# 4x100 big front rotor suggestions please



## boner (May 19, 2002)

hoping for some collective Vortex wisdom here. I'm looking increase the clamping force at the front end of my mk3 race car. it would seem that a good and surprisingly cheap way to go about this would be via some boxster 4 piston calipers (seen as low as $250 in some places). as part of that, upgrad, i'd also want to go for some ~12" rotors (16" wheels, which are cheaper and lighter than 17s, nevermind the tire aspect). i have access to (and credit at!) a quality machine shop to make whatever braketry needed to get it all to fit.

i would LIKE to stay 4x100 though in order to avoid the costs associated with 5x100 conversion (mainly the custom axles i've recently had made!).

are there any cars out there that you can think of that are 4x100 and have ~12" rotors that are readily available???

would it be simpler and in the end easier to get some Wilwood 2-piece rotors and hats... or custom machine hats if needed?

EDIT: another one which may provide better pad selection is from a late 90s lexus ls400....


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## OddJobb (Nov 6, 2004)

4x100 rotors in that size are impossible to find. 

The only 4x100 size that I can think of that you can buy separate from a kit are the 11.3" rotors from Techtonics Tuning. 

http://techtonicstuning.com/main/index.php?main_page=product_info&cPath=2_13_175&products_id=1269

I think early 2000 model Saabs had 4x100 bolt patterns but the offset may be different. I spent hours one time searching for such rotors and couldn't find anything. You'll probably spend the least amount of money on the Eurospec 11.3" upgrade for the MKIII (or even less if you get the parts from a junkyard and get the rotors from TT). If you go any larger than the 11.3" rotors, your going to need custom carriers.

http://store.blackforestindustries.com/eumk34xfrdiu.html

FWIW: I upgraded to the Eurospec 11.3" kit from the stock 10.1" kit and that alone made a HUGE difference in stopping power.


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## boner (May 19, 2002)

Well, i think in the end what i'll do is use audi tt 12.3" redrilled to 4x100 mated to boxster calipers and custom brackets.

I'll make myself a jig to redrill and call it a day.

Simpler solution as rotor holes have a bunch of slop in them (so a simple jig and hand drill will suffice) and as for the brackets, i have credit at a quality machine shop. Plus, don't hafta change outer cvs AND i can also correct geometry via balljoint extender, which can't be done with plus suspension...

If all goes to plan, might supply the parts to those that want.

The goal here is to significantly increase braking force at the front due to constant rear lockup under even moderate braking. Next year, i hope to have ~2x the power so it'll be important to really be able to drop the anchor. Increased clamping force, bigger pad area and greater leverage should do the trick!


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## Truckinduc (Apr 24, 2011)

I'm currently running wilwood 11" rotors and 4 piston forged dynalight calipers on my mk3 spindles. I plan on going bigger soon and this will be my setup. 

Afco F88 forged 4 piston calipers. 

11.75" wilwood rotors 1.25" wide

Mind you this is for 15" wheels. 

If I were you I would run the 12.19" rotors with the 1.25" width opposed to the .810" width. These rotors are 2 piece and use the common 8 x 7" bolt pattern. Wilwood makes aluminum hats with that pattern in 4x100 with multiple offsets. 

Calipers

http://www.speedwaymotors.com/AFCO-...liper-125-In-Rotor-1-3-4-In-Piston,66885.html

Rotors

http://www.speedwaymotors.com/AFCO-...ane-Slotted-Rotor-125-Inch-RH-Side,66961.html

Hats

http://www.wilwood.com/Hats/HatList.aspx


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## boner (May 19, 2002)

hmmm, interesting caliper. never heard of them before, they look to be monoblock construction too. will hafta do some research. seems that i'll still hafta get brakets made too... you got a 11.75" rotor/caliper to fit under a 15" wheel? that's impressive. if i can stick to 15" that'd be great... rubber is cheaper that way! is your wheel an OEM or aftermarket. right now i'm using a beat up set of passat 15s... the castelettes but the uglier cast version....


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## Truckinduc (Apr 24, 2011)

Afco specializes in dirt track racing where the wheels are 15" so theoretically the brakes should fit. Spoke clearance may be an issue with the 1.25" width stuff (opposed to the .810")

The calipers are forged but they are 2 piece. 

This is my current 15" wheel setup with the 11" wilwoods.


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## boner (May 19, 2002)

whoa! that's freakin impressive!!! so many questions!

how long is your extender? looks at least 2"

what was your welding methodology? ie: preheat, post weld heat? can it be done with a 120v welder?

why did you put the calipers on the trailing side as opposed to leading side of the upright?

what are you using this setup for?


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## Truckinduc (Apr 24, 2011)

boner said:


> whoa! that's freakin impressive!!! so many questions!
> 
> how long is your extender? looks at least 2"
> 
> ...


extender is 2.5", the longest i could run with the 15"s

I used er70s-2 with minimal pre heat. Kept the welds short to avoid excessive heat. when they were finished the bores were .0015" out of round, (wish i would have measured them before hand but i didnt think to) but i think pressing the bearings in straightened them out. A 120v should do it, If i recall right i did these with my eastwood tig. somewhere around 110 amps max. 

I did a trailing setup because i like to be different and i want the caliper weight towards the center of the car, not hanging out over the front. I had ample clearance since the extenders require the ball joint flip and move it down another half inch or so. 

I built this setup for my street driven MkII. The entire setup is now for sale so i can fund a new setup using the afco calipers and fully fabricated sheetmetal uprights of my own design. 

http://forums.vwvortex.com/showthread.php?6933011-Big-brakes-and-drop-pin-spindles


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## boner (May 19, 2002)

Hmmmm, you give me baaaaaad ideas

I wanna stick to bolt on stuff so that when i stuff it into a wall, i can get cheap replacement at the scrap yard. But now you've got me thinkin.

From you mk2 thread, You seem to know how to glue thinks together! Opinons on mig vs tig on the upright? Would probably just have more warpage but shouldn't have strength issues right?

EDIT: one last question bout the welding. did you determine if the knuckle is iron or steel? if i interpret correctly, if steel, MIG welding it is no biggie but iron presents issues, especially when used as a knuckle is....


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## OddJobb (Nov 6, 2004)

boner said:


> The goal here is to significantly increase braking force at the front due to constant rear lockup under even moderate braking. Next year, i hope to have ~2x the power so it'll be important to really be able to drop the anchor. Increased clamping force, bigger pad area and greater leverage should do the trick!


This may not solve the rear bias problem. Your Golf has a proportioning valve on the rear beam that can be adjusted to add/remove rear brake bias. The valve is dependent on the suspension position of the car under braking. Adjusting this is necessary on early non-ABS MKIIIs when the suspension and/or rear brakes are modified.


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## boner (May 19, 2002)

OE prop valve went a loooong time ago, even before the rear beam was tossed in favour of syncro. its a manual prop valve in the cockpit. still couldn't restrict it enough. 

gonna try a few things this season but ultimately stiffer calipers, bigger front brakes, non boosted MC is the goal... with maybe an A6 rear subframe as opposed to the crappy syncro rear suspension......


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## Truckinduc (Apr 24, 2011)

How about a dual MC pedal box with a bias bar?


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## boner (May 19, 2002)

Truckinduc said:


> How about a dual MC pedal box with a bias bar?


it's making its way onto the list... think i'm gonna start with the non boosted mc to start later this season and see how it feels. also doing more aggressive pads up fron t and shyte ones in the back to see if that corrects it. had HP+ and ceramics out back and it helped but not enough. this year, hawk blues and the ceramics.... should be a good stopgap...

still only have 205s for tires so the brakes are probaly going to be adequate. hopeing to build a ~400hp engine next winter and wanna get at least 225s for tires eventually. brakes will become an issue at one point...


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## boner (May 19, 2002)

So i did a spark test and weld test on a spare knuckle. Huzzah! It's cast steel not cast iron! Played with a coupla beads too. Regular s6 wire

The lateral one going all the way across suggests it's definitely doable with a MIG. Probably can optimize the wire used tho....










Soooo, armed with this knowledge, completely custom setup, here i come.


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## Truckinduc (Apr 24, 2011)

Whoops i forgot to answer. As you know now yes you can mig it. Personally id do some bending tests and make sure your material will bend before the weld fails, just to be on the safe side. Im 95% sure they are forged, not cast. Id also give them some pre heat with a torch before doing any structrual welds.


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## Truckinduc (Apr 24, 2011)

and be sure to grind down to clean steel and prep everything properly.


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## boner (May 19, 2002)

Oh ya, definitly aware of needing to do that. Just that i'd seen all manner of nasty pics of cracks on a simple bead on top of cast... Was afraid that's what would be the case here. When i do the actual work on them, they'll be sandblasted and preheated on the bbq

I'll try that bend test as well. But i figure i need the more appropriate wire before i do that...


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## Truckinduc (Apr 24, 2011)

Ive found that even sandblasting leaves them dirty with media stuck in them. here is my method. 

sandblast, blow off with compressed air thoroughly, wash with soapy water, compressed air dry. acetone and clean stainless wire brush right whre the weld will be. 

Brakes are one of those things you dont want to leave to chance.


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## jimbbski (Jun 3, 2007)

Just an FYI I believe that Mini's come with 4 X 100 rotors. I think that they are about 11 inch but you can look that size up on line.


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## jimbbski (Jun 3, 2007)

Truckinduc said:


> Ive found that even sandblasting leaves them dirty with media stuck in them. here is my method.
> 
> sandblast, blow off with compressed air thoroughly, wash with soapy water, compressed air dry. acetone and clean stainless wire brush right whre the weld will be.
> 
> Brakes are one of those things you dont want to leave to chance.


I've done a few brake mods like this on other cars and what you should do is grind the metal in that area to remove the outer layer. This helps get rid of any surface contaminants and you end up with a cleaner weld.
Most of the ones I did were for some Lemon race cars. I put Mini Cooper rotors on some Kia steering knuckles that went on a Ford Festiva that has a Mazda BP engine out of an early 90's Ford Escort GT swapped into it!
Talk about parts sharing!

FYI. I believe that the Mini has 4 X 100 wheel bolt pattern.


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## boner (May 19, 2002)

Don't worry, generally, i know enough to be dangerous but not enough to try sumthin without askin!!! Parts will be blasted, cleaned and cycled a coupla times in the bbq before welding.

How on gods green earth did you figure out that chump setup?!?!?!


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## jimbbski (Jun 3, 2007)

I can't take credit for all of the parts swapping. The race team that runs that car came up with that combo through internet research. The Ford Festiva is Korean and based on a Mazda design. Kia is also Korean and the steering knuckles seem to just be bigger versions of the Festiva. The rotors off the Mini was just because they were bigger and had the right bolt pattern to fit. 


Here's a link to info on the last race they ran and won their class. I was there as "team engineer/consultant".
It's the bright yellow Festiva with fender flares and a wing on the roof.

http://blog.caranddriver.com/lemons-wisconsin-winners-bmw-beats-acura-by-two-seconds/#more-126121


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## boner (May 19, 2002)

what about going "lo-fi"? just trolling the interwebs and it seems that ebay is littered with 4 piston calipers from Toyota tacomas... they fit 11.7" rotors and seem to go for bout $75 for the pair. in my case, I don't particularly care about unspring weight as its not like it's professional racing or anything.... I was at the track this weekend and basically, even with the hawk blues, the brakes just don't provide the clamping I need.

wilwoods are nice to look at but they are not cheap and it would seem they flex a lot. methinks a big cast iron deal from a major OEM won't.... although I bet pad selection is gonna limited for a taco... will hafta look into that particular one closer.


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## boner (May 19, 2002)

hmmm, i know not 4 psiton but possibly all the improvement i need. g60 dual piston calipers. i can make a bushing to sort the overhand problem but searching on the Hawk website reveals that the g60 caliper uses the same pad as the 280mm single piston brake. makes me wonder if i can plop a g60 caliper on a 280mm caliper carrier.....

anyone know?


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## petethepug (May 25, 2001)

Girling 60 on the Mk III 4x100 is the best bolt on bang for the buck. Make sure you get the girling 60 brackets/carriers too. Their almost the same cost as the semi loaded (with brackets) listed below at Rock Auto. A lot of folks complain because of their unsprung weight contribution. Funny thing is any other oe set up will add even *more *unsprung weight. The g60 rotors you'd use are 5.7lb They do clear some 14" wheels. The non abs Mk III have 22mm master cylinder so there's plenty to feed the girling 60's and keep the same pedal feel.

The 11.3" DE set up is a slightly heavier single piston caliper with heavier rotors
The 12.3" TT are even heavier but have twin piston calipers. 

http://jettajunkie.com/vw-jetta/sho...-dual-piston-caliper-on-mk3-2.0-(93-early-99)

http://www.rockauto.com/dbphp/x,catalog,171,partnum,12989,d,NASTRA_12989.html Left - 2 Left $75.79 with the bracket *inc *the core charge.

http://www.rockauto.com/dbphp/x,catalog,171,partnum,12988,d,NASTRA_12988.html Right - Last one

Just mentioned this to Frank. If you find a good deal on eBay for 99-05 Porsche 911/996/Carrera calipers (Part #'s 996.351.425 and 996.351.426), this kit for £104.99 works on Mk II (Mk III 2.0) spindles w/ a 305x28mm Cupra disc @ 7.9lb (#6KL 615 301). Not sure what the unsprung weight would be but NO OTHER Mk III 2.0 would be better braked. 

http://www.creationsmotorsport.com/p...il.php?pid=135









You'd have something that looks like this (custom 305 discs but with the Porsche calipers) ....
http://www.clubgti.com/showthread.php?240916-15s-over-305s








Same discs with the oe Seat Ibizia Cupra (4x100) 305x28 discs running the oe Brembo calipers and brackets/carriers
Loaded red Brembo caliper with carrier (left): Seat part # 6KL 615 123
Loaded red Brembo caliper with carrier (right) Seat part # 6KL 615 124
Individual carrier: Seat part # 6KL 615 421










NEED TO EDIT THE USE OF THE Creation Motorsport caliper adapters above. They're made to use REAR Porsche calipers on the FRONT of VW cars. There are NO REAR PORSCHE CALIPERS made that carry enough fluid to be used on the front of any VW car. You'll experience the equivalent of pulling your hand brake when stomping on the pedal.


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## boner (May 19, 2002)

Daaaaaaamn. That's some good info, thanks man

EDIT:

i only had about 3 seconds to look at this last night... g60 calipers are on the menu because of their cost competitiveness. i had been told locally that they can be purchased any and every day... your rock auto links scare me..... but maybe that means i;ll just buy them now as opposed to when i am doing the actual work.... they're a cheap first step so if it's still not enough, not the end of the world and i'ld be able to sell them to get some of my money back. i want to try and use them on the corrado g60 carriers if at all possible so that i avoind the pad overlap issue (as minor as it may be).

those 305mm rotors are definitly interesting. very good to know about so that i can just change the brakes and not everything else. also exceedingly happy that the adapter brackets are steel.... i would sooner get my own made in steel than use aluminum ones, can't believe people think that's a good idea :facepalm::screwy:

i guess the real dilemma to figure out now is do i go 16" now in case i wanna go to the 305s or stick with 15" and hope i don't need to get more brake....

EDIT 2:

oops, i got my PNs mixed up... g60 uses a different pad. that's unfortunate but it's not like i'd be able to use the same pad if i went for a brembo right away....


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## petethepug (May 25, 2001)

Gotta use Girling 60 caliper brackets w/ Girling 60 calipers on any VW. I might be confused though. The Corrado g60 uses Girling 54 calipers and Girling 54 brackets. Did you mean you were going to use Girling 54 brackets on the Girling 60 calipers? Won't work. If I misunderstood, never mind.

When "g60" brakes are mentioned it all goes to hell. The Nastra (semi loaded) rebuilds are the best bang for the buck. If they run out just get the loaded version with the pads for a few bucks more the try the Centric brand.


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## boner (May 19, 2002)

Lol, ya, g60 gets everything confused!!! When i first wrote that i could use my existing pads, i thought i was looking at a g60 pad listing which had the same pad form as my existing pads. But i realized today i was looking at a g54 listing sooooo ya, i gotta use the g60 carrier not my g54 (corrado g60) carriers

Oops, mixup pn my part....

Damned g60 being such a common use term in vag-land....


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