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Thread: THE Wheel & Tire Thread

  1. #1
    Senior Member Xusia's Avatar
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    THE Wheel & Tire Thread

    There has been a lot of discussion on wheels & tires, as well as a couple other threads. In the hopes this makes it as a sticky, I'm going to reference the other threads here:

    New Tire Options (High Performance Tires)

    Budget Lightweight Wheels Thread

    What I'm attempting to do is gather all the known info we have into a single thread so you don't have to glean it all from other threads like I just did for hours last night! The wheels & tires on my donor are toast, so I'm now in the market. Hence the reason wheel & tire info is now important to me.

    I'm going to update this a bit later, but for now, you all might find this document interesting. I put together a list of wheel & tire combinations with various specs so I could get a better idea what route I wanted to go:

    Wheel & Tire Combinations

    The blue highlighting indicates the - in my opinion - 2 best choices for 17" wheel & tire combinations on the street (The race track types will likely have a completely different plan of attack). The orange highlighting indicates the same for 18" wheels. For both, I've taken into account tire fitment, spacing/offsets (to make sure they will fit and not rub - given the best info we have at the moment), and overall circumference (to minimize speedo error).

    UPDATE 2013-05-26
    I've updated the document with specific wheel info, and specific tire info. I've gleaned the data from the previously referenced threads, as well as my own research (THANKS Google!). The document now has 3 tabs:
    1. Sizes - provides estimated fitment for both specific tires onto specific wheels, and for specific wheels onto the 818. I used this site for the measurement estimates: http://www.rimsntires.com/specs.jsp
    2. Wheels - A list of specific wheels, including available sizes (5x100 ONLY), available offsets, weights (where known), and prices. I can add links also if people care to provide them.
    3. Tires - A list of specific tires, including available sizes, weights (none yet, but when we learn them...), and prices. Again, I can add links also if people care to provide them.



    I will continue to update as I come across or see relevant information, but at this point I would appreciate any input you brilliant folks can provide!
    Last edited by Xusia; 05-26-2013 at 06:43 PM.

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  3. #2
    Senior Member Xusia's Avatar
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    Place holder #1.

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    Senior Member Xusia's Avatar
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    Place holder #2.

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    Senior Member shinn497's Avatar
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    sticky?

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    Senior Member Xusia's Avatar
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    I've done more work on the spreadsheet and added 2 new tabs for a total of 3 tabs. See updated first post.

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    Senior Member Frank818's Avatar
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    Quote Originally Posted by Xusia View Post
    In the hopes this makes it as a sticky,
    Well it hasn't. Yet. I was about to start one I thought I'd call "THE Wheel and Tire thread". Then I looked carefully through the pages and bam I hit on yours. loll

    Let's reference another thread: http://thefactoryfiveforum.com/showt...Pics-Thread%29

    There are various options on the wheel sizes and tire sizes.

    What are you guys going to fit?
    And how do you think it will be in terms of ride comfort, ease of steering, grip, clearance front vs rear (if you have too small tires up front vs rear, maybe you'll have too much clearance tire/fender up front and it will look ugly vs rear? Or you'll have to lower the front much more so the rear end will look jacked up, like those big Muscle cars you could see the rear differential bigger than anything else loll), etc.

    I do not know if 215 or 225 are better up front. 40 or 45 series? 17" or 18"?
    Back in the rear, 255s for me, 18". But 35 or 40 series? I cannot make the difference, I don't know if I could feel the difference on the road.

    How about you?

    Now I am not talking about rim sizes yet, but 18x9.5 rear seems the choice for me.
    Frank
    818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
    Go-karted Aug 5, 2016 - Then May 19+21, 2017
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    Senior Member Canadian818's Avatar
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    I'm just waiting to see what the first few guys run, and base my decision on theirs. I want as wide and as tall a tire as possible. If I can squeeze in 235/265 combo then I will.

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    Senior Member Xusia's Avatar
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    I'm waiting to see what FFR offers. I have a strong preference to run 17" wheel all around (to better protect the wheels on the street), ideally 8.5" in the rear, and 7.5" up front. If I can't find the widths & offsets I want to make this work, I'll just get 8.5" all around.

    My tire plan is to run 245/40 in the rear. Not IDEAL for traction, I know, but I'll have the RLTC system, so it will hook up as well as physics allow. If the front wheels are 8.5", I'll run the same as the front. If they are 7.5", I'll run 225/45.

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    Being a mid-engine RWD setup (MR) you may want to reconsider running equal tire sizes front and rear. Snap oversteer is already a common problem with MR cars and running big tires on the front is only going to make this problem even more prevalent mid-corner. Even if you do run the same size wheel all around, I would still suggest different tire sizes front and rear.

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    Senior Member wleehendrick's Avatar
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    Quote Originally Posted by bnr32jason View Post
    Snap oversteer is already a common problem with MR cars and running big tires on the front is only going to make this problem even more prevalent mid-corner. Even if you do run the same size wheel all around, I would still suggest different tire sizes front and rear.
    I agree, and think a staggered wheel & tire set-up is ideal for handling balance as well as aesthetics.

    I hope that snap oversteer (my biggest concern with the 818) has largely been mitigated by FFR with a solid and balanced chassis and suspension set-up. The quote from the Road and Track article:

    "the 818's a true sweetheart, pushing the front predictably before uncorking its tail in a lazy slide"

    seems to imply that they got it right, and that it won't be a tail-happy nightmare.

  13. #11
    Senior Member Frank818's Avatar
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    As far as I have read everywhere, they spent a lot of time designing the chassis but also those guys at KONI spent a lot of time tweaking the suspension. My guess is they did build something not too hard to drive and possible to drive fast without requiring Sebastian Vettel's skills.
    Frank
    818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
    Go-karted Aug 5, 2016 - Then May 19+21, 2017
    Tracked May 27/July 26, 2017
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    818 builder metalmaker12's Avatar
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    Quote Originally Posted by Frank818 View Post
    Well it hasn't. Yet. I was about to start one I thought I'd call "THE Wheel and Tire thread". Then I looked carefully through the pages and bam I hit on yours. loll

    Let's reference another thread: http://thefactoryfiveforum.com/showt...Pics-Thread%29

    There are various options on the wheel sizes and tire sizes.

    What are you guys going to fit?
    And how do you think it will be in terms of ride comfort, ease of steering, grip, clearance front vs rear (if you have too small tires up front vs rear, maybe you'll have too much clearance tire/fender up front and it will look ugly vs rear? Or you'll have to lower the front much more so the rear end will look jacked up, like those big Muscle cars you could see the rear differential bigger than anything else loll), etc.

    I do not know if 215 or 225 are better up front. 40 or 45 series? 17" or 18"?
    Back in the rear, 255s for me, 18". But 35 or 40 series? I cannot make the difference, I don't know if I could feel the difference on the road.

    How about you?

    Now I am not talking about rim sizes yet, but 18x9.5 rear seems the choice for me.
    I am running 17x7.5 Sti bbs with 235/45's all around for all most driving, but I will have a set of 17x8.5 225/40-45 front with 18x9.5-9.75 255-275 35's rear for shows and all highway smooth roads etc. I like Rays wheels and will prob get a set soon after I get her legit and on the road. I don't want to put to much on my car so I potentially get taxed more for those parts at inspection.

  15. #13
    Senior Member Frank818's Avatar
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    It seems so far no one is thinking of going as small as 215s. Everybody is talking about 225, 235 and even 245s up front.
    I thought of 215s to make it easier on the steering, but maybe it would be less good through corners.

    Looking at the 2013 458 Italia (which I want to beat in all performance aspects lollll), front are 235/35/20 and rear 295/35/20.
    So I guess 225s front on the 818 isn't that bad. 458 weighs a bit more than 1400kgs (over 3200lbs).

    For me so far I have 225/45/17 (OEM) front and 255/35/18 rear. Though I wish I could fit larger tires, I love large rear tires (GTM on 305s or 335s is awesome looking). But the 818 is there for agility, quickness, precision, lightness! Large tires are all but that.
    Frank
    818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
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  16. #14
    818 builder metalmaker12's Avatar
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    With some modification someday I might fit some wider stuff

  17. #15
    Senior Member Xusia's Avatar
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    I don't think I'm likely to be pushing it hard enough to worry about end swapping. Plus I'll have traction control.

  18. #16
    Senior Member Silvertop's Avatar
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    Quote Originally Posted by Frank818 View Post
    It seems so far no one is thinking of going as small as 215s. Everybody is talking about 225, 235 and even 245s up front.
    I thought of 215s to make it easier on the steering, but maybe it would be less good through corners.

    Looking at the 2013 458 Italia (which I want to beat in all performance aspects lollll), front are 235/35/20 and rear 295/35/20.
    So I guess 225s front on the 818 isn't that bad. 458 weighs a bit more than 1400kgs (over 3200lbs).

    For me so far I have 225/45/17 (OEM) front and 255/35/18 rear. Though I wish I could fit larger tires, I love large rear tires (GTM on 305s or 335s is awesome looking). But the 818 is there for agility, quickness, precision, lightness! Large tires are all but that.
    There ARE a few of us planning on using narrower tires. I'm planning on using 205/55-16's up front and 225/50-16's on the rear (on stock WRX wheels), and I know of at least one other forum member who is planning the same setup. And I expect that it will go around corners just fine -- probably well enough to handle any corner at twice the recommended speed. As has been noted elsewhere in this forum, the Lotus Elise, which is similar in design, size, and power, uses this same tire combination, at least in stock street form.

    Of course, I'm not planning on putting down great bucketfuls of horsepower. I'll be running a moderately tweaked NA engine, generating maybe 200-210 flywheel horsepower. I'm also going to run a Quaife LSD to help distribute that power as evenly as possible to those (relatively) narrower tires.

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    Quote Originally Posted by Xusia View Post
    I don't think I'm likely to be pushing it hard enough to worry about end swapping. Plus I'll have traction control.
    The traction control system from Race Logic will do absolutely nothing to prevent snap oversteer.

    You think you won't push it hard enough, until you are out on your favorite backroad (maybe the same one in your avatar) and decide you want to push just a little harder than last time, let off the throttle a little mid-corner because you went in to hot, and then all of the sudden your facing the wrong way.

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    Quote Originally Posted by Frank818 View Post
    As far as I have read everywhere, they spent a lot of time designing the chassis but also those guys at KONI spent a lot of time tweaking the suspension. My guess is they did build something not too hard to drive and possible to drive fast without requiring Sebastian Vettel's skills.
    They built the suspension to work best with a specific setup, namely staggered front and rear tires. You start messing with that critical part of the formula and you just thew off the whole suspension function.

  21. #19
    Senior Member DodgyTim's Avatar
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    I am keen to try the BFG g-Force Rival, lots of good reviews, but their sizes are limited.
    My 818R will be more track than street and the weather is warm to hot all year.
    The best size for the rears is 275/35 R18.
    These have a section width of 10.9" measured on a 9.5 rim, and do 814 rev/mile.
    From Jim Schenck's post the blue 818R runs 255 hoosiers, from the photos they appear to be 255/35 R18's, that have a section width of 10.8"
    At this size they have a slight rub on the outside with 35mm offset.
    I'd be trying a 40 mm offset to account for the extra width and to avoid the rub.

    Because the sizes are limited the fronts would have to be 215/45 R17, which do 844 rev/mile.

    The problem I have is I want to try and run the factory ABS, which will see the front tyres turning faster than the rears, and potentially start bumping the rears thinking they are partially sliding..

    I'd appreciate some feedback on how far you can go in diameter difference before it the ABS kicks in.
    Last edited by DodgyTim; 06-26-2013 at 03:19 AM.

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    Personally I'll be running Volk CE28N wheels 17x7.5 +50 front and 18x9 +40 rear. For tires, I'm not 100% decided on brand yet, but size will be 215/45/17 or 225/40/17 front and 255/40/18 on the rear. Brand and compound depend on if the 818 ends up being my daily driver or not. If I'm going to DD it I'm going have to get a tire that lasts more than 10k miles, maybe something like the Yokohama S-Drive, if not, I'll be going with the Yokohama AD08 probably. Not concerned with the speedo being off since I'll be running a GPS speedo anyways.

    I won't be messing with ABS or any of that stuff, but I am considering that RaceLogic traction control system.
    Last edited by bnr32jason; 06-26-2013 at 03:41 AM.

  23. #21
    Senior Member Frank818's Avatar
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    Quote Originally Posted by Silvertop View Post
    There ARE a few of us planning on using narrower tires. I'm planning on using 205/55-16's up front and 225/50-16's on the rear (on stock WRX wheels), and I know of at least one other forum member who is planning the same setup. And I expect that it will go around corners just fine -- probably well enough to handle any corner at twice the recommended speed. As has been noted elsewhere in this forum, the Lotus Elise, which is similar in design, size, and power, uses this same tire combination, at least in stock street form.

    Of course, I'm not planning on putting down great bucketfuls of horsepower. I'll be running a moderately tweaked NA engine, generating maybe 200-210 flywheel horsepower. I'm also going to run a Quaife LSD to help distribute that power as evenly as possible to those (relatively) narrower tires.
    You are right, I believe power/tq output will also drive the size of the tires, that's true.
    If you were to run a Toyota Prius engine, I doubt you'd stick 265s in. lolll
    Frank
    818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
    Go-karted Aug 5, 2016 - Then May 19+21, 2017
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  24. #22
    Senior Member Frank818's Avatar
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    Quote Originally Posted by DodgyTim View Post
    At this size they have a slight rub on the outside with 35mm offset.
    I'd be trying a 40 mm offset to account for the extra width and to avoid the rub.
    Careful with that, as apparently the clearance on the inner side was very minimal. If you increase offset, you push the tire further onto the spring (suspension).
    Last edited by Frank818; 06-26-2013 at 11:25 AM.
    Frank
    818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
    Go-karted Aug 5, 2016 - Then May 19+21, 2017
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  25. #23
    Senior Member Frank818's Avatar
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    Quote Originally Posted by bnr32jason View Post
    I'll be running a GPS speedo anyways.
    What will you change? The cluster completely? Just the gauges?
    How will fit the new speedo?

    I am currently looking at options to change the cluster or gauges, I'm having a hard time figuring out what can be done.
    Frank
    818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
    Go-karted Aug 5, 2016 - Then May 19+21, 2017
    Tracked May 27/July 26, 2017
    Build time before being driveable on Sep 27, 2019: over 6000h
    Build Completed Winter 2021

  26. #24
    Senior Member narkosys's Avatar
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    Frank,

    Check out SpeedHut. You can customize your gauges. I plan on getting a Speedo, Tach and a Quad Gauge to replace what is in the cluster.

    P

  27. #25
    Senior Member wleehendrick's Avatar
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    Quote Originally Posted by bnr32jason View Post
    The traction control system from Race Logic will do absolutely nothing to prevent snap oversteer.
    I made that point in another thread... to mitigate that condition, you'd need stability control which adds sensors for steering angle, yaw rate etc... and has the ability to brake one wheel individually. I don't know of any aftermarket stability control systems, although it's a mandatory feature on all new cars sold in the US.

    Quote Originally Posted by bnr32jason View Post
    You think you won't push it hard enough, until you are out on your favorite backroad (maybe the same one in your avatar) and decide you want to push just a little harder than last time, let off the throttle a little mid-corner because you went in to hot, and then all of the sudden your facing the wrong way.
    I agree completely... unexpected things happen on the street, and human nature is to lift. In the wrong situation, this can lead to bad things in a MR car. I'm used to powerful RWD cars, but never driven mid-engine much. This is why I'm happy to hear Wayne's comments and the external perspective from R&T on the handling balance.

    Although there's fun to be had sliding around with a limited coefficient of friction (hence why the BRZ and FR-S are fitted with Prius rubber!). I don't think it's a good idea on mid-engined 818 with high power to weight ratio. A staggered set-up (larger rear tires) will reduce the tendency towards over-steer and good sticky tires will provide an extra margin for error and I will be fitting something like a BFG Rival, Toyo R888, etc...

  28. #26
    Senior Member Frank818's Avatar
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    Quote Originally Posted by narkosys View Post
    Frank,

    Check out SpeedHut. You can customize your gauges. I plan on getting a Speedo, Tach and a Quad Gauge to replace what is in the cluster.

    P
    Yes I've seen that last week, it's VERY interesting, but I am unable to know if the gauges will fit in the cluster or not. It seems the OEM gauges plug in the cluster in a plug or something, according to the youtube videos I've seen. But will those SpeedHut gauges have that same plug or what, that's the part I am totally confused about...
    Frank
    818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
    Go-karted Aug 5, 2016 - Then May 19+21, 2017
    Tracked May 27/July 26, 2017
    Build time before being driveable on Sep 27, 2019: over 6000h
    Build Completed Winter 2021

  29. #27
    Senior Member Frank818's Avatar
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    Quote Originally Posted by wleehendrick View Post
    I will be fitting something like a BFG Rival, Toyo R888, etc...
    If other people come across this thread and look for tires, you got 2 options here, I am adding my option to that:

    Yokohama ADVAN Neovo AD08 (not the R). They are absolutely amazing! They are smoother and quieter than one would expect, much more than the older Bridgestone S-02s I had. They stick superb, extremely predictable and easy to control when you slide. That is on a FWD car, but since they are not expensive and seem to last long enough, they are no doubt my next buy again, they will be on my 818.
    Frank
    818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
    Go-karted Aug 5, 2016 - Then May 19+21, 2017
    Tracked May 27/July 26, 2017
    Build time before being driveable on Sep 27, 2019: over 6000h
    Build Completed Winter 2021

  30. #28
    Senior Member Xusia's Avatar
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    Quote Originally Posted by bnr32jason View Post
    The traction control system from Race Logic will do absolutely nothing to prevent snap oversteer.

    You think you won't push it hard enough, until you are out on your favorite backroad (maybe the same one in your avatar) and decide you want to push just a little harder than last time, let off the throttle a little mid-corner because you went in to hot, and then all of the sudden your facing the wrong way.
    1. A narrower tire up front isn't going to solve that problem, and a wider tire up front isn't going to cause it
    2. Both Wayne's comments and the R&T article would tend to indicate the car provides a bit more communication before all hell breaks loose
    3. If I'm going in hot enough to cause a spin under breaking, then I'm probably going off the road no matter what (otherwise I could just steer through the corner, right?)
    4. You don't know my nature when it comes to driving - I don't suffer ego and am just not likely to find myself pushing it harder if the previous speed was fun
    Last edited by Xusia; 06-26-2013 at 12:53 PM.

  31. #29
    Senior Member Xusia's Avatar
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    <rant>
    I think a lot of people are also forgetting the FFR designed this car to use the donor wheels & tires. Those are a LOT smaller & narrower than being discussed here, so I don't really think it's the "OMG, you are going to kill yourself if you don't run really wide staggered tires" problem it's being made out to be. My nature is more cautious, and as such I'm planning to run both the RLTC system and the factory ABS (assuming I can).

    Speaking of staggered wheels, the larger diameter of the rear wheel in a staggered setup doesn't increase the contact patch of the tire, and therefore doesn't affect grip appreciably. In another thread, articles were posted where they tested tires of the same width, but different diameters, and found very little difference - Stuff that would matter only when racing. I do not believe that running a 17" rear tire of the same width as an 18" tire is going to make my car more prone to snap oversteer. Sorry, but you aren't going to convince me of that. If the rear tire was narrower, that would make some sense because of the decreased contact patch.

    Unless something drastic happens, I'm GOING to run 17" wheel all around! And I will be fine!! The only variable is whether or not I can get narrower front wheels and therefore run slightly narrower front tires.
    </rant>

    There. Now I have that off my chest. Back to normal!

  32. #30
    Senior Member Frank818's Avatar
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    Well, to answer your question, 225/45/17 rear and 205/55/16 front. Both OEM sizes, both same diameter, slightly narrower up front.
    Frank
    818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
    Go-karted Aug 5, 2016 - Then May 19+21, 2017
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  33. #31
    Senior Member Silvertop's Avatar
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    Quote Originally Posted by Xusia View Post
    <rant>
    I think a lot of people are also forgetting the FFR designed this car to use the donor wheels & tires. Those are a LOT smaller & narrower than being discussed here, so I don't really think it's the "OMG, you are going to kill yourself if you don't run really wide staggered tires" problem it's being made out to be. My nature is more cautious, and as such I'm planning to run both the RLTC system and the factory ABS (assuming I can).

    Speaking of staggered wheels, the larger diameter of the rear wheel in a staggered setup doesn't increase the contact patch of the tire, and therefore doesn't affect grip appreciably. In another thread, articles were posted where they tested tires of the same width, but different diameters, and found very little difference - Stuff that would matter only when racing. I do not believe that running a 17" rear tire of the same width as an 18" tire is going to make my car more prone to snap oversteer. Sorry, but you aren't going to convince me of that. If the rear tire was narrower, that would make some sense because of the decreased contact patch.

    Unless something drastic happens, I'm GOING to run 17" wheel all around! And I will be fine!! The only variable is whether or not I can get narrower front wheels and therefore run slightly narrower front tires.
    </rant>

    There. Now I have that off my chest. Back to normal!
    If I was going to run anything other than the stock 16" WRX wheels, I personally wouldn't choose to go any larger diameter than 17" either. Part of that is just because I don't care for the look of extremely low profile tires. I don't want to date myself, but in my generation, a 60-Series tire was considered low profile. Not so anymore. But the ultra low profile stuff still just doesn't look right to me.

    Also, for ride purposes, I just think a taller sidewall is going to be more comfortable to ride on, as well as providing a little more protection for the wheels. But there are really no right or wrong answers here. It depends on the goals and preferences of the builder.

  34. #32
    Senior Member Frank818's Avatar
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    Exactly, depends what you are doing with the car and what you want in terms of comfort.
    The right answer will only come from you. I mean not "you" you, but from each of everyone for himself. Herself too.
    Frank
    818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
    Go-karted Aug 5, 2016 - Then May 19+21, 2017
    Tracked May 27/July 26, 2017
    Build time before being driveable on Sep 27, 2019: over 6000h
    Build Completed Winter 2021

  35. #33
    Senior Member wleehendrick's Avatar
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    FYI... by staggered I was referring to wider rims/tires in the rear rather than larger diameter rims (a staggered set-up in the general sense just means different size front/rear). I agree, that there's no necessity to go to large (>17") diameter rims, or have different diameter rims front/rear. However, to properly fit wider rear tires, wider rims are obviously ideal.

    As a point of reference, my current car has ~10lb/hp and ~50:50 weight distribution. I was not happy with the balance until I went to a more aggressively staggered set-up (245f, 275r). Intuitively, I think the 818 (with better power to weight ratio and more rearward bias) will be a bit unbalanced with the same width tires front/back.

  36. #34
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    Xusia you are taking this way too personally, try not get so upset about some simple comments.

    1) I never mentioned braking, not sure where that came from. I'm simply talking about weight transfer, lifting off the throttle will cause a weight shift forward, with equal tire sizes that means now the front will have more grip than the rear due to the increased load on the front. More grip in the front than rear = oversteer.

    2) Contact patch is dynamic, not static.

    3) If you truly believe you are never going to push the 818, maybe same size tires front and rear will be fine. I just find it hard to fathom why someone would buy a car like this if they weren't going to take it to a HPDE or push it a little on twisty roads from time to time.

    4) Running 17's front and rear is fine, no one is saying you have to run 18's on the rear like the R, or like the unveiled S model from the open house. This specific discussion is about tires, not wheels.

    In the end the decision is up to you of course, I'm just trying to get you to understand that an 818 with wider tires on the rear is going to feel much more comfortable when even approaching 70% of the limit. MR cars were designed to have wider tires in the rear, messing with that formula is going to yield undesirable results. If you choose to run same size front and rear, just know that you are choosing a path that is not technically correct.
    Last edited by bnr32jason; 06-26-2013 at 03:54 PM.

  37. #35
    Senior Member PhyrraM's Avatar
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    Quote Originally Posted by Xusia View Post
    .....
    I think a lot of people are also forgetting the FFR designed this car to use the donor wheels & tires. ........
    While I sincerely hope this is true, I don't think it is. From every post and picture that I have seen (I could have missed some) all testing was done with the larger wheel and tire setups that we have seen since prototype #1.

  38. #36
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    Quote Originally Posted by PhyrraM View Post
    While I sincerely hope this is true, I don't think it is. From every post and picture that I have seen (I could have missed some) all testing was done with the larger wheel and tire setups that we have seen since prototype #1.
    Exactly. From what I can see, all the way back to the go-kart stage, the 818 has not been developed using stock wheels and tires. This means all testing, development, etc was done on wider rear tires and more narrow front tires. There is a reason for that. The 818 was *absolutely not* designed to use the stock wheels and tires, the test mules prove that.

    Just because you CAN use the stock wheels and tires doesn't mean you should. There are many things that I could do if I wanted, I could use a set of cheap eBay knockoff Bride seats and not wear a seatbelt while driving, but that doesn't mean that it's a good idea or an optimal choice.
    Last edited by bnr32jason; 06-26-2013 at 04:11 PM.

  39. #37
    Senior Member Silvertop's Avatar
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    Quote Originally Posted by PhyrraM View Post
    While I sincerely hope this is true, I don't think it is. From every post and picture that I have seen (I could have missed some) all testing was done with the larger wheel and tire setups that we have seen since prototype #1.
    I am certain that you are right about this. It does seem to me that the original "kart" was outfitted with stock WRX wheels and tires, at least at the beginning. But ever since then, the bodied prototypes have definitely been fitted with larger wheels and tires, and they have also been delivering significantly more horsepower than stock WRX's.

    Nonetheless, I believe that the car will function just fine as a streeter with less dramatic tire/wheel combinations, particularly if horsepower delivery does not get too wild. And I also believe that forum chatter notwithstanding, many builders will ultimately choose milder power configurations, particularly those who are trying to complete their builds on the cheap.

  40. #38
    Senior Member PhyrraM's Avatar
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    Quote Originally Posted by bnr32jason View Post
    ......MR cars were designed to have wider tires in the rear, .......
    Not always true. Cars that are mid engined are primarily that way to reduce the polar moment - to make them turn easier. If the forward/rearward weight transfer cannot be sufficiently controlled with other design parameters, then larger contact patches can help control snap oversteer. An MR car can be designed with equal weight distribution if desired.

    FFR could have developed for any tire sizes/stagger they wanted to. They chose a size/stagger that they thought most customers would be happy with, as any company looking to maximize sales would do. FFR chose to slightly reduce "maximum performance" because they knew that smaller wheels are not currently popular, styling wise.

  41. #39
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    I don't believe there has been a modern MR car produced that has the same size tires front and rear.

    Could one be made to work with that setup? Sure, but it would still be less than optimal.

    I know quite a few guys in the MR2 community run a "square" setup because it's more "fun." The Road and Track article about the 818 mentioned the smooth transition into a lazy slide, and that was because of the tire sizes and suspension setup. You take away those wider rear tires and suddenly that lazy slide turns into a snap into oversteer. For some this could be great fun, especially if you are into the drifting stuff. But you are sacrificing overall performance for that extra bit of fun and fear.

    But you better be sure that you learn the car well and have quick reactions because when the car does transition from neutral steering or mild understeer into no-notice snap oversteer, things can go from "fun" to "holy crap I'm gonna die" really quickly.

    I setup my FD2 Type R Civic to have lift off oversteer by running 245's in the front and 225's in the rear. This made for a great gymkhana car, but I had to be VERY careful when driving on the local touges.
    Last edited by bnr32jason; 06-26-2013 at 05:15 PM.

  42. #40
    Senior Member Xusia's Avatar
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    Quick clarification, just in case there was any misunderstanding: I'm not talking about going narrower in the rear, so for the purposes of this discussion, rear tire width is the same and my intent is to go as wide as I reasonably can - to maximize grip. Also, I'm not taking it personally. My rant was more a humorous jab at the seemingly illogical over-concern about this issue.

    I understand what you are saying, but I still don't think it makes sense, so please help me understand. You are saying wider tires (in front) would have more grip, so that when weight transfers to the front, the front would stay planted, potentially causing a spin. Assuming I have that right, what doesn't make sense to me is how having narrower tires on the front solves the problem? It seems to me that would only result in a front end slide. Perhaps a bit less problematic, but could still easily put me off the road or into a head on collision.

    It also seems to me that if I'm at the point where the little bit of weight transfer caused by simply letting off the throttle is enough to cause the rear end to break loose, I am AWFULLY close to the limit. Mine will be a daily driver, and the street is no place to be driving that close to the limit. I do hope to take it to the track, but that will be fun based, and I'm very certain I can both have a ton of fun AND blow away a lot of other cars while not getting that close to the limit.

    As to why anyone would buy a car like this and not drive it at the absolute limit, there are several reasons:
    • No other car is even CLOSE to the performance for the price. BRZ, 370Z, etc. all fall far short. I want more. I may not need or use ALL the "more" this car delivers, but that's OK. Really!
    • I find it comforting to know the car has capability in reserve that I don't plan on using. Knowing it's unlikely I'll come close to the limit provides peace of mind. If I get into a situation, I can have confidence the car can handle it.
    • It's about fun, not outright speed or craziness. I can have a ton of fun without ever finding the limits of this car.
    • It's my project; my car. If I want to build a 1000hp monster and drive it only to church on Sundays, that should be OK.
    • Still on the "my project" thing, it's about doing it myself. Knowing I can. Having something to bring my son and I close together. But more to the previous point, my reasons should really matter to anyone else!
    Last edited by Xusia; 06-27-2013 at 12:37 PM.

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