Kate

Hi! I'm new, and pretty much entirely incompetent about cars.

I have a friend who's helping me reassemble my car (I bought it for next to nothing, some assembly required) and he wanted me to ask about tire upgrades. He has visions for my car that involving lowering it and putting on 14 or 15 inch tires. It's an 82, if that makes a difference.

I tried searching for "tire upgrade" which really didn't help. Something specific to tell my friend would be awesome, but even a push in the right direction would be great.

j_tso

iTrader: (2)

If it still has the wheels that came with the car, they are 13" and won't be able to hold larger tires, so your selection will be limited. Otherwise, you're gonna be looking to get new wheels. I suggest going to a tire shop, and asking for a selection, and if you are going for wheels, ask for ones with a 4x110 bolt pattern.

MosesX605

The best upgrade is a wide 13, IMHO.

Something in a 13x7 would be good. If you really want plus-sized wheels, a 15x7 works well, but are getting harder and harder to find. I wouldn't go bigger than 15 or 16 inch diameter, it begins to look a little silly.

Manntis

I've got 16" on mine and it looks very aggressive - though mine's a GSL-SE which has the far more common 114.3mm (4.5") bolt pattern.

sixstring4as

iTrader: (3)

michelin makes a great 205/50zr15 Pilot sport cup that is about the stickiest dot approved (department of Transportation) tire you can get in that size, if you are looking for more longevity rather than traction there are a wide range of 13 and 14 inch tires out there. That is what I would recommend. As for wheels almost all Hondas are 4x100 and we know how many aftermarket parst are around for them so the wheels should be pretty easy to find. just make sure that the backspacing and offset will fit without rubbing. Most tire shops will have a conversion that will tell you all the information you need to make the right tire fit.

Manntis

How does 4 x 100 help people with RX-7s, which take 4 x 110 or 4 x 114.3?

Oh, I forgot to post earlier: I'm running 255/55 R16 Pirelli P700s

Kate

Wow you guys are quick.

So then if there are two (or three?) different bolt configurations, how do I know which one my car has?

And if I can, apparently by some miracle, find a 15" wheel that will fit on my car, how much does it mess up the speedometer?

And, for a complete girl question, what difference do the bigger tires make anyway? My friend managed to convince me solely on looks, but I'm assuming, maybe falsely, that there is some performance aspect to it as well.

Is that you beside the car Manntis? Aggressive is a good description of that stance as much as the tires

1badFB

iTrader: (1)

Its 4X110, only 84-85 GSL-SE models had the 4X114.3 bolt pattern.

Manntis

Yup, it's me.

mar3

iTrader: (8)

His favorite DoO pic...

Manntis

Huh?

MosesX605

I think mar3 is referring to the 'total package,' as it were.

XLR8

iTrader: (52)

I would focus on reliability mods and general maintenance first.
I am almost positive that there are a few things that would help your cars dependability and drivability more then "lowering it" and "bigger wheels and tires"

There is an FAQ in this section. It will get you started on alot of the questions you will have about Rx7's. Start learning as much as possible. You may figure out that your friend has different plans then you will have for your car.

Good luck and welcome!

ray green

iTrader: (14)

Yes I would put a good set of stock tires on your stock wheels and give the car a chance to be as it was designed, which really is pretty good. Thenput your money and time into "reliability mods and general maintenance".

One warning about lowering the car, you will scrape just about anything in the road that isn't flat, the car is already pretty low in the stock configuration.

Have fun with the new project!

Manntis

Me, I like slightly larger, tasteful rims. It really updates the look of the car. if you're going to buy new tyres anyhow, now is the perfect time to upgrade the rims.

I spotted a typo in my earlier post - they're P7000s, not P700s.

mar3

iTrader: (8)

Yep, there is a history on how that pic first showed up for the Forum's collective conscious. We only had a head pic of him for the longest time...

Kouryou

If it is a 1982 car it has the 4 x 110 bolt pattern

There are some nice 15 x 7 Rewinds and I think Panasport makes 15 x 7 that will fit the 4x110.

However, think what you want the car to do - if it is just for looks then you can pretty much get away with anything

Remember though...

A 15" wheel and tire will weigh more than a 13" wheel and tire and therefore make your car accelerate slower because there is more rolling resistance and weight to get moving. Since our RX-7s don't have a lot of torque (pulling power) in stock configuration to begin with, this can substantially affect the performance of the car.

This is why most autocrossers and amateur racers opt to go with a wide 13" rim - 13 x 8 or so and suitable tires.

Bigger tires don't make any difference - wider tires do. But that is not the only thing that affects the performance of a tire and how it affects your car.

Here is a basic overview of tires and what those collection of numbers on the sidewall mean.

When you see a tire size like 205/60HR13...

205 is a measurement across the tread of the tire from sidewall to sidewall in millimeters (mm). So a 205/60HR13 is 205mm wide. Not all 205's are the same size, some are larger than others depending on manufacturer and construction of the tire. This gives you an idea of how big the contact patch of the tire will be - in other words, how much of the tire is in contact with the asphalt/pavement.

60 is the aspect ratio of the tire - so a 205/60HR13 has a sidewall that is 60% of the width of the tread. The lower the aspect ratio of the tire, the stiffer the sidewall will be and therefore not likely to fold or roll as the tire is turned. However, the lower you go in aspect ratio, the harsher the ride will be as tires often serve as "shock absorbers" for bumps, pot holes, and other nusances of driving before reaching the actual shock absorbers or struts.

HR is the speed rating of the tire. A HR rated tire will handle speeds up to 130 mph. Why does that matter, well, it also gives you an idea how well the tire will handle heat buildup during hard driving.

13 is the rim size that the tire will fit.

Tread design is another thing to consider.

There are some tread designs that optimize driving in snow - those are easy to pick out because they have large chunky treads, a lot of siping (siping is a cut in the block to help it claw its way through snow and mud and other gunk), and a tread compound that is soft even in colder weather. However, these tires suck to drive in because the tread often wanders and wobbles when pushed hard because that is what they are supposed to do.

The other side of the table is the "slick" - on slicks there is no tread what so ever and grip on the road is maximized because there are no voids in the tread since there really is no tread. However, since there are no voids, water can't escape from the tire and life and driving become very interesting when it rains, and positively entertainingly dangerous when it snows.

Most tires comprimise somewhere between these two - and with each manufacturer you will find a difference interpretation of what this comprimise is made up of, and with each model, an manufacturer tries to address different versions of this comprimise.

Then there is tire compound.

Tire compound affects how a tire handles and performs - tire compound is the mix of rubber and other neato chemicals used to create the tire. Some tire compounds are harder and therefore get better wear and gas mileage but don't handle very well, while others are softer and wear out quicker, reduce gas mileage but handle great, and then there are others which are a comprimise between the two (most fall into the comprimise category).

Remember that tires are the only thing in contact with the road (hopefully) and
therefore have one of the biggest influences on how your car handles and drives.

When you are considering a performance upgrade (not maintenance needs), the first one you should make is tires because it will affect the car that much and you will be able to feel the difference. If you spend $500 on a trick suspension kit from Racing Beat and keep the crappy things resembling round tires then you won't be able to feel how the springs, struts, and shocks are working because the tires are crap.

There was an option in LE cars for a 14" mesh wheel that looks very nice on our cars and they are available (if you know where to look and whom to ask) - they will usually run between $50 and $75 a wheel depending on condition.

However, as everyone else has said in here, take care of the boring wear items first - like tie rods, idler arms, pitman arms, bushings, brakes, etc. before spending a gob of money on wheels and tires. The car might look great but you'll hate to drive it.

Manntis

Affect? Certainly. Any change to unsprung weight will. But substantially? I disagree. Going to a 17"+, sure, as the weight difference is - well, substantial. But there are many owners running larger rims without crying about a huge - or even noticeable -drop in performance.

rx7learner

I hope not significant. I never experienced a 13" always had my 15". In adidtion my rims dont have much mass to them as you can see in my avatar however it brings to question the impact on my speedo but instead of hijacking I will wait for another thread.

Kouryou

My writing professor always told me adverbs were going to be the death of me...I stand corrected, it will not substantially affect performance...mea culpa, mea culpa, mea culpa