Cross drilled and slotted rotors - will it fit?

[Dave]

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2DDSEP%2D5382R&N=4294908110+4294922533+4294840072+115&autoview=sku

Anybody know if these will fit my Spirit?

I ended up developing high-temp. cracks in my rotors. I need something that will help me stop at higher speeds.

Thanks.

[turbovanman²]

Looks like there for a Dakota so probably not. Search Ebay, I found a few for sale and they appeared to be high quality.


http://motors.search.ebay.com/rotors-spirit_W0QQfromZR40

[contraption22]

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2DDSEP%2D5382R&N=4294908110+4294922533+4294840072+115&autoview=sku

Anybody know if these will fit my Spirit?

I ended up developing high-temp. cracks in my rotors. I need something that will help me stop at higher speeds.

Thanks.


Drilled rotors are even more likely to crack under extreme use in my experience. The holes also reduce swept area. I think you need to upgrade to bigger brakes.

[Speedeuphoria]

Drilled rotors are even more likely to crack under extreme use in my experience. The holes also reduce swept area. I think you need to upgrade to bigger brakes.

agree

[Dave]

Drilled rotors are even more likely to crack under extreme use in my experience. The holes also reduce swept area. I think you need to upgrade to bigger brakes.

How much bigger can I go? Bigger, meaning in just the rotors? I'm still using the stock 15" Snowflake rims.

I don't neccassarily use it "extremely." I just need something the breathe while stopping at high speeds. I can't have it glazing while trying to slow down.

[89acclaim]

You can go the 11" rt / shelby disks, the 91 rt's had snowflakes.:eyebrows: Dave are you still running the stock rear drums?

Daniel Merrill

[3Bar_Mopar]

Slotted rotors work better and aren't as crack prone as drilled rotors. I just wish I knew where I could find some.

[Dave]

You can go the 11" rt / shelby disks, the 91 rt's had snowflakes.:eyebrows: Dave are you still running the stock rear drums?

Daniel Merrill

I'm still using the stock rear drums. Haven't even touched them since I've had it for 40,000 miles.

What size are my rotors?

[ShelbyZD]

The holes also reduce swept area

I've heard that they actually improve stopping power.. due to the holes acting as sort of a grip for the pads.

[89turbomini]

I've heard that they actually improve stopping power.. due to the holes acting as sort of a grip for the pads.

When you brake hard a gas is created from the pad material between the pad and rotor surface, lifting the pad off the rotor, causing soft pedal feeling and reduced braking performance. The holes allow that gas to escape and your pads stay in contact with rotor giving you more stopping power.

[ssheen]

Since it has not been mentioned yet. If your rotors are cracking due to heat, perhaps look at getting them cryoed. Many police depts get them done, and some cars come from the factory treated, so I have been told. My cryo shop mentioned a study done were the temp was read from a treated rotor and non treated on the same car. The treated was ~30% cooler than non treated.

[contraption22]

When you brake hard a gas is created from the pad material between the pad and rotor surface, lifting the pad off the rotor, causing soft pedal feeling and reduced braking performance. The holes allow that gas to escape and your pads stay in contact with rotor giving you more stopping power.


You are correct, but slotted rotors accomplish the same thing, without the tendency to crack, or as much of a loss in swept area.

[89acclaim]

10.25 Your stock vs 11.25 RT/shelby/iroc.
http://i76.photobucket.com/albums/j8/89acclaim/10.jpg

The thing that bugs me is that the replacement rotors "11.25"" for the RT's are $19 more than the ones for the 11.25" Grand vans. $42.00 vs $61.00, the only difference is the grand ones are 5X4.5" vs the RT 5X100mm. I do wonder how hard it would be to do a 5X4.5" conversion... I hope I helped.

Daniel Merrill

[zshadow]

Hawk Pads/Rotors FTW! my buddy has pads and rotors on the front of his neon and the sweet part is the hotter the pads/rotors get the better they stop!

according to a couple buddies of mine, and what i have read and researched, drilled rotors USE TO out perform regular disks. since the brake pad manufactures changed the way they make pads, its a little different. the pads use to emmit smoke when they were used heavily, hence the drilled/slotted rotors to vent out the gases that were released and help grab the disk better. but since the material that is used is different it wont make too much of a difference slotted vs not.

the 11in rt brakes are a deffent upgrade! i switched them on the shadow when i had it, and man it stopped on a dime. if i were you id get the rt calipers and buy some hawk hps pads, rotors, and the super blue racing brake fluid, and call it a day. garuntee it'll be much better.

~Kevin

[turbovanman²]

The thing that bugs me is that the replacement rotors "11.25"" for the RT's are $19 more than the ones for the 11.25" Grand vans. $42.00 vs $61.00, the only difference is the grand ones are 5X4.5" vs the RT 5X100mm. I do wonder how hard it would be to do a 5X4.5" conversion... I hope I helped.

Daniel Merrill

Wouldn't be hard on a car with the 4 bolt on bearings. Just get a Grand wheel bearing and bolt it on, then get the Grand rotor and some new wheels, your good to go, :amen:

[dodge80_89]

Slotted rotors work better and aren't as crack prone as drilled rotors. I just wish I knew where I could find some.

Ask and you shall receive...http://www.raceshopper.com/sp_dodge.shtmlhere is a link that I found not too long ago. When I found it they actually had prices listed. If I remember correctly the front rotors for my 88 shelby z were $110 for the set, both right and left, and $90ish for the rear rotors. They have cross drilled, slotted, cross drilled and slotted, diamond slotted. They have them for a lot of different models. Hope that helps.

[Speedeuphoria]

I looked at all the local parts stores and napa has the cheapest 11" front and rear rotors. I printed out a napa online shopping cart with those items since it was a little cheaper than the actual store and they gave me the better price. They have the fronts for $26.99 and the rears for $24.99 vented or solid. Best prices by far. So I don't see why people are complaining about they cost more, I have them and the look goood and reasonable.

[89acclaim]

Wouldn't be hard on a car with the 4 bolt on bearings. Just get a Grand wheel bearing and bolt it on, then get the Grand rotor and some new wheels, your good to go, :amen:

I figured that but I haven't pulled some apart and tried it. Thanks for the conformation turbovanman, that very well might be the cheep upgrade on my nest TM...;)


I looked at all the local parts stores and napa has the cheapest 11" front and rear rotors. I printed out a napa online shopping cart with those items since it was a little cheaper than the actual store and they gave me the better price. They have the fronts for $26.99 and the rears for $24.99 vented or solid. Best prices by far. So I don't see why people are complaining about they cost more, I have them and the look goood and reasonable.

I was saying about the nice Brembo rotors at tirerack, two weeks ago it was $20.00 on sale. No complaining here, I just bought a Daytona Shelby to rob the brakes off of.:eyebrows:

Daniel Merrill

[turbovanman²]

I looked at all the local parts stores and napa has the cheapest 11" front and rear rotors. I printed out a napa online shopping cart with those items since it was a little cheaper than the actual store and they gave me the better price. They have the fronts for $26.99 and the rears for $24.99 vented or solid. Best prices by far. So I don't see why people are complaining about they cost more, I have them and the look goood and reasonable.


Remember this, the cheaper the price, most times the cheaper product. Instead of using pure metal, they use recycled tin cans. How else can they make a rotor for $26.99?

[Speedeuphoria]

Yeah well I got the brembo fronts when they were on sale at tirerack.com and got the rears from napa so will see how they hold up. You could cryo them with a bunch of other stuff and probably be better off, who knows.

There are still bargins in this world and just because one vendor sells the same part for more than the other dosen't mean it is better, its just more profitable. Look at Forwardmotions tourque convertor for like $900, Kevin Davis let me in on the same one for 1/2 price(and that is w/ modified 904 splines), no BS

[csteffee]

You are correct, but slotted rotors accomplish the same thing, without the tendency to crack, or as much of a loss in swept area.

Excuse me, Just how much swept area do you lose when you SLOT a rotor.

I keep saying this. If you want to keep your drilled rotors in one piece CHAMFER THE DAMN HOLES! 1/16" out x 1/16" deep both front and back.
The leading edge of the unchamfered holes are super heating and that's where the cracking starts. Chamfer the holes--increase the surface area--brake better, longer

Running the same drilled rotors on my road course Omni, my brother's Cavalier Z24, and my other brother's Saturn SC for FOUR, THREE and FIVE SEASONS respectively without cracking. I guarantee you we hit these brakes a heck of alot harder than you guys ever will.

BTW The swept area loss thing is cute though. Never heard that one before.

I haven't cryo'd these or had them "flame hardened" they're just a good grade of over the parts counter rotors.

[contraption22]

Excuse me, Just how much swept area do you lose when you SLOT a rotor.

A minimal amount compared to drilling. And you lose even more when you....



CHAMFER THE DAMN HOLES! 1/16" out x 1/16" deep both front and back.
The leading edge of the unchamfered holes are super heating and that's where the cracking starts. Chamfer the holes--increase the surface area--brake better, longer

Running the same drilled rotors on my road course Omni, my brother's Cavalier Z24, and my other brother's Saturn SC for FOUR, THREE and FIVE SEASONS respectively without cracking. I guarantee you we hit these brakes a heck of alot harder than you guys ever will.

Perhaps they were made correctly with the holes cast into the rotors rather than drilled in after the fact. Or maybe your vehicles are light enough to not really tax your brakes all that much. I have had several customers have problems with drilled rotors after track days... but these were fast, heavy cars, like Vettes, SVT Mustangs and one bad---- track prepared Chevelle. All of them switched to either slotted or plain-old flat rotors and experienced no cracking and no detriment to braking performance.


BTW The swept area loss thing is cute though. Never heard that one before.

No? Google much? http://www.google.com/search?hl=en&q=drilled+rotors+swept+area]




Here is a tidbit for you from http://www.rennsportsystems.com/2c.html

Porsche used cross-drilled rotors with mixed success. The Zimmerman rotors used on the 930 Turbo brakes were very soft and crack prone, even though the holes were chamfered. The later Brembo rotors will also show some wear when used with most performance brake pads. Some of the best rotors in the world are made in Britain by AP and Alcon. Those rotors, when properly adapted, seem to be superior to the Brembo ones in terms of wear and crack resistance. All drilled rotors will crack sooner or later if overheated. Slotted rotors are more durable in this regard however they are heavier. One reason that most large iron rotors are cross-drilled is to save some unsprung weight. Since nice big, light, carbon rotors cost $1000 each, saving some weight without bankruptcy, is important. Plus, carbon rotors possess very little friction until they reach 500-600 degrees F. Porsche's PCCB ceramic matrix rotors while very light, seem to have mixed success when used for track events.

[csteffee]

No.1 The slotted rotors I've seen have a hell of a lot more material and surface loss than I've seen in drilled. Get a like set of each and weigh and them. the lighter the rotor the more surface area lost. With drilled (Unless your like some ricers boys who like to "lace curtain" their rotors) the loss of "swept area" is nominal. Besides the gains you get in increasing the contact patch of the pad because it's not undulating under the piston more than makes up for the loss.

With slotting you run the rotor walls thick and thin. When the rotor heats up where will it heat up first? Where it's thinnest. Where will most of the heat be transfered? Where it is the thinnest. Where will cool off first? Where it's thinnest. YOU say they aren't prone to cracking. Knowing a little about metal fracture tendencies I would say there is a better tendency for cracking in the long run and warping in the short. (How many seasons do your "fast" "heavy" cars run on a set of slotted rotors?)

"Perhaps they were made correctly with the holes cast into the rotors
rather than drilled in after the fact. Or maybe your vehicles are light
enough to not really tax your brakes all that much."

Thanks for acknowledging that there are cross-drilled rotors that work.

Sorry buckwheat but 9" ventilated cross-drilled brakes on a 3200 pig of a Cavalier is hardly what I would call lightly taxing. On all three cars in competition we've all overheated our brakes to fade many times. No cracking. All the rotors we use are the best part store rotors we can get. I plotted the drill patterns on my CAD system, transfered the drilling points to the rotors and drilled AND CHAMFERED every hole on my drill press.

Now as far as your fast/heavy friends go, driving style has a lot to do with overheating of brakes. I've seen these guys heat their rotors to the surface temperature of the sun trying to brake with me or go deeper in a corner. They just need to realize that Miss Piggy can't hang with me there. And your right they probably did have problems with cross-drilled rotors on Vettes, Chevelles and Rustangs. So what Turbo Dodge weighs anywhere near these guys (even in "race" trim). Go cross-drilled.

[turbovanman²]

I have never seen a cross drilled rotor that wasn't cracked, on passenger cars or race cars. I had a Limo come in for an inspection a few months ago, guess what, CD rotors, and guess what-CRACKED. He paid alot for them AND they were less than a year old. He's not a late braker either.

[contraption22]

No.1 The slotted rotors I've seen blah blah blah blah blah blah


Ok you win.

[Dave]

lol okay slotted it is.

I'm gonna hunt down a local guy here (he's got a turbo Miada that he road races) and get his opinion for a heavy car and brakes. I raced him once by the way. That sure was fun. :eyebrows:

[Directconnection]

Why bother with trick rotors if the rest of the system isn't ... trick? Would you really be taking advantage of them on a street car when you should be installing R/T or the 11" brakes first?

[Clay]

Remember this, the cheaper the price, most times the cheaper product. Instead of using pure metal, they use recycled tin cans. How else can they make a rotor for $26.99?

sorry simon, they dont make cans out of tin anymore.

(and most of the aluminum products you buy have recycled aluminum in them)

[89acclaim]

sorry simon, they dont make cans out of tin anymore.

(and most of the aluminum products you buy have recycled aluminum in them)
I believe he is talking about the tin coated steel cans, that most people still refer to as "tin cans".

Daniel Merrill

[Clay]

yeah I know. but any opportunity I have to give simon some crap, is an opportunity I dont miss! ;)

[Dave]

Let's focus now.

I spoke with a vendor at The Steel Valley Nationals about brakes and he said the only way to stop "faster" is to go with a taller brake rotor.

So can I buy a 11.25" R/T rotor that's slotted, anywhere? That, 911 pads, and some DOT 5 brake fluid should do the trick.

[BIG PSI]

Let's focus now.

I spoke with a vendor at The Steel Valley Nationals about brakes and he said the only way to stop "faster" is to go with a taller brake rotor.

So can I buy a 11.25" R/T rotor that's slotted, anywhere? That, 911 pads, and some DOT 5 brake fluid should do the trick.


Just keep you high speed driving for the 1/4 Drag Strip!!!!!

Dad

[turbovanman²]

sorry simon, they dont make cans out of tin anymore.

(and most of the aluminum products you buy have recycled aluminum in them)


OYE, its a phrase, figure of speech, sheesh, :(

[omnivore]

I can't believe that no one has even mnetioned going with minivan calipers and pads on your existing size of rotor. This is your absolute easiest and cheapest method of greatly improved braking performance. You caliper's piston will be almost 30% larger in area than your current one, and minivan pads are almost double the swept area of your current pads.

[turbovanman²]

I can't believe that no one has even mnetioned going with minivan calipers and pads on your existing size of rotor. This is your absolute easiest and cheapest method of greatly improved braking performance. You caliper's piston will be almost 30% larger in area than your current one, and minivan pads are almost double the swept area of your current pads.

Unless you have a Minivan already, :eyebrows:

[Clay]

I can't believe that no one has even mnetioned going with minivan calipers and pads on your existing size of rotor. This is your absolute easiest and cheapest method of greatly improved braking performance. You caliper's piston will be almost 30% larger in area than your current one, and minivan pads are almost double the swept area of your current pads.

Does all this still apply with a spirit?????? I know its true for an l-body, but figured a spirit would have bigger brakes just becuase its a bigger car.

[3Bar_Mopar]

Sorry buckwheat but


Why the attitude? :confused:

[3Bar_Mopar]

I can't believe that no one has even mnetioned going with minivan calipers and pads on your existing size of rotor. This is your absolute easiest and cheapest method of greatly improved braking performance. You caliper's piston will be almost 30% larger in area than your current one, and minivan pads are almost double the swept area of your current pads.


Since I'm too lazy and it's too late/dark to go check....will the calipers on my '89 Turbo mini be bigger than the ones on my 1990 Daytona with 11" brakes?

[turbovanman²]

Since I'm too lazy and it's too late/dark to go check....will the calipers on my '89 Turbo mini be bigger than the ones on my 1990 Daytona with 11" brakes?

No, the 11 inch setup uses 60mm pistons if my memory is correct.

[capev86]

my advice....run regular rotors and ceramic pads!!! those pads take heat like crazy, have a long life and the rotors last a lot longer too!!!

i put Morse ceramic pads from autozone on my 89 lesabre and they have like 3/4 of their life left after 2 years. i picked up a set for my rt brakes going on my k wagon. Morse only makes them for 91+ applications, so thats a good excuse to upgrade your knuckles and front brakes!!!

[omnivore]

The rotor size of the minivan is the same as an ES Spirit, so you can run your stock wheels with no worries, and the rotors are dirt cheap. The added clamping force of the minivan caliper with the added swept area of the minivan pads will offer your biggest bang for the buck, and you need only swap out calipers and caliper locating brackets to minivan ones. And minivan stuff is alot more common to find for cores etc, than 11" Daytona CS/RT stuff.

[89acclaim]

The rotor size of the minivan is the same as an ES Spirit, so you can run your stock wheels with no worries, and the rotors are dirt cheap. The added clamping force of the minivan caliper with the added swept area of the minivan pads will offer your biggest bang for the buck, and you need only swap out calipers and caliper locating brackets to minivan ones. And minivan stuff is alot more common to find for cores etc, than 11" Daytona CS/RT stuff.

It isn't hard to peace together a 11" setup for close to the price of cross drilled/ slotted rotors. Get a 91 k-frame/ knuckles/ a-arms with 91+ "15" wheels" grand van calipers and offsets and use some new rotors. I bought a 91 k-frame with associated parts for $50. :D http://www.napaonline.com/masterpages/NOLMaster.aspx?PageId=430&CatId=3&SubCatId=4

Daniel Merrill

[20w/ashelby]

Ok I gotta jump in.

Cross-Drilled are not as bad as people make them out to be. A tendency to crack yes, but just like anything, the better the product the less likely it is to fail. I would avoid Ebay rotors. I know too many people with horror stories. X-Drilled and Slotted rotors are amazing. You may not notice the extra stopping power but it's the insurance that helps. Pads last longer. They are basically good for the whole brake system as long as they are good quality. Poor quality(which most are) are absolute crap and probably give them a bad name. When done right something with a circular hole can not be more prone to cracking. Think about it logically.

If you just want your brakes to withstand agressive driving you would be fine with just rotors and a sound brake system. Anything else screwed up in the system puts extra strain on the rotors. If you really want to stop faster then yes get some bigger hardware. In all of my cars personally I found that when everything is in good working order(caliper, piston, seals, pads, rotors and fluid) there is much less abuse on the whole system. I think pads play a much bigger role than they have been credit to so far.

[csteffee]

Ok I gotta jump in.

Cross-Drilled are not as bad as people make them out to be. A tendency to crack yes, but just like anything, the better the product the less likely it is to fail. I would avoid Ebay rotors. I know too many people with horror stories. X-Drilled and Slotted rotors are amazing. You may not notice the extra stopping power but it's the insurance that helps. Pads last longer. They are basically good for the whole brake system as long as they are good quality. Poor quality(which most are) are absolute crap and probably give them a bad name. When done right something with a circular hole can not be more prone to cracking. Think about it logically.

If you just want your brakes to withstand agressive driving you would be fine with just rotors and a sound brake system. Anything else screwed up in the system puts extra strain on the rotors. If you really want to stop faster then yes get some bigger hardware. In all of my cars personally I found that when everything is in good working order(caliper, piston, seals, pads, rotors and fluid) there is much less abuse on the whole system. I think pads play a much bigger role than they have been credit to so far.

I agree but there's on more point I failed to make previously. The cross-drilled rotors you guys talk about (if I'm not mistaken) are drilled thru each vane. The drilled rotors I made for me and my brothers are only drilled every other vane. There's enough overlap of the drills to bleed gases with out perforating the rotor till it's freaking swiss cheese. THOSE I could see cracking (with apologies to Mike M). As far as pads go there is a DEFINITE difference. There are low gas emission pads that use a different binder the name escapes me now. But I think the best system to use for the street is the mini van. you can't beat it for brake swept area in a fairly compact package. I'm running 11" on my Omni but, I'm thinking of changing to these for road racing.

[omnivore]

If cross drilled rotors were a bad design, then Porsches, ZO6's, BMW M cars, and numerous other cars capable of insane performance, as well as every single sportbike making over 65 hp wouldn't come with them from the factory.

I made some of my own, 5 yrs ago, and still no cracks. I used minivan rotors from Wagner to start with. the minivan rotors are the same overall size dimensions as Daytona or GLH ones, but have thicker rotor faces, and a little thinner vent/van channel betweeen the rotor faces. More material = less chance of warpage or cracking. I also staggered my holes so no two were side by side in one vane, and they progressively swept in 1/4" towards the center as I moved over one vane, until they got close enough to the center hat area that the pad wouldn't get to them, then I began the next row back near the outside again. I basically followed the same drilled pattern as my Honda CBR600 had.

[Boogieman142]

i got my rotors for 15.?? each for the fronts. 10.25"

[Boogieman142]

so if i have a 93 lebaron sedan, with ate 10.25 fronts, will ones from a mini be any better?

[Boogieman142]

well, i meant mini calipers.

[89acclaim]

well, i meant mini calipers.

The calipers for the 11" rotors are the same between the vans and the cars. Though the vans are 4.5" spacing and the cars are 100 spacing, the rotors and the bearing insert are the only different parts. You can swap in the 11" fronts pretty cheep.

Daniel Merrill

[89acclaim]

I saw that on TD you are looking for parts. You can find the calipers and the rotors new at napa for a not bad price for the fronts. You need to get the caliper spacer from a 91+ grand van with the big bolt pattern 11's. If you wanted too you could swap to the big bolt pattern 11s on front and the van drums on the rear, but you would have to change alloys then.

Daniel Merrill

[Boogieman142]

i am going with 11" rear disc, and i want to upgrade the fronts but everyone seems to tell me something different.

[89acclaim]

You can do a 11" front with the info from my previous post. If you need any help feel free to pm me.

Daniel Merrill