Ok going on my third season for autocrossing the car, first history of tires used.
1st season when I discovered autox used Pirelli PZero Corsa tires in Dstock 215/40/17 on stock rims.
2nd season Falken RT-615 215/40/17 on stock rims.
3rd season Falken RT-615 245/45/17 on 17*8 rims.
245 did not seem hot or even warm to the touch, now granted I still got a lot to learn on how to drive. I probably overdrove the tires. Would going to a 235 help in the tire temp to get max traction?
Also debating over Falken RT-615 or give the new Dunlop
Direzza Sport Z1 (Star Spec, Comes up to temp faster than Direzza Sport Z1).
Any help is greatly appreciated and thanks in advance.
What class are you in? What springs? What struts? Swaybars?
I did some size comparing on the tires you listed and came up with some interesting data:
The jumbo Falkens weigh 28.7 lbs a piece compared to some 235/40/17 max performance tires which are all around 24 lbs. 215/40/17 RT-615s are only 21.2 lbs.
The jumbo Falkens are an inch taller in diameter than 235/40/17s and would raise your car half an inch but are not signifigantly taller than the OEM 205/50/17 that came with the car. 215/40/17 RT-615s are shorter still at 23.9.
Treadwidth...jumbo RT-615 is 9.1", 235/40/17 max performance tires avg 8.5" and the little 215/40/17 RT-615 is just 7.4" (probably less on stock rims since they are so narrow).
One big consideration for me is weight vs. width. You will save 4 lbs per corner and give up only .5" in tread per tire. I figure unsprung weight (wheels and tires for the most part) at a factor of 10 over sprung weight (the rest of the car as far as we're concerned). So, this is like shaving 160 lbs out of the car or like getting rid of a passenger. IOW, a passenger typically costs me about .5 sec on a 60 second run on an autocross course.
Then, you need to think about the overall diameter and how that affects acceleration. How did your car feel and how easy was it for you to control wheelspin with the tiny 215/40/17 RT-615s? Those things are real short and real narrow so, if you did ok with the throttle control part of driving I would definitely argue for you to go with 235/40/17s as opposed to taller/heavier/only slightly wider 245/45/17s.
Another interesting thing you could do with 235s is put 215s on the rear, further reducing weight. You don't need all that contact patch in the rear anyway. A Hankook RS-2 235/40/17 is 24.4" in diameter and a 215/45/15 RS-2 is 24.6" in diameter, close enough for autocross work. I would look closely at the RS-2 because it is a real good tire and cheaper than any of the ones you listed. Also, the top performer street tire at the moment is the Bridgestone RE-01R while I think Falkens have fallen out of favor in recent years. Falken does make a 235/40 and 215/45 that you could use as well.
Steve, at twice the cost, are the bridgestones that much better than the 615's? The bridgestones are nearly the same price as same size Hoosier A6's.
Edge Racing Flakens are $128 235/40/18 - Bridgestones $223 235/40/18
Tirerack has the Hoosiers for my track rims $244 245/40/17
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Wiseman - Just cuz someone else has a fast car with the same parts as you, doesn't mean your car is fast.
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Other than the Flik Wasp wheels (17*8) my car is bone stock and a daily driver. On tight corners in which you have to accelerate out of I still get tire spin (its an 03, no lsd). I also have no plans to mod the car any this year.
Central Pa Region of SCCA has a new class (Street Tire Index) in hopes of recruiting more drivers who show up in cars that are modded for street looks but did not place emphasis on tire traction over looks of the car. In the 1st two seasons I ran DS and couldn't run close becuase of my tire choice (remember daily driver). On the 3rd season I ran STU but was 90% of the time running against myself.
The Street Tire index class consist of the mods to you car will account for the class you would normally be in but just on street tires (140+ tread rating) and the times then would be based on PAX. For example since I modded my wheels I would fall in CSP. I want to run in this class as I feel the competition will have me push harder to improve myself other than in a class by myself just trying to beet my quickest time.
Steve, at twice the cost, are the bridgestones that much better than the 615's? The bridgestones are nearly the same price as same size Hoosier A6's.
Edge Racing Flakens are $128 235/40/18 - Bridgestones $223 235/40/18
Tirerack has the Hoosiers for my track rims $244 245/40/17
Nah, they're not twice as good, it's just that if you want to compete at a national level in STU then that's the price of entry right now from what I've followed elsewhere. I just threw that tire in there for perspective and I hope that makes sense.
Other than the Flik Wasp wheels (17*8) my car is bone stock and a daily driver. On tight corners in which you have to accelerate out of I still get tire spin (its an 03, no lsd). I also have no plans to mod the car any this year.
Central Pa Region of SCCA has a new class (Street Tire Index) in hopes of recruiting more drivers who show up in cars that are modded for street looks but did not place emphasis on tire traction over looks of the car. In the 1st two seasons I ran DS and couldn't run close becuase of my tire choice (remember daily driver). On the 3rd season I ran STU but was 90% of the time running against myself.
The Street Tire index class consist of the mods to you car will account for the class you would normally be in but just on street tires (140+ tread rating) and the times then would be based on PAX. For example since I modded my wheels I would fall in CSP. I want to run in this class as I feel the competition will have me push harder to improve myself other than in a class by myself just trying to beet my quickest time.
Again thanks for the reply.
You're welcome!
Since you have a bone stock suspension why not look at a 225/45/17? If you stretch that over an 8" wide wheel, you'll have almost the same tread width as a 235/40 but with some more sidewall and a little better contact patch during high amounts of body roll from cornering. Weight will be similar but with a taller tire so, it will have better forward bite and braking.
You could do some cheap mods to really improve mechanical grip with your car, too. Install some larger sway bars front and rear and get some camber bolts for the stock struts so you have some camber, especially up front. Neither of those things would cost more than a couple hundred bucks altogether and really make the car more fun to drive without hurting daily driverness. Big bars, -1.5 degrees up front and 0 to -0.5 rear camber would make a real nice daily driver methinks.
Tirerack has the Hoosiers for my track rims $244 245/40/17
I would recommend you get a used Hoosier in that size to try out before you buy them. My 225/45/17's Hoosiers are MUCH wider (1 inch) that all of my other brand (GY, Yoko & H-kook) 245/40/17's. They BARELY fit my car.
If you had 245/40/17 Hoosiers, I don't think they will fit.... best to be cautious before you drop a G on tires.
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SO the 225's are really wide? My Avon Tech RA's are like that. They are freaking HUGE & Heavy. I had to raise the rear of my car big time to keep them from rubbing. Going to a stiffer spring on the mopar S3's will help. Anyone have any thoughts on how stiff I should go above S3 rates? I was think of moving the springs from the front to the rear & buying stiffer springs for the front. Has that been run with any success?
Oh yeah, good luck finding good used Hoosiers. I have been looking for like a year on eBay & craigslist.
SO the 225's are really wide? My Avon Tech RA's are like that. They are freaking HUGE & Heavy. I had to raise the rear of my car big time to keep them from rubbing. Going to a stiffer spring on the mopar S3's will help. Anyone have any thoughts on how stiff I should go above S3 rates? I was think of moving the springs from the front to the rear & buying stiffer springs for the front. Has that been run with any success?
Oh yeah, good luck finding good used Hoosiers. I have been looking for like a year on eBay & craigslist.
I am moving my 650's from the rear to the front this weekend and installing new 850's in the rear.
I bought my hoosier wets on ebay. Brand New with a huge discount!!! WOOT!
Just because a tire has 225/xx/xx on the sidewall doesn't mean diddly about how it really sizes up. What you need to do is look at the actual specs page and compare to what you know from some other tire. The Tirerack is extremely accurate with what they put up for tire specs and is usually a good resource to use when determining if one tire will fit or not.
For example: The Tirerack spec page for the Hankook Ventus RS-2 225/45/17 shows a tread width of 8" on a 7.5" rim. If you look further down the page and see how the 235/40/17 compares, it shows it is 8.3" on an 8.5" wide wheel. So, I will assume that if you mounted both on an 8" wide wheel, the tread width will be almost identical. The only difference will be sidewall height and overall diameter. Since the OP has a bone stock suspension I would think his car would do better with the taller 225/45 than it would with the low profile 235/40. Such a low profile tire needs a better dialed in suspension to keep the entire contact patch on the road surface during cornering, IMHO.
The 225/45-17 RT-615 heats up very well for me, on a grippy groomed concrete (LCAC landing pad) at least. It got to the point last year where I HAD to spray them down with water between runs to keep them from being overheated and losing way too much grip. If you aren't getting them up to temp, you aren't driving hard enough, if it's dry and moderately warm outside. This past weekend I couldn't get them above cool even after 20 minutes of track session, but it was 40° and wet.
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Need new tires for autocross . . .
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