New FR-S Owner - AutoX Question
 

Hi,

I just purchased a brand new 2015 M/T FR-S. My previous car was a fully bolted custom tuned "modded for autoX" 2013 Genesis Coupe 2.0T M/T. I loved the geneis, but i sold it to change things up.

I've read the entire owners manual, and I've read TONS on these forums and already have an idea of what I want to do with the car in the long run, but for the first 30,000 miles I'm going to be daily driving and autocrossing the car 100% stock (with the exception of wheels/tires that I'll be swapping out for autoX days.. )

Post 30,000 miles I'll be installing the KW 3 variant coilovers, and all sorts of of other suspension work, but for now, I'm just looking for the most cost effective way to get my camber front camber to the -2 to -3 range and my rear to the -1 to -1.5 range.

I've done tons of reading and there are just soooo many aftermarket options for this car, so I'd appreciate it if someone can give me some advice on what to buy and install before I go get an autoX oriented alignment.

I figured it'd be fairly straight forward - install some OEM camber bolts, get an alignment done and then I'm good to go. After all the reading I've done though, it looks like I may need to get camber plates up front and lower control arms in the rear to achieve what I want.

I'd like to just spend $200 max, preferably less, install myself, then go get a quality autox aggressive alignment.

Also,, question about my tire wheel set up that I have now - I've got 17x8 +40 offset wheels with 245/40/17 star specs that I plan to use for autoX. I would have purchased wheels and tires sized closer to OEM specs, but I already own these and using the online wheel/tire fitment tools, seems like i shouldn't have any fitment isssues.

Feed back on my wheel/tire set up would be awesome as well..
I love the car. At 350 miles so far, sticking with the "stay under 4k RPM for first 1,000 miles engine break in outlined in the owners manual. After I hit the 1k mile mark I'll be replacing the engine, gear and tranny oils, have my alignment set up and start autoXing the hell out of the car ;)

Thanks in advance for some tips to get me started!

New FR-S Owner - AutoX Question
 

Your 17x8 wheels put you into a SCCA STX classing which opens up a world of modding.

You are correct that you could not achieve your camber goals without what's stated. If you truly want to keep the car stock i would recommend going back to a 17x7 rim, getting some 225 sticky tires like RS3, PSS or StarSpecs to stay in the CS stock class.

There's threads in this forum section that detail the class rules more


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The simple answer is that you're not going to be getting into those alignment specs with that budget. I think the rear will be around that range stock but for the front, I'd just go OEM crash bolts (cheap from a Subaru dealer) and call it a day until you're ready to throw some money at it for quality camber plates. Even maxing out the OEM crash bolts makes a significant difference.

As mentioned, a set of camber bolts up front will get you some much needed negative camber and then just leaving the rear as is will get you close to where you want to be. spend the 200 bucks on bolts + alignment + entry fees.

I would recommend our RCE Tarmac 2s over KW V3 for autox. Our T2s are custom valved and custom sprung KW Clubsports with a lifetime warranty. We worked with KW extensively for a slightly more track oriented set-up (that still rides well). The V3s are great, but a little on the soft side. Just another option to look into when you get to that point.

Wheel/tire combo sounds good but will move you into STX. Which is fine if you're out to have fun and you can still do well locally. :)

- Andy

Cool thanks for the feed back. Good to hear that my tires n wheels will fit, figured they would. I've never cared about which SCCA class I'm in, all about fun for me :p. I just sign up for time only every time so I can choose my run group and work group.

Cool, I'll go with the OEM camber bolts, get an alignment and I'll be good to go for a bit.

Thanks for the suggestion about those coils too, ill look into them. On my genesis I ran stiffer spring rates in the front than the rear, 12K/9K respectively. I liked it a lot.

I didn't see bolt pattern on those wheels, and hate making assumptions. Are they 5x100? Is unclear if they're already on the car or were in your garage from a different car or...

I know the TEIN SRC has a 10/12k spring recommendation, and that's considered high by many on this platform without note power... A lot seem to run square for AutoX. I think you're being smarter than I am, running the car stock before diving in. :)

Come join us this weekend:

https://www.facebook.com/sandiegoautocross

http://sdrscca.com/

As far as alignment range goes, there's nothing you can do for $200 or less to get to the range you requested. I would suggest actual camber bolts instead of crash bolts since you'll be running in STX due to your wheel size. They offer a better range of adjustment, and you really need as much as you can get in the front. Aside from that, here's a quick and dirty upgrade path for you, @ButteR

Barebones STX build:

- Coilovers w/ camber plates (capable of reaching up to -3.5 in the front)
- LCAs (if you get too much natural camber from lowering)
- Header with good low/mid grunt
- Tune to optimize header gains
- 17x9 lightweight wheels
- 245/40-17 200uqtg tires (Rival, Z2, RS3, R1R)
- Upgraded front swaybar (For better turn-in. Several bars will work: Stranoparts, Whiteline, SuperPro, etc.)

Those are the bread and butter mods, along with a good alignment.

Then there are the marginal/subjective gain mods:

- Whiteline Rear subframe inserts (better seat of the pants feel for what the rear is doing)
- Lightweight seats (no lower than 25lb)
- Lightweight battery
- Front/Overpipe
- Lightweight catback exhaust
- Intake
- LSD
- Shifter and transmission bushings
- Short shifter

Plus whatever else I'm forgetting that's legal.

Don't cheap out on coilovers and header. Those are your biggest items. You'll have room to play with on the rest.

Also, if you want to continue to use hub rings, you'll likely find that you need different ones. Found that out when modifying my old wheels for the FR-S.

Thanks for the quick list. I've cheaped out on coilovers before, and i agree 100%, either do it right and spend the extra $ or don't do it at all.

The 245/40/17 tires on 17x8 wheels will put me into STX. The only other "mod" i will have is camber bolts + a good alignment (getting the most neg camber I can up front).... Yeah, running in STX with a stock car with big tires lol - maybe they'll work with me and put into a less modified class.

Taking a clip from your quote above "- 17x9 lightweight wheels". Any reason you run 17x9 wheels for 245/40/17? I have my 240/40/17 star spec IIs on 17x8 wheels..(this was recommended to me as the best wheel width for these tires by a tirerack rep)

The side wall will be more square on a 9in wheel vs 8in wheel. This should give you better feel because the tread wont move around as much in relation to the rim.

Crash bolts will get you to ~-1*.

I suggest you stay as CS, get some 17x7s and use the ZIISS on them. Use your stock wheels even and use the 17x8 with some street tires. You can the get a stiffer front bar later on for not much money. Save up for some good coilovers and 17x9s, then move to STX.

I see, that makes sense. I'm not sure what you meant when you said "use your stock wheels even and use the 17x8 with some street tires."

I'm assuming you mean use the 17x8 for daily driving and the stock wheels/autoX tires for the autocross days. You can go up to 225/35/17 on the stock wheels and stay in cs yah?

I like that idea, I'll be selling my tires (and wheels even) then so the rubber don't sit n get old. They have 4 autocross events on them and about 500 miles of daily driving to break them in. Tires are mounted on wheels, cleaned and dry, stored appropriately - in air tight bags etc. in my apartment.

I suppose there is a "for sale" thread here but if this forum is like most, I won't have access to posting there until I've been a member for x amount of time and or posted x amounts of time.

Thanks for the tips.. lot of good information here, lotsa reading to do :p

He means that if you want to be classed in C Street, you can get some lightweight 17x7s (or use the stocks) and put the Z2SS on them, and use your 17x8s for the street. But yes, a 245/40/17 mounted on a 9 will give better feel than mounted on an 8.

I'm going to hope the /35 is a typo and you meant 45. In any event, you can run whatever size tire you can get to hang onto the wheel, that doesn't rub. The stock size wheels (with some small allowances for offset and +/- 1" diameter) are the rule, the tires, with the exception of Treadwear Rating, are pretty much completely open.

There's folks around here that run anywhere from 215's to 245's on CS legal cars.

People are running 245 tires on stock wheel specs eh? Forgive my ignorance here but I'm learning a lot very quickly on these forums vs the genesis coupe forums. MUCH more useful knowledge and advice.

CS rules state no changes to stock wheel specs, but allow for any tires that you can fit on there. It took me a while to understand wheel offset, camber/caster/toe. I think im down to two more pieces of the wheel & tire puzzle that ive been seeking answers to for months, and I think yiu guys can seal the deal on these last two for me ;)

Tire size vs Wheel size: oversized tire on wheel and underside tire on wheel.
In order to fit a 245 tire on a 17x7 wheel (OEM spec wheel), the only unknownn variable is sidewall, yes? If I understand this correctly, by default, fitting a 245 tire onto a 17x7 wheel will require a very high sidewall, right? Where fitting a 205 onto a 17x7 wheel would naturally result in a shorter n stiffer sidewall. Couldn't one argue that putting 245 tires on the OEM wheels result in a decrease in performance due to having very tall and soft side walls?
I could see going with 225/45/17 on a 17x7 wheel, but any wider tire than that would result in diminishing returns.

the last piece of the puzzle that I've been trying to understand is how tire psi changes with all of this. Using the OEM Wheel is a constant variable here, how does the tire psi need to be adjusted when putting smaller tires on or putting oversized tires on? In my mind, the former will be stretching the tire requiring less psi where as the latter will have extra rubber and require more psi.

I realize that theres much more analysis that goes into wheel and tire fitment, but if someone could straighten me out on the last two pieces that I've been having a difficult time grasping, then a lot of other stuff is going to click and ill finally be able to link it all together.

Slightly off topic here, but on my genesis 2.0T, with a square set up, i always ran higher psi in the front than I did in the rears and loved the handling. I just did my first autoX in the FRS and did the same (prius tires will need to go soon). I thought I was going to miss the turbo, but the handling and overall feel of this car is amazing. I'm very happy I switched platforms.

With high performance tires and stiff enough sidewalls, you can get away with more pinching before diminishing returns (or physics preventing you from mounting the tire) come into effect.

DS national champion one year mounted 275 Hoosiers on a 6" wheel. The Hoosier has a ridiculously stiff sidewall, unmounted I can sit on the tire and take my feet off the ground without it collapsing.

Most CS folks run between a 225 and a 245. In general for autocross, the more rubber you can get in contact with the ground the better.

Ahh...I see I see. Very interesting. Stock class ain't as "stock" as one might think. They should make an OEM class for us new 86 owners to compete with and destroy these preius tires ;P

You can run those tires if you want, no one is stopping you.

They changed the name recently so its not 'stock' anymore its 'street', which makes more sense with the allowed mods.

no.. it's pretty stock. You have to buy tires either way, so this argument is moot. The only thing that changed is that before you had to buy Hoosier A6s, and change them at the event... and now you don't.

I ran 245/40/17 ZIIs on stock wheels and crash bolts for CS last year. I drove a car with 225/45/17s last weekend and it feels less vague on turn in, but not nearly as much grip as the 245s.

In a 245 on a 7, the only variable left is the sidewall. But doing so doesn't automatically necessitate a tall sidewall. Remember, you can also use tire size to make small changes to the effective gearing of the car (different schools of thought on that).

For diminishing returns, yes, probably after 225, you aren't getting all of the extra width actually converted into contact patch. But you're getting some of it, and a little better is usually preferable to no better. Although you may get a small amount of that lost extra width with a taller sidewall. Would it be of consequence? Don't know.

What tire pressures work have more variables than width. Buy the set you like, hope that your research on the pressures will at least get you in the ballpark, and then tune to suit. You'll have to do that with any tire. A good air gauge and 12v compressor will be your friend.

You fit 245/40 ZIIs on the stock wheels?? Didn't even know that was possible.
I figured you'd need at least an 8 inch wheel to fit 245's.

Did you have to do anything special to get a good fit?

Are you competing locally or nationally?

If its just locally in C-stock, stick with 225/45's... Maybe 235's at most.

That and the front swaybar with the camber bolts, thats all you need for C-stock.

I've seen his tires, as well as 245 Rivals and RS3s on stock size wheels. I ran 245 RS3s on the 17x7 RPF1. There really isn't anything special you need to do to make them fit. You just someone that'll do it. Some tire shops won't mount that size tire on a 7" wide wheel.

245s will work. I decided to try it when Des drove his car with 235s and another car with 245s back to back. The 245s were faster. My codriver and I have tried 225 and 245. We liked the 245.

Its still risky and I wouldn't recommend it... I've seen 235's on the stock wheels and thats more than I would even push it, unless you were seriously competing in nationals and ONLY using these wheels/tires in Autox and immediately removing them.

What do you mean by risky?

245's are not designed to be on 7" wide wheels. Its the opposite of "stretched" tires, but both scenarios risk popping a bead. Even more so, if a bead pops in a corner you could possibly flip the car.

So for saftey reasons, I can't recommend it.

Yeah trying to stay in C-Stock. Already got the camber bolts, gonna do the sway later on..wanna feel the OEM one out for a bit first to see how thick i wanna go.

:cheers:

That's the kinda intel i was looking for. I figured something had to be sketchy about that fitment.

Thanks for that info.

I ran the whole 2014 season with SFR SCCA and multiple AAS events in the Bay Area on 245s. I also went to the Crows Landing Pro and Tour. Most of these events were with two drivers (I had a third person drive my car at a few local events too since they needed a car to drive). I also drove to events with the tires on the car. I had zero issues, and neither did the others around me that had 245s as well. I understand what you're saying, and you could be right. However, by that logic you shouldn't attempt 235s as well, right?

I got gashed for saying this in another thread but yes, bead separation is a safety/rollover issue. As long as you keep tire pressures up it won't be a problem. If you start running drag race tire pressures because "more contact patch yo" then you're asking for problems.

Good to know.

Some racers have made a good argument that 225's may be better than 235's for the stock class (including Andy Hollis, multiple times National AX champion). The reasoning is the narrow tires will distribute the weight less, warm the tires faster and have more psi/sq ft to grip the track. I ran 235 Dunlops on stock wheels and did find I slid around alot more than I do now in STX with 9-inch wheels and 245's. Also the tire sidewalls should be fairly perpendicular to the tread when mounted on the rim. Otherwise you will get too much sidewall flex giving you that numb turn in feel.

Andy Hollis does indeed have some data to back that up, but all his testing happens on lightweight FWD cars with proper spring rates, proper camber, and 15" wheels. How much of that is going to transfer over to our 2700lbs FR car with stock springs, no camber, and 17" wheels?

To take this to an extreme, what works for your Yugo may not work for my Porsche.

IMO you're not giving up a ton by going with a 225 instead of a 245. That said I'm pretty sure everyone who beat me at nats had more tire than me.

I am new to autoX having only done it once. I thought it was cool and want to do it just for fun about once a month in the summer. I would like to buy some summer tires for my car and don't really want to mount and unmount tires for the winter. So I was thinking I should get some new lightweight rims and summer tires and just put the stock rims and tires back on in the fall.

I'm glad I read this thread because I didn't realize the restrictions on wheel size for autoX. duh.

I was going to do 17x8 235/40.....but I guess I can't do that now. So you guys suggest 225/45 or 40 for me on 7inch?

Ill have to research crash bolts, camber etc as well

If you are not trying to be competitive and win a trophy, worry less about fitting into a specific autox class and worry more about what you want to do with the car in general.

In other words, If you go with the wider wheels its perfectly OK for autox you just won't be in the "stock" class anymore. I ran in the modified class for years with my last car due to an engine swap and wasn't competitive at all but I was doing it for fun and learning not for a trophy.

Feel free to do what you want to do, then figure out what class you are in later.

I did the same thing as the previous poster when I first started autoX. My car hobby at the time was modding the car for the material high - installing the piece yourself and feeling the difference.

Then when I went to my first autoX, no videos, reading or anything..just heard about it and showed up late (wtf is a course walk and novice meeting? ;p) I didn't know about classes or the cones or anything. It was actually pretty funny as I just destroyed the entire course my first run and was immediately required to have an instructor.

...anyway, my mods put me into STX so I wasn't competitive at all....but the nice thing is you can run in time only which allows you more freedom in your work and run groups.

As a new person, If I were you, I'd just stick to OEM specs and not mod anything unless u got cash to dump. The only "mod" I'd do is have a separate set of wheels/tires (OEM specs) for autoX and daily driving.

Btw, anyone want to buy my 245/40/17 ZIIs and or rims? The tires are in really good condition and just have 500 miles of dd break in driving and a few autoX runs. They're cleaned, and have been stored appropriately in air tight industrial trash bags indoors for about a month now. The tires were driven on my genesis coupe.