Suspension / Wheel & Tire / Brakes “Frequently Asked Questions”:

How does the Supra TT look with Eibach Pro-Kit Springs, does it look too low?
With the stock wheels, it does have that “lowered” look, but it does look better than stock, IMHO. You definitely get used to it. But it looks GREAT with aftermarket 18" wheels.

Can Eibach Pro-Kit springs be used with the OE dampers (shocks)?
Yes, but it's not recommended. The dampening abilities of the OE shocks will be simply overwhelmed by stiffer than stock springs. This will cause the suspension to seem bouncy and uncontrolled. And since you have to remove the old, probably worn-out, shocks to replace the springs anyway, you might as well save some trouble and money and do it all at once. I recommend using Eibachs with a high performance damper, such as GAB Super-HPs, KYB AGXs, or Konis. I have the Eibach / KYB Combination on my Supra, and it works great, as well as being a great value.

Will stock wheels and tires rub with Eibach Pro-Kit Springs?
No they shouldn't rub.

My oversized rear tires rub the fender. What can I do?
Roll or trim the fender lips. I would recommend having an experienced body shop do this, as a couple wrong moves could have you needing a new fender, which is not cheap. Keep in mind, the downside of this is a loss in rigidity in the fender, so buckling during impacts could become more likely.

How good are the Stock Brakes?
The stock brakes are excellent. The rotors at each corner are almost 13" in diameter. The front rotors are clamped by 4-piston fixed calipers, and the rears are clamped by 2-piston fixed calipers. And all are controlled by a 4-channel ABS system (3-Channel on later models).

What is the best brake pad to use on a daily-driven Supra?
Believe it or not, the stock Toyota pads work as well or better than most aftermarket sets for street use.

Should I install Cross-Drilled rotors?
If you want them because they look real cool, then by all means get them. But if you are looking to improve braking performance, look elsewhere. Many people believe that cross-drilled rotors allow the rotors to cool more easily. This is not really the case though as air will not naturally flow through those small holes, they are facing the wrong direction! They are perpendicular to the rotation of the rotor and not efficient enough to allow significant flow. Cross-drilled rotor's primary benefit is that they allow the gas that certain types of pads release, to be more easily expelled from the pad’s surface area. But most modern high performance pads do not posses this trait. All that cross-drilled rotors really do is remove much needed material from the rotor. The rotors need to make as much contact with the pads as possible, so that the heat in the pads can be transferred to the rotors, and then expelled by the cooling fins in the rotors. Exotics like Porsches use cross-drilled rotors, but these rotors are cast that way. Most after market cross-drilled rotors are simply drilled, which weakens the rotor and makes it much more prone to cracking as they have been structurally weakened. Porsche installs them for one good reason, they look really cool, and make the car seem much more impressive in the dealer showroom.

Do I need to upgrade to braided steel brake lines?
I believe this is a worthwhile upgrade. You wont improve stopping distances or anything, but you will slightly improve pedal feel.

When I am in a panic stop, and mashing the brakes as hard as I can, I feel pulsation through the brake pedal, is something wrong?
That is the ABS system doing its job. Most people never hit the brake pedal hard enough to trigger the ABS system, so when it does finally happen, they are a little shocked by it. All ABS systems are like this, but the Supras system is much smoother than most.

What brake fluid is recommended for hard street use?
Motul RBF600 is good fluid. I have also heard good things about Ford’s Heavy-Duty brake fluid, no I am not making that up.

Is it worth the money to upgrade to Brembos on a street driven Supra?
The Supra has pretty good brakes to begin with, infact, it has some of the best brakes, if not the best brakes to ever come on a Japanese car from the factory. However, if you have the money to spare, or have serious horsepower, and use it, it would be a wise investment. However, one thing to keep in mind is that if you road race, you will eat up those rotors and pads just like the stock units, and they are more expensive to replace.

Were the Supra's wheels available in chrome?
Toyota itself never offered the Supra's 17" wheels in chrome. But many Dealers had the factory silver wheels chromed.

What about the 97-98 wheels, they look chrome?
They are polished aluminum, not chrome.

Which tires are recommended?
Michelin Pilot Sports, Yokohama AVS Sport, Pirelli P-Zero Rosso Assimmetrico and Bridgestone Potenza S-03 Pole Positions (in no particular order) are all great tires that are offered in many sizes commonly used on Supras. BFGoodrich g-Force T/A KD and KDWs are both good tires, but have a limited size selection.

What about putting wider tires (like 275s) on the stock wheels?
In my opinion, they are just too tall. I think a better size would be 265/40-17. It is actually much closer to being the same diameter as the stock front tire size, and are almost the perfect width. I don’t know why Toyota didn’t spec this seemingly more optimal size.

What are the diameters of stock vs. various other tire/wheel combos?
Front Tires:
Tire Size Total Diameter
235/45-17 (Stock Front) 25.33in.
235/40-17 24.40in.
245/45-17 25.68in.
245/40-17 24.72in.
255/40-17 25.03in.
265/40-17 25.35in.
235/40-18 25.40in.
245/40-18 25.72in.
255/35-18 25.03in.
265/35-18 25.30in.
275/35-18 25.58in.
Rear Tires

255/40-17 (Stock Rear) 25.03in.
265/40-17 25.35in.
275/40-17 25.66in.
315/35-17 25.68in.
255/35-18 25.03in.
265/35-18 25.30in.
275/35-18 25.58in.
285/35-18 25.85in.
285/30-18 24.73in.
295/30-18 24.97in.
315/30-18 25.44in.

What is the optimum tire section width for different width wheels?
8.5” - 235-245
9.0” - 255
9.5” - 265-275
10.0” - 285
10.5” - 295
11.0” - 305-315
11.5” - 315

What is the largest wheel and tire package I can put on the Supra TT without fender modifications, and with Eibach springs?
265/35-18s on 18x9.5" with a +50mm offset in the front, and 295/30-18s on 18x10.5" with a 53mm offset in the rear. The offsets are very crucial to make this work.(Information by Steve Jarvis)

What is the widest wheel and tire package that can be installed on a Supra with rolled or cut rear fender lips?
285/30-18s on 18x10” with a 47mm offset in the front, and 315/30-18s on 18x11.5” with a 45mm offset. The offsets are very crucial to make this work. Try at your own risk. (Information by Steve Jarvis)

What are the stock wheel’s offsets?
50mm front and rear

Is it safe to use wheel spacers?
No. Two things come into play when using wheel spacers. The first is the fact that less of the stud will be usable when installing the lug nuts. This means there may not be as much thread contact as there should be. Also, moving the tires outward, puts additional strain on the wheel bearings, and makes bearing failure more likely. You would not need wheel spacers if the wheels are the appropriate off-set.

Can I use MKIII Supra 16" wheels on the MKIV Supra TT with slicks?
NOT ADVISABLE. The MK3 Supra wheel is really too narrow (8") to support any useful slick on our cars. Some have tried using 9" slicks on these wheels, and have been terrified with the results. The car becomes dangerously unstable.

What about RX7 TT and 300ZX TT 16" Wheels?
They can bolt on, and are an acceptable width. But they don't clear the rear brake calipers. If you file, or grind the calipers for clearance, they will fit.

What should I set the tire pressures at for daily driving?
Toyota recommends 35psi for the stock tires.

What should I set the tire pressures at when I'm at the drag strip?
If you are using street tires, I would recommend no lower than a 22psi pressure in the rear tires.

Which drag radials are recommended?
The two most commonly used drag radials are the Nitto NT-555R and the BFGoodrich G-Force T/A Drag Radial. Both work very well, but many feel that the BFGs are slightly better.

How much of an improvement in ETs can I expect when using drag radials?
It varies, but I would say anywhere between 4 tenths and 7 tenths depending on conditions and the driver.


Information and content accumulated by Mike Thomas

Mike T
94 Supra TT 6spd

[This message was edited by Mike T on October 15, 2002 at 12:20 AM.]

[This message was edited by Mike T on July 18, 2003 at 07:40 PM.]