If you prefer not to bubble yes, 325 on 12" wheels will be a good fitment.

Widening will work, especially for racers that are generally crazy and do things on a low budget. For regular street use, you might not only have safety issues, but vibration and wobble issues, since wheels are orininally machined into their final form on a lathe to ensure perfect roundness...once cut and weled, the rear part of the drum won't ever lign up with the front perfectly as when it was cast or forged from a single piece of aluminum and machined into shape.

Also, if you widen wheels, that changes the offset, it makes it more positive (a higher offset number, tires further into fenders and towards the car).

Wider tires providing more traction is a misconception, the contact patch/surface area doesn't really increase, it just changes shape from a more square patch to a more rectangular one, unless with lower air pressure...and even then the only thing that happens is you have less weight per squate inch of contact patch, so it's good for mud and deep snow so you can stay on the surface without sinking in, but the weight per square inch is what gives you the traction in the first place...so it equals out, more surface area but less weight per unit means equal traction either way. Where wider tires do have a traction advantage is heat dissipation over longer track use or while doing burnouts, so it saves the tire, that less weight per square inch means the compound is under less stress, so wider lasts longer in general. Think of it as brakes, any disc brake small or large will stop your car from 100 equally as fast...once, because the brakes are strong enough to overcome the tires and the tires start skidding so they're the weakest link while stopping. Do that a handful of times however and the smaller brakes with less surface area and more pressure per square inch the pads exert on the disc means they will start overheating and fading sooner than the larger brakes with less pressure per square inch needed to stop the car.

While some of what you state is true, I take offense to your first sentence - prior to the big wheel becoming the norm in pro touring and 15+" rims in large widths not being available, unless you had $5K to drop on a set(2) of wheels you had to figure out alternative ways to get what you want.

I took a 18"x8" with a 3.5" backspaceing alloy rim, after much searching found Weldcraft wheels that would widen it for me, they added a 7" barrel to the rim to make a 18"x15" wheel. The wheel is guaranteed and when balanced needed only .25 oz of weight to be true with a 31"x18.5" radial tire.
Back in 2006, it was the widest and largest diameter rim they had done.

So before you spout off about us crazies doing it, do a little research, it can be done and safely... In regards to the crazy comment, it took me 3 weeks to hand polish from a 60grit finish to the final polish you seen in the pictures...

http://i14.photobucket.com/albums/a3...7/PICT0465.jpg

http://i14.photobucket.com/albums/a3...7/PICT0462.jpg

http://i14.photobucket.com/albums/a3...7/PICT0396.jpg

Haha, no offense man...but racing is expencive, especially if you're funding yourself, without a sponsor. I understand that it can be done and that people do it (and in your case the offset became negative instead of more positive as the drum was welded to the front part of the wheel, not the rear) but this is a case where in 2006, as you said, wasn't easy to find a 18x15 wheel (or impossible), you had to do what you had to do...

By "crazy" i hope you underatand what I mean, and that is anyone fully dedicated to something becomes "crazy" for that particular thing.

It's all good... :D

that's some good info. thanks guys.
yeah I read about weldcraft and that when there done with it the wheel is actually more balanced then it was stock but still ill just wait to get some new wheels.
I'm in no rush, I like the nismo rims.

Balance and wobble are 2 different things. It depends on the wheel quality obviously but it should be very near perfectly balanced from the factory. If it's not, well there's a quality issue there...that can be corrected later yes.

They should however be completely wobble free as they are finished on a lathe which makes them perfectly round...once welded they cannot put them on a lathe again because they'd be taking away from the aluminum and would make the 18" wheel less than 18" and as I'm sure you can understand, that wouldn't be good.

So, when matched properly which is very difficult...it can be close, but not completely wobble free as from factory. Again, it would work if done right, it just depends if you wanna go that route or not at the end I guess.

thanks man, already changed my mind.
I just think it's cool tho.

Hate to say it. BUT you have no concept on how some things are done. The company I used to work for. Did this stuff all the time on small and large equipment like steam turbines and gas turbines, and rotating equipment. Anywhere from and couple of lbs to 200,000+ lbs. Working with tolerances of ".0002, and balancing within a few in/oz. Doing wheels is child's play. ;)

I hate to say this too...but I don't think you realize that yes, even though this is possible with millions of dollars of equipment and someone that knows how to use it correctly, this WILL not be the case when someone gives their wheels for someone to widen at a local shop...or even shipping them somewhere. These type of skills take years of experience and lots of knowledge to possess...whoever works in a shop and widens wheels, you can trust me, 99% of the time will be someone that worked at jiffy lube or discount tire that butches oil pan threads, wheels, studs, and anything else they get their hands on. I have way too much experience with those types of people, including dealership technicians, to be extremely skeptical when anyone touches my car...and that's why I do everything myself.

At any rate, there's a reason forged wheels have an advantage over cast, and certainly welded wheels, and especially someone that will overheat the aluminum while welding it, making it even more brittle. You cannot tell me a welded aluminum seam will be nearly as strong as a forged single piece of aluminum.

I do agree that pretty much anything can be done with peoper equipment and professionals...but willl you to find this level of professionalism when looking to widen your wheels? Maybe you might...but not everyone will, life isn't this perfect...not even close. That's just my opinion though :)

First off, thanks for the info. So I guess my best bet is to stick with the same diameter tire as my front tires. Since I will only be changing the rears.


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Yes, that is a great setup. I just chose 285/35R19 for the front for 3 reasons.

1, I already had them in the rear so I saved money and just moved them.

2, my front end is slightly higher off the ground than it would of been with 275s, which is nice when climbing on driveways.

And 3, the 285s are extremely close to the 245/40R19 original tire, coser than the 275s. I'm really thinkinking about 295/35R19 for my next front tire change but I'll see :)

How much welding experience you have?

Weldcraft has been around for a long time. They had done 2 sets of motorcycle wheels for me years ago when I raced them. ;) They have experience people, and the equipment.

What it boils down to with the welded wheels. If you can't find the wheel style with the width and back spacing. This is an option. Myself, I run Forgeline wheels.

I know I don't have neraly enough welding experience to weld aluminum properly. Weldcraft is probably a good option for widening wheels...maybe even as good as you can find depending on the specific person doing the job. However, as you said...It's an option for making something you can't find/buy. If you can, I would suggest forged aluminum wheels over welded aluminum wheels haha.

This is what I mean by MEATY! :D

http://i74.photobucket.com/albums/i2.../ZDayZ/007.jpg

:D

http://i74.photobucket.com/albums/i2.../ZDayZ/010.jpg