Front Caliper Upgrade

[Richard S]

I know we have discussed the caliper upgrade using the Aurora Caliper. While wandering the wrecking yard, I happened on a 1999 Chev Malibu which appears to have light weight finned aluminum calipers. They appear to be similar in size to the Aurora [actually I was looking at an Intrigue which I think has the same caliper/rotor]. One would have to use the Do you think they will fit the Reatta, and if so, would they be preferable to the Aurora caliper because they reduce unsprung weight? I think the Malibu also uses a 5 X 115 bolt pattern like our cars.

[Barney Eaton]

We need someone that has access to a Hollander manual to do some research on what cars used the same rotors and calipers and the 1997 and later Aurora.

So far all we have are a couple of people that have done the conversion but have yet supplied any real details.

We need (1) a list of donor cars so you can either get the parts from wrecks or go to the auto parts store and picke them up. (2) More details on the conversion, particulary the areas that are not "plug and play" ie, can you use the Reatta brake hose, or must you have the Aurora, or something else. (3) there was some posting about making sure you got the caliper adaptor....what is this, how about a picture, etc.

I would consider doing the conversion, but don't want to

stumble around when others have already done the initial work. We just need good detailed instructions.

[D-a-n-i-e-l]

98 and newer cammaro and fire birds calipiers bolt up directly, but will not fit the stock rims

[Barney Eaton]

I can add more information, but we need a complete list in one place.......Example

Just checking 2001 models, the Impala, Lesabre (16"wheels) Regal, Pontiac bonneville, Cadillac Eldorado, Seville, and Deville all use the same rotors and calipers as the 1998 Aurora.

I still have the question about the caliper "adaptor"

[Richard S]

What is the advantage of the Camaro/Firebird calipers? Larger? 2 pistons?. I was taken by the Malibu set up because they are so light. I had meant to suggest in my original post that if the Malibu calipers fit, the Malibu rotors should also fit our cars because they have the same stud pattern. I will be running 17" rims so size of the caliper should not be a problem.

Barney makes a good point about the hoses. One would probably want to use the Malibu flex hose to the Reatta metal line.

[Guest F14CRAZY]

No adapter is needed with the "Aurora" calipers. The mounting holes have to be slightly drilled out with a 14mm or similar bit. I used a 14.3, I forgot the SAE equivelent.

You do not have to change brake lines. Your stockers will reach just fine, though maybe an extra inch would help. though stainless hoses would give better performance, and it wouldn't hurt to replace your old hoses.

Would upsprung weight be much of an issue?

I haven't looked into it much but late model F-body calipers would work a little better since they have two pistons. As far as I've researched, C5 calipers would work with an F body adapter, but rotors would be an issue...Vettes have a larger bolt pattern, though you could probably have them redrilled.

The front Aurora calipers, as mentioned, are used in most large/midsize GM cars from the late 90s to early 2ks. If you use the Advance catalog online you can click to see what else it fits. The rears are more specific though.

I'd find some shytti calipers from a yard then use those to exchange. I bought some from Shroyer's (remember to also get the bracket, probably another $20). Remanned Cardone loaded calipers from Advance are slightly cheaper than buying used calipers and brackets and getting Wearever Gold pads, and they're not all rusty and junk.

Fronts (I picked a '98, which is what I'm using):

BUICK

1997 - 2004 CENTURY

1997 - 2004 REGAL

2000 - 2005 LESABRE

1997 - 1999 RIVIERA

1997 - 2005 PARK AVENUE

CADILLAC back to top

1997 - 2005 DEVILLE

1997 SEVILLE

1997 - 2002 ELDORADO

2003 - 2004 SEVILLE

CHEVROLET back to top

2000 - 2005 IMPALA

1997 - 2005 VENTURE

2000 - 2004 MONTE CARLO

OLDSMOBILE back to top

1996 - 1999 AURORA

1998 - 2002 INTRIGUE

2001 - 2003 AURORA

1997 - 2004 SILHOUETTE

PONTIAC back to top

2000 - 2005 BONNEVILLE

2005 MONTANA

1997 - 2003 GRAND PRIX

1997 - 1998 TRANS SPORT

1999 - 2003 MONTANA

And rears:

BUICK

1997 - 1998 PARK AVENUE

1995 - 1998 RIVIERA

OLDSMOBILE back to top

1995 - 1998 AURORA

[Guest F14CRAZY]

Some people suggest not to get the Wearever rotors from Advance, but I've pushed em pretty hard and haven't warped em yet.

And also, with the pads that came with the front remanned calipers, they seem to make quite a bit less dust than the stock/normal Reatta setup. I'm thinking this could be because less effort is needed

[Guest TommyH]

I wish I could do that with the stock rims......

[D-a-n-i-e-l]

with the Camaro calipiers there is not drilling or having to use a sleeve. Use F-body mounting braket and caliper. OH and they are extremely light.

[Guest F14CRAZY]

What rotor would you use with the F body calipers?

[D-a-n-i-e-l]

if I remember I the same 97 aurora and 98-02 cammaro are the same part number so take your pick. You should remember you did most of the foot work on this on there F14.

OH here is the interchang from partsamerica, aka advanced, aka shucks, aka checkers

http://www.partsamerica.com/ProductGuide.aspx?mfrcode=RAY&mfrpartnumber=56641RGS

[Guest F14CRAZY]

According to the W-body board, I'd actually have to use bushings with the F-body calipers, because front Aurora calipers are the same as W body calipers, and they had to use them

[Richard S]

Just from the looks of the parts, the ideal caliper is the 99-02 Camaro aluminum dual piston. It certainly is not the same as the Aurora, which is a cast iron single piston affair. We could not, however, use the Camaro rotor because the bolt pattern is different. So if we used the Camaro caliper, which seems to require a bushing to fit our cars, which rotor would we use?

[D-a-n-i-e-l]

F-14 when you did yor brakes did you use bushings, did you drill, or did you not use any thing?

[D-a-n-i-e-l]

F-14, looking at your brake post I found you did have to drill your holes out. When the GTP guys do there F-body upgrade they must use a 14 mm spacer. So for us there is no drilling for this upgrade, we already have 14mm holes.

GTP brake link:

http://www.clubgp.com/newforum/tm.asp?m=2434239&p=7&tmode=1&smode=1

F-14's brake link: http://forums.aaca.org/ubbthreads.php/ubb/showflat/Main/88008/Number/374111#Post374111

I also double checked. The 97 Aurora and the 98-2002 camaro have the same part number for the front calipiers:

Part Number: 56641RGS

[Guest F14CRAZY]

Yup, according to my calculations, we would not have to drill for F-body calipers but would need bushings.

How about the C5 upgrade?

[D-a-n-i-e-l]

bushings? which ones?

I am not too interested in the C-5 upgrade. Too expensive and hard too find if you like the junkyard route. I just do not think the benifit would out wiegh the costs to do it and maintain it. You would probably pick up a tiny bit of wieght and they may not fit under a 17" rim. But I will research and see what I can come up with.

[Richard S]

I don't think that the 97 Aurora and the 2000 Camaro have the same caliper. For example, the AC Delco number for the Olds is 172-1634/35 at $125. The Camaro is 172-1603/04 at about the same price. The Olds, as I've said is single piston cast iron. The Camaro is dual piston cast aluminum.

As to rotors, the Camaro bolt pattern is 5 X 120mm while the Olds and Reatta are 5 X 114.3. I am not sure about the thickness of the rotors.

[D-a-n-i-e-l]

The calipiers are not the same. The rotors are sold under the same part number from partsamerica.com (aka schucks, checkers, advanced)

[Richard S]

I agree that the rotor number for the 2000 Camaro and the 1997-99 Aurora are the same, though I thought the Camaro and Aurora had different bolt patterns. Guess not.

As Barney sagely pointed out, if this is going to become an accepted upgrade, we need to collect all the relevant materials and instructions in one place. This means deciding on the best choices for upgrades that are readily available at reasonable cost, that do not involve major modifications.

1. So far, if the mount does not require any extensive modifications, the Camaro dual piston aluminum caliper seems like the best choice. A remanufactured caliper with the mounting bracket [unloaded] runs $38 + core from Rockauto.com.

2. Have we decided whether the Camaro caliper will require that we bush or drill the Reatta?

3. Since it appears the numbers are the same, either the Aurora or Camaro rotors should fit the Camaro and should fit our hubs?

4. The Camaro upgrade would require at least 16" wheels.

5. What about brake lines. I don't think the Reatta brake line will mate to the Camaro caliper. Do we know if the Camaro brake line will work with our suspension setup?

[D-a-n-i-e-l]

When I get out of Iraq and back to the states I will do the whole upgrade. I have already purchased most of the parts, I just ran out of time before leaving for here. I will be back state side by Nov 1st. I will make this part of my Reatta upgrade my first priority

[Richard S]

I'll probably do mine well before Nic gets back since the pads are already pretty low. I need to find a pair of Camaro calipers in the yard so I can make sure they will fit before I order them and the rotors. F-14, what is your feeling about using these versus the Aurora caliper?

[DAVES89]

I am curious as to why the big interest in the different calipers/rotors. In my opinion those of us with the Teves brake system should not be changing rotors and calipers. These are specialized systems. What's to say the master cylinder will keep up with a dual plunger caliper? I think the brakes are fine and extreme caution should be used with a brake system change. Please explain this to me. Thanks

[Barney Eaton]

That is one of the risk, one person makes a change (upgrade) and others think they have a better idea. Time will tell.

[Guest F14CRAZY]

Though we dont know of anyone that has tried F body calipers with a Teves system, I'd try the experiment. I'm certain that two pistons would provide better performance but I don't know to wat extent...braking systems aren't my specialty.

Keep in mind though that thw W body guys have used the F body calipers without any trouble

[Richard S]

Daves89 comment is an interesting one. He is, of course, correct that the stock set-up will certainly stop the car adequately, and there is no crying need for improvements. On the other hand, when one is going to invest the time and money doing a complete brake job, it would be nice to know that I installed the best system I could at a reasonable cost. If I can upgrade to dual pistons in an aluminim caliper with a larger contact area without having to make any substantial modifications, I see no reason not to.

I am really not sure what Daves89 meant by the Teves system "keeping up" with these mods. F-14 has already proven that the larger Aurora caliper/rotor improves braking performance with no side effects. We all know the Teves anti-lock system, like the Bosch system on the Allante, is tempermental, expensive, and potentially dangerous. And it is still far less sophisticated than Cadillac's Northstar and some other ultra computerized systems in which the brakes are part of a comprehensive anti-skid/stabilization system. I doubt the Teves master cylinder knows much more about what goes on at the wheels than whether the hub has locked up. I can't imagine a scenario in which the caliper/rotor set up could affect the anti-lock system.

[Guest F14CRAZY]

I don't know if any of this will make sense...

but as I see it, the ABS shouldn't be affected. Say if we had aftermarket 6 piston C5 calipers, the driver could probably get anti-lock to kick in pretty easily. The system doesn't really care and just depends on the wheel sensor to detect when a wheel locks up. The driver would just need a really steady foot.

At any rate, you guys ought to keep stainless steel lines in mind too. In older posts it was said that they improve braking performance considerably, which makes sense since pressure won't be lost by the hoses expanding

[Ronnie]

I doubt the Teves master cylinder knows much more about what goes on at the wheels than whether the hub has locked up. I can't imagine a scenario in which the caliper/rotor set up could affect the anti-lock system.

A larger piston (or pistons) will require more fluid from the master cylinder to move the brake pad a given distance when compared to the stock piston. That would result in more pumping to get the pads seated against the rotors the first time. After the pads are seated against the rotors and then released, it might require <span style="text-decoration: underline">extra travel</span> of the master cylinder piston (and brake pedal) to apply the brakes the next time they are used.

If that is the case, the result would be powerful brakes with a long brake travel that would not have a very desirable "feel" to them. I have experienced that in large trucks that have air brakes. You mash the brake pedal down to a certain point where the slack is taken up in the brake system and then they stand you on your head. It is only noticeable when the truck is empty due to the trucks ability to slide the wheels at will. When the truck is loaded you don't notice it because the truck needs the additional power just to stop.

My point is, too much stopping power is not a good thing at the expense of good brake reaction and feel.

just my $.02

[bobwhite]

When my wife first drove our Porsche 911 and our Citroen SM, and later the Citroen CX, she was scared by the brakes. They just stopped you so quickly. Soon they felt normal. Now the Reatta brakes scare her because they just don't stop you like most European cars. If you have never driven a car with great brakes, then the average US car feels fine. That's why I'm looking forward to putting bigger calipers on the Reatta. Too bad I have to change the 15" wheels, as I think they are very attractive.

[Ronnie]

Anyone know of any great looking 16" wheels that can be found in the bone yard that will fit the Reatta at a reasonable price? I wouldn't mind going with 16" wheels if all this upgrading works out well. It sure would be nice to see a step by step writeup of how to do the upgrade correctly and exactly what parts to use.

[Barney Eaton]

I agree that the potential problem is with a larger piston or multiple pistons that require more fluid. The master cylinder was designed for a certain amount of fluid to go to the front pistons, there is probably room of error, but if the total volumn of fluid required varies greatly, the master cylinder will not have enough travel to supply those pistons. Trial is the only way of find out.

Also, the Aurora caliper is often referred to as being bigger, I am not sure that it is any bigger, it is the design that make the Aurora a better brake than the Reatta.

It is a matter of a basic lever arm. Lets say the Reatta rotor is 12" in diameter (6 inch radius) the caliper is clamping at that 6 inch max point.

Because the Aurora was designed for larger wheels, the rotor can be larger, lets say 7 in radius, now the caliper clamps at the 7 in point and basic physics gives better stopping power.

The Aurora caliper may not have a larger piston than the Reatta, just the fact that its mounting design puts its piston out an inch further than the Reatta makes the system work.....all possible because the larger you make the rotor, you must also have room inside the rim for it to fit.

[Reattaron]

TDman asked about good looking wheels from a j-yard that will fit our Reattas. This summer i put on wheels from a 2002-2004 Rendevous (chrome 8 spoke) on my 90 coupe, and wheels from a 2003-2005 Lesabre (chrome 8 spoke)on my 90 convert. I think they look great. Just a suggestion.Oh, another wheel that i run on my coupe in the winter is the 7 spoke 15 in. aluminum wheel off the 1999-2004 Regal. Be careful buying chrome wheels from a j-yard.

[Ronnie]

Thanks for the info Reattaron. What do I need to watch out for at the J-yard. Bent rims, chrome flaking or something that I normally would not think of?

[Reattaron]

TD..... the things to look out for on the wheels from the j-yard are. The wheels that have been driven in the northern areas that use salt for traction in the winter.I've seen many wheels that the chrome was flaking off,especially on the backside of the wheel.Also look for pitting on the front side, this comes from people not washing off the break dust.

[Richard S]

I'm going to post my answer to the wheel issue on a separate thread so we don't lose continuity here.

The fluid issue is very valid one. I am no engineer so I am going to wait for the more expert of our contributors to weigh in on this issue.

[Ronnie]

Sorry, I didn't mean to hijack your thread about the brakes. I was just anxious to be able to take advantage of the updated brakes. I'll try to avoid doing that in the future.

[Guest F14CRAZY]

I wish I could experiment but my coupe will probably be back on the road around May...my dream would be to wear C5 rotors and calipers with stainless lines.

[Guest imported_dantm4]

I'm probably one of the few that actually likes the 15 inch wheels, but the brake upgrades seem to need at least 16's. With Reattaron fitting 15in wheels from other newer models on his Reatta, is it feasible that the brake calipers from these cars would work on the Reatta and be able to use the existing 15" wheels I have? With all this discussion I was also curious where the ABS sensors reside? Are they part of the caliper or are they somewhere else in the wheel assembly and how compatible would they be?

-Dan

90' Black/Tan Coupe

[Barney Eaton]

You could keep your 15" wheels and put 2" spacers between the rim and disc

[Ronnie]

Barney, I don't know if you are serious or not about the 2" spacers but in the '60 and '70s I saw a lot of Volkswagens sitting on the side of the road due to people using wheel spacers and adapters to make it possible for them to use custom wheels made for Fords and Chevys.

Spacing the wheel too far away from the hub puts too much stress on wheel bearings and lug bolts. The wheel being moved away from the hub works like a lever to vertically stress the wheel bearing causing it to overheat. Also addition stress is placed on the lug bolt.

Another problem is if any slack gets in the setup, shearing forces on the lug bolts are created between the wheel and the adapter. Most wheel adapters due not have a step that goes inside the wheel like the hub has to eliminate shearing stress on the lug bolts.

Our Reattas may have enough redundant strength built into the design of the hub/bearings/lugs that any of the above would not matter, but I doubt it.

Just something to keep in mind when using thick adapters.