16" rims with AP brake kit?

[Igor+]

Is it possible to fit?

[bigmack]

I believe the smaller AP kit that Ultima supplies will work with the 16" Ultima wheels, but you might need to check the fit on other brands of wheels.
Cheers!
-Mack

[Igor+]

16" Ultima wheels?
Do the factory supply 16" wheels?

[andycanam]

Pre GTR & Can-am the 16in rims were the largest size offered on the front I believe.

[bigmack]

They used to. Not sure if they still do. Actually, they used to supply a 15" front rim with the 17" rears but that looked a little funny to most people. Those 320mm or 328mm discs are about as large as you can go with a 16" rim. I was originally going to go with a 16" front rim on my sports, but a mix-up with compomotive left me with 17" rims. Now I'm sort of glad, as I plan on running the newer 245/35/17 goodyear Eagle F1 front tires on my sports. If you stick with the 16" rims, then try to find a tire that gives you about a 23.9" rolling tire diameter. I'm not sure if Ultima has fixed the problem, but running the newer 24.6" tire diameter with the 18" wheels doesn't allow you to run quite as low of a ride height for the track due to hitting the bump stops. May not be that big of a deal to you though.
Cheers!
-Mack

[Igor+]

I'd like to have 17" front, 16" rear for track.
Hoosier?

The question is in rear rims.
16x9 or even 16x10

[bigmack]

I would go with 12" wide rears and keep the rear tire diameter around 25.6". 315/35/17 tires. There are a LOT of issues that need to be worked out if you plan on running slicks. You might be able to get away with a DOT approved slick though.
Cheers!
-Mack

[gtrclive]

You can fitt 333mm Disc'c under a 17" rims, ( I did ) but I don't think they go under a 16".

[Igor+]

I've got following option from the factory:

Set of four 12.7" vented disc brake and callipers comprising X drilled
320mm x 30mm AP Racing curved vane vented discs with alloy bells
and AP Racing four pot callipers (1.5" & 1.625" pistons with double
seal) with Mintex 1166 pads. Complete with billet fixing kit, all bolts
and AP brake fluid.

So, 320 instead of 333.
Half inch less on brake disk.
Half inch less on rim (0.5*(17-16))

Can be fitted?

[bigmack]

Without a problem.
My 328mm set of Brembos were designed to fit inside a 16" rim. You shouldn't have any troubles.
Cheers!
-Mack

[marky p]

Its not the diameter of the disc which is the problem its how far the caliper sits up into the wheel, if you go onto the AP website you can bring up the technical drawing for the CP5200 caliper and it might give you the dimensions to work from.Or ask some of the guys here to measure from centre line of hub to the outer edge of the caliper.

[Igor+]

Sure, I can measure the distance between the centre of hub and the outer edge of the caliper.
I’ve built GTR already.
I can’t measure the internal radius of 16’ rim because I don’t have one.

[marky p]

Igor
Just had a quick look around for technical info and found this.

Brake caliper diameter.
The inner diameter of the wheel, as measured at the backmost edge of the wheel.

16" has a clearance of 14 1/8" which is 358.8mm
17" vary between 15 9/16"(395.3) & 15 5/8"(396.9)

So give or take a couple of mm on the 16" size should give you an idea but cant say that this is the same for all wheel manufacture

[bigmack]

I really think you'll be alright Igor since Ultima used to supply 16" wheels with that same caliper/disc combo. However, Marky has brought up some good points that are worth noting. Yes, the caliper position has as much to do as disc diameter. Some calipers have a lower profile to them than others. Like Marky, says, though its important to take the measurement from the centerline of the axle to the top of the caliper. While your at it, go ahead and measure the distance from the wheel mounting surface(i.e.disc hat or bell) to the outer most position on the caliper. This is your caliper clearance measurement that you might want to give to your wheel manufacturer. Just a little extra insurance.
Cheers!
-Mack

[gtrclive]

Just a question Igor, I must have missed the point here, why do you want 16" rims ? have you all ready got them ? do you own a Sport / Spyder.

>> Edited by gtrclive on Friday 5th March 15:41

[Igor+]

We’ve just built first Russian Ultima GTR.
And have arranged several car magazines for tests and photo sessions.
0-100 km/h, standsteel-400 m, top speed, hill climbing, road course.
For the first two tests I’d like to have tires with soft sidewall, like Mickey Thompson or Hoosier.
The maximum rim diameter for such tires is 16”.

PS: It took 5 weeks to build the car.
PS: The factory has a problem with OZ wheels supplier so my car is still on a dolly.


>> Edited by Igor+ on Friday 5th March 09:52