Anyone running 18x8" rims...

[bacarl]

Yeah I thought of that too. People are getting up there with these cars, 300-350whp and I'm the only one complaining! haha This is a fast car, but it gets so twitchy under power over rough stuff that it can't be driven fast sometimes

My buddy and I dialed in ~0.15* of total front toe-in last night, and it actually did help. Typically toe-in increases stability and decreases steering response, which is what I want. The car was toe'd out before, so this made a difference. The true test will be a particular strip of freeway that I drive on to work come Monday.

 

[bacarl]

my g/f is runing tenzo dc 6 with 235/40 falken ziex 912's on cobb stage 2 and the car feels and handles amazing. it's quieter than the stock setup too in my opinion

i say it's your alignment + tires maybe

The 912's are an all season tire, so they're liable to be quieter and more forgiving.

 

[Silver Ecstasy]

The true test will be a particular strip of freeway that I drive on to work come Monday.

If you're talking about i275 between i96W and i96E, it won't make a difference. Thank John Carlo Construction for that. They won the bid through the state to produce a low grade grooved cement. It'll hold up better than asphalt and won't develop huge dips where water sits and people hydroplane, but in the dry your tires will follow the grooves uncontrollably.

 

[mazdaspeedster3]

And Mike they gave a lifetime warranty on that job.

 

[Silver Ecstasy]

It definitely is holding up really good. I personally don't have any complaints with the grooves, but any aftermarket tire i've ever ran hits those grooves.

They need to re-pave i275 south of i96 east. From all the weight put on those roads, water just sits in those grooves and you hydroplane from one end of the freeway to the other.

 

[ThreeEdgedSword]

245s? i think those would probably be a little too big for the RX8 wheels. i think they might balloon up from fitting on the wheels. rubbing would probably be eminent

Going by tire companies' specs, 8" wide is about as small as they recommend, but you're probably right about them ballooning out. Wonder if 225/45s would be more stretched out on RX8 wheels enough to solve the rubbing issues they're known to have.

Either that or I'll just have to get over being OCD and go with the 235/40's - if I'm changing tire sizes I'd just rather be slightly oversized rather than undersized.

 

[Mid_Life_Crisis]

I'm curious if people are getting negative effects from their 18x8 wheels.

I have Rota P1's which are a 19lb 18x8+48mm wheel with 235/40R18 Falken FK452 tires.

My offset is 52, which centers the tires pretty much in the stock position (equal increase inside and outside) which I believe should have the minimum effect on steering geometry. What pressure are you running in your tires? If they are the reinforced variety, Falken recommends 5 or 6 psi over the stock pressures. Not sure how much difference that would make regarding what you are experiencing, but it is something to check.
Not at all surprised that torque steer feels heavier. With the increased traction, instead of the tires spinning, they bite down and haul the car, so you get torque steer. Of course, my wheel/tire combo weight ended up about the same as stock, which may also make a difference.

 

[bacarl]

If you're talking about i275 between i96W and i96E, it won't make a difference.

Ha, I know what you're talking about with 275. But the road I'm talking about is Southfield Fwy north of Dearborn. The grooves don't bother me as much as the bumps and patches on Southfield that literally throw the car off course.

... What pressure are you running in your tires? If they are the reinforced variety, Falken recommends 5 or 6 psi over the stock pressures. ...

I've been running stock pressures (34F 32R) on the street. I remember seeing your posts about reinforced Falkens so I tried running ~40psi for a while but the ride suffers too much. I haven't actually been able to determine for sure if my FK452's are reinforced or not.

I agree about the grip worsening torque steer. Some torque steer isn't a problem, but my real issue here is that if the car goes over a bump or asphalt patch under power, it jerks violently in the direction of the bump.

 

[bacarl]

If any of you Michigan guys are at the fun run on Saturday I would love to ride around with one of you for a while and see how your cars handle compared to mine...

 

[Quiksilver05]

Hmmm I have the rota Torques in 18x8 48 offset. Im gonna get them put on sometime this month so I'll see if there is any difference as well. Anyone know if I can just use up the stock tires on the rota 18x8 without any problems??

 

[strytnyne]

im using oem tires with my torques no problem, very mild stretch, just no rim protection at all haha

 

[bacarl]

You'll have to let me know if your ride quality or anything suffers with those, QuikSilver. But strytnyne said he's fine with that set-up...

I've autocrossed with a guy running 18x8 Torques and he says his ride sucks too but he's got 235/40 Azenis.

 

[Quiksilver05]

You'll have to let me know if your ride quality or anything suffers with those, QuikSilver. But strytnyne said he's fine with that set-up...

I've autocrossed with a guy running 18x8 Torques and he says his ride sucks too but he's got 235/40 Azenis.

Yeah I will let you know. I might just use my stock tires for now in the meantime.

 

[Saitech]

You'll have to let me know if your ride quality or
I've autocrossed with a guy running 18x8 Torques and he says his ride sucks too but he's got 235/40 Azenis.

Close...245/40. Ya, the ride quality is crap compared to the stockers. I did not run the stock tires on 18x8 so I can't comment on that.

There is also significant amount of howling and tire noise once you get close to the wear bars on the azenis.

 

[bacarl]

Hey, thanks for chimin' in man!

Do you ever run your Azenis on the street? Notice any of the weird twitchy stuff I'm talking about?

See you this weekend on Belle Isle...?

 

[AutoXRacer]

Close...245/40. Ya, the ride quality is crap compared to the stockers. I did not run the stock tires on 18x8 so I can't comment on that.

There is also significant amount of howling and tire noise once you get close to the wear bars on the azenis.

Performance tires are always noisy, especially close to wear bars... I think the Azenis are the noisiest...

I'm running 18x8 RX8 wheels and the ride quality is not as soft as stock, but better in terms of firmness...though I am running 225/40/18; I'll be upgrading to 235/40 which will increase sidewall height slightly

 

[Saitech]

Hey, thanks for chimin' in man!

Do you ever run your Azenis on the street? Notice any of the weird twitchy stuff I'm talking about?

See you this weekend on Belle Isle...?

Ya, I def do. I thought it was the wider rims but my friend who is running on 215 azenis on 7 in wide rims noticed the same too. So I am guessin it's the stiff sidewall on the azenis.

Wish I could come out to belle isle, 4 exams next week. (notcool)

Btw, I was classed in CMT last time per request. I think we technically belong in CMT, not BMT. But if you want a trophy, do BMT.

 

[Saitech]

Performance tires are always noisy, especially close to wear bars... I think the Azenis are the noisiest...

I'm running 18x8 RX8 wheels and the ride quality is not as soft as stock, but better in terms of firmness...though I am running 225/40/18; I'll be upgrading to 235/40 which will increase sidewall height slightly

Yea, i agree, I stopped daily driving on azenis after a couple months, just too noisy and stiff. I plan on having a dedicated set of rims and tires next season. I have all winter to decide tire and size.

 

[jon619]

I'm running 18x8 RX8 wheels and the ride quality is not as soft as stock, but better in terms of firmness...though I am running 225/40/18; I'll be upgrading to 235/40 which will increase sidewall height slightly

Actually, it'll reduce sidewall height slightly. I plan on doing the 235/40/18s as well as soon as I burn off my stock tires.

215/45-18 3.8" 12.8" 25.6" 80.5" 787/mi 60MPH 10000mi N/A
235/40-18 3.7" 12.7" 25.4" 79.8" 794/mi 61MPH 10085mi -0.8%

 

[AutoXRacer]

Actually, it'll reduce sidewall height slightly. I plan on doing the 235/40/18s as well as soon as I burn off my stock tires.

215/45-18 3.8" 12.8" 25.6" 80.5" 787/mi 60MPH 10000mi N/A
235/40-18 3.7" 12.7" 25.4" 79.8" 794/mi 61MPH 10085mi -0.8%

I was comparing them to the 225/40/18...the 235/40/18 should be slightly taller...