85 replies to this topic

[RARECRX]

http://www.grmotorsp...ally-better.php

for all the non-believers here is proven tests..for all to enjoy...very interesting article and well worth the time to read it.. yeah 13's are better 13x8's with big hoosier slicks on them.... but as far as street tires the answer is there... so leave the bling-bling guys alone LOL!!!!!

Edited by etmydst, 15 February 2006 - 11:38 AM.

[Greg Gauper]

Well....not exactly.

Basically, what they are saying is that if you replace the crappy OEM 14" tires with a higher performance version in a larger diameter, yes you will see an improvement. And that if you went larger on the wheel diameter but reduced the aspect ratio, yes the handling will improve due to less sidewall deflection.

However, what they did not do was perform an exact back-to-back test using the exact same brand and compound of tire with the same aspect ratio and width i.e. compare a 205/60-14 to a 205/60-15.

From a pure performance standpoint, the smaller diameter wheel & tire will be faster do to lower rotating mass.

An excellent example of this is on the full race prep Miata's that race in SCCA's E-production class. The Miata's are permitted to run either 13" or 15" rims in the same width. Guess what? The 13" rims are faster. The down side is that the wheels have to be custom made in 13" width in order to clear the brake calipers. They actually run a three-piece modular wheel with a spun rim to get more clearence. Needless to say that makes them very expensive.

That said, the use of 13" and 14" rims is non-existant on modern cars, and the availability of good tires in the smaller diameters is becoming rarer as well. So it would become much more cost effective to convert to 15" rims just do larger selection of wheels and tires. BTW - This was the main reason that SCCA mandated 15" rims on the Spec Miata class as opposed to the OEM 14" rims that came on the car. They were thinking long term for the class and the availability of good racing tires in 15" is far more plentiful than 14".

[RARECRX]

very good point greg but also compare a 15" same weight wheel to a 13" with same compound /tread etc...Im sure they would perform very similar but the 15 would be more responsive NO? im just guessing..... when plus sizing there is lightweight wheels to factor also... but good argument..this thread is gonna get hammered LOL... also we are comparing available street tires with no rules or regulations... most people here with street cars get bombarded by other RPR members saying oh dont put 16's or 17's ...13's are faster..we all dont want 13x8" hoosier shod race cars for the street.on a race car yeah.most average members have 13's with 185/70/13's on them LOL.cause thats the available size........... .. but with available tire sizes the bigger wheels win... so in all good faith street to street the 17's will win in handling and performance...

Edited by etmydst, 15 February 2006 - 12:03 PM.

[cbstdscott]

All this article "proved" is that OEM tires suck.

Frankly, I have stopped reading GRM largely due to misleading articles like this one. GRM used to be about inexpensive racing, but the success of the magazine has turned its editorial policy to hyping advertisers products like all the other ricer magazines.

I find it amusing that some people wish to argue with the laws of physics.

This thread should have a disclaimer on it, "Not Fact Supported."

Scott

[RARECRX]

All this article "proved" is that OEM tires suck.

Frankly, I have stopped reading GRM largely due to misleading articles like this one. GRM used to be about inexpensive racing, but the success of the magazine has turned its editorial policy to hyping advertisers products like all the other ricer magazines.

I find it amusing that some people wish to argue with the laws of physics.

This thread should have a disclaimer on it, "Not Fact Supported."

Scott

<{POST_SNAPBACK}>

I understand your point scott in the race aspect of the rims...you are correct..but as far as us street guys with the available tire options that are given to us..the logical street choice is to up the rim right? so there is a fact supported that the average consumer that is not "racing" with the available tire size reasonably available to us "the street tuner/weekend funster" will get better handling out of a 17" street setup.... i doubt the available tire size 175/70/13 will out perform a 215/40/17... but a 13x8 race compound will wax the 215/40/17 up... so to be honest there is a fact pointed...

Edited by etmydst, 15 February 2006 - 12:10 PM.

[E-AT_me]

i glanced over the article.. and the funny thing was that the most comment was on how the civic looked, over how it felt. kind of funny coming from a racing magazine..

believe what you want, but i know i've felt a difference..

and just cause one magazine says it so, doesn't make it true.

Modified mag says Lambo doors are in, you gonna go get some of those?

[cbstdscott]

A "rim" goes on the outside diameter of a round object. We are discussing wheels.

If you like the looks of blinging wheels, go for it.

As for performance, street tires do not deliever performance. Some street tires do perform better than other street tires. But even the cheapest street tire provides adequate results when driven at legal speeds. While it is possible to measure the difference between "lousy" street tires and "great" street tires, the scale of measurement is small.

If you wish to drive at extra-legal speed then the discussion then moves to racing tires.

Want cheap racing tires in a 13" size? Road racers discard perfectly good 13" race tires that can be bought for about $25 each. Combine them with some junkyard 13x6 wheels and you have a cheap set of racing rubber that nearly anyone can afford.

Scott

[RARECRX]

remember guys we are talking about AVAILABLE "STREET" tires not race compounds.. so if you think your 185/70/13's will out handle some 215/40/17's In the same cars with the same driver?? ill bet $100 bucks it wont... good example is my expedition stock tires were like 275/70/17's but i put 305/50/20's I had to do a quick sharp left manuever in it due to a metal picnic table falling out of some rednecks pickup at 75 MPH on the freeway if i had the stock tires my family and i would be dead now due to the sidewalls buckling under the load and thus rolling the beast over..but damn i praise those 305/50/20's and and happy they stuck to the ground like glue!!! I LOVE MY BLINGS... I LOVE FORM AND FUNCTION I GUESS>.. I am not using this thread to argue..just to hear some good opinions..I respect all your guys statements...

Edited by etmydst, 15 February 2006 - 12:42 PM.

[badpenny]

I am really confused on what is being discussed now. I like my 13's, I like the rarity of them. And so far, NO ONE is making one-off copies of 13's. I run 165/60's on mine. and I do just fine. Nimble and agile, hell yes. Stop before becoming road mush in a 5 car pile-up, that is what skilz is f0. But typically I can rely on the person behind me making sure that the person in front of me stops me.(There is really nothing I can do about that) And no, I am sure I will never find a great set of comp tires. I am too damn cheap to put something on my car that I know I will end up replacing in a year.(Its just my opinion, Yeah, if you feel it will make you feel good go ahead and flame me). I can't see putting 15's on my car just yet. I don't know what I am saying, I just posted to do so.

[RARECRX]

I am really confused on what is being discussed now.  I like my 13's, I like the rarity of them.  And so far, NO ONE is making one-off copies of 13's. I run 165/60's on mine.  and I do just fine.  Nimble and agile, hell yes.  Stop before becoming road mush in a 5 car pile-up, that is what skilz is f0.  But typically I can rely on the person behind me making sure that the person in front of me stops me.(There is really nothing I can do about that)  And no, I am sure I will never find a great set of comp tires.  I am too damn cheap to put something on my car that I know I will end up replacing in a year.(Its just my opinion,  Yeah, if you feel it will make you feel good go ahead and flame me).  I can't see putting 15's on my car just yet.  I don't know what I am saying, I just posted to do so.

<{POST_SNAPBACK}>

no flame.... I loved my 13's when i had my 1st 85 that ran 14's at the strip with 60 series on them.....they brang my rpm's up ,were light ,but to be honest when spirited driving was done they crapped out.. I love both rims thats why i went with 15's.. I have 13's,14's,15's,16's,and 17" wheels for my rex...but i went with 15's so i wouldnt get ballbusted here... but the 17's i have are ro-ja lt track series and weigh 14lbs each and are flat black....thats why i was thinking of running them... form and function..

Edited by etmydst, 15 February 2006 - 12:59 PM.

[JeepGirl]

i know i laid the smackdown on people running huge rims, but i also said not to take me the wrong way. i like the look of larger rims yes. some big rims do look really sharp on our cars. its just the lack of sidewall to smooth out some of the bumps that kills me. more rotational mass+next to no sidewall+bad city streets = horrific ride and bent rims.

in my city we have a honda club. mostly for newer gen civics. they all run rota slips or thier ilk. these people are always complaining about how much they spent on thier rims just to have to pay it over and over again because thier always bending/cracking thier nice new shiny rims. i'm sorry, you can argue with me all you want, but 1" of sidewall on a 17" rim at 50kph isnt going to save your rim from unavoidable 1' deep pothole. i have stock steelies on my car, new suspension all around and just driving normally in traffic going down the road i get stuff JUMPING off my dash because of all the splits in the road and stupid unavoidable potholes. if you live in a place like pretty much anywhere in BC like vancouver or victoria you can get away with driving on 17's/18's all year long and not have a worry in the world, because they have great roads. but if you live where i do or some place like buffalo these huge rims will be dead inside of 6 months.

note, nothing i said in this post had anything to do with speed or acceleration. just having them for asthetic purposes. because if the roads werent such garbage where i live i'd prolly be running something a bit bigger as well, but untill they put more infrastructure funding in the pot to fix our roads i'll be needing all the sidewall on my tires that i can get.

[crazi-85crx]

I find it amusing that some people wish to argue with the laws of physics.

<{POST_SNAPBACK}>

[mayhem019]

Im running falken azenis in 195 60 14 on steelies and with the amount of suspension mods done to the car it still feels somewhat spongy which I think is because of the sidewalls flexing... It bugs me so yeah I will probably go with at least 15s once these tires are done

Edited by mayhem019, 15 February 2006 - 01:26 PM.

[RARECRX]

I find it amusing that some people wish to argue with the laws of physics.

<{POST_SNAPBACK}>

<{POST_SNAPBACK}>

good example is my expedition stock tires were like 275/70/17's but i put 305/50/20's I had to do a quick sharp left manuever in it due to a metal picnic table falling out of some rednecks pickup at 75 MPH on the freeway if i had the stock tires my family and i would be dead now due to the sidewalls buckling under the load and thus rolling the beast over..but damn i praise those 305/50/20's and and happy they stuck to the ground like glue!!! stiffer smaller sidewall less buckle.... physics exactly...

[Surestick]

Correct me if I'm wrong but doesn't sidewall flex (and consequently the shape & size of the tires contact patch) when turning have a lot to do with the tire pressure you run?
Everything I've read says that you really do have to figure out what pressure gives you a balance between a tire that doesn't deflect enough to conform to the road & one that flexes too much & causes the tire to not put the maximum contact patch down in a turn.

If big rims & rubber band tires were better wouldn't that be what autocrossers, drag racers & F1 used?

I've always thought that the use of big rims & low profile tires were used to allow bigger brakes for heavier GT cars & were basically a trade off to get brakes that could handle the cars weight under racing conditions.

On a totally personal taste note, I find that big rims on Civics just look dumb - they make the brakes look puny. I prefer the look of nice fat rubber with the brakes filling the inside of the rim.

And, no offense etmydst but I don't think the tire needs & handling of an Expedition is comparable to a Civic. It's apples & oranges. You are probably lucky you didn't role the bloody thing (Sorry, I'm really really not an SUV fan).

Edited by Surestick, 15 February 2006 - 01:56 PM.