Took advantage of the cooler 50 degree weather here in Florida...had some fun with the car. All I can say is wow...and I'm going to need wider rear tires than these 305s. I'm still breaking loose at the top of 1st and 2nd gear. Traction is definitely still an issue, but the car is truly a beast.

 

I really like the cool weather on my car too, I can only imagine how does your car must feel...

 

Looks like you have the ESX kit on your car. A supercharger really loves cool air. How do you like the kit? Did you have to replace the clutch?

 

The kit is great...night and day vs. stock. I did upgrade the clutch with the ESX-sourced part. The stock clutch is barely up to the task of handling the stock power, much less 230 added hp at the wheels! I also upgraded the cats to the RSC 200 cell cats after the stock cats melted. Performance is impressive...see the other post I did today about 60-100 times. Next time we have another cool day I'm going to see how low I can get those 60-100 and 60-120 times.

 

Tahoe M3-

Cool weather is not a problem at this time of year in Seattle; just the rain that comes with it.

With your tires, what did the car come with, and what were your thoughts about those tire sizes/wheel for the stock set-up?

I plan on doing the RSC upgrade C package on the '10 that I am looking at, and believe that the tires will probably need to be changed to a larger size. Thoughts?

 

The stock size for all except the V12 is 19x8.5 front with 235/45 and 19x9.5 rear with 275/35 tires. For the pre-09s that's plenty from a power perspective, although going with lighter wheels/tires definitely helps with less rotational mass and unsprung mass.

For the 09s, there's a lot more power, and going with the RSC upgrades you can definitely make an argument for going with wider tires. Just make sure you go with good forged wheels and compare tire weights (tire rack has the weights if all the tires they sell on the website). People don't pay a lot of attention to tire weight, but being at the farthest point from the center of rotation it can make a big difference.

I think you can get away with going with 245 or 255 fronts and 285 or 295 rears. I think beyond that you're sacrificing straight-line performance. In my case, I would be more comfortable with 315s or 325s but it would be hard to do without messing up speedo calibration, so for my next set I'm staying with the 305s but using stickier tires.

 

Thanks for the great info. I am presuming that your wider set did not require turning the well lips?

When you say FORGED, do you mean aluminum? 3 piece/2 piece? I know bupkis about wheels.

 

No fitment issues...in fact I know that 12" width rims will fit in the back.

Forging refers to how the wheels are made. In the forging process, they basically squeeze an aluminum block into a wheel shape under great pressure and then machine it down into the final shape. This gives it great strength and lighter weight than the other option which is casting. Casting is how most basic wheels are made...just like it sounds, it involves pouring molten aluminum into a wheel-shaped cast.

Both are aluminum, but the forging process leads to a stronger but lighter wheel. Depending on the brand, they can be 1, 2, or 3 piece wheels. One piece are usually lighter but some of the newer 2 and 3 piece wheels have lowered weights by using titanium fasteners. Check weights with the manufacturer to know for sure before you buy.

If you want to really get fancy, you can go with one of the carbon fiber wheels, like the HRE carbon series, which save a lot of weight by using a carbon barrel and an aluminum center.

 

So you are suggesting that I can get a forged wheel, wider tires and be fine. Where do I check offsets to see if I will need spacers? If I do not go with lowered springs, what kind of size should I look for, considering that this car will be used on regular roads in L.A. and carving the canyons on weekends? Not likely to track. The trade off to a more comfortable ride seems to be filling up the wheel wells and making it look wonderful.

 

Yeah the stock wheels are probably fine for most driving, but considering the upgrades you are planning it won't hurt to go a little wider...just don't sacrifice weight in the process. Don't get spacers...get wheels with the right offset. All the major wheel manufacturers will know the right offset for the car. I went with HRE and they knew from pretesting which sizes and offsets would be best.

 

Tahoe,

Do you have a definitive maximum width for the rears? I am considering a larger wheel and tire combo for the V12. I was thinking 305-315. I have more torque and speed at the bottom but from what I am hearing from Stuart at RSC, there is more to be had. So, while I like the wheels on the V12, my car is Lightning Silver and I have planned a darker metallic wheel to contrast. So I figured that I would max out the rear width To accommodate a near 600HP car. You and RM would have the best point of view on max HP Vantages.

 

look into how the new nto5 r from nitto will fit. i have always been a nitto fan and the shelby crowd are claiming dead hooks on 650 at the wheels. i have yet to hear anything bad from them yet other than fitment with certain widths and diameter.

 

I know a 12" wheel will fit in the back and I think 12.5 will fit as well. Ask the guys at HRE...they test fitted to see the max size. My rears are 11" and there's plenty of clearance. You can fit 305 tires on the stock V12 rear wheels...they are 11" just like mine. That probably will be enough, but if not you can always go wider. But, just like me, you'll see that going with 315 or 325 is going to mess up speedo calibration. That's why I'm going to stick with 305s but use essentially DOT-legal competition tires...I don't drive it in the rain anyway.

 

The NT05R is a drag radial and is only available in one size for 19" rims. Their road course competition tire is only available for 18" rims.

Nitto is actually a subsidiary of Toyo and the Toyo R888 is probably the best competition tire out there...and it's available in the sizes I need.

 

my bad, i meant to write nt05, all i have had for the last decade is a drag radial..lol..

i am currently trying to figure out tire size a wheel width as i am having a 20" wheel made. i want avoid to short of aside wall and also i do not want a stretched look.