Looking for advice from track rats re: tradeoff between 205 (better acceleration) and 225 (better cornering).

I have to replace the Goodyear F1 215/40/16 that I have been running the past 2 summers and that tire is no longer available. I chose that size at the time to minimize tire diameter (maximize torque) and still keep a wide contact patch. Worked well. If I look at a tire like the Dunlor Star Specs then I can choose 205/50/16 with a 24.1 inch diameter at 22 lbs, or 225/50/16 with a 24.9 inch diameter at 26 lbs. By the way, wheel is Slipstream, and I do a few HPDE events per summer. I realize there are some 225/45/16's out there, but generally have to sacrifice tire quality (e.g. BFG KDW or Toyos).

Another option is to go back to 15's, but tire choices there are getting limited too.

Thanks in advance for any advice.

 

i too would like to know the advantages/disadvantages in terms of acceleration and cornering for 205/225

 

I have run only 205 45 17 and 215 45 17 on the track with a R56 MCS, about 22 track days total. I like and can feel better road holding and braking with the 215s. I do not feel much of a difference in accelration with the 215 because I think there is sufficient torque from the turbo to overcome the slight increase in diameter.

Anyway, the speed out of the turns is the most important determinant of your ending velocity at the end of a straight.

I am not sure about 225 but I may give it a try this year.

 

You can have both. I run 225/45/15s. Shorter gearing for acceleration and big contact patch for handling. I used to run 215/45/17s and I wouldn't go back to that for the track. The only reason to run a bigger wheel is to clear a BBK.

 

Is this a track only tire ? or are you also using it as a daily? Personally I always prefer wider as I want to be able to keep the turns as tight as i can, I dont like to pay for extra real estate on the track if I dont have to.
Also it depends are you looking at R compounds or not. If you are fairly new to DE events I would say stick with a street tire for at least 3 or so years, R compounds hide alot of Mistakes. Just my opinions here from tacking over 25 years.

 

Thanks for the advice so far. I run the same tires on the street and track. I have ~8 years of HPDE under my belt, and have been tempted by R's, but not ready to make the jump yet.

 

i'd say it depends a lot on what kind of track you run. the wider tire wouldn't effect your acceleration, but it's a general rule of thumb that the wider the tire the less "sharp" the corner turn in feels, you may have more grip, but communication will go down ever so slightly with wider tires. for instance, the classic MINI ran races with 165 section tires... that's small as hell but their major upside was that they were the most communicative car out there, so you could bomb it into any corner and know how to react simply by feeling the road/track. i personally run same tires street and track, Yokahama Advan Neova AD08s in 215/45-17

BTW try Nitto NT05s, a friend of mine has them on his M3 and raves about how close to an R compound they feel.

 

225 will be be better at acceleration and cornering (most of the time) 205 would be better at transitions like 2 or 3 corners linked together and tighter stuff like auto-x while 225 will stick better on sweepers and faster corners. Not to throw a monkey wrench in your tire choices but have you considered 225/45-16 Toyo R1R, Yokohama A048 or Toyo R888 track tire. The 45 series will give the better gearing while still keeping the 225 width to stick around corners. Have your cake and eat it, too. Also many tire shops still selling discontinued Hankooks RS-2s for cheap in 225/45-16.

 

in normal cooper , 195/50/16 is fine I think

 

I've run 205/50/16 on my Rota Slipstreams for the past 3 years, and have been happy with the cornering, but I've never gone wider so can't give you a reference point compared to how 225's would feel. I'd say stick with the lighter weight tire for the acceleration/braking/suspension improvements, and go with a stickier compound that would give you better cornering grip.

I also figure that my driving ability in the turns can be enough to offset a poor driver having a wider tire with more cornering grip, but a lighter wheel/tire combination will certainly make you faster in the accel and braking zones.

Ultimately, there may not be a "right" answer, but you can decide for yourself which properties are more important to you.

 

Best thing i ever did was get rid fo my factory S lites, and run flats
I first ran a 205 55 15 Coni, which were ok then a 205 50 16 bfg traction t/a
I lowered the car and went to a 225 45 16 bgf kdw g force, all on the same BBS wheel
On track days i would have wheel spin on inside tire out of the courners,

With the 225, no spin, even at WOT and i can carry much more speed with out the rear end feeling loose

i do have to run a lil bit more neg camber in the rear to keep them from rubbing

https://www.northamericanmotoring.co...hp/photo/92688

 

Also, if you are running oem 16x6.5 wheel a 225/45 will be sloppy near threshold, it will be better with 16x7, but ultimately a 16x7.5 or 16x8 if fittment issues and those pesky SCCA rules permit. But for oem wheels 205/50-16 is your best bet. Pretty much same applies to 15s.