The load rating is based on how much lateral acceleration the tire is capable of generating. 420 TW probably won't generate much more than 0.8 g's. If you plan on using something like michelin ps4s in the 300 TW range which can do about 1g, that load rating will drop significantly. ISF with driver is about 1100 lbs per wheel at the fronts. If you plan on using track day tires in the 200 TW category then I'd expect that rating to drop well below 1100 lbs.
Ultimately all wheels can fail if beat on hard enough on track but the main difference between forged and cast wheels is the mode of failure. Forged will usually start deforming before ultimate failure while cast tend to rupture suddenly without warning. I'd say go for it if you're after style but IMO these would be a major downgrade from the OEM forged wheels in terms of longevity and safety.

 

A 15/20mm spacer up front would really make this more aggressive.

 

Hi guys, need some help with a new set of rims im looking at
19x9.5 ET40 (F)
19x10.5 ET43 (R)
Should I expect rubbing?
What tire size would you recommend to avoid it?
Stock suspension
Thanks!

 

245/30 or 35 front
255/30 or 35 front

275/30 or 35 rear
285/30 or 35 rear
Will fit with no issue. Shouldn't rub on stock height. If there is any rubbing. It will be minimal.

 

Finally installed

Lowered on KWs

Front 19X8.5 +35 natural camber -1.4
Rear 19X9.5 +35 control arm camber -2.4

rub on big put holes etc

 

BC Forged LE10

 

Nice we sell a lot of BC Forged but not for Lexus. Awesome to see the MLE10 on the ISF!

-Josh

 

What are your tire specs and wheel offsets? I see a 265 front tires.

 

19x9.5 +40 265/35/19
19x11 +60 305/30/19

I do have 5mm spacers out back and planning on trying 10mm in the future.

 

Are you running any camber out back to fit those 305s? Any rubbing on the front 265s? Stock height? Any knocking shifting with those spacers out back? All the spacers I have run ended up shifting and clanking on heavy braking or acceleration.

 

The only suspension work I have on the car are the FIGs front lower control arm bushings and HKS coilovers. Stock camber all around and slightly lower than stock height. I do get slight rubbing on all 4 corner on very hard dips but I have determined the rubbing is with the fender liners (front and back). The front right rubs on reverse @ full lock to the left.

No knocks or any noise from the spacers. All in all I am very pleased with the setup given the wide spec and tire size. I previously ran TE37 10.5 +32 on 275 and the rubbing was very cringy.

I do intend on getting FIGs arms setup in the back to get it 100.

 

How's the clearance from the upper control arm crown nut? I'm running contis in that size at et+45 and have about 1mm clearance. You have 5mm less offset though the ps4s run wider. Worth checking if you haven't yet.

 

I have been following your thread. It’s tight but no contact or at the very least no indication of any contact.

 

I am ready to buy a new set of BBS wheels and need to make a decision on offsets.

The fronts are 19x8.5" and have 2 offset options to choose from, either +38 or +43.
The rears are 19x9.5" and have 2 offset options to choose from, either +45 or +53.

What are the pros/cons of either? I plan install Sport Cup 2 255/35/19F & 275/35/19R on them. Is one offset better for wider tires and one better for brake or suspension clearance?

 

You should go with the 19x9.5 +45 all around.

I'd recommend running 245/35 275/30 on those offsets...or even 255/35 and 285/30.

The fronts you will probably want to heat the plastic to push in the fender liner slightly