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hondaman9468
04-12-2003, 09:35 AM
Anyone running 18s. got a pick. I dont know if i am going to 18 or 17.

AznPower
04-12-2003, 03:37 PM
my car on 18s after my tire rolled off

SpoonK20
04-12-2003, 05:19 PM
OMG!!! How that happened?

rswbrixton
04-12-2003, 05:35 PM
What the %$#% !!!

How is that rim ?

AznPower
04-12-2003, 05:47 PM
rim still holds air but i sold it, its bad luck

IceD out N CALI
04-12-2003, 06:19 PM
that sucks

EP3Hatch
04-13-2003, 10:27 AM
I've got 18's on mine. it rides great and corners even better. Check the member's ride section under EP3Hatch.

mental
04-13-2003, 09:05 PM
i dont have to get that small a tires do i ... thats fuken gay! i mean like i know they are 18s but cant i get like 40s or something like that...

jaydub
04-13-2003, 09:12 PM
Originally posted by mental
i dont have to get that small a tires do i ... thats fuken gay! i mean like i know they are 18s but cant i get like 40s or something like that...

uhh, that's the whole point of larger wheels is smaller tires. :rolleyes: It kind of goes hand in hand when you get big wheels, you get small tires. If the overall diameter changes you're asking for trouble w/ your speedometer.

and what's "fuken gay" about it?

hondaman9468
04-14-2003, 06:57 AM
hey ep3 how much did you lower it?

EP3Hatch
04-14-2003, 07:13 PM
I lowered it between 2-2.5 inches

justifiedSi
04-14-2003, 07:36 PM
18s w/ "small tires" :p

03hatch
04-27-2003, 11:40 PM
Originally posted by justifiedSi
18s w/ "small tires" :p

what series tires is on your 18s?

chunky
04-28-2003, 07:14 AM
18's for show, 15's for go.

anyone buying 17's or 16's is just confused, or wants the show, but can't afford 18's.

I personally wouldn't ever wanna have to pay for tires for an 18" rim with that low an aspect ratio. not only that, the less sidewall you have, the more likely the tire is to bubble.

15's for lyfe!!

CleanBlackSi02
04-28-2003, 07:47 AM
Originally posted by chunky
18's for show, 15's for go.

anyone buying 17's or 16's is just confused, or wants the show, but can't afford 18's.

I personally wouldn't ever wanna have to pay for tires for an 18" rim with that low an aspect ratio. not only that, the less sidewall you have, the more likely the tire is to bubble.

15's for lyfe!!
I think you might find a few people on here who disagree... Like me.

Dunrick
04-28-2003, 08:09 AM
Yeah 15's are good if you got slicks strapped on them.....other than that - if you got the stickiest rubber, and I got the stickiest rubber on my 17's...I would smoke you @ launch.....17 " w/ 45 tires are a hair off of the stock 15" 60 tires...and my 17's weigh 16 lb's....yeah that might not be mind boggling light, but I cant defintely out launch somebody w/ 15's - if you have the same tires on....

Silver Bullet
04-28-2003, 09:03 AM
I have 18" and they are great!

chunky
04-28-2003, 09:09 AM
Originally posted by Dunrick
Yeah 15's are good if you got slicks strapped on them.....other than that - if you got the stickiest rubber, and I got the stickiest rubber on my 17's...I would smoke you @ launch.....17 " w/ 45 tires are a hair off of the stock 15" 60 tires...and my 17's weigh 16 lb's....yeah that might not be mind boggling light, but I cant defintely out launch somebody w/ 15's - if you have the same tires on....

negatory.

the 15's have a taller sidewall.

if you're familar with how slicks have sidewalls that wrinkle to help with the launch, you'll understand why a taller sidewall works to your advantage in drag.

the sidewall flexes & stores some of the energy from the clutch dump - your tires would spin b/c the sidewalls can't flex as much, so you loose traction. the 15's sidewalls will flex, allowing for good hookup, then they will release the energy by snapping back gradually, so you don't loose the energy to spinning the wheels.

i garantee you that if you had 225/xx/17, and i have my 225/50/15's, i WILL outlaunch you. I can drop my tire psi lower (more sidewall) and i can't think of a single 17" wheel that's lighter than mine (10.7 lb).

IceD out N CALI
04-28-2003, 09:14 AM
18's on an ep thats dropped 2 inches looks pretty good:p

chunky
04-28-2003, 09:19 AM
Originally posted by CleanBlackSi02

I think you might find a few people on here who disagree... Like me.

how do you disagree?

anything larger than 15's, and you are compromising performance for looks. that is a fact. the lightest 15" wheels are always lighter than the lightest 16" wheels. period. You could argue that the shorter sidewalls allow for more favorable slip angles resulting in more precise handling - but you can't forget that tire compound & composition have a huge bearing on that, and the difference is minimal when going from a 50 aspect ratio to a 45.

if you're gonna go for looks, go all out. if you're gonna go for performance, go all out.

that's how i see it as far as tires go. to me, there is nothing better looking than a set of 15" wheels with some meaty tires on them sitting under a clean exterior.

When i say that people with 17" and 16" are confused, i don't mean it in a bad way necessarily, i just mean that they are willing to compromise between the two ideals of show & go.

I obviously am heavily slanted towards the go end of the spectrum.

ssvr6
04-28-2003, 09:32 AM
What's wrong with doing both? Nothing IMO.

Don't hate on others because they have the $ to get whatever wheels they want.

I personally hate 15's for daily driving. I'd rather have a set of 15's with some DR on them or slicks for the track and cruise all day on my 17's. (If they ever fuggin' arrive. :( )


Steve

chunky
04-28-2003, 09:47 AM
Originally posted by ssvr6
What's wrong with doing both? Nothing IMO.

Don't hate on others because they have the $ to get whatever wheels they want.

I personally hate 15's for daily driving. I'd rather have a set of 15's with some DR on them or slicks for the track and cruise all day on my 17's. (If they ever fuggin' arrive. :( )


Steve

i'm not hating - but like you said, 15's are for go. 17's are for lookin cool. If i wanted to afford 17" wheels, I could, but 15's perform better, and i have some extra $$ left to do other mods.

i guess tire expenses add up quickly when you go through a set of tires in a year.

Dunrick
04-28-2003, 07:54 PM
Originally posted by chunky


i'm not hating - but like you said, 15's are for go. 17's are for lookin cool. If i wanted to afford 17" wheels, I could, but 15's perform better, and i have some extra $$ left to do other mods.

i guess tire expenses add up quickly when you go through a set of tires in a year.


There have been studies on tires and 17" have been proven to be the best overall - fifteens might have they're advantages at overall top speed - but not handling

plus for you to get the same tire mass to the ground as me, you need a 60 series tire...which offer too much flex on corners, vs a 45 or 40 series tire, that will be stiff and precise while taking a corner at pulling the g's on the freeway, you might be able to slightly slightly creep away.....but then again, you gotta beat my factory freak...The only advantage I see to 15's is the luxury ride, and the fact that they are best on the freeway

chunky
04-28-2003, 08:18 PM
Originally posted by Dunrick



There have been studies on tires and 17" have been proven to be the best overall - fifteens might have they're advantages at overall top speed - but not handling

Show me these studies.



plus for you to get the same tire mass to the ground as me, you need a 60 series tire...which offer too much flex on corners, vs a 45 or 40 series tire, that will be stiff and precise while taking a corner at pulling the g's on the freeway, you might be able to slightly slightly creep away.....but then again, you gotta beat my factory freak...The only advantage I see to 15's is the luxury ride, and the fact that they are best on the freeway

what do you mean by the same "tire mass" to the ground? Why would I need a 60 series tire?

do you mean contact patch? so long as the overall width and diameter of the tires are the same for the two sizes, the contact patch will be identical. But i can get more contact patch by lowering the psi more than you could.

i have 225/50/15 tires on my car, they will hand a 225/40/17 it's ass in all respects. the 17 will have sharper turn in due to the lower slip angles, but that's about it.

how do you figure you have a factory freak? 15.651 bone stock v.s. my car which ran a 15.737 with only an exhaust midpipe, bald stock tires (spun the 2-3 upshift badly) at what i'm sure is a higher elevation than seattle in the afternoon sun. if i had newer stock tires, i'd be at least 2/10 faster, the bald tires hurt my times a lot. I wouldn't say you have a factory freak.

I'll have new slips soon enough. but i have the 225 wide tires now, so look for me in the low 15's.

i'm just amazed that you really think that 17" wheels/tires offer superior performance to 15" wheels/tires.

Maybe on a car with a larger overall wheel, but not on a civic that comes stock with 15's.

FailureToStop
04-28-2003, 09:06 PM
Well I agree with you... when it comes to drag racing the typical 15 set-up will out perform the typical 17 set-up assuming the same type of tire and same width --- 15's will be lighter.

But for overall handling it is a toss-up. One of the "studies" was the GRM article:

http://www.grassrootsmotorsports.com/plustest.html

Unfortunately, while they kept the tire brand and model the same, they didn't keep the same width as they changed rim diameters and I don't believe they kept the weight constant.

But notheless, an increase in diameter had a generally negative relationship with track times --- as the diameter increased, track times decreased.

So in their somewhat convoluted experiment, even with the increase in weight and loss of acceleration, the higher diameter rims lapped/handled better. I believe that if they had kept the tire widths the same the larger rims would still have lapped/handled better.

Personally, I think 16's would be the way to go for overall performance. The 16's would have less sidewall than the 15's and would be lighter than the 17's.

Dunrick
04-28-2003, 09:23 PM
Originally posted by chunky

Show me these studies.



what do you mean by the same "tire mass" to the ground? Why would I need a 60 series tire?

do you mean contact patch? so long as the overall width and diameter of the tires are the same for the two sizes, the contact patch will be identical. But i can get more contact patch by lowering the psi more than you could.

i have 225/50/15 tires on my car, they will hand a 225/40/17 it's ass in all respects. the 17 will have sharper turn in due to the lower slip angles, but that's about it.

how do you figure you have a factory freak? 15.651 bone stock v.s. my car which ran a 15.737 with only an exhaust midpipe, bald stock tires (spun the 2-3 upshift badly) at what i'm sure is a higher elevation than seattle in the afternoon sun. if i had newer stock tires, i'd be at least 2/10 faster, the bald tires hurt my times a lot. I wouldn't say you have a factory freak.

I'll have new slips soon enough. but i have the 225 wide tires now, so look for me in the low 15's.

i'm just amazed that you really think that 17" wheels/tires offer superior performance to 15" wheels/tires.

Maybe on a car with a larger overall wheel, but not on a civic that comes stock with 15's.
[/B]

Oh and my stock tires weren't bald? Ontop of that, the track is not @ sea level...nor in seattle....just use seattle as a reference, because they are fairly close....

Also, I have 45's on my 17's...so yes, I do have more "contact patch" - I have more contact patch than 60's on 15" rims...

This is going to sound really out of line, but why do you think ferrari's and other sport cars dont come w/ 15" rims? Not all sports cars are much bigger than our civics

FailureToStop
04-28-2003, 09:39 PM
This is going to sound really out of line, but why do you think ferrari's and other sport cars dont come w/ 15" rims? Not all sports cars are much bigger than our civics Well, if you are taking a look at other cars, take a look at dragsters. They generally have small diameter rims with huge tires that also have a large sidewall.

It all depends on what you consider performance. If you want it to handle (Auto-X), you are probably better off with 16's or 17's. If you want to accelerate quickly (drag racing) you should get 15's.

BTW, the rims and tire size on the GRM tests:

15x6.5" Kosei Racing Senekas....... 15 lbs.
195x55x15 => 107.25 mm sidewall
595.5 mm OAD

16x7" TRM Typhoons............... ?lbs.
205x45x16 => 92.25 mm sidewall
590.9 mm OAD

17x7" TRM Typhoons............... 23 lbs.
215x40x17 => 86 mm sidewall
603.80 mm OAD

It's interesting to note that the 15's were 8 lbs(!) lighter than the 17's for a total of 32+ lbs less in rottating mass! Furthermore, the 15's had a smaller rolling diameter (quicker) than the 17's. And yet the 17's out timed the 15's! If you take a look at some affordable rims in both sizes:

Typical lightweight (and affordable) 15's:
Heliums (10.8 lbs) ~$4-500.00
Slips (12 lbs). ~$4-500.00
Axis Mag Lite (11 lbs) ~ $400.00
Konig Traffik (12.42 lbs) ~$436.00

Typical lightweight (and affordable) 17:
Konig Heliums (16.2 lbs) ~$5-600.00 (+5.4 lbs)
Rota/Konig Subzeros (16.9 lbs) ~$4-550.00 (+4.9 lbs)
Axis Mag Lite (14 lbs) ~ $600.00 (+3 lbs)
Konig Traffik (15.9 lbs) ~$600.00 (+3.48 lbs)

The average difference in the above sampling of a 15" vs. 17" weights is 4.2 lbs vs. the 8 lbs in the GRM article. So in "real world" terms, the weight difference between the two sizes would have been less and the GRM results would have indicated even more that the 17's and 16's out pace the 15's in handling (auto-x type events).

02SilverSiHB
04-28-2003, 09:53 PM
I do feel that 17's will had better handling, but like most have said, will hamper you drap strip times.

I know this is a terrible way to show proof :rolleyes: but I noticed a lot of people complaining about the new Si's small 15's and how they can't handle compared to some of the other cars with 17" wider tires. Now it could be of course the wider tire they are talking about...but I've been noticing a lot of cars with wider bigger rims handling just fine, if not better than those with 15's. I used to feel the same about 15's being better than 17's because the 15's usually weigh less, and of course have a less rotational mass....sooooo, maybe the only way we can prove it to our selfs is if we have 2 sets of wheels. Take my stock 15's, if I put some 205/50 falkens on them and go autoxing....and then compare those to my Velox VX-8 215/45 Khumo Ecsta 712's and go autoxing with those...do you guys think that would be a fair comparison? I can actually do this once I get back to the states...which should be in the near freakin future :)

but seriously, do you guys think this would be a fair comparison?

EDIT:
Those "people" I was referring to were articles in Car & Driver, Road & Track, SCC :) , Super Street, etc.

Dunrick
04-28-2003, 09:58 PM
I think you need to compare the same exact tires.....on the 15's and the 17s....well I guess that doesn't speak for sizes....

Id say compare a 215x50 15" vs 215x45 on the 17"

same brand...like azenis, or ecsta etc etc...

anjapower
04-28-2003, 10:19 PM
Gimme a 15" wheel with the same width as a 17" wheel and I will outhandle you. Smaller and wider = better for handling. On another note, I believe 16" is the best compromise for looks and handling. Unlike Chunky I want a little of both.:p

chunky
04-28-2003, 10:39 PM
Originally posted by Dunrick


Oh and my stock tires weren't bald? Ontop of that, the track is not @ sea level...nor in seattle....just use seattle as a reference, because they are fairly close....

Also, I have 45's on my 17's...so yes, I do have more "contact patch" - I have more contact patch than 60's on 15" rims...

This is going to sound really out of line, but why do you think ferrari's and other sport cars dont come w/ 15" rims? Not all sports cars are much bigger than our civics

were they bald? as far as I know i have one of the highest mileage ep's on this board. when I ran the 15.737 I was at about 27k miles. When I say bald, I don't just mean worn to the wear markers, I mean smooth to the touch, no grooves, on the verge of showing steel belts. I'm not making any excuses - your time was less than 1/10th of a second better so at the very least, your factory freak is more or less equal to my pretty normal factory edition.

45 with what width tire? if your overall diameter is within a few 10ths of an inch of stock, and your tire width is 225, then you certainly do not have more contact patch than a similarly sized 15" wheel. The 225/50/15's have more sidewall than the 17's, you can lower the pressure more to get a bigger contact patch than is possible with the 17" wheels. trust me on that.

As for that GRM article, that article was total trash. I've read it before. anyone reading it should see that it was not a fair comparison. the 16" and 17" wheels were 7" in width, and the 17" wheels got the widest rubber of all, 215. Well gee, i wonder why it turned in the best track times. It had the widest tires by far. also, read this.


"This is why I could turn the same times on the 16- and 17-inch tires."

He turned in the same times on the 16" and 17" tires, even though the 16" had less contact patch. so it would seem that the rotational weight savings of the 16" tires evened the odds v.s. the wider rubber of the 17".

If that test was intended to explore the performence benefits of a lower sidewall aspect ratio, they would have used 15x7, 16x7 and 17x7 wheels all fitted with tires that have the same tread width.

Oh, and the last gripe, some of you are trying to use that poor excuse for a "study" to establish that 17" wheels are just as good for drag as 15" wheels. . . . They didn't even do straight line acceleration tests. the 17" wheels would have lost bar none.


15's or die.

how about this, anyone ANYONE in the atlanta area that has 16" or 17" wheels on their cars with 225 (or very close, 215 or 235) wide rubber, I CHALLENGE you to meet me once at the drag strip, and once at the auto-x. Since the two cars most likely won't be modded the same, we'll SWAP WHEELS. This isolates the variable to just the wheels. no excuses, about as pure a comparison as you can get.

Same driver, same car, two different sets of wheels. who's down? I'm serious about this, I want to prove to you guys that 15" wheels given equal treadwidth are better for straight line, and roughly equal for auto-x/road racing - and much easier on the wallet.

*edit*

I'll drive one state over too. alabama, TN, SC, FL. if you're near the GA border, let's rock.

hondaman, you live like 10 min from me. are you interested? i know my wheels are better suited for drag as they are like 1/2 the weight of yours, but how about the cornering? wanna meet at the next auto-x?

sniperSI
04-28-2003, 10:55 PM
if we started pushing 250+ whp + 18 inch do more better then worse.

FailureToStop
04-28-2003, 11:29 PM
The only argument is in handling. I think you are padding your argument a bit by writing:


I'm serious about this, I want to prove to you guys that 15" wheels given equal treadwidth are better for straight line, and roughly equal for auto-x/road racing - and much easier on the wallet.
There is no real argument here that 15's will out accelerate 17's. Even though you diss the GRM article, they clearly state that the 17's had lower acceleration. And from personal experience I can attest to it.

As far as being easier on the wallet... you would have to be a fool to disagree that 15's aren't cheaper than 17's.

As far as handling..."roughly equal for auto-x/road racing." Are you admitting the 17's or 16's are better (performance wise) for auto-x than 15's? :D

If you take a look at the GRM results, the 15's are "roughly equal" to the 17's. If you take the average of each drivers fastest time, the 17's only had -.6168 second advantage over the 15's. (But of course that could be the difference between winning or losing. :) )


But I think it still would be a kick-ass idea if you could hook-up with Hondaman.

chunky
04-29-2003, 07:20 AM
Originally posted by FailureToStop
The only argument is in handling. I think you are padding your argument a bit by writing:


There is no real argument here that 15's will out accelerate 17's. Even though you diss the GRM article, they clearly state that the 17's had lower acceleration. And from personal experience I can attest to it.

As far as being easier on the wallet... you would have to be a fool to disagree that 15's aren't cheaper than 17's.

As far as handling..."roughly equal for auto-x/road racing." Are you admitting the 17's or 16's are better (performance wise) for auto-x than 15's? :D

If you take a look at the GRM results, the 15's are "roughly equal" to the 17's. If you take the average of each drivers fastest time, the 17's only had -.6168 second advantage over the 15's. (But of course that could be the difference between winning or losing. :) )


But I think it still would be a kick-ass idea if you could hook-up with Hondaman.

I'm not padding my argument. Dunrick did say that his 17" wheels give him better contact patch than my 15" wheels, that he would beat me for sure, but that I might creep up on him on the freeway. Look back in the thread, he said it.

As for me saying roughly equal for 15" v.s. 16" or 17" i mean that if the width of the tire is the same the times will be very very similar. The 15" would still come out on top though b/c of the advantage in acceleration. They all have the same grip (assuming similar tire compound), so they will both create the same cornering force, the lower profile tires will just have more favorable slip angles, resulting in slightly more precise handling in the from of sharper turn in. A competent driver would be able to make the adjustments in his timing to compensate for any rate of turn in.

And I diss the GRM article b/c they make the wrong point, it's not that the 17" wheels yielded better times, it's that the tires with the most contact patch yielded the best times. the 16" & 17" were very very close, there was only 10mm difference in tread width so it makes sense. there was 20mm difference in treadwidth between the 15" and 17". Doesn't take a genius to see why the 17" performed better in a track enviornment.

If you've ever looked at f1 cars, you'll notice that they never have sidewalls less than 40 series, and that's with a 300+mm wide tire which makes their sidewalls bigger than my 225/50/15. . .

obviously sidewall hieght is something that can be overcome with proper engineering. And today that is the case as there are more and more 15" tires with the latest in sidewall construction technology incorporated into their design. That wasn't the case when I first started getting into cars. If you wanted a stiff sidewall engineered to corner, you had to go to a 16" wheel at least. But a lot of today's 15" sidewalls are stiffer than yesterday's 16" sidewalls and just as stiff as the sidewalls of 16" tires of today.

Dunrick
04-29-2003, 07:41 AM
I still think I will get a better 60ft - just because the more contact patch I got will allow me to launch higher in the rpm's....obviously not much higher...but our car isn't a b16 - we have plenty of trq @ 3.5rpms launch to where I dont think 17" on 45's will make any difference vs 15" 50's...


I think the demonstration must be done between two ep's - I'm willing to eat my words...but even then I will still find it hard to believe until I see it....I'm stuburn like that haha:*

chunky
04-29-2003, 09:08 AM
Originally posted by Dunrick
I still think I will get a better 60ft - just because the more contact patch I got will allow me to launch higher in the rpm's....obviously not much higher...but our car isn't a b16 - we have plenty of trq @ 3.5rpms launch to where I dont think 17" on 45's will make any difference vs 15" 50's...


I think the demonstration must be done between two ep's - I'm willing to eat my words...but even then I will still find it hard to believe until I see it....I'm stuburn like that haha:*

how do you figure 17" will give you more contact patch? are your tires 235mm wide? if you have 225 mm wide tires, I can get more contact patch than you by lowering my tire psi more. what tire size are you running? 215/45/17? 205/45/17? as you know i'm running 225/50/15

i tried to illustrate it here.

Dunrick
04-29-2003, 09:13 AM
Originally posted by chunky


how do you figure 17" will give you more contact patch? are your tires 235mm wide? if you have 225 mm wide tires, I can get more contact patch than you by lowering my tire psi more. what tire size are you running? 215/45/17? 205/45/17? as you know i'm running 225/50/15

i tried to illustrate it here.

You are on 50's, I'm on 45's and 17 inches....I got more contact patch....plus how much more can you lower the psi??? like 3 lb's??? There isn't a big diff between 50's and 45's...45's and 60's there is a difference though....dont get me wrong, there is a difference, but seriously...not much at all...

Plus I dont think I got more width grip than you, I'm talking horizontal contact patch...and the little bit more you "might" be able to lower your psi isn't going to compete....

napapacoda
04-29-2003, 09:28 AM
Originally posted by chunky


i'm not hating - but like you said, 15's are for go. 17's are for lookin cool. If i wanted to afford 17" wheels, I could, but 15's perform better, and i have some extra $$ left to do other mods.

i guess tire expenses add up quickly when you go through a set of tires in a year.

oh come on, let people have their fun no matter what size they want. Wanna see what will happen when you race a M3 with 18's on it?

ssvr6
04-29-2003, 09:37 AM
I'm going to agree with Chunky on this. 15's with dropped psi will have a greater contact patch.

I drop my tire pressure to 22lbs at the track and I'm sure that's a bigger patch that the ones that 17 X 7's would provide.


Steve

chunky
04-29-2003, 09:38 AM
Originally posted by Dunrick


You are on 50's, I'm on 45's and 17 inches....I got more contact patch....plus how much more can you lower the psi??? like 3 lb's??? There isn't a big diff between 50's and 45's...45's and 60's there is a difference though....dont get me wrong, there is a difference, but seriously...not much at all...

Plus I dont think I got more width grip than you, I'm talking horizontal contact patch...and the little bit more you "might" be able to lower your psi isn't going to compete....

what size are your tires?

45 is the aspect ratio. the sidewall hieght = tread width * aspect ratio. You can't say you have more contact patch than me just b/c you have a 45 aspect ratio & 17" wheels. 205/45/17 has LESS contact patch than 225/50/17 by far. The length of the contact patch is about the same b/c hte overall diameters are about the same (616.3mm v.s. 606mm). 10mm difference in overall diameter translates into maybe 3mm longer contact patch, but i have a 20mm wider contact patch.

so for my tire size 225/50/15 the sidewall hieght is

sidewall hieght = 225mm * 50% (or .50)
sidewall hieght = 112.5mm

for a 205/45/17, the sidewall hieght is

sidewall hieght = 205mm * 45% (or .45)
sidewall hieght = 92.25

I have almost a full extra inch of sidewall, meaning i can lower the psi quite a bit more before rim damage/tire bead separation becomes an issue.

so i ask again, what size are your tires? even 215/45/17's won't have as much contact patch as 225/50/15. however, 225/40/17 does have as much contact patch, but at the strip, you can't lower the tire pressure as much, so the 15's can "get" more contact patch.

chunky
04-29-2003, 09:39 AM
Originally posted by napapacoda


oh come on, let people have their fun no matter what size they want. Wanna see what will happen when you race a M3 with 18's on it?

if they want 17's or 16's that's great. I think they look good. I'm not knocking the style at all.

but it's incorrect to say that 17 & 16" wheels can equal the performance of a 15" wheel given similar sizing.

Dunrick
04-29-2003, 07:59 PM
I have 215/45/17 tires

What I'm trying to get at, and what I dont understand is.

I have 17 " wheels w/ 45 tires....

There is like one inch wheelgap, all the way around the tire...You probably have like 2-3 inches...How would I not have more horizontal grip??? I can lower my tire pressure to 25 lb. with no problems whatsoever...You really think 22lb in a 50 tire on 15's is going to have more grip?? Yeah you got me on vertical (width) grip by a little bit.


\______/ <--- your 15" w/ 50 tires \________/ <-- 215/45/17


Say thats the tires from the side view - I know its not a good one, but still....if you were to measure my wheels (tires included) I would have about what....1.5 inches??? You really think a few more lb's you can drop out of the tires is going to give you that edge??? I say the grip > few lb.'s

I wish I didn't live so fucking far - I would really love to test this out. Cause I'm not argueing, just trying to figure shit out - There isn't enough of this on Ephatch. Cause we cant just show our timeslips and say "oh look I'm right!" there are too many things that come into play...like the obvious - elevation...how much weight redux...what kinda gas...mods (big one)...weather...

chunky
04-29-2003, 09:14 PM
Originally posted by Dunrick
I have 215/45/17 tires

What I'm trying to get at, and what I dont understand is.

I have 17 " wheels w/ 45 tires....

There is like one inch wheelgap, all the way around the tire...You probably have like 2-3 inches...How would I not have more horizontal grip??? I can lower my tire pressure to 25 lb. with no problems whatsoever...You really think 22lb in a 50 tire on 15's is going to have more grip?? Yeah you got me on vertical (width) grip by a little bit.


\______/ <--- your 15" w/ 50 tires \________/ <-- 215/45/17


Say thats the tires from the side view - I know its not a good one, but still....if you were to measure my wheels (tires included) I would have about what....1.5 inches??? You really think a few more lb's you can drop out of the tires is going to give you that edge??? I say the grip > few lb.'s

I wish I didn't live so fucking far - I would really love to test this out. Cause I'm not argueing, just trying to figure shit out - There isn't enough of this on Ephatch. Cause we cant just show our timeslips and say "oh look I'm right!" there are too many things that come into play...like the obvious - elevation...how much weight redux...what kinda gas...mods (big one)...weather...

your drawing is incorrect. the LENGTH of the contact patch is determined by the overall diameter of the wheel/tire and tire pressure. your overall diameter is 625.3mm. Stock diameter is 615mm, and 225/50/15 is 606mm. You have 19.3mm (3/4") more overall diameter. that translates into a contact patch that is 10mm longer assuming equal tire pressures. Not a huge increase, but still an increase. I have 10mm more width than your 215's. Your wheel gap should only be 3/4" less than mine btw.

But the real deal-breaker is the fact that i can lower my tire psi more. You can probably run 22psi at the lowest. With my tires, I can drop them down to 20 or lower and still have enough sidewall to protect the rim. But what you have to understand is, when I drop my tires to 20psi, my sidewalls have collapsed a lot more, which translates into a longer contact patch. I guess i'd have to show you for it to make sense.

but look at it this way. say the minimum sidewall thickness that you need to have adequate rim protection is 2", that's 50.8mm. Your sidewall is 96.75mm tall, so you can lose at most 45.95mm of sidewall, or about 2". My sidewalls are 112.5mm tall, so i can lose at most 61.7mm of sidewall or about 2.5". Now with some simple geometry, you can figure out what the max contact patch length you can get is.

for you, overall diameter of 625.3, 2" of sidewall deflation = 342mm long contact patch.

for me, overall diameter of 606mm, 2.5" of sidewall deflation = 371mm long contact patch. that's technically a contact patch that is 1.14" longer than what you could achive by lowering tire pressure.

If you want me to post the math, I will, it's just a simple formula for finding the length of a chord.

so i CAN get a longer contact patch b/c i CAN lose more sidewall than you to deflation. That gives me a longer contact patch, and on top of that, i have a wider one. Still think you'll get better 60fts?

Also, you've effectively given yourself longer gearing by increasing the overall wheel/tire diameter. That's gonna hurt your 60ft times v.s. me. And keep in mind you're always going slightly faster than what the speedo says, probably by 2-3mph at the most. but just keep that in mind when you're crusing around speed traps.

Dunrick
04-29-2003, 09:31 PM
Originally posted by chunky


your drawing is incorrect. the LENGTH of the contact patch is determined by the overall diameter of the wheel/tire and tire pressure. your overall diameter is 625.3mm. Stock diameter is 615mm, and 225/50/15 is 606mm. You have 19.3mm (3/4") more overall diameter. that translates into a contact patch that is 10mm longer assuming equal tire pressures. Not a huge increase, but still an increase. I have 10mm more width than your 215's. Your wheel gap should only be 3/4" less than mine btw.

But the real deal-breaker is the fact that i can lower my tire psi more. You can probably run 22psi at the lowest. With my tires, I can drop them down to 20 or lower and still have enough sidewall to protect the rim. But what you have to understand is, when I drop my tires to 20psi, my sidewalls have collapsed a lot more, which translates into a longer contact patch. I guess i'd have to show you for it to make sense.

but look at it this way. say the minimum sidewall thickness that you need to have adequate rim protection is 2", that's 50.8mm. Your sidewall is 96.75mm tall, so you can lose at most 45.95mm of sidewall, or about 2". My sidewalls are 112.5mm tall, so i can lose at most 61.7mm of sidewall or about 2.5". Now with some simple geometry, you can figure out what the max contact patch length you can get is.

for you, overall diameter of 625.3, 2" of sidewall deflation = 342mm long contact patch.

for me, overall diameter of 606mm, 2.5" of sidewall deflation = 371mm long contact patch. that's technically a contact patch that is 1.14" longer than what you could achive by lowering tire pressure.

If you want me to post the math, I will, it's just a simple formula for finding the length of a chord.

so i CAN get a longer contact patch b/c i CAN lose more sidewall than you to deflation. That gives me a longer contact patch, and on top of that, i have a wider one. Still think you'll get better 60fts?

Also, you've effectively given yourself longer gearing by increasing the overall wheel/tire diameter. That's gonna hurt your 60ft times v.s. me. And keep in mind you're always going slightly faster than what the speedo says, probably by 2-3mph at the most. but just keep that in mind when you're crusing around speed traps.


When I placed my current wheels (with tires) next to the stock setup 190/60/15 it was about .5 inches taller...The difference between a 50 and 60 sidewall height tire is more than an inch is it not?

chunky
04-29-2003, 09:42 PM
Originally posted by Dunrick



When I placed my current wheels (with tires) next to the stock setup 190/60/15 it was about .5 inches taller...The difference between a 50 and 60 sidewall height tire is more than an inch is it not?

when figuring overall wheel diameter, you add the rim diameter to the sidewall hieght times two.

so 225/50/15 translates into

225 * .50 * 2 + 15 * 25.4 = 606mm

195/60/15 translates into

195 * .60 * 2 + 15 * 25.4 = 615mm

and 215/45/17 translates into

215 * .45 * 2 + 17 * 25.4 = 625.3mm

so your tires to stock is 10.3mm difference, or about .4" from stock. my tire is 9mm difference from stock, or about 3.5". Add those two together and you get .75" or 3/4"

now if i had kept the tread width the same, and gone 195/50/15, it would have been

195 * .50 * 2 + 15 * 25.4 = 576mm

which is about 1.5" smaller in diameter than stock.


But i have 225 mm wide tires. my 50 series sidewall is the same hieght as the stock sidewall more or less. Remember, the aspect ratio is just that, it's the sidewall hieght expressed as a percentage of treadwidth. 50 just means the sidewall hieght is equal to 50% of the treadwidth.

Dunrick
04-29-2003, 10:00 PM
If your 50 series has as much sidewall as the 60 (stock) then overall you do have more contact patch....shit dude....you get all einstein and what not - breaking out mathmatical equations...haha I dig that shit

rock on!

chunky
04-29-2003, 10:52 PM
Originally posted by Dunrick
If your 50 series has as much sidewall as the 60 (stock) then overall you do have more contact patch....shit dude....you get all einstein and what not - breaking out mathmatical equations...haha I dig that shit

rock on!

haha. not really einstien, but math helps break down a lot of language & comprehension barriers. It finally got my point across in a way that made sense to you!

And it also helps figure stuff out when you don't have the luxury of just experimenting with the objects in question in front of you.

mental
04-30-2003, 08:12 AM
OKAY OKAY... I MEAN REALLY THOUGH HERE IS MY QUESTION...


HUH??????? I AM SOOOOOOO CONFUSED!!!!!

chunky
04-30-2003, 07:38 PM
Originally posted by mental
OKAY OKAY... I MEAN REALLY THOUGH HERE IS MY QUESTION...


HUH??????? I AM SOOOOOOO CONFUSED!!!!!

about what?

put it in question form and i'll do my best to answer.

02SilverSiHB
04-30-2003, 07:55 PM
Originally posted by chunky


about what?

put it in question form and i'll do my best to answer.
I'm starting to lean more towards what you are saying. I thought about it for a while. I have to say, it does seem that 15's would be better, as long as you have a wide enough tire...which 225 is definitely wide for us. When someone asked, then why are the high performance cars using bigger wheels...well they have usually way wider than 225, so 15's wouldn't be pratical for that size tire, that I know of.

Also, it's proven time and time again, that 15's will give you less rotational mass. So, lightweight 15's with wide tires seems better than more rotational mass with 17's.

That less rotational mass will help when cornering, I would think.

chunky
05-01-2003, 07:23 AM
Originally posted by 02SilverSiHB

I'm starting to lean more towards what you are saying. I thought about it for a while. I have to say, it does seem that 15's would be better, as long as you have a wide enough tire...which 225 is definitely wide for us. When someone asked, then why are the high performance cars using bigger wheels...well they have usually way wider than 225, so 15's wouldn't be pratical for that size tire, that I know of.

Also, it's proven time and time again, that 15's will give you less rotational mass. So, lightweight 15's with wide tires seems better than more rotational mass with 17's.

That less rotational mass will help when cornering, I would think.

lowering rotational mass helps during acceleration. Greater rotational mass is only good for one thing - slightly better gas mileage on the highway, b/c it takes less energy to keep them going as they have a lot more inertia than wheels with less rotational mass.

However, lowering unsprung weight helps during cornering. Reducing unsprung weight pays off big on the track.

By getting light wheels, you kill two birds with one stone.

Dunrick
05-01-2003, 08:12 AM
With all this said, whats the point of low profile tires and larger wheels? I know its not just looks

Yeah they are better for acceleration and gas mileage...

But you guys are making them to be too good - I just dont see how 15" wheels on 50 series tires are the king...

there is a reason for low profile tires and 16/17" wheels

I know they handle better.....You can get them just as light as 15"...maybe a few lb's diff....but thats it

anjapower
05-01-2003, 08:15 AM
NO. Smaller is better. Bigger wheels are only needed to clear bigger brakes. That's it, that's all man, it's just fo decorashun.

chunky
05-01-2003, 09:58 AM
Originally posted by Dunrick
With all this said, whats the point of low profile tires and larger wheels? I know its not just looks

Yeah they are better for acceleration and gas mileage...

But you guys are making them to be too good - I just dont see how 15" wheels on 50 series tires are the king...

there is a reason for low profile tires and 16/17" wheels

I know they handle better.....You can get them just as light as 15"...maybe a few lb's diff....but thats it

when you need a bigger overall wheel/tire diameter, then you'll need bigger wheels.

But for the size wheel that the si uses, a 15" is fine. The RSX gets a 16" b/c it's gearing was planned around a wheel with a larger overall wheel/tire diameter in mind. Corvettes & vipers get bigger wheels b/c they need a much larger overall wheel/tire diameter.

But a corvette z06 with a 295/35/18 tire has a sidewall hieght of 103.25 mm v.s. the 112.5mm sidewal hieght of my 225/50/15. There is only 9.25mm difference in sidewall hieght, even though the corvette has 35 profile tires on 18" wheels.

So while it SEEMS like you have to go to a lower profile tire/larger rim, it's not always the case. The actual sidewall hieght is a much more important factor, and with a 15" tire, you can get a sidewall that is short enough to where it can be made very very stiff. Going to a 16" or 17" isn't going to get you a sidewall that is that much stiffer.

tony speed
05-31-2003, 09:41 PM
Originally posted by chunky
18's for show, 15's for go.

anyone buying 17's or 16's is just confused, or wants the show, but can't afford 18's.



2 words.....brake clearance
4 words.....more width==better handling
final word.....forged 17s 12 lbs...stock 20 lbs

mhx
05-31-2003, 11:05 PM
17'in rims would help autox people correct?

I mean you can get a Wider tire and put more rubber to the ground getting your better traction?

also could help your stop faster since there is more rubber to the ground.

what yall think??


chunky makes a good point to about the tires being able to flex
more if the height of the tire is taller

small sidewalls = very very cauious driver not to HIT ANYTHING... been there done that!!

glw
06-01-2003, 01:07 AM
Originally posted by mhx
17'in rims would help autox people correct?

I mean you can get a Wider tire and put more rubber to the ground getting your better traction?

also could help your stop faster since there is more rubber to the ground.

what yall think??


chunky makes a good point to about the tires being able to flex
more if the height of the tire is taller

small sidewalls = very very cauious driver not to HIT ANYTHING... been there done that!! its all about rotational inertia... there is an article on it in the latest grassroot motorsport magazine. i need to read the article a couple more times but here is a summary..

good=less unsprung weight (lighter wheels and tires, brakes, etc.)

less weight usally equals smaller wheels, but you may be able to find some forged 17" much lighter than some cast 15" wheels. my understanding would be that the lighter forged 17" wheels would be the best choice vs. the heavy cast 15" (all else equal).

i've been eyeballing the velox progear wheels --- 11.5 lbs for some good looking 17" wheels... cost about $350 each though.

mental
06-01-2003, 12:12 PM
for AUTO X i would go with 16s on our cars and for the strip i would go with a really lite set of 15s and for the track i would highly recommend 17s or 18s and by track i mean a motorsports track with real corners and corners you can apex! not a parkinglot which would be auto x... lol...but yeah for auto X you really want good acceleration and alot of break clearence which 16s allow for and for the strip you need 15s with like a 225/45/15 for a lot of grip on the ground and not a whole lot of rim for the motor to spin, and one last time for the track 17s and 18s help you to carry your momentum through turns and put a great deal of tread to the ground for turning grip!

staticflo
06-01-2003, 12:25 PM
personally i think 17's are the perfect size for the ep as far as looks 18 i feel look a little to big but with the right suspension work im sure they can look sweet anything less then 17 is "fuken gay" and low profile tires are cool big tires with 17 or 18 inch rims would look stupid..