Winter tire setup for Centri S/C car?

[cavero]

Wondering everyone's thoughts of this. I usually rotate between summer tires and all-seasons for the winter, with the summer tires being on 19" Bridgestone S04's (285 width in the rear) and the all seasons being on the Continental ExtremContact DWS on the original stock wheels (235/55R17). Virginia winters aren't that bad, we typically go down to the 20's - 40's. Mostly rain, but sometimes some snow and slush.

But like the title implies, I picked up a centri blower this year, and my shop is warning me the stock 235's aren't going to cut it for the winter anymore. I don't know how much power I'm making (shop has been too backed up to schedule a dyno run), but we're guessing between 500 - 550 RWHP. Boost doesn't kick in until 3500 RPM so driving around town you'd hope the 235's would be up to the task, but at the same time the car's overall more powerfull across the board and a bit touchy down low.

Plus you have 1-2 punch of colder air = MORE POWER and colder tires and roads = LESS GRIP.

Now, I won't be driving in snow (SALT) or any colder than 25 deg (Vortech's manual explicitly forbids it due to tolerances) so -- will 235's be up to grannying around town? Yeah probably, but if I need to step on it to get onto the highway or scoot to make an opening in traffic, I don't want the taillights leading the way.

What do you think? Would 255's be up to it? Or would I have to go wider (275's)?

 

[stkjock]

I'd go at least 255s and get a winter tire or DR, not an all season, I had a centri w/ 500+ whp, did drive it in cold weather, never rain/snow, I ran a MT ET Street, 265/40/18 on stock rims, they worked well, but in the 30-40s, they would still spin in 2nd with the tr3650 & 4.10s

they don't make the 265/40s any more, you could use the 275/40/18 if you have 18s wheels, or try the 275/40/17 - but those may bulge a lot

 

[cavero]

Thanks, I do actually have an extra set of 18's (18x8.5, 18x9, and 18x10) which gives me some options. For 275's on a stock 8.5" rim I remember back in the day reading you wouldn't really want to go more than 255.

Looking at TireRack, man the options are really limited for winter tires. I did find a set of Pirelli's available in 265/40R18 but...it's discontinued and they've got exatly 1 left in stock! Going to have to do some digging on sites other than TireRack for these sizes:
Stock - 235/55R17 - 742 revs/mi
255/50R17 - 745 revs/mi
245/50R18 - 729 revs/mi
255/48R18 - 745 revs/mi
265/45R18 - 736 revs/mi (59.5 mph indicated @60 mph)
265/40R18 - 765 revs/mi (61.9 mph indicated @60)
275/40R18 - 756 revs/mi (61.2 mph indicated @60)
285/40R18 - 747 revs/mi (60.4 mph indicated @60)

 

[stkjock]

For 275's on a stock 8.5" rim I remember back in the day reading you wouldn't really want to go more than 255.

Really depends on the aspect ratio, a 275/45 will be ok, IMO, vs a 275/40 or instance, as they will not bulge, for instance, I run a 325/45/18 on a 10" rim.