Then why did you buy and RX-8? Why do you assume that my set-up understeers?

BTW, I enjoy driving fast and I have a clean driving record.

If you take your foot off the throttle completely you are correct. I am on part throttle during a high speed turn. Something like ~25% of full throttle now instead of say ~15% on stock rubber. And yes I am faster.

Argumenative again. Have you looked at the tread pattern to Yokohama dB2? There are far more grooves for water than the stock rubber. The amount of rubber making contact with the street is probably about the same as the 225/45 RE040. I already told you why I went all-season and yes I have much better wet weather traction even with my wider tires. I light the DSC far less often (i.e. almost never) now versus stock.

You do have a point here IF we are talking about tires with the same effective wear rating. A summer tire that performs better in the wet is softer and thus doesn't last as long. The stock RE040's, T1-S, GS-D3 won't last nearly as long as the dB2's if you made the dB2's out of the same gumball compound they WOULD work better - same adhession AND more grooves.

Yes a 245 summer will likely outperform at 275 all-season IF it is a softer compound. I don't want anymore <20,000 mile tires for my car. If I got a summer (i.e. intermediate) with a harder compound, it will be worse than my 275 in the rain because it doesn't have as many grooves.

Trust me my 275's work a lot better in the rain than my stock 225's did. I been through this on the RX-8.

Not that I really care, but I am wondering what you are thinking:

A. "This guy is lying."
B. "The RE040 is a dog shit tire and thus ANYTHING is an improvement wider or not."
C. "The guy is imagining the differences" (i.e. placebo effect.)

Gord, you argue your points as if they are mathmatical certainty. But they don't match my experience and I have given you good plausible explainations (with niether A,B, or C being one of them)

-Mr. Wigggles

nice enkei's:D i'm looking at the enkei OR52 either in silver or Anthracite (18 x 8.5 with Pirelli PZero Nero M&S 2456/40/18). i got a silver 8 as well. not sure which to go for. silver woudl match..but i've seen some silver 8's with back rims they looked pretty sweet....ooooh decisions decisions:(


edit: hmm now if only i could photoshop these on a silver 8..then i cudl see if they will look good or not:p

im surprised the fact that the mazdaspeed suspension would look as low as depicted. Doesn't look .8 inch drop to me at all. Looks very nice...

Coming from an RX-7, I will say this -

I drove around with 235s all around for a while, the car was functionally useless. I put on 235 fronts on 18x8.5s and 265 rears on 18x9.5s, the car barely held the power

As far as understeer, off throttle the car had a hint of understeer, but you can easily control understeer with the throttle on a car that actually has power, transitioning slowly into oversteer.

For the RX-8, if you're stock engined, fine, stick with an even setup, however, I plan to go FI and if my experience with the 7 is anything, you can never have too much in the back. My plan is 18x8.5 on 235/40/18 fronts with 18x9.5 285/35/18 rears. I'll let you all know how it goes.

^^when are you putting this set up on your car?

Well, as soon as my 8 goes into the shop (negotiating on price for install and on the kit itself) and gets the turbo, I'll place an order for these so when the car is done I can put them on

Hopefully by the end of February if everything goes according to plan (usually doesn't, but we can dream).

...so cretinx, from what you say, a 255 rear should be okay on a modded NA rx8...

sweeeeeeet, can't wait to hear about it/ and hopfully see pictures of the install:D

I think the distinction between whether to use a staggered set up or not goes to individual driving style. I am not going to address appearances because that is wholly subjective. However, if one is the type of driver who uses the gas pedal to make it around the track then the staggered set up will be more comfortable for them. On the other hand, there are many drivers who insist that the proper way to approach a turn is to do so in a neutral(no power) fashion until the apex and then power out of the turn, in which case neutral tire sizes would suffice. Since the only cornering experience I have is from running from the cops as a young man I don't consider myself an authority unless the fact that I am still free counts.

CRH

From my own testing and research I decided to run 245/40/18 rubber alla round on my car. Alex did a staggered setup and alighenment to match, and I didnt like the feel of it since I already thought the car was a bit understeer happy (even with a good alignment). I couldnt stand it with wider rears pushing the car all over the place. With a even setup I find myself much more able to control the cars direction.

Staggered doe slook cool, but I'm making my car quick on teh track, not cool looking :D (alright, alright, I did put on clear corners, but thats a necesity!)

As I said before - on stock or mildly modified power, stock rubber or maybe 245s should be perfect all around - it will maintain the balance of the car.

When you start adding power however, there is no way in hell a non-staggered setup is going to be able to contain it. I speak from experience - 235s all around on a high horsepower RX-7 resulted in uncontrollable tail wiggling through 4th gear. I'd expect something similar on an RX-8, even though it has a longer wheelbase - the balance is very similar with the low, mid-mounted rotary engine.

I challenge anyone to find someone running a turbo RX-8 with even wheel setup that is properly balanced.

Look at these cars for example
DB9 runs 19x8.5 on 235 fronts, 19x9.5 on 275 rears.
F360 ran 19x7.5 on 215 fronts, 19x9.5 on 275 rears, the new F430 runs 225s/285s
SL65 AMG uses 19x8.5 fronts on 245s and 19x9.5 rears on 285s

All of these cars are high horsepower, the Ferrari being a sports car and the other two being Grand Tourers. Look on simliar high horsepower cars and you'll find the same types of setups - a lot depends on engine placement (mid engine tend to have even bigger rears because they tend to have insane lift-throttle oversteer) and vehicle weight.

Front drivers and all-wheel drivers never run a staggered setup because they already have terminal understeer - when you're pushing a lot of horsepower, the oversteer becomes so ridiculous on even tires that putting a staggered setup actually results in a balanced car.

To describe the feeling - the steering is a bit heavy at lower speeds, and off throttle you have to actually rely on more than the power steering to make the car move where you want, start feeding throttle halfway through the turn and it gets neutral, and give it enough and you'll still break free - apply full throttle past the apex and enjoy.

I get around the track with as much throttle as much as I can, and I insist on using same size tires as I purposely break the rear loose to combat understeer. If I had larger tires in the rear I do not believe this would be possible with the lack of torque and factory bias to understeer in this specific condition. It does not even make sense to me that larger in the rear would do anything but give more push to the front as it breaks loose first and your slip angle in the front is pointed out more than the rear pushing away from the corner.

Speculation is just speculation. On THIS car Mazda tuned the suspension using the same size all around. Unless you think you can tune the suspension better than Mazda (you might be able to if you do this all the time and have a very specific driving style and environment you are tuning for) it works best with matched all around.

Now saying that, if I go with forced induction, I would definitely reconsider, but only after I had it installed and, as all my mods have been done, felt what it really does to the car on the track. I do suspect you could make more use of larger tires in the rear with a turbo or roots/whipple compressor, but trying to compare directly to a previous gen rotary built on a shorter chassis with a different suspension setup is not enough validation to go wild with it.

Please first find someone with a turbo RX-8 who has actually been to the track and then maybe this would be a more useful challenge.

I do not doubt you would need something a bit larger in the rear though.

We'll see how well a turbo works on the course in March. If I am lucky I'll also see where a turbo'd and nitrous'd RX-8 stands in the street game, as well.

CRH

I ran staggered for several reasons, but it boils down to driving style and future plans for the car. Those plans have changed recently and I have four 275 Kumho MXs on order. The wheels are still 17x8 front and 17x9 rear, and will stay that way beacuse of the effect on slip angles.

...again, driving style. There is no "one way is better than another" when it comes to racing. What ever works for you is the best way.

It is not that simple, staggered can be a very good thing and you can tune for it many different ways... Many cars with 50/50 weight distributions have staggered setups... Mazda went with and tuned for non-staggered because it is cheaper for them per car and most owners like to rotate...

When the power of the car goes up with FI and such you will eventually need to stagger and tune for it in order to get the power to the road as going wider in front has its own set of issues...

^^i'm not too good at this...how would you tune for putting on wider tires? did you mean suspensions wise...or are you talking more power from teh engine?

Here'a a thought about tuning for staggered with the goal of higher overall cornering ability (higher g-force) than stock. Stiffer rear sway bars decrease overall tire grip on the end of the car they are put on, while reducing understeer on the opposite end of the car. So although wider, higher grip tires are mounted at the rear, you put the stiiff rear antisway bar to work to equalize front-rear grip.

End result, decreased front understeer while regaining front-rear grip balance and less overall body roll while total lateral grip capability (g-force) increases. This leverages the wider rear tires to help the front end.

I was thinking the same thing.




And for all the posts above, I simply CANNOT reiterate enough how much of a bad idea it is to run same size wheels/tires on a car with significant horsepower upgrades. I can break traction easily on the RX-8 with the DSC turned off, it's going to be ridiculous once the turbo is installed (just sent in the deposit yesterday).

Not to slight Alex's setup. I am just stating how ti feels to me. I've had much different driving experience than Alex and am definitely a much less agressive driver, with less expeirence as well. So for me the staggered setup didnt work. But then again, I dont run through 2 sets of tires in what has it ben? 20K miles?

Hell, I still have my stock brake pads at 32K!

Also, something to consider, if you run wider wheels at the back, your gonna have trouble lowering the car if thats in your plans. Gonna have to roll the fenders for that if you get a big dropping spring like I did.

ooo i see i see. tha tmakes a good amount of sense:D thanks

just wondering does anyone know how much the stock wheels weight? i was just curious b/c teh wider rims would more than likly wieght more...how would this effect your acceleration (i think that's all it woudl effect)?


edit: hehe just found out the stock wheels weigh in at ~23lbs not bad the ro_ja rims i'm looking at weigh in at around 25-26 (in a wider size) so that isn't too bad ...so i doudt that it woudl make a noticable (or even messurable) difference. am i right in concluding this....or am i way off?

you can get even lighter rims. the ce28s I'm considering weigh ~17lbs at 18x8, the 18x9 for the rear won't be much heavier...
also less unsprung weight makes it easier for the suspension on many other occasions...

Actually, 23 lbs for the stock wheels is too heavy, IMHO (I mean, those wheels are too heavy for the RX-8 already). Lots of us are running lighter winter wheels, mine are 17" at ~17 lbs. 6 lbs lighter per corner - and it makes a very noticeable difference, even dramatic difference, to the ride quality and responsiveness. The whole car rides smoother, and feels lighter and more nimble. I'd consider 23 lbs the very maximum weight I'd get for wheels, and I'd pay more (or get smaller wheels) to get the noticeable benefits of lighter wheels. I certainly would never bother putting heavier wheels than stock on the car.

Check out this new thread, Effects of wheel size/weight on performance , for lots of information on this. It's really important if you want to improve the performance and not just the looks of your car.

Regards,
Gordon

My wheels are 20lbs each without center cap in a 18x8.5. Tires are 25lbs each in a 245/40/18. You should definitely try and do better than stock.

And you potentially add more twitchy handling and lose some straight line stability. Sounds like a complex solution to a simple problem unless you really have a different driving style, more power, or just asthetics.

If someone tells me they did big in the rear for asthetics that is a perfectly valid reason. I am not sure why it must be justified in terms of handling. Reality is if you do not track your car I doubt you would really notice anyway as the limits are so high.