[Rezox]

I'm running:
Yokohama S.Drive
275/30 R20 (97Y)
on
360 Forged wheel
20 x 9.5
(and H & R Premium Coilovers)

Using about 32-31 PSI in the tires.

The issue I'm having occurs on very wet pavement, otherwise the car is silky smooth. It seems when the ground is very wet in the rain my steering wheel shakes like a mofo at about 60mph. The issue is corrected when I'm back on dryer pavement and after I have come to a complete stop and started moving again (which alleviates the shake).

Can't seem to figure out the problem here. I have done 2 alignments and 2 Hunter road force balances.

 

[michaecl]

um.....no clue..

 

[TXcarguy]

Sizzle and SAJ have reported a similar issue with their aftermarket wheels when it's raining. See this post.

 

[KevinS4]

Have you raised the tire pressure to see if that help the problem?

 

[Rezox]

I'm going to try that, I like the pressure now though because the ride is very smooth.

What would you recommend (PSI) for these tires?

I was thinking of just changing the tires to something else but it seems everyone uses a different tire.

Any tire recommendations? (Cost isn't an issue, I want the best)

 

[ranger22]

As Tx said, I don't think changing the tires is going to help you. If you want the best, then the Michelin Pilot Sport II A/S's (I think) seem to be considered top of the line. Although, the reviews on them vary.

 

[Rezox]

You mean Pilot Sport A/S? I don't see 2's anywhere.

 

[ranger22]

You mean Pilot Sport A/S? I don't see 2's anywhere.

Ya, guess so. I was shooting from memory, but after looking it up there aren't any 2's. Sorry.

 

[Rezox]

Is there a benefit for keeping all tires the same width or getting bigger backs, smaller fronts?

Isn't there some type of issue with doing this on AWD systems?

Is it possible that maybe the problem is because these Yokohamas are summer performance and not all weather? They run great dry and light wet, I just can't understand what's causing this issue. Wouldn't All Season tires lose performance over summer tires?

What would be the optimal tire width for 9.5" rims?

 

[Rezox]

I found out why there is vibration in hard rain.

The problem is inherent in the design of 3 piece wheels. Water gets trapped in the groove of the wheel behind the spokes in hard rain and stays until you come to a stop -when the water can escape.

The problem does not happen to all 3 piece wheels because it is also a combination of the car design, wheel well, and rim design.


Tires are not the issue here. I also found out that the Michelin Pilot Sport PS2* is the best summer performance tire out at the moment.