Benefit of going to 215?

[RAAMaudio]

Sorry, I left out a bit, they are 225/45/15s I run so no, not going to work on stock rims.

I would use the stock rims for your all season tires as they are quite heavy and you would not want a 225 of any sort on them as far to wide, to tall, to heavy.

Stock setup is around 42lbs or more per corner, my 15" setup is around 34lbs, 10lbs per corner is a huge improvement but I can feel a lot of gain with far less weight saved than that.

40lbs of weight off the car in the most critical place possible is the best single mod one can do to make a great car a great deal better at everything at least most of us bought this car for

 

[IrishST]

Appreciate the lengthy updates. I totally hear what you're saying, but as someone that doesn't do serious autox or track events, I'm not sure I want to go all the way down to 15" with fat tires. I'm not part of the image only stance nation crowd by any means, but I definitely do want the car to look nice and I kind of want to stick to 17s as a trade off between looks and performance, though I'm not ruling out a middle ground of 16" completely. I really think I've narrowed it down to the Star Specs as the tires I want for my warm weather set, the only issue is I can't find a good selection of wheels in 17x7.5" with the proper bolt pattern and I'm not sure that the decently wide Star Specs will be optimally mounted on a 7" rim. Maybe it will?

Back to the wheels, I'm finding tons in 16x7 and 17x7, but that 7.5" width is a tough one for our less than ideal bolt pattern. Though if I do drop down to 16" I could change the tire... the Potenza RE-11 looks promising and its ideal width rim is in fact 7" when you go 205/45/16 so it should be nice and flush. There is also the Star Spec available in 205/50/16 and it has good looking specs with an ideal rim width of 6.5" and a range of 5.5" up to 7.5" so 7.0" shouldn't stretch them too bad. The biggest issue is most of these high ranked tires are heavy, a good 2-3lbs more per corner than the stockers.

I dunno... 16x7 seems like it might be a good compromise... Decisions!!!

EDIT:
[MENTION=636]RAAMaudio[/MENTION] You got me thinking more about 15's and I've been looking. I'm not seeing a ton of selection in 15x8, but I'm probably also looking in the wrong spots since wheels/tires are something I haven't dealt with a lot in the past. That said, 15x8 w/ 225/45/15, it looks like that'll fit without fender well modification, yes? If the car is lowered about 3/4 of an inch do you think it will still fit? I'm assuming the offset needs to be pretty aggressive at 35 or so? The measured sizes for the tires themselves seem pretty close to stock and so I assume it would be fine as long as the offset is right, even lowered, since you can lower about an inch on stock wheels/tires without issue.

Also, what about going 15x7 and sticking to 205/50/15? The Star Specs look good in this size with a tread width that is just shy of stock and it's just short of the stock diameter by like 0.3". I found some 12lbs rims in 15x7 for $200 each so that's not terrible considering the lower tire price of like $35 per. Jumping from that, would a 225/45/15 be alright on a 7" rim? I see the BFG Rival S is available in that size and it states a range of 7-8.5" so I know it will fit, but would it be ideal, or is it going to result in bulging? I ask because for that tire in 225/50/15 it doesn't show the measured rim width to give me a feel for what is recommended, thought the Proxes R1R in the same size has pretty similar measurements and it has a measured rim width of 7.5" so that gives me pause.

Looking at 205/50/15 I see a decent selection of summer tires, as well as a few track/autox only tires, so maybe 15x7 is a good option... I tell ya, I'm starting to wish I was part of the "appearance only" crowd because it would be so much easier, lol .

 

[RAAMaudio]

Those are not ideal rim widths, those are as tested widths and they generally mount them on the middle of the manf spec width range which is not optimal. Not sure why even Tirerack does that as they know better that you want a slight stretch on any tire to optimize the grip and feedback.

It has been well explained but you are getting mislead by info on the site that is not the best way to go.

The 205/50/15 Star Spec has an 8.4" section and 7.5" tread width thus would be better on an 8" wheel but will work on a 7"wide one pretty well. Being just 19lbs on 12lb wheels would be a very fine low weight setup.

There are no 225 tires, no matter the actual specs, I would put on a 7 or likely 7.5 wide wheel (not many 7.5" wheels made) If you put them on a narrow wheel like that you would have very flexible sidewalls which give poor feedback to steering input and overall feel of what the car is doing plus the side to side movement of the wheel inside the tires means the body is moving around that much, not a good thing.

I have the 225/45/15 Rival S and love them, they work very well on an 8" wide wheel but testing by GrassRootsMotorSports magazine with Andy Hollis, many times national champ driver, proved it worked better on a 9" wide wheel, 1 second a lap faster on a 45 second course is considerable so I have them on 9" wide wheels just as I do the 6 race tires that are also 225's.

-----------
Here is a tire to consider since you are not autocrossing or doing track days these will give you a lot of grip but last quite a bit longer and cost less. They are a very good tire and were ran on the Octane Academy cars on stock rims and they worked quite well. They have a very wide tread for the specs listed but seem to do well on narrower wheels though I would personally still use them on wider ones.
BFG Sport Comp 2
195/55/15, 23.4" diameter so same as stock, 7.9 section, 7.7 tread width, 21lbs so a bit heavier, just $78 each.
They make suitable sizes in 16 and 17" as well.

I understand liking bigger diameter wheels, I have ran 18's on race cars but that was because the tires I wanted to run, big brakes, etc demanded it but on any street or race car I use the smallest diameter wheels that fit over the brakes I am using for the best balance between width, sidewall support, etc....and enjoy a much better ride, less stress on the chassis, lower cost, enhanced fuel mileage.

I do not build my cars to get looked at except perhaps the rear view when blowing by somebody on a race track yet my car on 15's gets constant comments, looks, waves, thumbs ups, lights flashed, peace signes, etc, from people of all ages. It helps that the spokes go all the way to the rim edge which makes them look a bit bigger than 15's, more like 16's, when I had the 17's on the car it got barely any attention at all.

Our big turbo car on the wide wheels and tires has achieved a best of 41.5 MPG on an easy run from CA to AZ following our RV so no reason to get into much boost but that is pretty amazing and less rotational mass as well as overall weight is part of what makes it do so well, bigger turbo helps a bit due to less back pressure when out of boost.

 

[IrishST]

-snip tons of good info but snipping for post length-

Thank you so much for taking the time to reply in such detail, I really appreciate it. Thank you for explaining the rim width deal on tirerack as well, I was misunderstanding that a bit. I have just a few final questions and I will try to keep them simple. I will say this too, you have pretty firmly convinced me of going with 15", though I am considering a BBK in the future so I might go 16", but 15" is looking like the winner.

Anyway, the questions:

1. If I go with a 7" rim, 40-42 offset should be fine, yes? Stock is 47.5 and it's my understanding that we can safely go down to 35, but you seem way more knowledgable on this and hearing it from you gives me more confidence.

2. If I go with an 8" rim, how much farther would I have to go on offset to account for the extra width while not requiring fender mods or wheel well mods? 35? 37?

3. Finally, considering a wheel that sits farther out in the well, in your experience, if I go with an offset in the range of 35-42 and I lower the car 3/4 of an inch, do you think I'll have outside rubbing? I know you did pretty extensive work to make your 9's fit, but I'm not going to 9. 8 is the upper bounds and considering I can't seem to find much that is easily available in 15x8 (or 16x8) I'm probably going to go 15x7 (or 16x7).

 

[RAAMaudio]

I do my best, I do not know it all so I do a lot of research for my own setup but also enjoy doing so for others

Since you plan on a BBK you will likely have to run 16" wheels and then make sure they will fit over the brakes.

I have a set of 16x8 RPF1 wheels that fit over my custom 11.75" rotor BBK and need to test fit the 16's so I can measure the clearance to see if they fit over the standard 12.19" rotor BBK. The RPF1 has a smaller inner bore diameter than most wheels so if they do not fit other 16's should.

I should do that in the AM and will if sent a reminder, at least hope to, only a few days left to cover many gem shows here in Tucson.

There are other 16's in the works but it will be some time before available and only in 4x100 like the RPF1, I most highly recommend a 4x100 conversion as some great 15s and now some 17's in roll formed, low weight, strong and very good priced wheels being made and 16's on the way.

It cost a bit to do the conversion but you get far more good wheels at great prices and 4x108 is never going to get much support. If one is not planning to keep the car along time the conversion would not make sense of course.

A lot of rubbing issues are caused by the 3rd bolt location on the bumper cover to fender mount which is pretty easy to trim off.

+35 effects the scrub radius a bit but also adds track width but could be an issue with really wide tires.
+40 is likely a good compromise overall.
+45 should be OK, could need a small spacer but probably fine depending on how wide the tires are.

If you plan to keep the car for quite a while you might want to consider the 4x100 conversion as many great wheels available, roll formed so very strong, low weight, low priced...some great 15's and 17's now and some 16s coming out sometime this year.

 

[IrishST]

I do my best, I do not know it all so I do a lot of research for my own setup but also enjoy doing so for others

Since you plan on a BBK you will likely have to run 16" wheels and then make sure they will fit over the brakes.

I have a set of 16x8 RPF1 wheels that fit over my custom 11.75" rotor BBK and need to test fit the 16's so I can measure the clearance to see if they fit over the standard 12.19" rotor BBK. The RPF1 has a smaller inner bore diameter than most wheels so if they do not fit other 16's should.

I should do that in the AM and will if sent a reminder, at least hope to, only a few days left to cover many gem shows here in Tucson.

There are other 16's in the works but it will be some time before available and only in 4x100 like the RPF1, I most highly recommend a 4x100 conversion as some great 15s and now some 17's in roll formed, low weight, strong and very good priced wheels being made and 16's on the way.

It cost a bit to do the conversion but you get far more good wheels at great prices and 4x108 is never going to get much support. If one is not planning to keep the car along time the conversion would not make sense of course.

A lot of rubbing issues are caused by the 3rd bolt location on the bumper cover to fender mount which is pretty easy to trim off.

+35 effects the scrub radius a bit but also adds track width but could be an issue with really wide tires.
+40 is likely a good compromise overall.
+45 should be OK, could need a small spacer but probably fine depending on how wide the tires are.

If you plan to keep the car for quite a while you might want to consider the 4x100 conversion as many great wheels available, roll formed so very strong, low weight, low priced...some great 15's and 17's now and some 16s coming out sometime this year.

Thanks again, much appreciated. PCA has a set of TD Pro Race 1.2 in 15x7, 42mm offset in their thread in the sponsor forums and I'm considering pulling the trigger on those. I'm seeing good tire choices in 205/50/15 as well as 195/55/15 so I think all around it will be a good fit. Decent amount of choices that mostly retain the stock measurements but result in equal, or a bit more, tread width. I also have an inquiry with them on when the 8" version will be in stock again and if the wait isn't too long I might just go all in on those.

Thanks again, you've been a HUGE help and your advice got me reading the right things and I've definitely picked up knowledge that will help down the line. As of right now I do intend to keep the car for a bit, but I honestly can't say if it's going to be truly long term or not. I absolutely love it at the moment, but I'm giving it 2-3 years to decide if I'm going ALL IN, or if I'm going to move on to something else, and that's why my mods for now are focused on handling and light power, but nothing super extreme.

 

[RAAMaudio]

Glad to help

One note, I would not try to match or exceed the stock tire tread width, not as a priority. Instead I would look to maximize the particular tire and wheel you choose which is much more important. Some tires are designed to work better with a certain tread width but that information is only available normally by those with great experience using tires in more extreme situations.

As mentioned some tires are exceptionally wide, some pretty narrow, some in the middle, no matter the posted or stamped on the side specs. Going fast is not about ultimate stick if the car has poor feedback, moves around on the tires, it is far more difficult to fully exploit the extra stick of wider tires if to wide for the wheels.

Since some of this is pretty hard to find out sometimes taking a stab at it is the only way. It has happened to me more than once but I have gotten far more careful though just gave my expensive all seasons to my daughter as they were far to loud and rode far to hard on my particular application I had no basis to go on when picking them for this specific car.

If the wait is not too long on the 8" TD wheels I would wait for them as that extra inch with the right tire combo can help a great deal.

2 years used to be a long time for me to keep a car no matter how modded, then it got a bit longer, one I kept 8 years with 8k miles on it, some less than a year....the FiST had 293 miles on it for the first 9 months, 7500 miles now and most of those in the last 6 months, two years old, plan to keep it a very long time as long as I keep it on its wheels and not hit by some dumb arse texting......

 

[IrishST]

Glad to help

One note, I would not try to match or exceed the stock tire tread width, not as a priority. Instead I would look to maximize the particular tire and wheel you choose which is much more important. Some tires are designed to work better with a certain tread width but that information is only available normally by those with great experience using tires in more extreme situations.

As mentioned some tires are exceptionally wide, some pretty narrow, some in the middle, no matter the posted or stamped on the side specs. Going fast is not about ultimate stick if the car has poor feedback, moves around on the tires, it is far more difficult to fully exploit the extra stick of wider tires if to wide for the wheels.

Since some of this is pretty hard to find out sometimes taking a stab at it is the only way. It has happened to me more than once but I have gotten far more careful though just gave my expensive all seasons to my daughter as they were far to loud and rode far to hard on my particular application I had no basis to go on when picking them for this specific car.

If the wait is not too long on the 8" TD wheels I would wait for them as that extra inch with the right tire combo can help a great deal.

2 years used to be a long time for me to keep a car no matter how modded, then it got a bit longer, one I kept 8 years with 8k miles on it, some less than a year....the FiST had 293 miles on it for the first 9 months, 7500 miles now and most of those in the last 6 months, two years old, plan to keep it a very long time as long as I keep it on its wheels and not hit by some dumb arse texting......

I ordered the anthracite 15x7 TD wheels today and they should ship tomorrow since they're in stock. 42mm offset so I'll gain a tiny bit of width. I went with this as my daily driver, spirited backroads wheel and down the road I will consider going 15x8 w/ ~35-37 offset for track or autox if I end up getting into it. One of the biggest deciding factors was wait time - I was looking at an unsure timeframe but "no earlier than May" and then it would have depended on me beating others to the punch.

For the tires, I'm still torn. I really like the price on the super comp 2's, but I'm concerned they won't be grippy enough. I'm also torn on going 195/55 or 205/50 if I do go with this tire. The 195 is a wide 195 and matches stock diameter exactly but I'm concerned they will end up too skinny. Going to such a thick sidewall concerns me as well despite the good width since I don't want to heavily dull the turn in or have sidewall roll issues. The other option is an extreme summer since this will truly be warm weather only wheels so I might go with the D2 Star Specs but they are more expensive and this is a DD/fun backroads car right now so I'm not sure the extra cost is worth it.

Thankfully I have a few months to decide. Also, my original wheel choice was the OZ Ultraleggera and even at 15x7 they would have been $200/wheel for a total of over $900 after getting TPMS hardware. Going with the TD gained me about 1.7lbs per wheel, but saved me like $250 after TPMS and that gives me more room to get more expensive tires. Even with the higher weight on the TDs if I go with Star Specs I'll save just shy of 36lbs from stock and like 28-32 if I go with the sport comp 2s depending on the size.