Thats a cool tool and really does make much more sence of waht you were saying.

SuDZ

 

first of all you are completely right about the weight.. the wheel diameter is not the issue since they are all about the same if you choose the right tires. The weight of the rim does effect speed, I was a phsyics major and had classes where we discussed this EXACT THING. It is harder to spin a rope w/ a 20 pound weight on the end, harder then it is to spin a w/ 15pounds on the end.. or even if you want to take that to another level, a 15" rim/tire combo with the EXACT weight of a 18" rim/tire combo, would have a SLIGHTLY higher topspeed.. the reason is, the weight is further from the center of the wheel ona 18" rim (I KNOW THE OVERALL DIAMETER IS THE SAME!!!) and is harder to spin up, so at the VERY top end where the engine balances with air friction and you are speed-limited, the engine will not be able to push the rims to the very highest speed as with the 15"'s

think about that -

str8ridin, where are you runnin topspeed tests? I am on exit 55 of I69 outside of indy (muncie)... you should roll up here sometime or somethin haha..

 

so you are agreeing with me that a 235/40 - 18 tire and 215/55 – 16 tire will yeild the same top speed? right?



what are you talking about? i am not saying weight has nothing to do with top speed.. i am saying that size or rim does not depending on weight of both rims and tires being the same..

the original argument was that 18 inch rims will be slower at high speeds than a 15 or 16 inch rims would.. you decided to argue with me on this factor.. my point was.. size of rims do not matter because .. if you have the right tire size at 18 inches to match the tire size at 16 .. then the top speed is NOT affected..

then you wanted to argue about weight factor.. again i said 18 inch wheels would not matter at high speeds vs 16 inch wheels because some 18 inch wheels weigh less than 16 inch wheels.. so therefore.. the lighter 18 inch wheels would yeild a higher top speed than the 16 inch wheels.. so therefore the theory of 18 inch wheels being slower at top speeds than 16 inch wheels is thrown out the window..

Please stick to the original argument.. which is 18 inch wheels are slower than 16 inch wheels.. i argued that point.. at which you lost and you decided to change the subject.. please stay on topic..

Thank you

 

read my post from right before yours

 

The original point which you did not understand:

you: "and it doesn't matter at high speeds the size of the wheel.. that rotational mass BS doesn't mean anything.. "

me: "In most cases, larger rims have a higher rotational mass, meaning it takes more energy to rotate than a smaller rim, thus yeilding a slower accleration time and a lower top speed. Also, Larger rims have a greater contact patch which adds greater rolling resistance, which decreses top speed...for ex. 215 width vs. a 235 width tire."

So, IN MOST CASES, larger rims slow you down because of rotaional mass/inertia. I suggest looking that up in a physics book before you continue to argue.

Regards

 

Phew...a physics major! Thanks!

Anyhoo, I dirve back to Bloomington on 74 from Indy and there is a stretch of newly paved straight road that I can let her out on. But yeah, I'll hit you up in Indy next time I'm there which is every damn weekend (the lenghts I go through for some booty). You still have all your stuff on your car?

 

couple points i am picking up here.. you are Assuming that being that a rim is 18 inches vs a 15 inch wheel that most 18 inch rims are going to be heavier than 15 inch rims.. have you ever weighed GXE Steel Rims? lets just say that they are heavier than alot of 18 inch rims out there.. i have both 15 inch steelies and 18 inch 5Zigen GT8's.. the GT8's are lighter than my 15 inch steelies..

now you are trying to throw into the equation the width of the tire.. man.. i can't argue with you... you try to take 5 differnt routes to prove your point that has no relivance to the original question.. let me type it again.

are 18 inch wheels slower at high speeds than 15/16 inch rims

 

hehe, hopefully sprint will read it..

cool cool, yeah I am still modded.. I was in a hit and run about a month ago, just got my car back saturday, and still waiting on 1 rim (got screwed in the wreck) plus my paint is screwed, so it has to be re-sanded and re-painted but ypiipe comes soon, and so does the 300zx TT

booty = worth the drive

 

I think you're both right. I think Sprints point is that the change in top speed is in-significantly smaller, but the smaller wheeled cars will be a wee-bit faster. Not much, though.


As for your suggestion that top speed will be higher with taller tires, well, it should be higher but probably won't be. Why? Because the higher top speed means higher aero drag, which means higher hp is needed to overcome that drag. Taller wheelers only change the gear ratio thru your final drive. Your VQ motor has not changed at all.



DW

 

DAMNIT , I have to quote myself! read my post from page 3.. just incase you dont want to go to it, here it is...

READ THE WHOLE THING!!

"first of all you are completely right about the weight.. the wheel diameter is not the issue since they are all about the same if you choose the right tires. The weight of the rim does effect speed, I was a phsyics major and had classes where we discussed this EXACT THING. It is harder to spin a rope w/ a 20 pound weight on the end, harder then it is to spin a w/ 15pounds on the end.. or even if you want to take that to another level, a 15" rim/tire combo with the EXACT weight of a 18" rim/tire combo, would have a SLIGHTLY higher topspeed.. the reason is, the weight is further from the center of the wheel ona 18" rim (I KNOW THE OVERALL DIAMETER IS THE SAME!!!) and is harder to spin up, so at the VERY top end where the engine balances with air friction and you are speed-limited, the engine will not be able to push the rims to the very highest speed as with the 15"'s

think about that - "

 

WRONG!!!!


its harder to accellerate a 18 wheel over a 15 inch wheel.. but once they are at high speeds.. that gets thrown out the window..

 

I agree with the fact that once you reach a top speed you can maintain it nomatter what the weight, 100lb rims.. cause it is spinning weight. but in order to spin up more weight requires more engine power, which means there will be a slight decrease in top speed w/ heavier rims b/c the engine wont have power to spin them up any further.

 

jeez, go take a physics class and ask the prof.

 

Dude! It's about the DISTRIBUTION of weight! Your 18's can be lighter than your 15's, but, as most rims are, more of the rim's weight is distributed on the outside of the rim to maintain structural intergrety even though the rim may be lighter than a smaller one. So Read hlh0501's post if you lost your physics book.

p.s. I know you're a smart guy and I don't mean to be condecending when I talk about your physics book. sorry if I come off rude.

 

Yeah, I edite my post. 17' rims will be insginificantly slower in top speed than 15s, but they will be slower. OK ,OK.

DW

 

distribution of weight, thankyou str8ridin, that is the word that i was strugglin for in my post

 

whatever... whatever you all say.. arguing this is pointless

 

Accelerating to top speed will be slower with a bigger rim, but the top speed should be the same.

 

watch out.. the physics majors have the floor

 

Yeah, I agree, but the physics guys are being detailed about it. It'll be like 1 mph slower because of what they said earlier. I've always neglected that small difference, given that a POP, Y, or CAI will more than make up for that very very small loss.


So, top speed will be the same! . . . . .approximately

DW

 

Just one question, though, what would the difference be in the top speed of 15's vs 18's.. 1 mph, 5mph, 10mph.. I've gone 143 with 15" and 142 with 17's Chrome both on different days and of course environmental differences per day, what gas I was using and other day to day variations could be a factor but lets say in a vacuum what would be the difference?

 

Who knows anymore...

 

By the way str8ridin, your car is gorgeous. Those wheels are to die for, too

DW

 

Thanks man!

 

yes he is wrong.. but his car still looks good

 

since you dropped the compliment, I'll let that comment slide....

 

Yes, it would be a verry small difference.. I could do the stupid math and figure it out, but im not going to waste an hour of my time to give you an exact example, but we are talking SMALL difference, maybe 1mph ? yes, environmental variables (octane, air temp, etc) could make as big of a difference, so its not like you are going to notice a big dif btwn rim sizes of top speed, but there is a difference.

 

you guys are trying to argue that wheel size x may or may not return a higher top speed than wheel size y. that is an impossible position to argue without defining the weights and distrubution of that weight on the wheels.

the facts are:

-assuming everything else is equal, a heavier wheel will return a lower top speed than a lighter wheel

-assuming everything else is equal, a wheel that has more weight distributed to the outside will be slower than one with less weight distributed to the outside.

-given the fact that wheel/tire weights don't vary dramaticly, performance losses will be minimal but measureable.

based on those facts, in some cases 18s will be faster than 15s, and in some cases 15s will be faster than an 18s

 

Trying to figure this all out will make your head explode.

SuDZ

 

Cool, thanks..

 

Medic: so if my speedo is pinned and the tachometer started jumping around, i guess id be doin like 141.7mph right? lol Im glad you know EXACTLY how fast your top speed is, unlike me i could give two $hits. But as long as i bring home the trophy at the end of a show thats all that matters to me!
But i guess you cant say much in that department now can you?

 

Find me a pin at 140. The speedo continues on past the numbers. Next stupid question please...

 

yes sir you are correct

 

still cant take home a trophy!!

 

Obviously, you haven't seen my car for a while. BTW, I'll take a fast car over a looker anyday. Anyday.




Oh, and having mom make you a 'special star' for shiniest intake manifold doesn't count as a trophy.

 

i still get a sticker everyday im good that i put on the frig from my mom, so!

oh and BTW 2 1st place trophies, 1 Best of Show, and one Second place trophy within 2months dont come from just my intake manifold jack-a$$!!

 

My REDONE (yes I had an accident so the car has been redone) 15.2 second 1/4 mile car will still rip yours a new ***.

BTW, was this a Hogan sponsored event? Or did Freddy sponsor it?

 

http://www.bags533.com/loop%20part%202%20again.wmv

Video: 4:10 .. reason #1 WHY BAGS OWNS YOU ALL

 

English Town, Atco and a bunch of Local NY shows my friend!!

im done here!
lates,
Ant

 

Hmm, I guess making a statement and having it proved wrong means you should try to change the subject. Nice try anyways.