pearlrx7

I have 18's on my fc convertible. I personally love the way they look even though they do sacrifice handling and performance. I didn't have have the money to buy the performance rims I would like to have on my fc but I was given these 18" chrome rims that look dang good on the car, so it was either them or stock. One question though, lets say I was going to race someone... would i be smart to throw the stock rims on there... how much would it affect performance. I had my n/a pulled and did a full T2 swap. I have had the big rims on there since the swap and don't know how much quicker it would be with the light wieght 15's back on it. The good thing about the heavy rims is that they keep the car on the ground pretty good through turns, and when i drive it hard they dont spin too much b/w 1 & 2, and 2 & 3.

Jigsaw

I'm sorry, but those rims look terrible on that car and I don't think those rims would make any car look good.

V8slayer

+1

jackhild59

iTrader: (7)

To answer your question, those 18's are really big and heavy. The car would be much quicker if you go back to oem because the unsprung weight and the rotational inertia will be much lower. Those oem vert wheels are really light. Think quick response.

If you want, put some 215/50/15 tires on the oems. Your choice of brand. The question of brand will start a whole 'nother thread of opinions.

cool_as_crap

yes, put the stockers back on. they are light, they are your friend.
ideally you would want wider rims for cornering and such, but you dont want more rotating mass that will slow you down.

BLKTOPTRVL

Yes, those wheels probably weigh at least twice as much as the stockers (~28 vs. ~13 lbs).

That is going to kill performance and handling...

pearlrx7

well i appreciate the input... i thought they looked decent, or atleast better than the stockers. and yes they weigh a freaking buttload. when i put them on i was like dayyyumm! took all i had to pick them up and line them up at the same time. i'll prolly throw the stockers back on there when i get a chance and see what it feels like. anybody like the Borbet type FS rims... is 16x7 or 17x7 ideal?

BLKTOPTRVL

Even though I can't put words into anyone's mouth, I believe most of the people here prefer RX7's that are clean - without a lot of add-on body glitz. That is certainly how I feel.

But you are the one who has to look at / drive the car, and if you like those wheels. Then keep them.

I have a set of Moda wheels on my vert. They weigh in at 25 lbs. or so and they absolutely ruin the performance of the car.

I am now looking for wheels that will get me closer to the original weight again.

Black91n/a

Lighter is better, so is smaller. A lighter and/or smaller diameter wheel (assuming it's no heavier) will have a smaller moment of inertia. The moment of inertia is analagous to mass. It takes more energy to accelerate a wheel with a higher moment of inertia. This means that the smaller and/or lighter wheel will help the car to accelerate and brake more quickly. Ligher is better for handling too. Heavy wheels don't help the tires stay in contact with the road, lighter wheels and tires do. That is because the suspension's job isn't to keep the car in the air, it's to keep the wheels on the ground. When you hit a bump, the wheel and tire are thrust into the air, if the wheel and tire are heavier, it'll take more energy to stop them and move them back down into contact with the road, meaning that it takes longer, and you loose grip because the wheel spends less time on the road when bumps are encountered. The tire doesn't have to come off the road for the car to be affected, the tire will loose pressure against the road and grip will diminish.

Lighter wheels are ALWAYS better for performance, smaller wheels are ALMOST ALWAYS better. The problem with smaller wheels is usually tire selection, as nowadays getting good sized, good tires in 15's and 16's is getting harder, man y good tires are only available in 17's and above, or they've only got a few sizes below 17's. For grip, wider is better, but it comes at a price of increased weight and moment of inertia.

When shopping for performance wheels, get the lightest, widest ones you can afford. Sacrifice weight for width if you have to.

The stock vert wheels will be faster, much faster. I also don't like those wheels, too big and flashy for my tastes, but if you like them then that's good, just don't expect to get many compliments on them on this forum.

BTW, street racing is BAD! Don't do it! I'm hoping you mean sanctionned racing on a closed course, in which case, have fun, don't worry too much about winning, just have fun and improve your driving.

deagle50ae

rule of thumb: removing 1lb or unsprung rotational mass is equal to removing 5lbs of sprung non rotational mass. (many articles suggest up to 8lbs comparison weight for a 1lb unsprung reduction)

if each of those weighs 13lbs more than the stock wheels (and by the looks of it, those suckers are HEAVY, chrome = BAD!), that's 52 extra lbs of sprung weight. which is about equal to 260 sprung lbs. your handling and acceleration will greatly suffer. and i'm willing to bet throwing your stockers back on would easily knock 1/10th off your 1/4 times. (actually, if you go by the 100lbs = 1/10th then you're knocking off 1/4 of a second... but that seems too much to me)

in short... those wheels are about the worst thing you could do to your car for performance aside from maybe pouring sugar in your gas tank.

deagle50ae

read these if youve got some time.

http://hondaswap.com/general-tech-ar...art-1-a-29057/

http://hondaswap.com/general-tech-ar...art-2-a-29058/

Funkspectrum

iTrader: (5)

get yourself some clean 17" BBS meshies...

some similar to the stockers...

deagle50ae

I just painted my stockers. I can't be happier with them. best $14 I could have ever spent (7 for gunmetal, 7 for clearcoat 2coats of each)

anewconvert

iTrader: (1)

Another thing not mentioned is that by changing the diameter of the tires/wheel combo you are effectively shortening the final drive ratio. Doing this lets the engine rev freer. In some cases, N/A particularly, this is a good thing.

Larger wheel/tires can allow the engine to build more boost in lower gears by keeping it in the powerband longer. This keeps the engine from getting ahead of the turbo and forcing you to shift before you have full boost. Not such a big deal ona stock turbo, but larger turbos it could help.


BC

pearlrx7

deagle50ae: read these if youve got some time.

http://hondaswap.com/general-tech-a...part-1-a-29057/

http://hondaswap.com/general-tech-a...part-2-a-29058/

Thanks, that really helped alot.

Wow thanks for everyone not beating up on me about the big rims, like i said, i like them and they were given to me.

I never realized though how much they really do affect performance.

As soon as i can get some decent tires to put on my stockers i'll be sure to put them back on... i might have to remove the wing though... its a little to big to be on there with the stock rims. it would look too funny...

diagoro

this is insane, do you people honestly think a huge 55 series minivan sidewall tire handles better than a good 17 or 18 inch tire? there is a reason every sports car in the world is not rollin on 14s these days, and its not just cause they arent "flashy" enough (which is a such an old man argument, it hurts my head).

BLKTOPTRVL

The argument is not about the size of sidewalls. The point is the lighter weight wheels are better. Period.

diagoro

right, but it was pretty clearly stated that smaller wheels WILL handle better, which is a load of horse dick. sure lighter wheels are great, but there is a point when you have to balance out a good size with a light wieght.

aznpoopy

this is only true because you run into practical problems with small and wide wheels... like the fact that very few companies make them, good tire sizes are hard to come by, and people try to keep oem overall diameter so their speedo reads mostly accurate...

in an ideal world, the best wheel would be the one with the smallest diameter and the widest width you could cram under your fenders and over your brakes, and clear all your suspension junk.

Nihilanthic

Smaller diameter can often matter more than the weight of the rim in regards to rotational inertia, just FYI... PMOI goes up with the square of the distance.

That said, light rims, no bigger than what is required to clear your brakes (or to find tires of the width you need) are ideal. Bigger is only better if you NEED it to clear big *** brakes, and there are wide *** tires available for smaller rim sizes - you just have to step up to real rubber.

Black91n/a

Cars handle just fine on taller sidewall tires. Look at the height of the sidewalls on F1 cars., they handle pretty good. In fact, with a taller sidewall you don't need as much camber control to keep the tread flat on the ground. On cars with soft suspensions and poor camber curves (most cars) you'll often times make the car handle and grip worse when going to shorter sidewalls because part of the tread will have lifted off the ground, or will have at least become unweighted.

With lighter wheels the suspension is more easlily able to handle the forces generated by the wheel and tire moving up and down, which makes for a better handling car. It's a lot easier to get a light wheel if it's smaller, therefore in general, smaller wheels handle better. Shorter sidewalls generally give better steering feel and have more immediate reactions, but that doesn't mean they handle better or grip better.

Sports cars have big wheels because it's the cool thing to do, just like big brakes are cool, so more and more cars have large brakes, that require the large wheels to fit over them. More people are influenced in their buying decisions by style and perceived performance than by actual performance and handling.

pearlrx7

does anyone know exactly how much the stock 1990 convertible bbs rims weigh?

7 freak

+1 i prefer the factory BBS on it,but is his car so everybody has different taste!

Black91n/a

The 2nd gen FAQ sticky says vert wheels are 11.0lbs, which is very light, most aftermarket wheels in that size weigh more.

pearlrx7

wow, i knew by picking them up they were light but not that light.
thanks