Wheel Size Indecisions

[XkillerX]

Hi everybody,

this is my first post here, so thanks in advance for reading it.

I drive a 1990 Corolla Sedan XL (the classic) and was hoping to get a '97 celica this year, but it looks like that ain't gonna happen

So, i decided to visually tweak out my faithfull baby. 1st stop, are of course, alloy wheels. I found a set of great Borbet 6 spokes in excellent condition, but they are 15". My friend is a mechanic, and he says those wheels will rip the car apart unless i change the complete suspension and wheelbase system (something like that), and that anything more than 14's is pushing it too far for the poor car. On the other hand, on sites like tirerack.com, there are no warnings even for 215/40/16 wheels and tyres?!?! (which, according to a couple of calculators, replace the factory 155SR13's perfectly).

Does anybody has real-life experience with this subject? Should i stick to 185/60/14 or go ahead and try larger ones? If so, what modifications or repairs can i look forward to in the future?

Thx folks. Cheers.

[Unity Jon]

13 ? are you sure ??? anyway, stick 17's on and dont worry about it.

[XkillerX]

13 ? are you sure ??? anyway, stick 17's on and dont worry about it.

yes, 155SR13 are the factory default, it says in the owner's manual. after all, it's a tiny family sedan... for how long have you been driving with 17" rims? oh... and you're driving a GTi obviously. i only have a 1.3 carburator engine :(

you can check it out here (pic taken at part1 of music installation...)

http://www.pcservis.net/killer/1.jpg

[Unity Jon]

the engine size doesnt really matter with wheel size, just rolling radius (unless your going to get all picky and say wider wheels add more drag, but seeing as the wheel is turning and no the road the drag effect is almost zero, plus you'll stop quicker too.)

when people go up in wheel size its important to go down in tyre wall profile to keep the rolling radius (the distance from the center of the wheel to the outer edge of the tyre) about the same give or take a few mm then your speedo will not give a false reading.

With that in mind if the cars stock setup is :

185x60x13 (only a guess) you'll be able to fit 205x30x17 with ony the smallest (.something of an inch !) difference.

try this: http://www.miata.net/garage/tirecalc.html and input your factory spec wheel tyre size (you appear to have lower profiles fitted in the pic - Dont use the size from these) then put in the size you'd like to have and adjust the specs until its the radius as the stockones.

If your prepared to have your speedo recalibrated you can stick whatever you like on there (wheel arch permitting)

I've been rolling these 17's for 3.5 years now.

[JT]

i dont understand it then.

my car's got 185/60/14 wheels and tyres on it, standard. i recently tried some 205/40/17s on it, and even up off the floor, they were sat on the base of the spring, and apparently they were the right offset.

[XkillerX]

jon, thanx for the info, meanwhile i also found out an interesting fact... running large rims is generally not recommended in YU because of the horrible road conditions! :ffs:

because larger rims are heavier every time you hit a bump or a hole you slam the suspension and the whole car a lot more than with stock stuff. goddamit, looks like i'll be stuck to something like 14's, maybe 15's. and yes, i put lower profile tyres up front, they are 155/70/13 so the car is something like a few centimeters tilted toward the front, kinda giving it a sporty look. don's ask, i did that 2 years ago when i didnt know anything about this subject.

your car looks hot with those rims, man it would be nice to roll something like that . anyways, thanks again for all the help, i'll update this topic with pics once the thing is done.

[Unity Jon]

The 17's only just fit under the spring perch but the coil/strutt bottom and wheel all moves together so it will never get any closer to the spring perch unless you break something there is about 5mm gap between my tyre and the strutt ! but its always 5mm and never changes.

as for this

because larger rims are heavier every time you hit a bump or a hole you slam the suspension and the whole car a lot more than with stock stuff

no offense but you need to get a new mechanic thats not going to bull$hit you.

The new 17" wheels being alloy will weigh less than your steel 13's. The only reason it seems that it hits pot holes harder is because of the low profile sidewall that is extremely hard compared to sloppy 60+ profile tyres, the 40 or even 35 profiles have almost zero flex in the sidewall which makes for better handling but poorer road noise. The larger wheel-tyre combo doesnt have a larger diameter or radius remember !!

[4afe]

I have 16's on my 91 corolla, the only thing is because I do have A LOT less rubber around them I feel every thing on the road. I know person like that he told me all kinds of crap like "a stock car is a very fine tuned car, if you mess with it you will ruin it and things will break like crazy", then he said "if you want a sport car just buy a corvette like me". If you dont hual ***** on a horrible road you wont break your car. One of my buddys have broke 2 rims on his eclips so far because he is not careful when it comes to pot-holes and bad roads.

[XkillerX]

alrighty then, i think i got more than enough info with this topic.

as long as i keep on the lookout for potholes and drive carefully on crappy roads, i should be able to roll 16 or 17's easily... yeahhh

thanx to everybody who posted here, you made a difference. bye!

killah

[Unity Jon]

Pleasure, i hate it when less experienced or narrow minded people let their 'opinions' affect others.

[GSB]

The new 17" wheels being alloy will weigh less than your steel 13's.

Wrong!

A 17" alloy is a heavy *****, especially a non-forged one. A 13" steel rim will be far lighter. Even the difference in wieght between my 15"alloys (205/50/15 - 16lbs) and my 17"s (225/35/17 - 24lbs) is enough to knock the performance.

The problem with this extra wieght is this...

The extra wieght adds to the unsprung wieght at each corner of the car. This mass has to move up and down with the suspension in response to bumps. The heavier it is, the less sensitive it is to small bumps and the more force is required to move it, thus the more unsprung weight you have, the greater the tendency for road shocks to be transmitted through to the car.

Next is the effect on performance, and this isnt simply due to any difference to the overall size of the wheel/tyre combination. Your engine has to accelerate your car. To do this it must first accelerate your wheels. The heavier they are, the more energy it takes to acclerate them. Hence, heavier wheels = slower acclereration.

If it were just a question of :

"I've added four lbs per wheel, so thats 16lbs. So I'll remove 16lbs of wieght from the car to be even!"

It would be simple... But its not like that, this is rotating mass so its a whole different ball game.

That said, physically they will fit. The only question is do you want to put up with the performance hit, and the rougher ride?

[Unity Jon]

The new 17" wheels being alloy will weigh less than your steel 13's.

Wrong!

A 17" alloy is a heavy *****, especially a non-forged one. A 13" steel rim will be far lighter. Even the difference in wieght between my 15"alloys (205/50/15 - 16lbs) and my 17"s (225/35/17 - 24lbs) is enough to knock the performance.

????? funny in our club every single alloy wheel has weighed in at around average 5lbs less over original Steel stock wheels.

Not sure where your info comes from but in my case i know its right because the guy at the wheel place first picked up both an alloy and a steel and said "!Removed! hell feel the difference between these' which i did, we then went to the workshop next door and weighed them (they use it for postal rates) and the alloys (with tyres) were 12lbs less than the stock steels with tyres.

Make your own mind up but everyone knows that 'alloy' wheels are preferred in motorsport because of the strength/weight reduction. ...... not the looks

just dont buy crap ones !? It probably has something to do with the style of the wheel also ? fewer thinner spokes = less alloy = less weight (obviously.)

[Unity Jon]

just to add to this....taken from the Leico wheel design and manufacture study in 1984 so you can bet the talked about 'new' technology is in place today....

One-and two-piece alloy wheels

One-piece alloy wheels are mainly produced by low -pressure die casting with subsequent machining. Because of the relatively porous grain structure a given minimum wall thickness must be maintained in order to guarantee adequate mechanical strength.

For this reason, cast alloy wheels carry hardly any weight benefit over conventional steel wheels. Whereas in the past styling was a major factor in favour of alloy wheels, weight considerations are today becoming increasingly important.

BUT

In recent years, the use of Leico flow forming technology has successfully met both requirements. The latest developments with the goal of still further weight reduction include, for example, a full-face wheel with formed undercut yielding up to 25% reduction against a conventional cast wheel and up to 48% reduction against a stamped steel wheel.

[GSB]

????? funny in our club every single alloy wheel has weighed in at around average 5lbs less over original Steel stock wheels.

Make your own mind up but everyone knows that 'alloy' wheels are preferred in motorsport because of the strength/weight reduction. ...... not the looks 

just dont buy crap ones !? It probably has something to do with the style of the wheel also ? fewer thinner spokes = less alloy = less weight (obviously.)

I gaurantee that the sort of 17's likely to be fitted to 14 year old 1300 corolla are not going to be anything like "motorsport" quality and wieghts...

Yes, a forged magnesium alloy wheel will weigh bugger all compared to the equivalent steel rim. But a set of cheapo "looks good in the mcdonalds drive thru" alloys with tyres will wiegh plenty more than the 155/13 super skinnys he's got on at the moment.

Die casting is as common today as ever, simply because there is a huge market for cheap wheels in ever increasing diameters because people are more intersted in looks than performance, and the cheapest, simplest way to make them is to cast them. Why do you think a proper set of light alloys is so expensive?