Gord96BRG

Lots of people here seem to be looking to install wider tires and wider wheels at the back of their RX-8s. We have to assume that they really like the look of wider wheels and tires on the back of a vehicle, but there may also be an impression that staggered tires and wheels somehow must enhance handling? Well, the short answer is - they don't.

There was an excellent article in Sport Compact Car recently where they installed new tires and wheels on their Project 350Z part II - Balance . The 350Z from the factory comes with staggered wheels and tires - and it understeers. To achieve neutral handling and eliminate the understeer, SCC found they had to install the same size tire on the front of the 350Z as the rear, and it greatly improved the handling and balance of the car.

So how does that translate to an RX-8? Easy - if you install wider tires on the back of a stock RX-8 than you have on the front, you will transfer the handling from neutral to understeer. Lots of people will say they only drive on the street and so they don't mind - but if you enjoy the neutral balance, be aware you'll be changing it for the worse if you go staggered.

The article has some interesting comments on tires, wheels, and handling that are relevant to RX-8s and other sports cars - definitely worthwhile reading.

Regards,
Gordon

Kel Rx8

i will look into that article for there reviews
but my wheels arent going anywhere
see sig

PUR NRG

Why didn't you just address this to Bassik directly? Good info.

rx8power

Good find,

but in 2 seconds I will forget about it!!!

RX8Power - Staggered

bigblockbeater

only two reasons for staggered wheels. straight line racing and/or looks.

RotorManiac

Do you guys think this setup 225/40/18 front and 255/35/18 rear on 18x8 and 18x9 is ok for the street? This way the wheels have almost the same diameter, but I heard that 255 is too much for the 8...
I'm gonna keep the stock rims (without staggered setup) for track use but I don't want to degrade performance much. I like the looks and I don't do street racing.

Anyone has a good advice on what tires to put on these wheels?
Thanks

flip

Very good find.. i found it very... STAGGERRING!

LiL BenNy

whats staggered mean lol in terms of rims...

Sputnik

For how we are using the term in this thread, staggered refers to the width of the rear tire compared to the front tire. What this means for the rims is that the rear rim will normally need to be wider in the rear for the tire to be wider in the rear. It does not refer to the diameter of the rim or the overall diameter of the tire (not the way we're using the term here).

---jps

Red Devil

Staggering never made sense to me except, as already stated, really just for drag racing.

I've been thinking about this subject recently with the introduction of FI kits. How large should we need to go to accomodate the power? For the 240whp that the Greddy kit provided, I would think 255 or 265 is more than enough to handle that. Anyone have any thoughts?

PUR NRG

My thoughts are since people actually have FI kits installed there's no point in theorizing what will and won't work for tires. Just ask them what they have and how it works. I'm sure they have enough incentive to do that research themselves.

MrWigggles

WHOA WHOA WHOA,

Not only is the 350z a different car. Guys, they put wider tires on the front not narrower tires on the rear. There is a difference

If a car understeers and your stock tires are 245 front and 275 rear, then going to 275 on front and rear will universally help things. More grip on all corners and less understeer.

That doesn't mean that going to 245's on all corners would give the same results. You are improving the balance but at the cost of less total grip. Taking the argument to the extreme, would 185's on all corners be as good as the stock 245/275 combo? I think most would say no in a heart beat.

The reason I bring this up is that I have 245/40-18's on the front and 275/35-18's on the rear and I love them - and not just for looks. I drive very fast at times of day that have little traffic. I enjoy taking turns as fast as I can. I have no doubts that my new combo (which uses Yokohama dB2 tires) is more stable or at least as stable as stock rubber.

Now if someone told me, "You will get better performance with 275's all the way around." I would probably say yeah you're probably right*. But if someone said, "You should go back 225's all the way around for better grip." I would say not a chance - been there, done that (245's all the way around would be an interesting experiement, but I don't think that would be better either).

The SCC article is hardly an end-all of the debate that will never end. The staggering/no-staggering debate has reach religious proportions. Well I'm an athiest. I go by what I have experienced and what works for me.

-Mr. Wigggles

*275/40-18's wont fit on the front without sticking out or rubbing in some fashion. But for auto-X I would go 275/35-18's all the way around with maybe a little bit wider rubber in the rear. But with a reduced weight load in the rear (1/8th or less of a tank of race gas and all accessory items removed) 275 all the way around would probably be perfect.

RotorManiac

Wiggles, since no one answered my question, based on your experience, can you help me with this setup:
I'm thinking 225/40/18 fr and 255/35/18 re will it be ok?

Charles R. Hill

iTrader: (7)

I am currently running KDW 255's on the stock wheels and there is no problem with interference. Wiggles seems to spend a large portion of his post addressing a matter that was not discussed in this thread; going to smaller tires in the rear to achieve better balance. With regard to Gord's post, going smaller in the rear tire size was never mentioned. Going with 4 equal sized tires for better balance was the point. I thought about the staggered look for my own car but decided against it for the reasons discussed here. Since the RX-8 has 50/50 balance I didn't wan't to upset or alter any handling or traction balance by using a staggered set-up. I figured by keeping the equal tire sizes on all 4 corners, as they did from the factory, I would be assured that any driving problems were strictly the fault of the driver. Since I am running an odd-size 255/45 the handling is a bit softer and the turn-in is not as quick but the overall balance is exactly the same. I think that was Gord's point in the first place. BTW, as soon as winter is gone I will be switching to 245/45-18's, still on the stock wheels.

CRH

p.s. RM, your own choice in tire sizes will be fine as long as they are the same diameter. Each manufacturer differs in diameter even though the sizes listed are the same so make sure you look that up first.

p.p.s. Staggering tire sizes, or not, depends on the driver's own style in taking turns.

murix

But it looks mad tyte yo!

Gord96BRG

Charles Hill is right - my point, and the point of the article, is about balance. Sure, MrWigggles, your car is more stable with the staggered setup - because it's got more understeer. If you want more understeer, then that's a very easy way to get it! The article wasn't talking about ultimate grip (and for MrWigggles again, if you wanted more grip you could have simply put on grippier tires, rather than those Yoko all-seasons. Nice tires, but certainly not at the top of the performance heap).

The RX-8 is very neutral from the factory. Going to 245/40-18s all around is a great way to increase overall grip (assuming you get good max performance tires, of course) while retaining the neutral handling. Going to a staggered setup can increase grip at each end, but not proportionally, so you end up shifting the handling balance to understeer. Who wants more understeer on a sports car? In fact, I'd happily trade a few fractions of a g in grip for better balance - you can't safely corner at the limits of traction on public roads anyway, and you can enjoy neutral balance a lot more often. But again, as Charles points out, you can have your cake and eat it too, just fit same-size tires of max performance type all around.

Read that SCC article again - not how they specifically mention bucking the popular trend of using staggered sizes, and that going to same-size tires all around cured the 350Z's terminal understeer and vastly improved the handling. RX-8s already have that neutral handling they fought to achieve - why convert the RX-8 to 350Z-style terminal understeer just for the sake of trendy looks?

It comes down to whether you want a sports car or a cruiser for posing...

Regards,
Gordon

dmp

I couldnt stand the thought of MORE understeer in this car. I'd only resort to staggered if I added so much power to the car required the extra rear-grip. Apart from that, It's not required.

Gord96BRG

How's your alignment? I had mine done last spring, and I found that it was sorely lacking in front camber. Had it reset to some nice numbers (I think I posted them here), and it was much more neutral and balanced. You probably know not to just show up and ask for "an alignment", but to get the exact numbers you want, and ask for a precision alignment to exactly the specs you give them. Also, for best results it's necessary to sit in the car or have it weighted as you normally drive it - it makes a significant difference to the camber results, especially on the right rear corner!

Regards,
Gordon

Charles R. Hill

iTrader: (7)

Gord, can you publish those numbers again, please? I'll be hitting Road Atlanta in March with my new turbo setup and I'd like to have some killer adjustments going. Thx. Are those specs street-drivable?

CRH

MrWigggles

Gord,

Actually I want to get from point A to point B as fast as possible. That is my goal and think most people's goal.

You failed to mention in your first post that they made front tires bigger to match backs - ie. big/big on front/back is better than small/big on front/back. They did an enormous amout of trial and error to get 275's on the front. If you can get 275's on the front and back of the RX-8 so be it. (and for a racing app where you don't mind a lower profile tire and the wheel sticking out of the wheel well, that would probably be the way to go.)

But the RX-8 is limited to 245 in front with proper diameter tires. "So you think staggered tires/wheels are a great idea?" Well to answer your question again yes, because the RX-8 is predominantly neutral (maybe a pinch of oversteer with the stability control off?), I think small/big on the front/rear is better than small/small. BTW, getting on the trottle just a pinch more in turns and I have no problem getting the rear end to come out.

Regardless the differences are minute. On a twisty road, at most I am a little faster than stock but I am definitely not slower than my stock.

-Mr. Wigggles

FYI, Houston gets about as much rain as any city in the US. Using anything other than an all-season is foolish - IMO. For auto-X I would definitely use a different tire, but with the reduced weight load in the rear (as I described earlier) I would go with 275/30 - 18's or 275/35 - 17's all the way around and have them stick out of the wheel well a little in the front.

MrWigggles

Comments like these is why I made my detailed post.

The looks are much better but so is the performance to some level.

Staggered is just for show, therefore rice, therefore stupid is the opinion I am trying to fight.

And my car is mad tyte. Thank you very much.

-Mr. Wigggles

Gord96BRG

You're fooling yourself if you think that you can legally get anywhere as fast as possible that tires will make a difference - even the stock 225s give you capabilities far beyond the legal limits - if you try going anywhere as fast as possible, you're going to get arrested. My goal is to enjoy the journey as much as possible, which is why I prefer a more neutral and responsive setup to a understeering, more stable setup.


But you wouldn't be any faster, as the small tires on the front would still be the limiting factor. Put bigger tires on the back, you'll still be limited to the cornering speeds permitted by the front tires when understeer sets in. It's just that at the limits of the front tires, your rear tires will have more grip, so you'll get understeer. With a same-size setup, the rears could slide at or near the same time as the fronts, so that gives the driver more options, but the limit actually would be the same.

Two points - wider tires are much worse in wet conditions, as they will aquaplane earlier than a narrower tire. With 245s on the front, your car has less capability to get anywhere fast than a 225 shod car - the 225 car would not aquaplane until at a higher speed than a 245-equipped car. That's the same reason that narrower tires should be used in winter - better grip from the narrower tires because of aquaplaning and float!

Second point - you are misinformed if you believe that all-season tires have better grip in wet conditions than performance summer tires. You can read the test results on Tire Rack yourself, where they've proved that performance summer tires have better wet performance than performance all-seasons - even and especially in standing water that could cause hydroplaning. A summer performance tire like a Toyo T1-S, Goodyear F1 GS-D3, or Bridgestone SP9000 will outperform ANY all-season tire you could come up with in wet conditions - that's a fact. It's a common misunderstanding that all-seasons are better in wet - in fact, that's not a design goal of all-season tires at all. What makes them all-season is that they change the rubber compounds to be more pliable at freezing temperatures, and change the tread pattern to provide some modicum of snow capability. No optimization for wet weather, compared to summer performance tires, is done at all. Further, it's extremely likely that a 245 summer performance tire would outperform a 275 all-season tire in dry (and especially in wet, again the width thing) conditions.

Regards,
Gordon

RotorManiac

Charles thanks for the answer.
I did a small survey myself and found that the 225/40 and the 255/35 setup is almost the same wheel (rim+tire) diameter. The difference is 0.24% that's why I think its good.

Only problem is that the difference with the stock setup is 3.43% and 3.66% respectively. I read that no more than 3% should be exceeded:o... I dunno, guess I have to try it and see...

Another good option is 235/40/18 fr and 245/40/18 re with 1.21% difference. Opinions?

dmp

I guess I don't know - it's stock...on my Miata I had "Lanny's Alignment" done, while I was seated in the driver's seat, and loved it :D
I'll search for your numbers...

murix

You are welcome. No other reason I can think of for going with staggered unless I somehow found a whole lot of torque.

My setup - 18x8.5 +35mm Enkei RP01 with Kumho Ecsta MX 245/40/18 using Mazdaspeed springs/struts.