SRT Brakes on an R/T: Getting around the knuckle issue. What about a bracket?

[Junior]

So I know a lot of folks try to put SRT Brembos on R/T cars, and you can't do it without the SRT knuckles.

Without getting into the other options (such as Wilwoods, which I have on the front, and love), and without having gotten my hands on the SRT knuckles to compare them, I'm wondering if it would be possible to make a bracket to adapt the SRT Brembos onto the R/T knuckle?

That's essentially what Todd TCE (http://www.lxforums.com/board/member.php?u=3662) did to adapt the Wilwoods onto the LX - a custom bracket.

If someone could do the same, it would sure open up a lot of doors, and folks wouldn't have to search all over for knuckles.

Before getting into who and how much, would it even be dimensionally and mechanically possible to adapt the SRT brakes onto an R/T with a custom piece?

For me, I'm looking at the rear setup, but I suppose the question applies to the fronts as well.

[ZeGuru]

:popcorn:

[Junior]

Anybody seen them side-by-side and have any thoughts?

[SublimeDaytona268]

Hmmmm, if I could take a look at how somebody's Brembos bolt up, I could probably tell you exactly how similar (or not) they are. I did the WIlwood install myself and know/understand exactly how the bracket works, so if I could just see a Brembo caliper up close I could tell you if the bracket idea is even worth pursuing.

I have a feeling it is..... so you might be onto something Jr!

-Pat

[RobAGD]

here Jr

http://www.robagd.com/cars/robs/brakes/rear-knuckles-srt-rt.jpg

-R

[Junior]

^^^ I assume that's the SRT mounted, and the R/T in your hand, right?

They appear to be essentially the same except for the brake mounting bosses, don't they?

Maybe I'll shoot Todd a note and see if it's something that's possible. If so, then whether it's practical is a whole other thing, but one step at a time...

Thanks fellas.

[MAGFX]

Hey Mike, in a couple of days I will have my brakes off, since I am switching my rotors and pads (long story). If you could drop by, we can do a show and tell and maybe figure something out. I have to take my car to the dealer either tomorrow or the next day, then I will be ready. I'll let you know.

[Junior]

Heck you could probably make them! :mrgreen:

Yeah, let's get together.

[blumagrt]

Hey junior let me know how that goes, I'm in the same boat, I have the front brakes on my rt but don't have the knuckles for the back and something like your idea would really be helpfull if you come up with something.

[gameover]

Interesting! Keep us post Junior. :popcorn:

[Todd TCE]

Maybe I'll shoot Todd a note and see if it's something that's possible. If so, then whether it's practical is a whole other thing, but one step at a time.

I "could" be done. Perhaps.

The need for the custom bracket is not out of the question. However the hole spacing is but part of the question. You'd also need to know the caliper mount offset relative to the center line of the rotor being used. With all the parts on hand...I'm sure I could come up with something (if possible). Is it really worth it?

[Junior]

I "could" be done. Perhaps.

The need for the custom bracket is not out of the question. However the hole spacing is but part of the question. You'd also need to know the caliper mount offset relative to the center line of the rotor being used. With all the parts on hand...I'm sure I could come up with something (if possible). Is it really worth it?

Let me send you that PM - wanna run a couple things by you first.

[SublimeDaytona268]

I "could" be done. Perhaps.

The need for the custom bracket is not out of the question. However the hole spacing is but part of the question. You'd also need to know the caliper mount offset relative to the center line of the rotor being used. With all the parts on hand...I'm sure I could come up with something (if possible). Is it really worth it?

Todd, if I remember correctly, I believe buying new knuckles/spindles from the dealer is QUITE costly.

If you could make a bracket to allow Brembos to mount up to sotck R/T setups, Im sure that would make the swap A LOT easier for people to do. Heck, before going with the Wilwoods, I almost opted for Brembos, but turned back on it because all I could find at the time were rotors/pads/calipers.... no knuckles or spindles or whatever else was needed.

I think this bracket would be worth your time to make the swap that much easier, but it's obviously up to you. You'd still be getting the business in the end.

Then again, I should make it clearly known that I think the Wilwood setup is vastly superior to the Brembos.... but that's just my opinion!

:beerchug:

-Pat

[OLJustice]

I have a front SRT setup on my RT and posted a thread about my observations about the difference between the 2. Here is a link: http://www.lxforums.com/board/showthread.php?t=124628

Hope this helps!

[gameover]

^^Very interesting thread. Someone should give that a try if they have an extra knuckle laying around. Looks like the hole needs to be a tad bit larger to fit the caliper bolt.

[RobAGD]

Mike yes the SRT is installed and the RT is in my dads hand.

-R

[MattRobertson]

.. I should make it clearly known that I think the Wilwood setup is vastly superior to the Brembos.... but that's just my opinion!That makes two of us. If you really drive the car, Wilwoods give you pad choices that make the Brembo's a very poor alternative by comparison. If you are after performance, SRT take-offs are not the solution unless you get them *real* cheap and are willing to settle for lesser capability.

[RobAGD]

That makes two of us. If you really drive the car, Wilwoods give you pad choices that make the Brembo's a very poor alternative by comparison. If you are after performance, SRT take-offs are not the solution unless you get them *real* cheap and are willing to settle for lesser capability.


3x on this and I have the Brembos. I got them stupid stupid cheap

You can find many post from me for peopel asking about the Brembos, the thing they have going for them is the name.

-R

[Cam]

That makes two of us. If you really drive the car, Wilwoods give you pad choices that make the Brembo's a very poor alternative by comparison. If you are after performance, SRT take-offs are not the solution unless you get them *real* cheap and are willing to settle for lesser capability.


um, X4 guys. Not long ago, I made that comment in front of HalV, he almost busted a gut laughing. But I'll stand behind Matts words 24/7.

[Junior]

Well, I've been firmly in the Wilwood camp too - I love mine.

But if someone has Brembos to mount, and no knuckles to be found, I think this may be an elegant solution, as I've said elsewhere.

[gameover]

^^Agreed. If all it takes is to drill the holes bigger on the RT knuckle to mount the calipers, that would save people a lot compared to purchasing the take-offs or a BBK. Now all we need is someone to be a lab monkey. :mrgreen:

[LX HEMI]

I hope this doesn't work. I'll be pissed at all the money and hours I spent on the Brembo set up. J/K...maybe...

Since I changed to Brembo's my car sounds like the front suspension is going to fall off. Knocking, creeking, rattling, banging. I hate driving the car now!

[OLJustice]

I hope this doesn't work. I'll be pissed at all the money and hours I spent on the Brembo set up. J/K...maybe...

Since I changed to Brembo's my car sounds like the front suspension is going to fall off. Knocking, creeking, rattling, banging. I hate driving the car now!

Is that the Brembo's making all that noise? Here I thought that it was my takeoff SRT suspension going bad... Can you describe this in more depth?

[SublimeDaytona268]

^^^Hmmmm, very interesting outcome. DId you do the install yourself? I fos, might just wanna double check things and go over everything twice. If not, Id take it bakc to who ever put it on for you. Those are definitely problems you should not be having.

-Pat

[Junior]

Here's more food for thought - if drilling the fronts works (and that remains to be seen, not just about the drilling - as Todd mentioned, the centerlines must match as well as the height off the radius), even so, it won't work on the back - the bosses are obviously different distances apart.

Another thing that may keep this from working is the fact that on the Wilwoods, the bracket mounts to the caliper via vertical studs, whereas on the Brembos, the caliper mounts directly to the bosses. It'll be much clearer when we can put them next to each other, and harder to put into words. The Wilwoods mount from the top, whereas the Brembos mount from the back... no bracket will solve that (at least not the bracket that I've been visualizing).

[SublimeDaytona268]

Here's more food for thought - if drilling the fronts works (and that remains to be seen, not just about the drilling - as Todd mentioned, the centerlines must match as well as the height off the radius), even so, it won't work on the back - the bosses are obviously different distances apart.

Another thing that may keep this from working is the fact that on the Wilwoods, the bracket mounts to the caliper via vertical studs, whereas on the Brembos, the caliper mounts directly to the bosses. It'll be much clearer when we can put them next to each other, and harder to put into words. The Wilwoods mount from the top, whereas the Brembos mount from the back... no bracket will solve that (at least not the bracket that I've been visualizing).

I totally understand what you are saying here. Folks who have never seen the Wilwood setup are probably scratching their heads right now, but I got ya.

Im still not convinced that a bracket cant work for the Brembo though. Id need to see one of those in person before I entirely wrote off the idea. I understand what you are explaining, but I think somethign could still work.

-Pat

[LX HEMI]

Is that the Brembo's making all that noise? Here I thought that it was my takeoff SRT suspension going bad... Can you describe this in more depth?

^^^Hmmmm, very interesting outcome. DId you do the install yourself? I fos, might just wanna double check things and go over everything twice. If not, Id take it bakc to who ever put it on for you. Those are definitely problems you should not be having.

-Pat

Yeah, did the install myself. Got the kit from CPaP.
1. never noticed any of the clunking, rattling, creeking, swoosh-swoosh-swoosh(rotors i think), until after the job (sounds like if you were to take all the bushings out from the front end and drive it like that)
2. i think maybe CPaP gave me bad rotors (from 06 charger, I think theres a TSB on those rotors)
3. I've taken it to the dealer and had most of the front end (suspension, tie rods) replaced, rotors turned. helped for a few days then gradually got worse.
4. I'm ready for someone to A. steal my car or B. some idiot to run a red light so I can smash into them. That's how bad it is, I hate driving it now. :panic::panic:

[Junior]

There are some more pics on this thread:

SRT8 Brake Upgrade Package Spindles, Hubs, Calipers, BREMBO, COMPLETE! (http://www.lxforums.com/board/showthread.php?t=137574)

[SoCal Gixxer]

i have a set of 5.7 spindles somebody that could try drilling, if they lived locally, i live in huntington beach

[OLJustice]

FYI I have a set of front RT spindles (duh... i replaced mine!) that are lying around...

[Junior]

I wouldn't try drilling the knuckles without a good drill press and a lot of clamps, and of course the right drillbit and cutting oil... don't put it in your lap and use a DeWalt... ;)

But even before that, I'd make sure to check the centerlines and the "radial height" for lack of what I should probably be calling it.

But even if the rears don't work, this could be a good (relatively easy) front caliper swap solution.

We still may be getting together this week to tinker a bit.

[SublimeDaytona268]

Yeah, did the install myself. Got the kit from CPaP.
1. never noticed any of the clunking, rattling, creeking, swoosh-swoosh-swoosh(rotors i think), until after the job (sounds like if you were to take all the bushings out from the front end and drive it like that)
2. i think maybe CPaP gave me bad rotors (from 06 charger, I think theres a TSB on those rotors)
3. I've taken it to the dealer and had most of the front end (suspension, tie rods) replaced, rotors turned. helped for a few days then gradually got worse.
4. I'm ready for someone to A. steal my car or B. some idiot to run a red light so I can smash into them. That's how bad it is, I hate driving it now. :panic::panic:

Wow, I am totally blown away by this... Never heard of anything like this happening before.

Im quite fascinated as to what could be causing all these problems. Ive never heard of anyone say that theyve had so many problems with a Brembo swap.

Sorry to hear about your misfortune (honestly, I am... I cant imagine not even wanting to drive my car!). However, I am incredibly curious as to what is causing these problems. Do keep us posted if you ever get it worked out.

-Pat

[Junior]

Yeah, me too - I hadn't commented on it, but I'm really curious as well.

[LX HEMI]

sorry for the thread hijack

[HEMIDON]

I have considered this too. Some things to think about, the rotor center offset, rotor thickness and the diameter need to be considered. There are 2 piece rotors that can be had allowing a hat with the proper offset and various thickness and diameter rotors. The stock SRT knuckles and calipers fit a larger rotor than a stock RT, thats why they need 20" wheels. I'm sure someone could make a bracket that would make the Brembo calipers fit in a 18" wheel. The Brembo calipers are actually an inner and a outer piston housing bolted to a bracket that bolts to the knuckle. With some fabrication a replacement bracket could be used. With some research, a bracket from another application might be available that would work. Whatever is fabricated or modified, a lot of consideration needs to be given to the strength of the mounting points. Simply ovaling out the existing holes in the knuckle or caliper would weaken the mounting area. Also our knuckles are threaded to accept the mount bolts. If the knuckle holes were offset then they would have to be welded up and the threaded holes repositioned.

I'm sure it can be done but, would the work and cost be better spent on an available caliper / rotor set up?

[MattRobertson]

Simply ovaling out the existing holes in the knuckle or caliper would weaken the mounting area.I've been thinking the same thing. If there's one place you don't want to be potentially removing structural integrity, I have to believe the front brake caliper mounts are close to the top of the list.

I'm sure it can be done but, would the work and cost be better spent on an available caliper / rotor set up?The knuckles aren't cheap to be sure. $700 each or something ridiculous like that? Makes a bracket awfully attractive if you can't find the pieces cheap at a junkyard.

[devilrt]

if u only have to open the holes up 10 thousandths them is will not weaken the knuckle at all you just have to drill it out right

does anyone have pics of the willwood setup

[Todd TCE]

Assuming one was to oversize the holes or elongate them a bit for the bolts to fit (validity of such aside) that puts the caliper in "position A" relative to where the pad sits upon the rotor. Now, unless that same spot is the same as "position B" on the SRT spindles the pad may or may not sit at the same place.

The key is that the top (viewed as the outer edge) of the pad should be flush with the edge of the rotor. Swapping the calipers alone even if the holes are off but .020" of an inch won't guarantee this. You might find that the then required rotor size is perhaps 13.830" diameter. Obviously here neither the stock RT or SRT part will fit this without a bit of work. And as I mentioned before; that's assuming the rotor and caliper centerline all line up as planned based on the interface of the caliper ears to those drilled out spindle ears.

FWIW, aside from the brilliant cost cutting design of those oem Brembos...aluminum housings bolted to some universal iron bracket body mount (i.e. it can be used on a lot of other oem apps pretty quickly) I don't see anything about them that has me excited. They are a low budget, high mark up, dealer demand selling point but not much of a quality part. I say that not as a competitor but having looked at the package and been less than impressed.

[Junior]

I will be tearing all my stuff apart tomorrow, and I'll try to take as many pictures as I can. Any requests, let me know.

Long story short, I found an entire set of brand new SRT brakes, for what Rob called "stupid cheap". I know that they're not what the Wilwoods are, but I couldn't pass it up - they were essentially free after the swap.

So tomorrow, I will have R/T knuckles, SRT everything, and Wilwood front Bls6r Calipers and rotors, all side by side.

Let me know what you want to see, and I'll try to get pictures.

[Junior]

Well, I'm pretty well convinced that this idea won't work.

On the rear, the spacing between caliper mounting bosses is different, as is the centerline offset.

On the fronts, the spacing is the same, but the mounting hole sizes are different, as is the centerline offset.

I didn't bother trying to mock up the SRT calipers to the R/T knuckles to check the radial height, because I think it's a moot point.

I'm waiting until tomorrow to finish the install, because I found out too late that the rear dust shields are different, so I could still take some pictures and take measurements if anyone needs convincing, but as for me, I'm convinced it won't work.

The knuckle swap is pretty straight-forward, and I did take some pics of the tricky bits, so if anyone goes the full SRT swapout route, I can help you through it. I won't be doing a step-by-step on it though.

[Todd TCE]

Kind of a lot of work for nothing eh? My guess all along was that if it were that simple, someone would have done this by now. But it's always worth a look.

[MattRobertson]

I didn't bother trying to mock up the SRT calipers to the R/T knuckles to check the radial height, because I think it's a moot point.
Beans to you for using 'moot' in a sentence, both spelled correctly and in proper context. 2 million red beans go to the first guy I catch saying "mute point".

[RobAGD]

Mutt point ? We talking about dogs now ?

-R



:mrgreen:

[SublimeDaytona268]

'Preciate you gettin down to the bottom of this Jr. Even though the commentary has been to a minimum on this thread (aside from a few of us), Im sure there were some people keeping a watchful eye on this thread for the outcome.

Had it turned out otherwise, I think Todd would be a busy guy making up brackets for people!

Either way, it was worth a shot if you ask me.

-Pat

[gameover]

Thanks for clearing this up Junior. On a side note, are you swapping out your wilwoods for the srt take-offs? What are your plans with your wilwoods?

[Junior]

Either way, it was worth a shot if you ask me.
Yeah, I really thought so too.

It's pretty clear to me now, the reason it won't work is the fact that the Wilwoods are radial mount - which if I understand it correctly is what you and I mentioned before - meaning that they mount from above, not beside. That lets you make a bracket to spec, to fit exactly what you need it to.

On the Brembos, the mount is integral to the caliper. There's no room to fit a bracket in between the caliper and the knuckle.

Here's the SRT knuckle on the left; and the same with the bracket on the right (I was just confirming what we already knew - that the spacing was the same on the SRT front knuckle):
http://i117.photobucket.com/albums/o73/itllgrowback/Projects/Brembos/IMG_6448.jpg http://i117.photobucket.com/albums/o73/itllgrowback/Projects/Brembos/IMG_6449.jpg

And here are the two front calipers, side by side (keep in mind that some of the Brembos' mass is due to the fact that the mount is integrated):
http://i117.photobucket.com/albums/o73/itllgrowback/Projects/Brembos/IMG_6437.jpg

And here's why we bother: :mrgreen:
http://i117.photobucket.com/albums/o73/itllgrowback/Projects/Brembos/IMG_6462.jpg

[Junior]

Thanks for clearing this up Junior. On a side note, are you swapping out your wilwoods for the srt take-offs? What are your plans with your wilwoods?

Yeah, I found a deal I couldn't pass up on the entire set of Brembos, brand spanking new, all four wheels, with knuckles.

As for the Wilwoods, I offered the first right of refusal to the fellow who acted as my go-between on the sale (because the seller was out of state, and I wanted to be sure I wasn't being taken for a ride). He said he was interested, but if he turns out not to want them, I'll post them up here for sale. It's the front setup - calipers, rotors, hoses, hardware.

[HemiPowered5700]

I don't know what is going on.

[skippytrailer]

WOW !!! that pic of the rears is CRAZY !!! soooo puny next to the SRT !

Need any help with yardwork for the Wilwoods? hahaha I'll exchange labor for those !!

big backyard !!

[SublimeDaytona268]

I don't know what is going on.

Do you ever?

Try to keep up here, kiddo. This thread is a good read for someone like you, being in the market for brakes and all.

-Pat

[HemiPowered5700]

Dude, I'll just wind up buying the same kit you have....I'm not going through all this.

[Junior]

Dude, I'll just wind up buying the same kit you have....I'm not going through all this.

That's the best way to go. Talk to Todd, he'll get you squared away.

[SublimeDaytona268]

That's the best way to go. Talk to Todd, he'll get you squared away.

Oh trust me Junior.... he knows. That joker was supposed to go in on a two-car deal with me for brakes from Todd but he couldnt do it at the time.

But when the time comes, Ill make sure he talks to Todd, no question about it. He has seen all the parts up close when I received them, and he too was highly impressed with the quality of the Wilwood setup.

-Pat

[Todd TCE]

Kinda interesting seeing things side by side by side really. For size I'd like to see the W6a included with those too as it is a more "full size" part than the SL6. Not that size alone is a direct indication of function, just the visual.

Oddly enough the rear caliper is really a more quality piece than what I've seen in the past. It's really a correctly built part (two body halves etc) whereas the front ones are the "budget el cheapo" parts I've seen others taken apart for service. My money says the rears are shared with some other app and the fronts were built for this car that needed something not already available. Look at the basic construction of both including the more conventional external cross over tube. Seems the rear is also a differential bore part. Curious to the size of those two pistons- check below the rubber bellows too as they can be larger than you see at the top.

FWIW the correct term on the mounting is "radial" vs "lug" mount. The Wilwoods being radial, the Brembo lug.

If you guys want to dig deeper here.....check out a set of the common Evo Brembo take offs. They have a wider mount than what these have I think but the body type is identical to the rears- not the iron/alum hybrid shown here. Maybe there's hope for that to work somehow with a lug mount adapter?

Hat's off to Jr here too. He's got a lot of time into all this!!

[Junior]

Thanks Todd. I can measure the piston bores if you want some numbers. I ordered the rear backing plates, but they got SNAFU'd in dealer transit, so I just went ahead and notched out the 5.7 ones. Pictures will make that clearer... did that just before I went to school tonight, after putting the project on hold for a day while I waited for them to come in - and they didn't... so anyway, I'll have the rears back together tonight.

Long and short of it, the rears are still off, and the fronts are coming loose again tomorrow temporarily, so I can measure the bores if'n you want.

And there's too much information I found out from doing this swap, and I'll also be putting the R/T stuff on an SXT, so I'll be getting it all together into one big info thread at some point soon.

EDIT: The rear bores (at least the exposed part) are 1.0375" and .875". I didn't feel like peeling back the boots... so pretty and new and seated down in there... :mrgreen: I guess I should have measured the outer diameter of the boot though. I didn't think to. I'll try to get the front diameters tomorrow.

And also - I bought a Mity-Vac thingy for sucking the brake fluid through the bone dry calipers and lines. Didn't even open it. Gravity feed, baby. I'll pressure bleed everything tomorrow, but might first let them drain out a bit more until I know I have all new fluid throughout. Might as well.

[Junior]

Here's an impromptu write-up I did in the middle of a thread over on chargerforumz, to help clear up some confusion:

SRT Brembo Swap Information (http://www.chargerforumz.com/showpost.php?p=395037&postcount=21)

and from later in the same thread:

Wilwoods vs. Brembos (http://www.chargerforumz.com/showpost.php?p=395288&postcount=24)

I'm going to rewrite some of that, and include it when I do the thread on the swapouts.

[Todd TCE]

EDIT: The rear bores (at least the exposed part) are 1.0375" and .875". I didn't feel like peeling back the boots... so pretty and new and seated down in there... :mrgreen: I guess I should have measured the outer diameter of the boot though. I didn't think to. I'll try to get the front diameters tomorrow.


Sounds like a 28/24mm combo. Both a bit larger than your numbers. 1.5sq" or so from what I see. I'd have thought a bit more...if you see them close up I'd be curious.

[Junior]

Well, I didn't get the specs for the front pistons - I just had too much going on. I still could at some point, but let me let the smoke clear.

I am finally finished with the install. Good grief. I started last Sunday morning. I wasted 24 hours waiting for rear shields that didn't end up coming, nor did I end up needing. It was together at different times - yesterday I drove it around to get the parts I still needed (new front axle hub nuts and a torque wrench that was accurate up to 184 ft-lbs). I also had not drilled and tapped the new front knuckles to hold the dust shields on, but I did that today when I had it apart to replace the hub nuts.

All done! [whew]

[Junior]

Dude, I'll just wind up buying the same kit you have....I'm not going through all this.

Thanks for clearing this up Junior. On a side note, are you swapping out your wilwoods for the srt take-offs? What are your plans with your wilwoods?

Wilwoods for sale, fellas:

Complete Wilwood 6-piston caliper front setup, with rotors (http://www.lxforums.com/board/showthread.php?t=139860)

[Junior]

And here's the complete write-up on the Brembo swap:

Swapping SRT Brembos onto an R/T or 300C - Everything you need to know.
(http://www.lxforums.com/board/showthread.php?t=140055)