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Discussion Starter · #1 ·
I just got the GM MotorSport Rotors and on the back of them was Made In Brazil.:mad:

Gee the stock rotors are made in Brazil.:eek: So I have a strong opinion that the MotorSport Rotors are nothing more then thicker rotors manufactured to the same quality as the stock rotors. Not quite was I was looking for.

I am really wondering if I should have purchased a stock set and had them cyro'd.

Comments:-?
 

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What do you have against Brasil?? GM's highest tech plants are there. Also if you ever drive there you would realize that its a good testing ground for rotors.

Bob
 

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No direct experience, but people are reporting 5-6 hard track events using Hawk Blue's :eek: ... That must be close to 10 events with a less aggressive pad, Hawk Black / HP+ or the PF's.

Same people report 1-2 events out of the stock rotors w/Blues.
 

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If you are looking for a high quality rotor w/ anodized hats (Ft & Rr) Call Ben @ Dilusi @ 281-536-0053. These rotors use the stock parking brake, too. There is a link in my Sig. They have everything from stock sized replacement rotors to full blown race set ups like mine. Sam & Ben there are GREAT, also. If you do a search, I posted a thread a couple months back about my brake set up, along with pix.
 

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Darth, do you know what the deal is with Dilusi "being under new management"?? What happened to the old management? Why did they want to get out of the brake business?

Any insight would be appreciated. Thx.
 

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I believe Dave Tittle ( former owner) has some health issues that prompted him to sell the company.
 

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Discussion Starter · #7 ·
I have don't have any issue's with Brazil. In fact my wife and I have spent 2 two years on a foreign assignment for our company as a techincal adviser's (pural). So I have seen how things are manufactured outside of the US. Some things are excellent, some things have poor quaility. Just like here in the USA

Here are the facts:

Same people report 1-2 events out of the stock rotors w/Blues.
Stock rotors are manufactured in Brazil. GM wants to make money. So spec out stock rotors from the same plant to be a little thicker and jack up the price.

This is what I am thinking and of course alarms are going off in my head when I see a "Motorsport" rotor made at the same plant as the stock ones. I assume same materials, same manufacturing process, same junk.

But here are some more facts:

I took some measurments last night

Outside wall thickness
Stock Motorsport
.290 .346
Inside wall thickness
Stock Motorsport
.318 .330

The overall thickness of the rotor is the same. So that means a different casting was used.

Also
but people are reporting 5-6 hard track events using Hawk Blues
So maybe the rotors are better. But I question these people above. Did they cool down the stock rotors like they now are cooling down the motorsports? Once you break something and you know how you did it you advoid doing it again. But I would think if these people are doing hard track events they know about cool down.

I guess my own experience will be the judge for me. I think that based on the facts on this post and others I have seen on the forum I am in a better situation using the Motorsport Rotors then the stock ones. I am planning on cyro'ing them before I put them on. Another suggestion from this forum

I have to say thanks for all the information from everyone, I could have never gotten this far in this short of time. :cheers:
 

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Time for new rotors

I put the $89 GM Motorsports rotors on after having them cryo'd at 500 miles. Now at 10276, 9776 miles later, including daily driving, 3 Pro Solo events, 1 Regional Championship (Solo II), 15 local AutoX, and 2 Solo I track events, its time to at least resurface them. The Mallett Gold front pads are very agressive and I have worn a "pad" groove in the rotors with ridges at the inside and outside edgeof the rotors.
No cracking or warping.
Not bad for $89 bucks!
 

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Discussion Starter · #9 ·
I put the $89 GM Motorsports rotors on after having them cryo'd at 500 miles.
After thinking about the difference between the Stock and Motorsport thickness, I am wondering if the .05 thickness difference really manners.:-? If I was a betting man I would say the cryo'ing treatment had more to do with it.

Or is it the Z06's front brake ducting coupled with the proper cool down :-?

DJ I thought you said you had stock rotors that were cryo'ed. Did I miss something?

Anybody know if there is a cryo shop in the Dallas Fort Worth Area :-?

Again Thanks for the information
 

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I have both sets of rotors

I had both of them cryo'd. I ordered the GM Motorsports (T1) rotors then sent them off to be cryo'd. When they got back I put them on the car and sent the stock ones to get cryo'd and when they got back I used the stock ones as back ups in my parts trailer at the track. As I said the GM Motorsports have been thru numerous low speed AutoX, street miles, and high speed track events with no warping or cracking. This is probably due to a lot of things. Cryogenics, cool down, fatter cheeks, better vane cooling.

BTW I just got back from the shop after having the GM Motorsports rotors milled and resurfaced to get out the pad grooves from the aggressive race pads I run in the front. They are now down to stock thickness. I will now use these as back ups.

I am going to Cad. plate the next set that I get alonng with cryoying them just for appearance sake. I think a clean rotor is a cool rotor.

Of course, when I ran Pro Solo Super Stock I only ran the stock rotors.
 

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Dreamin said:
Darth, do you know what the deal is with Dilusi "being under new management"?? What happened to the old management? Why did they want to get out of the brake business?

Any insight would be appreciated. Thx.
I read David was body slammed by a buddy of his at a card game. No malice intended, just a throw that hurt him. I also saw his car for sale in the paper last week.

RG
 

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Discussion Starter · #12 ·
I ordered the GM Motorsports (T1) rotors then sent them
DJ was your GM Motorsport rotors made in Brazil like the ones I got?

DJ was the increase in thickness from the stocks ones, .05 inches inside and .01 inches outside, about the same about the same as I reported? (.05 more wall thickness does not seem all that much and could be more of a manufacturing tolerance.)

Right now I am wondering if I really did get the Motorsports rotors as they sure look like the stock ones. The only different I can see is that the stamped part numbers are different.
 

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I never really measured mine but....

... I ordered mine using the part numbers listed in the
SCCA tech sheet for approved rotors other than stock.

Funny, they visually had thicker cheeks, were wider ID between the rotors so appeared to have better cooling, They were stamped USA, but had the same part numbers as my stock Z06 rotors. They were also stamped LF/RF/RR/LR just like the stock Z06 rotors.

As I said, I had them cryo'd and have used them quite hard with very aggressive full race pads, I did burnish them in correctly and I always warm them up before getting on them and I always let them cool down after an event. I never spray cold water on hot rotors. If the rules would allow I would have them gas relief grooved but not cross drilled. I will cad plate my next set.

And if rotors were "open" in the class I run I would have the Brembo's on if I could.

All this makes me believe that some T1 or close to T1 parts are already on the Z06. I have been trying to find out what the similarities and differences are between the stock C5, Z06, and T1 parts are but as yet can find no answers.

The T1 parts were made to upgrade the C5 to a track car, The Z06 is supposed to be a track car out of the box; so we miight be able to infer something here. Did Chevy use T1 parts to upgrade the Z06 on the assembly line? If you ordered T1 parts trying to upgrade a Z06 are you just putting on new Z06 parts?
 

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I don't know about all the other susp. pieces, but I added the T1 Sway Bars & they are NOTICABLY more HUGE than my stock sway bars.
 

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Discussion Starter · #15 ·
... I ordered mine using the part numbers listed in the SCCA tech sheet for approved rotors other than stock.
These are the part numbers you gave me.

LF 12480155
RF 12480156

So I got the right numbers.

But you said yours where stamped made in USA. The ones I got were made in Brazil

from another post on this subject:

...The rotors are thicker plates when viewed down the vanes. The dealer can contact Service Parts Organization < SPO > @GM for dimensional particulars.
.05 inches thicker on the outside and .01 on the inside is not all the visible. I really am getting the feeling that I have gotten stock rotors.

I am contacting the SPO for the particulars.


You know after doing all this, I am really wondering if I should have just gotten a good set of rotors for the high -speed driving events and use cryo'd stocks one for the Autocrossing events. Then I stay within the rules. I feel like the ScareCrow in the wizard of OZ if I only had a "Brain"
 

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Those are the correct #'s

It would appear that possibly Chevy has 2 suppliers or 2 plants that manufacture the GM Motorsports rotors. One in Brazil and another in the US. That is not uncommon in a large corporation. It is also possiblr\e that different GM parts Depot's are supplied by different manufacturers or GM factories.

I know in the medical field we always evaluate many suppliers and always have 2 different manufactures on line in case of a recall, labor problems, shipping problems etc.

With many Dealers cutting inventory and relying on "Just in Time"
delivery. I can see where to 2 consumers might order the same product, with the same numbers and recieve products manufactured in 2 different parts of the World to the same spec. It is a Global Economy.

In short I would just cryo those GM Motorsport rotors, slap them on and run them in a stock class as they have the same parts #s.
No body will be the wiser. You will get reasonably good life from $89 rotors, with no warping or cracking and will still have pristine stock rotors when you sell the car.
 

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Discussion Starter · #17 ·
DJ in additon to your information (Thank you), I got some information from GM. Gm could not give me the information directly and I had to contact a dealer in my area. The GM way :roll: :roll: :roll: Nothing like going throught a middle man to get your answers.:mad: :mad: :mad: Yet GM managment thinks this is the most effect way to service the customer via the dealer. NOT

What I found out is the motorsport and stock Z06 and C5 rotors are pretty similar and the thickness increase that I measured is what they are quoting.

In addition to cryo'ing I am thinking about using some flexiable ducting to blow air throught the vanes.

Thanks all
 

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Ducting....

.... would definitely help.

1. I would extend and direct the stock front brake duct by either using flexible vent hose to the caliper area attatching to the A arms or ordering the Doug Rippie vents

www.dougrippie.com

2. I would also think of installing a NACA duct in the high pressure area on the bottom of the front fascia just in front of the right and left air dam, ducting this air to the calipers as well, This would result in a double air inlet with direct venting to the calipers and rotor.

Another racing trick is to install wheel well "whiskers" on the leading vertical edge of the wheel well fender. Letting this plate stick out 1/2" - 1". This creates a negative pressure in the wheel well and helps pull ducted air through the rotors and wheels and helps evacuate the wheel well. It also may add a touch of front down force.

BTW I have a SpeedLingerie Bra and the wheel well attatchment points are 2" wide plates that attatch to the stock fender bolts on the leading edge of the front fender well. These act as clips for the bra. When racing with the bra off, I reverse these plates and let them stick out of the wheel well and walla; instant "whiskers". If tech asks I say the are the bra attachment points, are for appearance and convienience only and do not in crease performance in any way and actually add weight to the car.
If they ask how they work I just say that the bra clips on to them. No one has ever asked why they are on backwards during a race!

Drop me an email address and I will send you pictures of the "whiskers" in their normal position.

[email protected]
 
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