CADCHRIS

Thanks Mc_Reatta for your well written explanation because I couldn't believe what I was reading in the article..... I still don't get it. I guess no one can give me what God didn't..........or, just buy his book! So no matter WTF I do, the car's not going to stop any shorter distance with my current mods. now vs. the o.e. setup vs. the big brake setup as discussed here over the years? So it's just less braking effort and being able to use my pinky toe to stop the same distance with the big brake mods vs. me standing on the brakes now? I just made an impression/rubbing of the part #'s under my master cylinder on my Brougham tonight to see if I indeed at least have the right Delco m/c that I bought a few years back and I'll have to do the same on the Eldorado tomorrow. I'm so disappointed. I was hoping for really shorter stopping distances.

With consideration of what that Brake Engineer states, I did a quick look up of the different calipers pistons and calculated the area of the pistons: Instead of calculating the area in square inches, I calculate the area in milimeters. Original 10.25" Rotor: 91 Eldorado/Reatta Caliper: CENTRIC 14262088 - single piston 63.5mm piston bore = 3166.92 mm piston face area 2003 Aurora / 2004 Deville 11.92" Rotor; Caliper: CENTRIC 14162146 - single piston bore 63.5mm piston bore = 3166.92 mm piston face area 2000 Camaro 11.92" Rotor; Caliper: 2 Piston CENTRIC 14162126 - (2) 45mm pistons/bores = 1590.53 piston face area x 2 pistons = 3181.06 mm total piston face area. I used this simple calculater below: CalculateMe.com - Calculate the Area of a Circle So I guess I kind of jumped the gun.....sorry. Looks like the piston areas are very close between all 3 calipers so it should not affect the master cylinder like the Engineer states when going to larger calipers. I just wonder what the total extended piston area would be to lamp the rotors for all three calipers.......:confused: I won't even go there! I'll compare the Rear STS conversion as compared to the original calipers and edit this......... Let me know if I'm not making any sense and doing these calculations correctly, but I was just trying to rationalize this Engineeringly! 1991 Eldorado/Reatta Rear Caliper - CENTRIC 14262521 = 38 mm piston bore 1996 STS Seville Rear Caliper - CENTRIC 14162548 = 38mm piston bore Looks like everything is the same hydraulically in (fluid displacement), except for the increase in Rotor Sizes and Larger Pad contact areas.............don't know if that could somehow be negative. It would also be interesting to somehow compare all 3 cars master cylinders hydraulic displacements as there could be some benefit there if they could be converted. Just a random thought...... I'd still be interested in knowing stopping distances and pedal feel from those who have performed this big brake upgrade.

Memory Relapse......I just remembered "WHO" mentioned Porterfield Pads to me last week.....It was the Raybestos Tech Line Guy who said that's what he uses on one of his vintage hot-rods.....pretty funny. Anyway, here's how I got linked to the "SAE Brake Engineers" pg. I got a very long detailed e-mail back from HydroBoost and he basically said : " I do know that this will dramatically increase your overall braking in both vehicles, to the point of not having to pursue any further upgrades at the wheels! But now I'm still concerned with what I read and do not fully understanding on the "Brake Engineers" pg. below. Hydroboost indicated that my 91' Fleetwood Brougham utilized something called a "3 Piston Quick Take Up Master Cylinder with a exaggerated rear register size......" I said to myself: "A What?":confused:................So I had to do a search on that kind of MC I had. So here's where I started, but just go to the other 3 links below. Note the link in post #11 no longer worked and I used "Waybackmachine" that revives dead links: braking force, quick-take-up, - Automotive Forums .com Car Chat And here is where I ended up: James Walker, Jr. (SCR Motorsports) is a licensed and registered Professional Engineer specializing in chassis, brake, and electronic brake control systems http://www.teamscr.com/about-james-walker-jr/about-james-walker-jr.html See this article under "THE CALIPER". http://www.teamscr.com/motorsports/tech-articles/34-braking-systemsin-plain-english.html?showall=1 He cautions about using larger piston or multi-pistons with more fluid to piston area which does not match the rest of the systems original design. BUT, he does not state anything about using larger rotors when upgrading to a larger caliper, so maybe it balances the end result....... I don't know what to make of all this now. Could the upgrades that have been put together here going from the 10.25 to 11.92 rotors and single or 2 piston calipers be just "Dumb Luck" and it works just because it does??????! A long time ago, I think I once read somewhere that the caliper must match the master cylinder or something to that effect....... Here's his book: "High Performance Brake Systems" by S/A Books: http://www.teamscr.com/the-book/about-the-book.html Sample pages from his book: http://www.teamscr.com/the-book/sample-pages-pdf.html Here is the main Tech Page: http://www.teamscr.com/motorsports/tech-articles.html Has anyone here who has gone "Bigger" ever performed a before and after 60-0 brake test maybe using a G-Tech, Vericom, or Smart App to measure stopping distance? I'll have to read the NTSB link that Mc_Reatta posted above...... Mc_Reatta, I'm sure you've seen info somewhere in that paper that contradicts what this engineer is saying.....

Thanks "wws944". Yeah, I've heard about specific temp ranges in pad selection. I have AXXIS Metal Masters on both Cadillacs. I'll have to find my old boxes because I think one was Axxis Ultimate's and the dealer I bought all my stuff through can't determine what I bought due to an error when they entered all my parts on the invoice. Someone recently told me about Porterfield Pads who make them for HAWK. I just did a search on AXXIS pads and found these debates of Axxis vs. Hawk.......interesting reads. Hawk HPS vs. AXXIS metalmaster - DSM Forums How does Axxis Metal Master and Hawk HPS compare? - BMW M3 Forum.com (E30 M3 | E36 M3 | E46 M3 | E92 M3 | F80/X) Axxis Metal Master vs Hawks pads - RX7Club.com Maybe I should just go back to Delco Pads. Now I've really got a headache after some other stuff I read from a well known SAE Brake Engineer........I hate to post it, because it just might get me banned here! :eek: But, I need you guys to look at it even though I'm still going to upgrade to the bigger brakes like everyone else did here.......I'll post it up soon. Regards, Chris

Like I mentioned in post #99 for my Eldorado: "I put a lot into my original brakes trying to improve them for daily driving. I upgraded to front/rear Powerstop or Centric's X-drilled/Slotted rotors, Axis Pads, new Delco Master Cylinder, fr/rr Wagner reman. calipers and new rear proportioning valve, and fr/rr stainless steel braided hoses including powerflush and bleed and still NO improvement in stopping!!!!!!!!!!! :(" On my 91 Fleetwood Brougham: NEW: stainless steel braided hoses, Wagner calipers, Axis pads, Delco Master Cylinder, , x-drilled Raybestos front rotors and new Raybestos shoes, Wagner wheel cylinders with hardware and pressure flushed. I did not put a front proportioning valve on the Fleetwood that goes under the Master Cylinder. I still may buy a Phoenix Reverse Pressure Bleeder since the concept seems logical. Something tells me its inherent to the design of the Brake Booster on both of my 91's. I wish I could find the same models to drive and compare them too. This is why I was reach'in for the stars on all the crazy brake mods......

Thanks for the link. Like I mentioned, on both my 91 Eldo, and Brougham had all upgraded factory components, even if I stand on the brakes in an emergency low speed stop around 35mph, they won't bite and feel glazed. They both DO NOT have a high hard pedal under normal braking like a bad booster. One anomaly that really bothers me is when jamming on the brakes, the pedal does not go down quickly and is slightly hard. This only happens when quickly applying the brakes and it is momentarily hard and feels like I'm trying to push the pedal through sand. I even hear a woosh sound on both cars that I presume is coming from the booster action. The booster is the only part I have not replaced on both cars but its been doing this for years. It holds vacuum and passes other tests so maybe there is something going on inside. I even thought about increasing booster ratio. I think I really noticed it when renting a few newer cars and how touchy and powerful the brakes are with newer technology. Still kind of p.m.o. that these brakes never felt right. Well...........I know where I've been, and I know where I'm going! Bigger Brakes! I still have to figure out what to do on the Fleetwood and is limited to doing discs in the rear, and upgrading to better friction in the fronts.......

Thanks McReatta, I'll have to measure my Eldorado Wheels. Now I know why 16's are needed. How about lay'in those Engineering sites on me! I like to read crap I don't understand. The HydroBoost claims more psi to the caliper which should be greater clamping force when even more pedal effort is used, right? I'd still like to see their hard data before and after. Some of their demo vids testing looked authentic like here at 2:12 but I wonder what system they had when they say before / after: Of course, It looks like it was with the stock system and the improvement was with a total big brake system and custom suspension ect. and huge a.ssss tires along with their HydroBoost......so hard to compare what the HydroBoost does by itself: http://www.classicperform.com/ProjectNova/ProjectNova.htm Handmedownreatta; Wow.............what a link and website. Thanks! That guys got his sh-t together. Very interesting projects including his GM HEI to DIS conversion. I have to pass it around to see if we can do the same for our Cadillac 4.9' HEI's. What that guy was doing in brake mods in the link you posted reminds me of what I saw on the Impala sites brake upgrades for the Imapal's, Carpice, and my Brougham. A guy over there also offers a piece mill version using some parts and hubs from the company KORE3 but uses DBA rotors that are only thicker and not larger in order to keep 15" wheels, but I think the concept is not beneficial unlike going to larger diameter rotors all together like KORE3 offers: KORE3 Industries LLC: On and Off-Road Performance Automotive Components I'd post the Impala link if you want, but its so confusing and doesn't apply here.

Thanks.........sounds more complicated than what I was imagining. I was hoping others who had tried it would really know where it was hitting and from what measurement, and how much of a spacer was needed to clear a 15" wheel without making the front end stance of the car look ghetto-goofy. I'd also have to back-space the rear the same so the tracking is not off. I guess I'd have to buy/borrow some calipers and brackets from the parts store bolt it up and see how much my 15" wheel needs back-spaced and still look o.k. I wonder if the Caddy 15" wheel is different in certain dimensions than your Reatta 15's.

Thanks guys.....informative write-ups. Mc_Reatta; I think I once heard something to the fact you mentioned about rotational force applied further away from the center of rotation now that I think about. Probably when I was researching how to improve my brakes way back. I wonder if we both read it on one of the "Big Brake" mfgs. sites like Willwood, Baer, Stainless Steel Brake Corp., Stoptech, Brembo.... Do you have any links that talks about the concept that you know of? I wonder if that concept directly applies to drums? But of course drum system have their own issues which I'm also trying to decide what to do for my 91 Fleetwood Brougham since the guys on the Caddy/Impala Forums are converting the rears to Impala/Caprice discs and I'm still debating on using the product below that eliminates the vacuum booster and convert to a "Hydro-Booster" which will give me more clamping force without having to go with the front big brake kit and larger wheels. Is this the front 2 piston caliper from the 2000 Camaro/Firebird you guys are using below?......the fins are on the top not sure if there will still be enough clearance though to use a 15" wheel. Hopefully someone might remember who ground their's down for more clearance and which wheel they used: Product Detail I was so disgusted back when I did all those upgrades to the original set up, I was wondering if maybe increasing the booster size would improve clamping force. I then stumbled onto a few full page ads by different company's for this device in the Street Rod and Trucking Magazines called a "HydroBoost" where you eliminate the booster and use power-steering hydraulic pressure to assist the brakes which far exceeds booster clamping force pressure. Good Video: V8TV, Muscle Car Of The Week, V8 Speed & Resto Shop 314.783.8325 - Hydroboost Brake Booster Cures Bad Brakes Hydratech Braking: Welcome to Hydratech Braking Systems :: High Performance Hydraulic Brake Assist Systems I know that I'll be happy with the upgrades everyone here figured out, but I was really looking down that path back then when I didn't know what to do. I'm sure the HydroBoost would do a lot, but would probably warp even x-drilled/slotted original sized 10.25 rotors. It would be interesting how much it would do since they sell a universal unit. I wrote to them yesterday about my 91 Brougham and also asked them about my 91 Eldo. I'll let you know what they say. "Handmedownreatta": So the backside/inner of the stock 15" Reatta wheel is larger in diameter? If you ever take that wheel off, can you measure it. Do have the 2 piston calipers on your front yet? Or can someone else measure a the inner back edge diameter of a Reatta wheel who might have it off the car? Just for laughs, I want to be able to stop my Eldo so hard and fast, this happens! See :33 sec mark: Thanks, Chris

I was even considering these different mods since I was so disgusted with my brakes I didn't know what to do a few years back. More cool technology in brake pad cooling....just posting for the h'll of it just in case some of you guys are really gett'in on that center pedal or racing your Reatta's: STUFF WE LIKE: Fade Stop Brake Coolers | Safe BrakingSafe Braking Four Products Four Products - CoolShim Technology Fade Stop Brake Cooler Water Cooled Brakes on GTR's! Willall Racing WR35WS Brake Cooling System for Nissan GT-R | Nissan GT-R News - GTRBlog.com Idea: DIY heatsink brake pad shims: Grassroots Motorsports forum: Grassroots Motorsports Magazine Patent Info on Brake Pad/Caliper Cooling: Patent EP1929171A4 - Brake pad cooling apparatus and method - Google Patents

Thanks Daniel, I'm glad to know the p/b will be 1 pump because I was wondering. The rear STS conversion is what I'll do. Thanks also McReatta for answering my question.........I think I want to do one of the bigger conversions either the DeVille/Aurora or Camaro/Firebird because the Eldorado is a little heavier than your Reatta's and is really scary trying to stop it. I wonder if I could get enough clearance by grinding down the top heat-sink fins on the Camaro/Firebird duel piston calipers and still use my 15" wheels: Product Detail If so, I wonder if NuLock NU-LOK | PISTON CUSHION or any others make the titanium piston ring isloator shims which stops heat transfer into the caliper which I'd use if they are made for those 2 piston calipers like even these from "Hard Brakes": Hard Brakes - Titanium Brake Backing Plates, Brake Shims, Brake Heat Shields D749 Titanium Brake Heat Shield for Chevrolet Camaro, Pontiac Firebird [TS-T-D0749] : Hard Brakes - Titanium Brake Backing Plates, Brake Shims, Brake Heat Shields I put a lot into my original brakes trying to improve them for daily driving. I upgraded to front/rear Powerstop or Centric's X-drilled/Slotted rotors, Axis Pads, new Delco Master Cylinder, fr/rr Wagner reman. calipers and new rear proportioning valve, and fr/rr stainless steel braided hoses including powerflush and bleed and still NO improvement in stopping!!!!!!!!!!! I really wished I would've researched this back around 2006 when I did everything because I would've probably at least seen Scott Persons/The Autoshop's conversion info that he posted in 2006 on his site. I just hope I could somehow use my 15" wheels with the bigger conversion. Not sure how that 16" DeVille wheel will look but that's the only wheel I like. I don't think I'd be happy with the Grand AM Conversion which was noted to be marginal over the o.e. design but Grand Am does at least use aluminum calipers for the front and has slightly 3/4" larger rotor. Bigger is definitely better to get these cars to stop and I'm just driving around town and not even on the track.......so many idiots cutting in front of me down here in S. Florida, jamming on their brakes, and people walking out in front of me and I can't believe I haven't hit anyone or anything yet, so I drive it like I'm "Driv'in Miss Daisy" at 19mph with those puny 10.25" rotors ! This is the reason I tried to improve on what I had which still didn't do crap. I can't believe GM let these cars go with such inferior undersized brakes for even safety sake. Of course, it wasn't until 1997 the 11.92 rotors were available in DeVilles/Aurora's and then became intengrated into other models in the latter years. So much for the NTSB back then. The original brakes just always feel glazed. Not sure if you guys experienced that feeling with your Reatta's under heavy or emergency braking situations with the smaller rotors????????? Thanks again for your advice, Chris

Thanks guys. Daniel, I've seen that thread a while back and forgot about it so thanks for posting it again. So there are basically 3 stages of upgrades for the front brakes......right? #1. 2000 Grand Am 10.94 Rotors, Aluminum Single Piston Calipers. Use 15" Wheels. #2. 2000 era Aurora/Devilles 11.92 Rotors, Cast Iron Single Piston Calipers. Use 16" Wheels. The best: #3. 2000 Camaro/Firebird 11.92 Rotors, 2 Piston Aluminum Calipers. Use 16" Wheels. I still hope someone knows that if option #2 or #3 is used, can wheel back-spacers be used to clear the calipers/rotors if still wanting to use a 15" wheel? By the way, I went looking for this old thread regarding the rear brake rattles on the 91 Eldorados. Hopefully it will help you guys with Reatta's....... Note post #8, #10, and #24 for some good solutions to stop the rear brake pad rattle. 91 Eldorado rear brake pads rattle Here are some items that "MAYBE" could be made to work to stop the rear brake rattles on your Reatta's. Not sure if you would have to drill the brake pad or not but maybe someone could come up with a way to use these clips used on a C4 Vette with the same problem: C4 Corvette Anti Rattle Clips Carlson Quality Brake Parts #H5610 1988-96 Anti-Rattle Front Clip | Vette Brakes & Products Maybe Carlson makes something specific to stop the rear brake rattle.... Carlson Quality Brake Parts Sites: Carlson Quality Brake Parts - Putting it together in Brake Parts! [ Quality Brake Hardware ] C3 Corvette Pad Inserts that slide over the ends of the pads: C3 C2 Corvette Brake Anti-Squeak Kit 1965-1982 - Mid America Motorworks

Thanks "HandMeDownReatta". Very informative. Another question for you guys. I've read a few times where it was always brought up if these brake conversion would fit your 15" wheels. Is it a backspacing problem where the caliper hits the back of the wheel's face, or do the larger calipers or rotors hit the inner radius of the 15" wheels? If it's a backspacing problem, why not use high quality "hub centric" wheel spacers which would also provide a wider track. I saw that Jon/63Viking did this on his rears, but was not "hub centric" and was a "lug centric" setup: http://forums.aaca.org/f116/new-brake-upgrade-255932.html A quick search showed some very good vids on "The TUBE: Eibach Wheel Spacers, but nothing really close in their product line to our lug pattern ect....: Eibach Site: Wheel Spacers | performance-suspension.eibach.com "Lugmanusa.com" looks good: This guy looks like he knows his stuff and made in the USA. Long but very informative video: "Mywheeladapters.com": Regards. Chris

Thanks guys! Yes I'd like to upgrade to this 16" Caddy wheels: http://www.lawheel.com/newchrome/4507/w06.JPG The original 15" Snowflake Wheel: 1991 Cadillac Eldorado | Flickr - Photo Sharing! I guess I should somehow start to compare wheel specs. from the Eldo:Reatta:Trofeo: and the new wheel to see if I'm going to have a problem or buy a used 16" wheel like above and mock up everything. I'm glad the whole 5x115mm and 5x118mm is not going to be a problem. I've checked out "The Rock" (Rockauto's site) to get an idea of what I'm looking at. I can't remember from everyone's discussion on this forum when or what makes/years the special brake hose banjo bolt is used or if there is a hose mod needed for one of the upgrades single or 2 piston???????? Daniel; I'm curious, what years for the Grand AM and do you think it will fit the 15" wheels? Scott Person from The Auto Shop link above said it could be a problem using the single piston caliper from the 2004 DeVille, 98' Aurora and others that use the 11.92 rotor on the same cars with the JL9 Code which "I think ??" he's selling in his kit. By the way, I just wanted to mention this innovative company I found a few years ago since you guys are really into brakes! They might have applications for the upgrades you guys are doing but not for our original brakes: Pretty cool technology! Looks like some of these parts are private labeled for Raybestos by Nucap. NuCap DRT: (Drag Reduction Technology) pad springs I don't see them for the 2 piston calipers but I think they have them for the single pistons like the DeVille, Aurora: DRT Nu-Lok ( Piston Cushion/heat isolator) probable not beneficial with Phenolic Pistons or if they even have an application for a 2 piston caliper : NU-LOK | PISTON CUSHION Brake Align Latteral Runout Correction Plates: BRAKE ALIGN™ - LATERAL RUNOUT CORRECTION PLATES They have other technologies also that are integrated into mainstream brake pad manufacturing. Not sure what brands or if the Hi-Performance Pad companies use their specialized "Backing Plates". There's a "2 Guys Garage" video that talked about it also......missed that episode. NUCAP | Videos They have lots of videos about their technologies. I think NAPA carries the DRT, Nu-Lok, and Brake Aligns. Just a few "Centavos" for you guys! Now I have to figure out what I'm go'in do. I hope something will fit my orig. 15" or flashy 16" wheel I'd like to get! This should be your theme here: "Drive hard...........and brake harder!" Regards, Chris

Hi Guys. "Good Threads Should Never Die"! Over the past few years, I saved many of your "Brake Upgrade" threads and was overwhelmed and impressed with what everyone had accomplished here with the complex brake upgrades to your Reatta's . To answer "Greg Ross's" question above from 2007, here is the link I also saved from Scott Pearson/ The Auto Shop's tutorial which hopefully helps a little of where all this "Craziness" of big brakes may have started: GM E Body 12" Front Brake Conversion Installation Or here is the website. Just close the address and insert ".": www (dot) theautoshop (dot) net/12BrakeInstall (dot) htm That is where I basically started with wishing to upgrade the front brakes on my 91' Cadillac Eldorado which is why I'm here asking for advice for my "Cadillac" so I hope I'm not way out of line for not being a "Reatta Guy"! Anyway, I hope all the experts can lend me a hand and your thoughts are greatly appreciated. The 1991 Cadillac Eldorado has 5x115mm rotors like your Reatta's use....right? My first concern is that the upgraded 12" (11.92") rotors from the 2004 DeVille, 98' Aurora, and others use a 5x118mm bolt pattern. Will these fit on a 5x115mm bolt pattern like my Eldorado uses, along with your Reatta's, and like the original Scott Person upgrade above on the Olds Toronado Trofeo that also used the 5x115mm pattern? Did I miss somewhere that everyone needs to re-drill the 5x118mm rotors to fit the 5x115mm pattern or is it close enough to fit the original pattern? I'd also like your thoughts on taking this mod further like some of you guys have done with the Camaro/Firebird duel piston calipers, and rear large caliper upgrade I also read about that Daniel put together a few years ago. By the way, does anyone have the current link to the rear upgrade or any other new info on "Ronnie's" site that was mentioned in post #22 here by Ronnie? http://forums.aaca.org/f116/new-brake-upgrade-255932.html Thanks to anyone and everyone, and I appreciate your thoughts because this is the only place that "Can Help" on this subject! Hope everyone had a Happy and Safe 4th of July! Kind Regards, Chris