615zenis in 215/40/17 flavour for autocross

rice_eater · Post by **rice_eater** » Mon Jul 11, 2005 4:32 pm

i forget how the hight of the sidewall affects cornering but i'm sure you guys can quickly explain that in a couple words... my real question is i currently have 215/40/17 falken zeix tires on the used wheels i bought and am thinking about switching to azenis for some roadcorse and mostly auto-x/solo fun. any problem with getting same size azenis? the zeixs have a very small profile so i'm wondering how this will work out. this is for an 05 with konis and SRT springs for now, sway bars to come later this summer. thanks in advance

Sean R/T · Post by **Sean R/T** » Fri Aug 19, 2005 4:29 am

The Falken 615 is a much better autoX tire than the Ziex. So any size you get will be an improvement, however, you'll probably find best results with a 205/50/15 size, just find some OEM SXT rims to put them on. The 15inch size will also give you a better gear for acceleration while pulling out of corners than any 17 inch size.

lensam69 · Post by **lensam69** » Sat Oct 22, 2005 12:57 pm

Not really.

The final gear is determined by the outer diameter of the tire.

The wheel has nothing to do with it.

However, a lighter wheel will provide better acceleration because the engine has to do less work to move it.

And to answer the originall question,

More sidewall = more flex = less responsive tire.

When you turn the wheel, that movement is going to take longer to reach the bottom of the tire which is touching the pavement, because the tire is being distortioned.

Baal · Post by **Baal** » Sat Oct 22, 2005 6:28 pm

lensam69 wrote:Not really.

The final gear is determined by the outer diameter of the tire.

The wheel has nothing to do with it.

However, a lighter wheel will provide better acceleration because the engine has to do less work to move it.

And to answer the originall question,

More sidewall = more flex = less responsive tire.

When you turn the wheel, that movement is going to take longer to reach the bottom of the tire which is touching the pavement, because the tire is being distortioned.

however our cars have faster times with 15s than bigger rims, the sidewall flex is less harming than the extra rotating mass (because of neons low HPs)

JustANeon · Post by **JustANeon** » Sat Oct 22, 2005 8:07 pm

lensam69 wrote:Not really.

The final gear is determined by the outer diameter of the tire.

The wheel has nothing to do with it.

However, a lighter wheel will provide better acceleration because the engine has to do less work to move it.

And to answer the originall question,

More sidewall = more flex = less responsive tire.

When you turn the wheel, that movement is going to take longer to reach the bottom of the tire which is touching the pavement, because the tire is being distortioned.

a 205/50 17 is much smaller in diameter than a 205/40 17 so Sean R/T is right

lensam69 · Post by **lensam69** » Sun Oct 23, 2005 10:37 am

however our cars have faster times with 15s than bigger rims, the sidewall flex is less harming than the extra rotating mass (because of neons low HPs)

I was just answering the question,

But what you say is 100% true. Especially with the Falkens. Those tires are unbelievably stiff for their big sidewalls. I use 14" Wheels with Azenis. Not only does it save me a lot of money, (Edge Racing has the 14" size for about $45 each, plus I live in Miami, so I pick them up Myself), but the acceleration is great.

a 205/50 17 is much smaller in diameter than a 205/40 17 so Sean R/T is right

Ok, but still, the wheel has nothing to do with it. Its the outside diameter of the tire that changes the final ratio.

Oh, by the way I think you got it the other way around

Given equal widths, Smaller ratio = smaller sidewall = smaller tire.

So, the 205/40 17 is smaller overall than the 205/50 17 .

unsuper man · Post by **unsuper man** » Sun Oct 23, 2005 7:34 pm

i also picked up 195 azenis for my steelies from edge racing in weston. theyt dont carry them anymore as they are discontinued. id say get some steelies and pick up a set of the new azenis, my freind has a set on his 17s, and from a 2nd gear roll, theyt hook better then his BFG DR's.

of coruse, they lose out the whole, but thats what DR;s are for

lensam69 · Post by **lensam69** » Mon Oct 24, 2005 12:02 am

Well, I know for a fact that they have 14"'s

I picked mine up two weeks ago, and I saw with my own two eyes that they still had plenty at the warehouse.

But yeah.... Edge racing roxrs.

rice_eater · Post by **rice_eater** » Mon Dec 19, 2005 7:01 pm

i dont even have the size of tires you guys are talking about so i'm a bit confuzed on the whole 205/40/17 and 205/50/17 thing. i understand what you're saying about size thought, so my question is this

you think that 205/55/15 tires on my stock 15s would be a better choice than 215/40/17? i know i could use more power but i'm more concerned about keeping the speed through the corners not so much acceleration out of the corners.... are you sure i'm not giving up a lot of grip for a couple hp? again, i dont care about speed too much, i'm getting pretty fast times as it is, so a couple hp is pointless. what i have more problem with is the heavier feel underbreaking with the bigger wheels, however i like the very quick turn in... my current 17" nexen3000 tires, though pumped almost all the way up, have ridiculous amount of wear on the outside of the tire and you can see it has flexed as much as to rub part of the lettering on the sidewall. i dont want that from my future set of azenis. i think i might try 2 15" azenis for testing purposes to see how well it works out. other opinions?

nodestiny · Post by **nodestiny** » Tue Jan 17, 2006 1:49 pm

im going for a 16"

Right in between!

The way i look at it, it a whole freakin .5 lb more per wheel (slipstreams), which will probably come off in the weight of the rubber (even if it didnt, would anybody even notice .5lbs of weight more per wheel? Honestly?) Probably do a 215 or 225 /40/16

rice_eater · Post by **rice_eater** » Tue Jan 17, 2006 4:35 pm

nodestiny wrote:im going for a 16" Right in between! The way i look at it, it a whole freakin .5 lb more per wheel (slipstreams), which will probably come off in the weight of the rubber (even if it didnt, would anybody even notice .5lbs of weight more per wheel? Honestly?) Probably do a 215 or 225 /40/16

that's what i'm saying, there are even light weight 17s... the ones on my srt wiegh 17lbs, probably the same as the stockers if not less