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Discussion Starter #1
Well, I must have been hiding under a rock the past year. I remember when the ‘05’s came out and when we first noticed they had different brakes. But I had kind of forgotten about it and I don’t remember hearing much talk about them or how big they are.

Well, there’s some information in this thread that you guys will definately be interested in.

<u>Edited and updated in an attempt to clarify:</u>

Rotor sizes:
--'00-'04 Focus (All) front: 258 x 22 mm
--'00-'04 Focus (All) rear: 253 x 11 m
-- SVT (all years) front: 300 x 24 mm
-- SVT (all years) rear: 278 x 11 mm
--'05 Focus (All) : front 278 x 25.5 (<---anybody verify that width?)
--'05 Focus (All with rear rotors) : rear ??? x ?? (Possibly SVT rotors at 278 x 11)

Also note that the new '05 front rotors are siginificantly less costly through Ford than '00-'04 front rotors($39.81 -vs- $63.47).

Now on to the wheel/fitment testing. The bulk of testing has been done with the 15" 'wagon' wheels. Some new, some old. I'll try and summarize:

-- 15" wagon wheels do fit over the '05 brakes although it is a tight fit.
-- There may be a difference between the '00-'04 15" wagon wheels and the '05 wagon wheels but it has yet to be verified. Lets call them 'OLD' wagon wheels and 'NEW' wagon wheels for simplicity (assuming that there might be a difference).
-- 05STZX3 tested NEW wagon wheels on an SVT and says that they fit.
-- Ataru tested NEW wagon wheels on an SVT and says that they don't fit.
-- seanmc tested OLD wagon wheels on an SVT and says that they don't fit. (we kind fo knew this but had to try it again now didn't we)

Where's that leave us? A few points...

1) It appears that any 15" wagon wheel (OLD or NEW) will fit over the '05 brakes.

2) How close that fitment is, I don't know. I can only say that I really doubt that Ford would have designed the caliper to be too close to the wheel. Remember, the wagon wheels now come on all 15" alloy wheel equipped Foci.

3) We have a conflict because both 05STZX3 and Ataru got different results from the same test. You'd think it would be a pretty straight forward test so I'd like to give 05STZX3 the benefit of doubt that he did test an '05 wagon wheel on an SVT and that it did fit. Perhaps Ford actually initiated a running change on the wagon wheel design to make them slightly larger to give more clearance? (Yes, I know...Pipe dream.) Its just that, at this time, I can't disregard 05STZX3's test.

4) If the '05 rotor dimensions actually are 278x25.5mm, I did some math for comparison. Neglecting the hub mounting portion of the rotor and just looking at the mass as calculated by diameter and width using material properties for a generic cast carbon steel out of my material database:

Mass
--'00-'04 front rotor: 8,871 grams
--'05 front rotor: 12,072 grams
--'SVT front rotor: 13,232 grams

--Since all we're really worried about is the difference from rotor -to- rotor, it may be safe to assume that the inside portion of the rotor doesn't matter as long as they're similar in size. So if my math is correct:
--The '05 rotor is a 35% increase in mass over an '00-'04 rotor
--The '05 rotor is only a 9% decrease in mass from an SVT rotor.

5) It seems to me that if the rotor is thicker, that the pad might have to get thinner. Although, I think you gain more overall mass by concentrating the mass in the rotor instead of the pad. This all needs to be looked into before I'd consider swapping to '05 breaks.

Any other points or observations?

Here's some other calculations from later down in the thread:

Moment of inertia
--'00-'04 front rotor: 74,644,188 g*mm^2
--'05 front rotor: 116,630,962 g*mm^2
--'SVT front rotor: 148,864,367 g*mm^2


Surface area:
--'00-'04 front rotor: 122,390 mm^2
--'05 front rotor: 143,668 mm^2
--'SVT front rotor: 163,991 mm^2

The actuall numbers aren't important. The difference is what we're looking for.
-The '05 front rotor has 20,323 mm^2 less surface area than the SVT front rotor.
-The '05 front rotor has 21,278 mm^2 more surface area than the '00-'04 front rotor.
 

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Professor PowerSlide
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Re: Finally a front brake breakthrough!

Im sorry the rotor differs..the ST model is similar.

The disks are bigger on all models. starting at 10.9" around and thinker as well

SVT's were 11.8 front and 11 rear
 

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Liter-a-cola? I measure my drinks in YARDS!
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Re: Finally a front brake breakthrough!

have any proof that the new 15's fit over our SVT brakes?
 

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Re: Finally a front brake breakthrough!

the important part is that they are on the same line in the Street Prepared update/backdate list!
 

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Discussion Starter #7
Re: Finally a front brake breakthrough!

Well now I'm even more confused than ever. I asked 05STZX3 how he got the info. Hopefully he'll respond quickly.
 

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Discussion Starter #8
Re: Finally a front brake breakthrough!

Even if the 15's do fit over svt brakes, aren't they like 6" wide?
Yes they are only 6" wide but without rolling the fender or other modifications, 6" wheels will hold plenty of rubber for 90% of our needs. Widest tire I've had on them was a 225 and I regurally run a 215. All within the recommended rim width range of the tires.
 

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Re: Finally a front brake breakthrough!

Even if the 15's do fit over svt brakes, aren't they like 6" wide?
Yes they are only 6" wide but without rolling the fender or other modifications, 6" wheels will hold plenty of rubber for 90% of our needs. Widest tire I've had on them was a 225 and I regurally run a 215. All within the recommended rim width range of the tires.
Recommended? 6" rim and 225mm tire? Possible, but not recommended.
 

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Discussion Starter #10
Re: Finally a front brake breakthrough!

Even if the 15's do fit over svt brakes, aren't they like 6" wide?
Yes they are only 6" wide but without rolling the fender or other modifications, 6" wheels will hold plenty of rubber for 90% of our needs. Widest tire I've had on them was a 225 and I regurally run a 215. All within the recommended rim width range of the tires.
Recommended? 6" rim and 225mm tire? Possible, but not recommended.
Kumho ECSTA V700 - 225/50 ZR15 - Rim width range = 6-8"

Possible, but not not recommended?


Yea, its on the low end, and yes I understand what happens.
 

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Re: Finally a front brake breakthrough!

Kumho ECSTA V700 - 225/50 ZR15 - Rim width range = 6-8"

Possible, but not not recommended?


Yea, its on the low end, and yes I understand what happens.
Yes it is safe, so I suppose it is recommended, but if you ask anyone at Kumho if that tire will perform optimally on that rim width, they will be lying if they say yes.
 

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Discussion Starter #12
OK, we're getting closer here. The above mentioned thread in my first post has been edited and updated with some pics. But, I'm still confused at to what wheels will fit over what brakes. But we're getting closer. I think.


Anyway...for discussion's sake.
If the 00-04 brakes are 258x22 and the 05 brakes are 278x??, would a 20mm increase in rotor size(and not sure about the thickness) be worth the cost and hassle? How much more effective would it be? It sure would be nice if we knew the thickness because if the '05's are 24mm thick like the SVT, that sure wouldn't hurt.

We know that, with the proper pads, the 300x24 SVT sized rotor/caliper combination seems to work pretty damn well on track even without cooling. So how would a 278 compare? I guess the thickness would make a big difference as well.

Pics for comparison.

2001 Focus SE wagon:


2005 Focus


05STZX3 did also say that the 15" wheels DID fit over the brakes on a 2004 SVT focus that he had on the lot.
 

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Faster than a Cobra
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There's a guy right up the street that bought an 05 ZX4 with those 15" wagon wheels. He will probably be buying my stock SVT wheels, so when he does, I'll take one of his 15's and see if they will mount over my front brakes.

Sound like a good enough way to prove if they do or don't?
 

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Discussion Starter #14
There's a guy right up the street that bought an 05 ZX4 with those 15" wagon wheels. He will probably be buying my stock SVT wheels, so when he does, I'll take one of his 15's and see if they will mount over my front brakes.

Sound like a good enough way to prove if they do or don't?
Excelent. I think its the only way.


You do that and I'll try and find somebody local with an SVT to see if the old skool ('00 - '04) wagon wheels I have in the basement fit.

If I were going to Pocono this weekend I'd try it on Gary's car. Hmmmm....anybody with an SVT close to Harrisburg, PA want to try?

Edit...Alghough, I thought somebody had already checked this years ago but I can't find the post.
 

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^ I'd swear that Rich tried it on Gary's car, but I'm not sure now...Jeez, I've got to think it's been done.

I'll try to remember to bring one of my wagon wheels (bought from thetable, who I think bought them from Rich) to Pocono this weekend and do a test fit. Let's hope that I remember to do so...
 

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Discussion Starter #17
If the wagon wheels fit, I then know where to upgrade my brakes from.
Don't get your hopes up on the old wagon wheels fitting. But the new ones, if there is a difference, who knows...

Sean, if you can do that test, you'd be the man.
 

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If the 00-04 brakes are 258x22 and the 05 brakes are 278x??, would a 20mm increase in rotor size(and not sure about the thickness) be worth the cost and hassle? How much more effective would it be? It sure would be nice if we knew the thickness because if the '05's are 24mm thick like the SVT, that sure wouldn't hurt.



25.4mm=1'' so 20mm=.75'' (approx, dont feel like doing the math now)


So .75'' (approx) would be worth it ONLY if you were able to score a set at a reasonable price, IMO.


Scott
 
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