paul_huryk

Yes they are.

Probably about 25,000? Maybe a bit less?

rlewi771

Thank you John, that was exactly the type of professional opinion/analysis that I was looking for. These hubs have been a piece I have considered for quite some time but safety is always far more important than shedding some unsprung weight. With the analysis that you gave, I certainly feel better about running them and for an extra cost I very well might go the 7075 route.

As far as these wheels, the more i've looked at them the more they are starting to grow on me. At first, I personally didn't like them aesthetically, but after taking into consideration a lot of the aspects of these wheels i'm giving them serious consideration. For me the selling points are:


-the cost, as much as I love some CCW's and the rest out there, is it really necessary for a car I consider more of a track car than a cruiser/show car
-17x9.5'' offers a tremendous amount of tire selection.
-no spacers/adapters necessary, I was never fond of the 2'' adapters to fit corvette wheels
-Same offset front and rear means you can rotate these, which I think will get me at least another track day or two out of a set of tires. Not being able to rotate tires, my fronts have always worn out much sooner than the rears
-20 lbs per wheel is LIGHT when considering the cost
-tire prices for a 275-40-17 is more reasonable than the 285/295 route I had considered previously. and when I will use a few sets in a summer, it certainly adds up

Thanks Paul and John for providing us with more options than what are currently out there

87350IROC

iTrader: (2)

No problem. I love talking about this kind of stuff.

I agree with all your points.

87350IROC

iTrader: (2)

Here are some pictures of the Wilwood FSL caliper on the C4HD rotor. Tons of caliper to spoke clearance due to the high offset rotor. Looks nice.

As always, right click - view image for a larger version

87350IROC

iTrader: (2)

The rain held today. I got the Wilwood setup outside for some natural light.

I really like this combination. Highly functional. This is enough brake for virtually anyone wanting to take their car out on a road course. It is also fairly inexpensive and light weight. Pedal feel is excellent. And its even easy to keep the inner wheel and calipers clean, due to all the clearance.

As always, right click - view image for a larger picture.

paul_huryk

Your welcome...

CTW Motorsports had a tough time when looking into putting out a 17" wheel like we did - the combination of cost, fit (no spacers), weight, and tire selection was a big undertaking - but we got it right with help from our manufacturer. The only thing we are waiting on is testing the wheels on an actual CMC race car (one of the top cars in the country) to determine race-worthiness.

Some people love the looks, others hate it - all is good either way. I personally like the Ronal Firehawk wheels, but the brake clearance is bad - probably wouldn't fit the 4 piston Wilwood kit John posted below, not to mention an honest 25lb weight (5lbs more than ours).

285-40-17 is a decently available size; 295 width in 17" is a tough one these days. But for those 18" wheel guys with a 10" or 10.5" wide wheel, a 295-35-18 is one hell of an option, but it is a bit taller than a 275-35-18, which is same diameter as stock.

paul_huryk

This is the system I will be putting on my GTA once John has them in production, and I have the ability to fit just about anything on the car - which says a lot about the performance vs. value equation.

rlewi771

yep, looks great with the wilwoods, which I currently have as well. Any idea if these 17's will fit the Howe .75'' taller ball joints?

87350IROC

iTrader: (2)

My Spohn a-arms have Howe 0.75" taller ball joints installed. I'll check the fit. I can't guarantee that just because they fit on my a-arms, they will fit on stock. But I expect the stock a-arms have more clearance than the Spohns.

John

iansane

iTrader: (1)

For what it's worth I have the summit brand 1" extended balljoints in factory arms.

rlewi771

awesome, i'll assume it fits then, thanks

TEDSgrad

iTrader: (4)

Wouldn't two piece rotors also assist with any thermal concerns regarding aluminum hubs?

paul_huryk

Ted,

I'm sure they would and would also keep the possibility of warping to a minimum. Not sure of the price or size, but that is something John can talk about.

87350IROC

iTrader: (2)

Two piece rotors are awesome. No doubt.

They are lighter, provide a thermal break, a floating rotor is less likely to develop thermal stress.

They are however very expensive. The C4 HD 2pc rotor from Wilwood is $666. They are beautiful and I would be happy to build a kit with them or any other 2pc rotor, I just need a customer first. By comparison the Centric Premium rotors I like to use in general are less than $150 for the pair.

For comparison,

The Wilwood 2pc rotor is 16.3lbs for the ring and hat, and figure another 1/4 lb or so for the bolts.

The Centric rotor is 20.3lbs.

So in my opinion its a worse weight/dollar comparison to the aluminum hubs which save around 4lbs each, cost under $350/pair, and have other benefits.

If you are willing to spend the money, it is still a pretty good weight savings.

paul_huryk

$666 each or for the pair?

87350IROC

iTrader: (2)

Ah, I didn't specify, that is for the pair.

Baer also makes a C4 HD 2pc rotor for $550 for the plain rotors and $600 for dilled and slotted for the pair.

paul_huryk

That is a pretty large increase in price - about 4x the cost of 1 piece rotors!

But if you race and warp the 1 piece ones, the 2 piece are the hot item...

87350IROC

iTrader: (2)

Here are some pictures of the 12.8" C5/C6 setup.

As always, right click - view image for a larger version.

paul_huryk

Very nice!

87350IROC

iTrader: (2)

Here is the C6 caliper on the C6 Z06 14" rotor. Unfortunately, the caliper is touching the barrel of the wheel. It is very close. Perhaps a C5 or LS1 caliper would fit. I may try one later. Raining outside today, so indoor pic.

As always, right click - view image for larger.

87350IROC

iTrader: (2)

Here is the C6 caliper on the C6 Z51 13.4" rotor. Fits nice with around 5/16" clearance between the caliper and wheel barrel.

As always, right click - view image for a larger picture

87350IROC

iTrader: (2)

The weather broke. So I have some nicer pictures of the 13.4" C6 Z51 setup.

As always, right click - view image for a larger picture.











John

paul_huryk

Very interesting since the Z06 caliper on this rotor did fit...

87350IROC

iTrader: (2)

Yeah. I guess the C6 caliper isn't as compact in that dimension as the Z06 caliper. Really we are only talking about 1/8" difference.

Zach/90\irocZ

iTrader: (6)

Nice pregress with the brake setups curious about the SS Camaro Rotor/SS Camaro Caliper looks like it would be a close fit as caliper seems to be taller as compared to the wilwood setup


also whats the name of the style the wheels are modeled after just want to research some color schemes i thought enkei used to make something similar couple years ago

Second the center caps for CTW Motorsports Wheel are made from Plastic ?

Also how much of the hub sticks out with stock brake configration VS Aluminum hub
as i seem to like the smaller dust cap as it goes better with the design of the wheel

Thanks John and Paul

87350IROC

iTrader: (2)

Thanks Zach.

The center caps are plastic.

If you were running the stock brakes, the hub would stick out the wheel about 0.3" further than in these pictures. I can get some measurements if you like. As some point I will also mock up these wheels with stocks brakes.

Zach/90\irocZ

iTrader: (6)

Thank You no no measurements needed just wanted to know how far they stick out compared to stock setup

87350IROC

iTrader: (2)

I just wanted to let folks know I got my hands on a C6 ZR1 caliper. So this should be pretty exciting to work with. Unfortunately I have not yet located a carbon rotor for me to play around with. So for the time being, I will test the ZR1 caliper on the following rotors.

gen II CTS-V
Camaro SS

paul_huryk

Zach,

The wheels are a spin-off of the D-Force BMW wheels, my manufacturer makes them for other cars too, Miatas, Subaru and new Mustang also - all have different offsets, hub sizes, and wheel circles.

http://dforcewheels.com/pages/products.php

Zach/90\irocZ

iTrader: (6)

Roger That

Thanks Paul Ill check it out

87350IROC

iTrader: (2)

I got the Camaro SS / gen I CTS-V setup pretty nailed down. This one was a bit of a pain, but I like the results. Fits in the wheel with about 1/4" to spare between the caliper and wheel barrel. Looks good to me. This is on the Camaro SS rotor.

And yes, I am aware the caliper is upside down. I only have a passenger side caliper and this a drivers side spindle. But it doesn't affect the fitment.

As always, right click - view image for a larger picture.

paul_huryk

Very nice!

May be the best looking kit...

87350IROC

iTrader: (2)

Paul, I would only qualify that statement by adding a "yet". Lets see how these look on there.

As always, right click - view image for a larger picture.

Corvette ZR1




Notice the piston radiators.


gen II CTS-V

Zach/90\irocZ

iTrader: (6)

Yea have to agree but 2nd to ZR1/II CTS-V are very gorgeous as well lol

loving the blue it think blue and yellow are sweet spot also like your dark mettalic gray nice to see different colors besides red or black

87350IROC

iTrader: (2)

Agreed, its a nice change. The CTS-V calipers are going on my car.

However, I do like how the ZR1 caliper is 1.5" longer than the CTS-V caliper. So maybe I'll go in that direction. AAAHH, it ever ends.

John

Zach/90\irocZ

iTrader: (6)

I know how that is.... so many things you want to do then your relieze that you only have one car to do it on.lol not to mention ive been wanting a 87-90 Firebird Formula now to also lol so that doesnt help keeps the brain healthy

paul_huryk

Let's see if they fit...

stereojnky

iTrader: (2)

Are the zr1 calipers brembos?

87350IROC

iTrader: (2)

Yes sir. They are made in Italy just as the gen II CTS-V calipers are.

87350IROC

iTrader: (2)

Well here is the gen II CTS-V caliper on the Camaro SS rotor. Looks pretty good if you ask me. I'm not sure if I'm going to offer this kit though, as the bracket gets a little tight.

Caliper to wheel clearance is around 1/8-3/16".

As always, right click - view image for a larger picture.

paul_huryk

Nice!

rlewi771

Is there a consensus out there as to which performs better, the C4 HD or the C6? Looks like one has a slightly larger diameter, while the other has a slightly larger thickness. (so small that I dont believe it would make a difference) and they weigh about the same. Does one dissipate heat better than the other?

FWIW, I have the Ed Miller Wilwood FSL kit with the two piece rotors, and am thinking the rotors are about done. No way of knowing for sure as I have no clue what brand rotor he uses, therefor, I cant find out a minimum thickness spec. (and actually getting a hold of the guy for some information is out of the question) The rotors haven't warped, or cracked, but they have had two summers of hard track abuse. I'm going to be switching up a good bit of the suspension (bye bye drop spindles) and am trying to decide which route I'm going to go with brakes. One of the hubs supplied with Eds kit is shot, so I think it's time to make some changes. I will stick with the Wilwood calipers, as they have been excellent, just need to decide on rotors, hubs, brackets etc.

Any information on the brackets you will be manufacturing? I've seen one that uses 3 mounting holes as opposed to the traditional two, it seems like a good design.

Thanks

edit: How close are you to taking orders?

TEDSgrad

iTrader: (4)

http://www.colemanracing.com/Brake-R...ane-P3549.aspx

This might be what you're looking for depending on your set-up. I have them with 6pot FSL, 2 pc, alum hubs, and the drops.

rlewi771

those look similar. I know the ones I have a 1.25 thickness, those say they only go up to 1.1

87350IROC

iTrader: (2)

Sorry for the delay.

In my opinion, in short, they are quite similar in performance.

To break it down, based on observations only, I have no actual test data.

C4HD
12.99" x 1.10"
21 lbs
36 directional vanes

C5/C6
12.80 x 1.26"
19.5 lbs
40 directional vanes

The vane length is also quite important, as vane surface area is where the cooling happens. Overall the C4HD has slightly longer vanes. All its vanes are the same length. By comparison half the C5/C6 vanes are about 3/8" shorter. I suspect this is done for packaging as more vanes on a smaller rotor means the vanes get quite close together in the hat area.

The C4HD should have slightly better heat capacity due to the extra weight. The C5/C6 probably sheds the heat very slightly better due to the extra vanes and larger thickness.

So basically I would use them interchangeably, performance wise. Use the C4 HD where you need more caliper to wheel spoke clearance. The C5/C6 advantage is there are more replacement rotor options and generally are a little bit cheaper. The change in diameter is so minor of course that the difference in braking torque is negligible.

87350IROC

iTrader: (2)

What wheels are you using?

What size rotors are on your kit? Do you have a picture?

By the way, I believe its law that the minimum thickness be indicated on the rotor somewhere. Typically its engraved in the outer edge of the vanes.

Are your current hubs aluminum? Are the hubs themselves shot, or just the bearings?

I agree on keeping with the Wilwoods, they are pretty awesome, especially for the price. I am glad to hear they are working well for you on the track.

87350IROC

iTrader: (2)

Sorry for the multi replys, this is easiest for me.

All my kits include the following standard features:

- 304 stainless steel brackets
- ARP 12pt stainless steel hardware (where available) - all Wilwood kits include the SS ARP hardware
- all critical hardware is drilled for lock wire and torque sealed
- 6061-T6 aluminum hubs (dual drilled for M12 press in & 1/2" screw in studs), (anodized black)
- Centric Premium rotors (where available) - (e-coated black for corrosion resistance)
- choice of premium street pads (BP-10, Hawk HPS, Hawk Ceramic, etc...)

Optional features

- 7075-T6 aluminum road race hubs (dual drilled for M12 press in & 1/2" screw in studs), (anodized black), (larger SET3 (1LE) outer bearing)
- 6061 or 7075 hubs dual drilled for GM 5x4.75" and BMW/Modern GM 5x120mm bolt patterns
- rotors - 2 piece, slotted, etc...
- racing pads
- powder coated (spindles, calipers)
- titanium pad insulators (reduce heat transfer to caliper/fluid)

For you I think the ultimate setup would include the 7075 hubs. Also, if you ended up going with the C4HD rotor (1.1" thick) you could get the titanium pad insulators which would keep excess heat out of the caliper and fluid but also make your 1.25" calipers fit better on the 1.1" rotor. They are not excessively expensive at under $100.

Regarding production. I have a bunch of Wilwood (C4HD rotor) brackets being produced right now. I should have them in around 2 weeks. The rest of the components are either in stock or will be ready before the brackets. Custom stuff would be around 3-4 weeks as I'm at the mercy of my machine shop.

My goal is for the best possible customer service, and that starts with being available. Below is my email and phone number. Feel free to give me a call or email any time, I love talking about brakes.

Regarding 3 bolt brackets. I have not seen those, do you have a picture? I have thought about using the 3rd dust shield bolt for some weird stuff, but nothing practical yet. On that subject though. I only use 7/16" or larger hardware. The Wilwood calipers are sized for 7/16" bolts so that is what I use for the bracket to spindle attachment. For some of the larger calipers that use 14mm caliper bolts, I use 1/2" bolts for the bracket to spindle connection.

For comparison, a 7/16" and 1/2" bolt torqued to their recommended specs produce a clamp force of:

7/16" - 10300 lbs
1/2" - 13200 lbs

If we continue with the 7/16" example. That 10300lbs on each bolt produces about 6200lbs of frictional force between the bracket and the spindle. There are two bolts, so the bracket is held to the spindle with about 12400 lbs of clamp up.

If we look at the loads involved, making some assumptions. Lets assume a full weight thirdgen with two big dudes in it, weighing 4000lbs. This is likely conservative. Now lets assume at full braking you have 100% weight transfer to the front tires, again conservative. So each tire has 2000lbs of weight on it. Now lets assume again to be conservative you are running full racing slicks, that about about a 1.2 coefficient of friction between the rubber and the road. The normal force on the tire is 2000lbs, the coefficient of friction is 1.2. So the friction force is 2400lbs from Ff = Fn * cf. That friction force gives us the maximum force the tire can withstand before it locks up. That force produces a torque around the wheel center of 31,200 in-lbs or 2600 ft-lbs for a 26" tire. This is the torque the brakes need to put out before they will lock up the tires. The bracket to spindle bolts are about 4" from the center of the spindle. So the load at 4" is around 7800lbs. Compare this to the 12400lbs of force available, we see that the 7/16" bolts produce enough clamp up to do the jobs, WHEN PROPERLY TORQUED. Now granted we added a ton of conservatism into the calculations, and I made some assumptions, but the story is 2 7/16" bolts are enough.

This however is why I ALWAYS lock wire critical bolts. This ensures the connection will not lose its clamp up.

John
john@perdoch.com
610-554-6503

scooter

iTrader: (11)

If you have the 12.2" rotor it is a Coleman, but I dont know which one exactly. I asked Ed years ago when I got my 12.2" setup from him.

rlewi771

I plan to use the CTW wheels now that i'm ditching the drop spindles

Current rotors are 13'' dia. 1.25'' thickness. I was shocked when I put a magnet on the hats to find out they were aluminum. I swear the two piece rotors feel like boat anchors. The inaccurate cheap scale I have at my house weighs them in at ~19lbs. I do not trust this scale one bit, and think I will pick up a good one this weekend to try and confirm that. I recently did a big brake kit on an 07 Mustang and the Baer 2pc rotors were feathers compared to mine. I'll try and get an accurate weight this weekend. Who knows, I could just be crazy.

Current hubs are not aluminum. I shake down the front end of my car often to check for wheel bearing looseness, tie rods, etc and was finding that I was getting some play at the wheel bearing. I'd tighten the nut, run it some more on track, come back in and the play had returned. Upon disassembly, I have found on the problematic hub, the inner wheel bearing race is free to wobble back and forth. It does not sit snugly where it should and replacing/reinstalling does not do the trick. It's as if it's worn, or machined poorly.

While the two piece rotors have performed admirably, zero brake fade ever, the kit is certainly not perfect. I've had rubbing issues in a couple of areas that I have had to make adjustments to try and correct.

87350IROC

iTrader: (2)

It looks like those are around a 32 vane rotor. Can you measure the bolt circle of the rotor hat bolts? I'm sure we can find a replacement ring, if you wanted to go in that direction.

For that rotor size, 19-20lbs is typical. You can certainly lighten the weight, but you are trading weight for heat capacity, it really depends what you want.

Regarding the hubs. The iron hubs are not the greatest. I bought a few stock rotors and played around with turning them into hubs. I was appalled by the quality of the castings. There was no way I would supply those in a kit. Granted I didn't measure the bearing bore, but just the general condition of the rotors were not very good.

It does sound like your inner bearing bore is a little oversized now. I wonder if you can get oversized bearing races. It may not be worth the effort, but something to look at.

Where have you had rubbing issues? That caliper is maxed out on a 13" rotor and it is a tight fit over the rotor. That brings me to my only major gripe about the Wilwoods. I have had 4 different sets of pads for these calipers and they all had the friction material bonded in a slightly different place. This compounded with the alright tight fitment means the brackets have to be pretty dead on for things to work correctly. Even then, when switching pads, you can expect the top of the pad to be in a slight different place than before.