07TLFIXITUP

Ok so for the first time since i bought it brand new, my brakes made " the sound" when I was stopping tonight. I'm completely new to mods and everything so I have a plethra of questions. I want to put some 20's on my TL and was curious, in order to maintain the incredable braking power that this veh came with do I just need to go back to factory stuff? I was under the inpression that I needed bigger rotors if I moved of my rim size. The only name I keep hearing is Brembo! So many questions. Please help.

HigdonTL05

the first thing we need to know is if you have a 6mt or a 5at because they different set-ups

07TLFIXITUP

It's a 5at.

Speedy Six

iTrader: (2)

Opposite. If you want to go with significantly bigger brakes (rotors and aftermarket calipes) you will need to get larger diameter rims to clear these new brakes.

You can certainly run larger rims with the stock AT brakes you have now. However there are two drawbacks.

One is the the look. Big rims creates more space between the inside of the rims and the brake rotor, making your brakes look tiny. You have the AT, which has smaller front rotors and calipers than the MT. Good thing about this is you can run almost any rim you want without clearance problems, whereas the MT with the stock Brembos can only run certain rims due to clearance issues.

The other is larger diameter rims are heavy and have more of their mass located to the outside, increasing the flywheel effect. This may have a detrimental effect on acceleration and braking. However, many people don't worry about the performance aspects, willingly trading if off for the look.

07TLFIXITUP

Thank you for your response. So in your expierenced opinipn, brake issue aside (leaving stock rotors) Should I go with a 19 or a 20? It really doesnt matter to me but my original concern was acceleration and braking. How much power will I lose if I go with the new rims? I understand that weight is an issue so having already taken that into consideration, is there really that big of a diff? Also, what about speedometer calibration?

Speedy Six

iTrader: (2)

19" or 20" wheels really is a personal choice, if you remove the other considerations. I'm not sure you'll feel a performance difference between the two, as two different models/designs in the same diameter can be very different in weight (ie. you can probably find a 20" wheel that may be lighter than some other mfgr's 19" wheel).

The 20" wheel will require a tire with shorter sidewalls to maintain the same overall diameter. This reduced sidewall could result in a harsher ride and greater risk of denting or cracking the rims when hitting a pothole or broken pavement, since there's less sidewall to absorb the impact.

Speedometer calibration is not an issue if you stick with a tire size that's close to the original 235/45-17 tire diameter, as the speedometer only cares about the total rolling diameter (or circumference). You can play with online tire diameter calculators like this one to get a sense of which tire to use with your 19" or 20" wheels http://www.discounttire.com/dtcs/infoTireMath.dos

A 235/35-19 or 235/30-20 would be very close to stock diameter.

07TLFIXITUP

OK, so I found some 19's and i cant help but wonder if you know if I should upgrade or not.(the brakes) The wheel calc you sent was perfect, thanks. But in order to keep my speedo in "close" proximity is a 235/25/19. Do you think that is too low of a profile and potentially could damage rims easier? I've NEVER owned an aftermarket rim so I'm such a novice in this feild.

Speedy Six

iTrader: (2)

Depends on how you drive and the quality of the roads you drive on. If the roads are smooth and well maintained, and you're quite careful and slow down to take edges and potholes you might be okay.

But it might take only one good hit to damage either the sidewall or rim.

You could go a bit taller to get back some of that sidewall. A 245/35-19 or 235/40-19 gets you back some sidewall height at the expense of a slightly larger diameter wheel/tire combo which will result in slightly slower acceleration (same as making the gearing taller).

Check some of the other threads and ask what other member's experiences have been. Personally I think 18" is big enough. I run a 235/40-18 on my daily driver, and a 245-40-18 on my wife's TL (her daily driver) so I don't have any firsthand experience with ultra low profile 19s or 20s.

Keep in mind there are economics to consider as well. Larger diameter wheels cost more per wheel, and the required ultra low profile tires are also more expensive, partly because they are lower volume so most mfgr's only provide these sizes in their premium lines.

Not sure what you meant about upgrading the brakes if going to 19" wheels. As mentioned earlier you won't need upgrade the brakes unless you wanted improved braking performance or couldn't stand the empty space between the stock rotors and inside of the rim.

Speedy Six

iTrader: (2)

Sorry for the extra post. Ran out of time for the edit.

One other thing I forgot to mention. If you're going for looks, the design of the wheel can have a significant effect on how "large" the wheel appears. A particular design in 18" may actually appear to be more like a 17" wheel, while another design may make the wheel look larger than 18".

Personally I think there's a point when the wheel is actually too big, making the car look cartoonish, like a Tonka Toy or HotWheel. But that's just my opinion.

Check the thread at the beginning of this Wheel/Tire/Susp forum. It has pics of owner's cars with different wheel diameter, design and tire size combos.

07TLFIXITUP

HMMMMM....definately giving me a lot to think about.

this is the rim im wanting.with.

Speedy Six

iTrader: (2)

Sharp looking wheel! The spokes going right to the edge of the rim help to make the rim "look" it's full diameter, but the very thin polished outer edge may not be quite wide enough to fully complement the effect.

I'm more of a "traditionalist" (simple and functional, like a Ferrari 5 spoke) when it comes to wheels so keep that in mind.

Again, have a look at the pics other members have posted of their wheels and tires mounted on their cars.