I need some help figuring out which fix to try. I have a G37s sedan with 18x8.5 Enkei Tuning Raijins with +38 mm offsets on all four corners. Tires are Michelin 245/45 18 Pilot Sport AS3. Compared to my winters tires, which are staggered Blizzaks mounted on the stock rims, the tires are terrible when it comes to "road wander". On a flat road, no problem. On a road with an uneven surface or ruts, the car darts all over. Tire pressure is good, alignment is good. Tires are at the end of their useful life which likely isn't helping.

Compared to stock, the front wheel center is 10 mm further out, which could (at least in part) explain the wandering. Thing is, I've heard the Michelins are particularly prone to this problem as well.

I've got three choices for the fix:

1. Keep the 18x8.5s on all four corners and replace the Michelins with Yokohama Avan Sport A/S v405s (I've heard they are better).

2. Buy staggered Yokohamas and put them back on the stock rims.

3. Have ~7 mm machined off the inside surface of the wheel hubs on the front to knock down the 10 mm down to ~3 mm (change the 38 mm offset to ~48 mm). (Move the front tires in ~7 mm). That's about as far as I'd got before risking hitting the brakes on the front. I'd have to check that the lugs still get tight before bottoming out on the wheel studs.

I love the look of the Rainjins, but the road wander is driving me a little nuts.

Suggestions?

Thanks!

John

 

Tires being toward the end of their life would get my vote as the main culprit. Did you have this setup when the tires were new? I assume this problem has been getting worse the more the tires wear. Your offsets aren't extreme enough to cause a significant change in your handling, adding positive scrub radius will result in more road feedback but shouldn't induce tramlining.

 

Yes, I did have this setup when the tires were new and I don't remember it being like this, but I don't trust my memory. Will try a new set of tires this weekend and see what happens.

 

+1 For what blnewt said. You have a printout of your last alignment?

 

I've found my G37 is far worse than my 09 STI hatch was for this. Both cars had 255 wide tires. My PSS tires are at most 50% worn and it's getting worse. In addition, I got an alignment a few weeks back and it seems worse since then. Even though I'm more in spec than I used to be.

At this point, I believe it's just the nature of the car. I'm hoping coilovers and a camber kit will fix some of this.

 

With a front camber kit you can add some caster, this will improve straight line tracking, I have the SPC camber arms and I have my caster about 1 over spec and wouldn't want it any other way.
Unfortunately there is no caster adjustment w/ the OEM UCAs.

 

(Edit - blnewt beat me to it)

Some of the camber kits allow for an increase in caster. And extra degree or so may help out quite a bit in this respect.

 

Thanks for the info guys. This will help sell my fiancee on the suspension upgrade as she hates when the car is "darty"!

 

Based on the advice in this thread, I just got back from Discount Tire with a new set of Yokohama Sport A/S 245/45R18s on the Enkei Tuning Raijins I already had. I can't believe the difference. Night and day. I can change lanes without the darting. Even low speed maneuvering in parking lots feel better. Less wheel effort at low speeds. I'm shocked. I had no clue tires (of the same size) could make this big a difference. I think the Michelin's I had before started worse than this and got progressively worse with age. I've only put ~10 miles on the Yokos, but so far I would do this again in a heartbeat. Price was good too - less than $800 out the door with certificates, environmental fee, tpms kits, etc.


Yokos look good on the Raijins too.

Thanks for the advice!!!!

 

Glad to hear your happy now. Tires, especially as they start to approach the wear bars can change quite a bit in their road holding characteristics.

And like you recall, some tires can be more prone to this behavior.

Hopefully your tramlining days are put to rest.

 

I am running a 19x9 +38 with 275/35-19 Continental DWS's, and on anything but flat roads, they require some muscle to keep the car straight.

 

The stock offset on the front is +45, so running +38 is only a 7mm difference (center of your setup is 7 mm further out than stock). When I was having trameling problems, I wondered if the offset was to blame (in theory, the stock suspension should rotate about the center of the tire and when you move the front tire out, road imperfections have more leverage if you will to move the suspension around), although 7 mm = ~1/4" is so small.

I also wonder, if just having a wider setup on the front leads to problems on uneven surfaces and/or with worn tires as the outside edge of the tire is that much further out from the axis of rotation.

In your case, the outside edge of the tire is 26 mm (about an inch further out). See attached picture.



For me, new tires was the fix. Don't fully understand why.

 

That's a lot of tire in front, and the wider you go the more prone to tramlining, I don't think I'd want to go wider than a 255 in front TBH.