, but if things were right, I know that the difference should not be easily detected by hand. The hottest part was inside third. The middle was slightly cooler and the outside third was very cool. I will get a gauge before my next event.

If you can't take temps, mark the tire the full width of the tread and see what wears off.

Isn't fun to obsess about this stuff, when it's still weeks away? It turns me inside out. I'd over think opening a bottle of beer if you gave me weeks to plan it.

In reply to sachilles:

Tell me about it.I usually win my class, but that is mainly because the cars which show up are less-well-prepared and the drivers are less experienced. My goal has been to score in the top 10 in PAX. I did that a few times in 2011, but never in 2012. In 2011, I was running V710s with fronts at 27 or 28 psi and the rears around 38 PSI. Still wore the inside of the tire, but was quicker versus my peers. Maybe it is I who is slowing down.