Wheels and tires for road course

[Doc B]

I'm new at this and use my 2019 wide body as a daily driver. I have started to do Track days and really enjoyed it. After spinning it out into the grass last October, I decided a couple of things....
A. Never run in 34 degree weather and
B. Get better tires for track days.

I have emailed back and forth with a performance company about wheels. His suggestion was to go with 11' rims on front and 12" on back....305/35/20 on front and 345/30/20 rear.
I've read all I can on these forums but still wonder...
For road racing, should all 4 tires be the same size?
Are 30 vs 35 tires (either all around or only on the back) going to affect anything and/or necessitate any need for further modifications?
Thinking about Toyo r888r's but can be convinced otherwise. Don't have a trailer so will switch tires at home and drive to the track.

 

[DGatzby]

Well the 34 degrees sure may have made it run well, but the tires may have been nearly rocks! The Toyo's are not that special IMO. Some people like them! I spun out my RE on a track where I have run over 100 laps last June with them. Screw that action! They get hot if they are over driven and can get slippery without warning. I just won't be running them "on the edge" the next couple times at the track before they become burnout/drifting and video fuel. They are also repulsively noisy. Also I attempted a couple of standing starts with them on the street. They suck there also. My PS 4S rears do a night and day better job at hooking up.

I have @TRIUMPH working on four 12" wide 20" diameter wheels for me right now for exclusive track use. This is one of his first 12" square sets, so we are working closely. You could put 13" on the rear, pretty easy really, but I believe the 12" wide wheels will help. I have a 12" wheel on the back for my street set now with 345/30's and they do hold on well and look about perfect. For track tires, I am going to finish off the 305/35 R888R's on my 11" OEM wheels, then remount the PZeros (brand new in my garage) for when I want to take the car on a road trip and not worry about my expensive after market sets being stolen. For the new 12" track wheels, today, I ordered four 325/30 PS Cup 2's. Discount Tire is offering a 15% rebate, so that is hard to beat, when a guy knows he will need some new expensive rubber soon. A set of 345/30's for the rear and 13" may help, but for us common mortals I think the square set will be fine.

Further mods to support that! Well of course. For me, all four corners will have adjustable control arms, the front will have different springs and a strut brace, and out back the cradle gets Whiteline bushings to work with all the more tight control/trailing arm bushings. Mine will start with those mods that worked well on my '15. FYI my '15 modified like that with 285/35 tires on 9.5" wheels ran equal times to the stock RE. Oh, both had the same exact brake mods (Demon Performance/Hawk with racing fluid) also.

 

[TRIUMPH]

We’re on it buddy...looking forward!