SlowB16

I'll be getting new tires this year and I can't decide whether I should get another set of 205/50/15's like I have now or get a new set of wheels that will allow me to run 225's. So my question is, for those of you that have run on both, is there a noticeable difference between the two? Do you feel like it is worth the cost of having to buy a new set of wheels that got the wider tires?

Fyi this is for an eg hatch with an h2b setup that I use for hpde events.

Thanks!

joel n

There was a very noticable difference for us. We had 205/50/15 toyo R888 and a set of BFG R1s. We danced back and forth from the 205/50/15 and 225/45/15.
We run a 95 delsol with a B17A1 motor. Car weighted 2570LBS race weight. With the 205s i could run hard for 5 laps then they fadded off (toyo R888) same tire but in a 225 and they went all race. The BFG R1s worked good in really hot days but i could do the same lap times on the 225 R888 with a little handy hand work. Now this is race conditions not HPDE. So you wont be as agressive. I mark all the races we run on each set of tires and the 225/45/15 gave us about 2 more races (15 laps races) per set then the 205. There may have been many other contributing factors there as i wasnt including days temps/weather at first but we havnt raced much in the rain. We have run the 225 on 6.5 to 8 inch wide rims. Havnt noticed a any difference in lap times from the different rim sizes, so if you have a set of 15X6.5 rims and want/dont mind spending the extra $20 a tire then do it. But for HPDE it may not be a cost you need to put on yourself if you have a wallet like mine.. Empty

Xian

It'll also depend on tire type (street vs. R-comp) and actual wheel width.

Davidss

+1

Weston

R888's are prone to heat-related issues, for both short-term and long-term performance. Years ago, they were the spec tire for 944-Spec, and they were almost universally hated with a passion... I held out hope for longer than most, but eventually gave in to the overwhelming reality that they suck. They'd get you about half the way through a race and then lose performance, and also only last about 12-16 heat cycles. It was so bad that I once replaced R888's with heat cycles in the mid-teens with my much older RA-1's in the same size with 30+ heat cycles and easily picked up 2 seconds in lap time on Miller's outer loop. The old beaten RA-1's also had consistent performance throughout the race, yet we were force-fed this story that the R888's are somehow a "superior race tire". Bullshit. The class eventually went back to RA-1's, and plenty openly-defied the rules and ran NT-01's in the meantime. There was a time in there where the tire vendors couldn't seem to give away R888's for free.

What you've experience in getting them to act better in the wider size gives me the theory that the wider size ran at cooler temperatures, so perhaps the crap performance and life comes from overheating them, which apparently happens at lower temperatures than other tires.

SlowB16

It'll be star specs, rivals or rs3's.

I currently have 6.5" wheels so ill need something wider in order to run the 225's.

navin

iTrader: (1)

^I'll have a set of 15*8 949's for sale soon

Xian

My $0.02 would be to buy those ^^^ wheels and get some 205's.

FlewByU352

I'm torn and tempted to get the 225-45-15 R888 versus the 205-50-15. The tread width is like 3/4" wider and the tire is about a 1/4" shorter overall. I see both of those as a plus! Price difference is minimal too.

I wish someone would make a 15" tire in a 245/255 that is around 23" or 24" tall. 15x9's and grip for days with our light chassis'.

10cjennings

iTrader: (1)

R6's come in 245/40, and 245/50, you'd want a 10''.

joel n

You dont need to buy 8inch wide wheels. Its a extra exspence. We have run 225/45/15 on 6.5 wide wheels with no problems. we have also run 225/50/15 on a 6.5 wheel with just needing a small bump in tire presures to calm it down. We also have 3 sets of 7inch wide wheels and 2 sets of 8inch wide wheels. The 8inch wide wheels are dedicated for hoosier and Khumo tires now. If you were buying hoosiers or even Goodyear or khumos id say buy a 8inch wide wheel, but with street tires i would save to money and stay on the 6.5.
Also i would go with either the rival or RS3.

Xian

If you decide to go with the R888's, I've got a lightly used pair of 205/50's that I ran on the rear of my EF (was running 225/205 stagger). Since you're in FL, shipping should be cheap...

Errrrr... I'll disagree. Strongly. I've played with street tires on 6", 7", 7.5", and 8" wide wheels. For street tires, there's no way I'd put the 225's on anything less than an 8" wheel. This has been backed up by the testing Andy did with/for GRM (225 was no faster on an 8" wheel than the 205). Running a wide street tire on a narrow wheel makes turn-in and slalom behavior pretty terrible for autox. It doesn't feel "as bad" on track but there's still not an advantage to over-tiring when you're running street tires. R's are obviously a whole ''nother ball of wax...

johnjw

^ how about lasting a bit longer? 225vs205 on the same 7 inch wheel? I know the 205 would "perform/feel" better on a 7 but I tend to think the 225 on a 7 would last a bit longer but give up turn in and transition in the tighter stuff.

joel n

I havnt run street tires for autox for years now so I have no doubt iam wrong. lol. I cant remember the last time I used street tires at the track or a auotslalom.

Get the 225s and fit the widest rim you can pending $$$ and fender clearance. We have a set of 949 and TRM 8 inch wide wheels. Very nice and dosnt cost $$$. the 949s have been track for 3 years on a miata ( we havnt raced them yet. 2nd gen wheels) Fitment is great and with the 225/45/15 NT01s currently on them. Hoosier should fit as we have lots of room. As for the TRM wheel, we raced them for a year now and love them. Currnetly have 225/50/15 R6 hoosiers. Fitting them was fun. Roller plus hammer. Running a 3/4 spacer in the front. the 949s are a +38 offset and the TRMs are a +20 offest.

Xian

Possibly? Dunno. With the relatively soft sidewall on street tires, you may end up with enough rollover to end up with uneven wear (which means having to flip the tire more often).

LOL. Street tires are really good for what they are but they're still much more sensitive to wheel:tire width sizing.

gramkrackers

Any links to some testing numbers for this? I finally picked up two sets of 15x8's and I had figured I would run the 225 Rival's on my R this year, but I always really loved the Star Specs. I was able to do back to back testing last year with my EK coupe on 205/50/15 Rivals vs 205/50/15 Z1's, both with 15x7" rims. The Rival was about 7 thenths faster, but the Star Spec's felt so much better, I was really shocked when looking at the data afterwards.

I drove an E36 328i racecar at the end of the year with the new ZII and felt the tires were excellent, they had a very progressive breakaway unlike the Rival. The owner of the car (very fast, very good driver) ran on RS3's, Rival's and finally the ZII at various points throughout the year and said he by far he liked the ZII the most. But thats comparing apples to oranges in our situation.

I would love to give the new ZII a shot but just can't away from the fact they are only available in a 205/50.

To keep the post on topic, my personal opinion is that no matter what tire you get, invest in 15x8's. I went two years with 15x7's and 15x6.5's and feel like I gave away alot. Its one of those things that I feel is worth it, especially when dealing with street tires.

Xian

It was in a semi-recent article @ GRM but, in a nutshell: On track both the 225 and 205 Rival laid down almost identical lap times when put on a 15x8 wheel. They drove very differently though. When the 225 was put onto a 15x9 wheel, it became the faster option.

This ^^^ isn't really any different than what Andy's been saying in person and online for several years so it wasn't a big shocker to many folks out there...

PS
Keep an eye out for a revised compound Z2... supposed to be out sometime 2015 for North America. Hankook is also working on a revised RS3 that is supposed to be out later this year in NA.

RR98ITR

The story of "wide tires" as they quickly developed in the 1960's Can-Am era was again retold in some story in Motorsport or somewhere recently. McLaren tried their tires on wider rims and they went faster...the tire engineers said "that's not the rim width those tires were designed for" and went and made new wider tires for the new wider rims...and then McLaren made even wider rims...and then the tire engineers made even wider tires...and...and...

*** I remembered wrongly - it was Jim Hall on his Chaparral's http://www.insideracingtechnology.com/jimhall.htm ***

Crudely speaking, if you were able to get the contact patch where you wanted it geometrically, you'd like it to stick pretty close - wide tires on skinny rims are not usually helpful with this. Done right there is supposed to be some riding on rails synergies.

Scott, who, there's more to it than just this but, has enjoyed driving 205's more than 225's on 7's at the front....

Xian

Yeah, "stretched" (y0!!1) isn't fast... "square" is what you're aiming for. But, again, something like the A6/R6 is more tolerant of being shoved onto a narrow wheel and they've got a semi-cantilever design anyway...

0philstireservice

Don't forget the new Toyo RR in 225/45R15.

egvera89

This is a good topic to discuss. Helped answer a couple of my questions.

SlowB16

I have the article. If anyone wants it send me a pm with your email address or phone number and I'll send you pictures of the pages.

Thanks for all the responses so far. Very informative

gringotegra

Hey Matt, just get some 205 take off Miata tires!

SlowB16

I think im going to grab some 205/50 star specs....and maybe some wider wheels.....but if you have a lead on some take offs let me know.

granracing

I ran Hoosier 225s for many years on a 6" wide tire (SCCA ITB class where 6" was the max width). However, I still believe there are some tracks where a 205 would be faster due to rolling resistance. Not that it matters for HPDEs.

For a street tire, I do agree that the sidewalls probably flex too much.

Take offs are usually pretty easy to find. Go to an SCCA or NASA race, become friends with the tire vendor, ask for some old take offs. Especially in competitive events, drivers get rid of tires with just a few heat cycles. It costs the tire vendor money to dispose of the tires, and they don't need to put them in the truck then unload them after. A couple of my friends still do this.