Bargain Basement Big Brakes

[wortdog]

The $20 is not a typo, www.rockauto.com has them for $23 for Raybestos PG Plus brand.

They do sit on concentric circles, they just don't LOOK like they sit on concentric circles The ex-Formula SAE kid in me has a fetish with designing parts to mount as low as possible in order to lower the CG height, which is why the caliper sits slightly lower than if the caliper was spaced directly out from the mounts.

 

[wret]

Nice drawing. Yes, I can see the concentricity now. My focus was keeping the circles as close together as possible without radically changing mounting positions.

 

[blinded]

Wret, can you clarify what you did as far as spacers? From your posts, it sounds like you used over the counter washers.

Also, what is the offset of your rims, and do they have a lot of clearance for calipers?

I'm trying to get an idea of what it might really take to get wheels (such as a 97-99 GSX wheel) over these calipers.

Looks great and thanks for sharing.

 

[wret]

I bought a big pack of washers from McMaster-Carr. Most of the hardware is stainless steel, which is in short supply at the local hardware store. Stainless AND metric? Forget it. Nothing says the hardware must be metric but I don't have to reach into a different box of wrenches to work on this stuff.

I'm not sure wheel offset or even width has much to do with the caliper clearance. It's more the shape of the wheel spokes. Typically the spokes are curved or convex in the caliper area. As I stated, my goal was to do this with NO wheel spacers. My wheels are already buldging out from under the car slightly and I've heard numbers like 15 or 20 millilmeters thrown around for the amount of spacing needed to fit over 4-pot calipers.

 

[poorboyj]

Here's a picture that shows the orientation of the bracket and mounting ears. You can see where the ears interfere with each other and must be trimmed.

Awesome information. Do you have distances from the bracket you made to the caliper surface & from your bracket to the knuckle? I would like to make a 1 piece set of these without using washers. Again, thatnks for this information.

Jay White

 

[wret]

You must have access to some better machining capabilities than I. If one were to build the offset hardware into the bracket, it would be as pictured below. You would not need spacers on both sides I needed 6mm spacer washers on one side to compensate for the 17mm high flange nut being 6mm higher than necessary for exact alignment. This alignment is for the Audi rotor. Any other would likely be different.

 

[TechT]

Very nice write up wret and a job well done.I'm lokking into upgradeing my brakes as well thanks for the info.

 

[arash15]

is there any way to eliminate the ring of rust on the rotor.? there is no contact with the brake pad and the rotor in that area so it rusts.

 

[EuroGSTSpyder]

This was a very very intersteing thread since I have been thinking of this for along time and I have a set of TT calipers at home, both front and rear. The wheel issue you are talking about is this referring to stock wheels? I am on 18" set Kosei wheels now (cant rmemeber off set) and I am going to go see what it takes to get those calipers on. I can get the stock TT rotors as well for free so...thats the question about the issue of stock wheels or not. Is it the thickness only that is the issue with the stock TT rotors?
What else did you need to do to make those fit except the brackets?

My dad works at a factory with laser cutting machines and all so I have no prob making the brackets if a CAD drawing is made of those with all meassurmenets and so on.Could be made in a regular program or a drawing with exakt scale and meassurments as well but it takes a little more job though.Then they can be made in one piece. Let me know if you want to try it out

 

[wret]

is there any way to eliminate the ring of rust on the rotor.? there is no contact with the brake pad and the rotor in that area so it rusts.

Yes, I should have spayed them with hi-temp aluminum but I was impatient. It's done now though.

The wheel issue you are talking about is this referring to stock wheels? I am on 18" set Kosei wheels now (cant rmemeber off set) and I am going to go see what it takes to get those calipers on. I can get the stock TT rotors as well for free so...thats the question about the issue of stock wheels or not. Is it the thickness only that is the issue with the stock TT rotors?

You can use the 3000GT/Stealth rotors if you are willing to use 10-20mm spacers. I don't think the offset of the wheel will make any difference, it's the shape of the spokes. Unless you use 3000GT/Stealth designed wheels, you will have clearance problems. My 8.5" wheels /245 width tires are already as fare out as I want to go and I was not willing to add spacers, that's why I shopped around for rotors with more offset and finally decided on the Audi rotors. The A8/Lucas rotors I tried were promising but actually had too much offset and rubbed on things on the inside. I was close to giving up at that point but tried the A6 rotors. They are not as thick which helps to keep the calipers further in. Spacers are required behind the brake pads to prevent overextension of the pistons.

What else did you need to do to make those fit except the brackets?

If you use Audi rotors, you will need to reduce the size of the hub flange from about 140mm to 134mm. This was actually easier than I expected it would be.

 

[EuroGSTSpyder]

Ok..will try and see what Ican come up with. I asked some 3Kgt guys for their rotors tonite and I will see if they can give me some to test this with.
I dont think I can go any further out with my tires though since they are flush to the fenders as is....would be too much with 10-20mm spacers definitly.

Do you have the exact template for the bracket on file or is it the one you showed on here? I can ask my dad to cut out them for me so I can get something to start with Only if you feel like sharing of course!!
[email protected] is the email if so

The hubflange is not all that hard to grind then I assume? You shouldnt have posted this cause now I feel the need to do this**

 

[wret]

Okay, I touched up my original drawing to make it a little more clear. I changed the shape in a couple areas to leave more material for strength. I also made the upper hole into a slot. I don't think there is any way around it because this will allow you to slide the caliper in place.

Sorry. no CAD but you can either reproduce it on 0.2 inch grid paper, redo it yourself in CAD, or copy the bitmap and play with the scale until you get it right for printing.

The thing to remember is, the only critical thing about the shape is the spacing of the holes. Refer to the dimensions I posted above. You can round off corners and trim excess material as much as you wish but I tried to avoid cutting closer that .25" from the holes. Removing the gray area at the top MAY be optional. This area, as it is drawn, is where it is on my plate but I haven't checked to see how much clearance there actually is when bolted in place. Too much material there would eventually hit the back of the caliper.

#^$#@#, *$#&($. I can't upload my bitmap. Email me if you want the full size version.

 

[EuroGSTSpyder]

xcellent. WIll make a template of thinner plates first to see how it matches up and then make a fullscale testversion of it. Got some 3Kgt rotors now as well so I can tsst fit it and see how it works out eventhough I believe you when you say it wont work without spacers. Doesnt cost anything to try so ;-)

Will see if I can get this going asap so I can try it out. Thanx alot for being so helpful!!

My email is [email protected] if you wanna send the bmp

 

[wret]

Okay, template sent, but the deal is you have to post any further advice you have for others to follow.

 

[EuroGSTSpyder]

But of course I am not known for holding back secrets I think if you check my project threads**

Dunno when I can get started on this but hopefully next week if I get the rotors.I might even have some brembo rotors at home I can use as well..will have to look into that

 

[wret]

Roger,

You may want to look into these rotors:
http://www.coximport.com/store/BR25611

These are for an S8 with Brembo calipers. They cost a bit more but they are about 13.5" diameter and about 3mm more height compared to the A6. I don't think the additional height will cause any rubbing on the inside and it will give you more wheel clearance.

I wish I had seen them before committing to the A6 rotors.

 

[Phatblackhatch]

Great write up and drawings....I emailed ya about the audi rotor center bore..why gring your hub, why not open up the rotor?....I'm sure a hole saw exist that could do it...harbor frieght maybe...I dont know...just asking...

 

[wret]

Great write up and drawings....I emailed ya about the audi rotor center bore..why gring your hub, why not open up the rotor?....I'm sure a hole saw exist that could do it...harbor frieght maybe...I dont know...just asking...

Two reasons:

1). Material must be removed from outer edge of the hub flange not the center hub protrusion that you may be thinking of. There is insufficient material thickness in the "hat" of the rotor to remove any.

2). The spinning hub essentially becomes a lathe, making it easy to remove material evenly. I actually considered fabricating a tool rest and using a carbide cutting tool to cut the hub down to size without removing it. I gave the grinder a try first though and found it very easy to remove the material.

I don't know if this helps but here is a spread sheet with some of the viable rotors I've researched.

 

[98spydert]

Did you look at any other OEM calipers? Or are most larger, 4+ pot calipers way more expenive?

Those VR4 specs in your spread sheet, are they different than the 2G VR4 brakes?

Do you have any plans for the rear?

Thanks for all of the info wret, I just put on the AWD 2-pot brakes on my Spyder but now it looks like I've got something else to save for

 

[Phatblackhatch]

WRET- You rock!!! thanks for the clarification. Like I said in my email, I plan on doing this to a 1g tsi. the only reason I love the audi rotor idea, is that I dont neet to buy $125 spacers ... ..anyway thanks for the info again

 

[wret]

Did you look at any other OEM calipers? Or are most larger, 4+ pot calipers way more expenive?

Those VR4 specs in your spread sheet, are they different than the 2G VR4 brakes?

Do you have any plans for the rear?

Thanks for all of the info wret, I just put on the AWD 2-pot brakes on my Spyder but now it looks like I've got something else to save for

I chose the 2g VR4 calipers because of availability and low cost. Calipers from other cars may work but I didn't look at others. The 2g VR4 calipers are sized for a smaller rotor than the 3g. I haven't looked at 3g calipers but I suspect that they have longer mounting ears possibly making them more difficult to get into proper mounting position.

I've thought about the rears but until I can think of a way to determine the braking performance balance between the front and back, I'll leave them alone.

 

[98spydert]

I've thought about the rears but until I can think of a way to determine the braking performance balance between the front and back, I'll leave them alone.

Assuming mitsubishi got it right with the VR4, wouldn't the VR4 fronts and rears be a decent match?

 

[The1Bill]

Given equal weight distribution, the TT fronts and rears would work together well in concert. Being a FWD, though, I would venture to guess that the weight distribution is too much different, and that the car would be out of braking proportion.

You don't want your rears to lock up before your fronts.

Another thing to note, is the proportioning valve the same on the 2G DSM as it is on the VR-4?

-=B-=

 

[Phatblackhatch]

Wret\Wortdog,

Here a quick question, any confirmation that the Master cylinder from the vr4 will fit, the eclipse booster?. Cause on my 1g, I was looking, it looks like the body my fit, but I would have to adapt the current resovoirs [ which are mounted off to the side] to the 3000gt M/C body..not even sure this could work....Just a question, this is becoming more appealing by the day, so I am doing some initial investigations into it...becuase if this can be done, its a GO!!!

 

[wret]

Another thing to note, is the proportioning valve the same on the 2G DSM as it is on the VR-4?
-=B-=

This site provides some insight into the proportioning valves available, although it deals mostly with 2 piston calipers on a 1g:
http://www.vfaq.com/mods/BigBrakesInfo.html

No info on the split points of 2g cars but it wiould seem that switching to an AWD valve would give the FWD cars some more rear force.

Here a quick question, any confirmation that the Master cylinder from the vr4 will fit, the eclipse booster?. Cause on my 1g, I was looking, it looks like the body my fit, but I would have to adapt the current resovoirs [ which are mounted off to the side] to the 3000gt M/C body..not even sure this could work....Just a question, this is becoming more appealing by the day, so I am doing some initial investigations into it...becuase if this can be done, its a GO!!!

I've not seen any info on swapping MC's from VR4/TT's. I would try SS lines first and see if that firms up the pedal stroke. Changing MC's would be unnecessary on a 2g. The pedal feel is fine.