VT Brake Upgrade on VS

[scvs6]

Hey guys,

I have a set of DBA 4000 series wiper slot rotors that I bought for my WH Statesman, I never got the chance to put them on so they are just sitting in my garage, so I was wondering if they would fit on my VS with no modifications to the hub? If so, I might just fit the rotors on my VS instead and get the VT calipers and brake hoses.

Thanks.

Part number of the rotors DBA4040SL and DBA4040SR

[HamaTime™]

The rotors will bolt straight up. Exactly the same mounts etc, just a bigger/thicker disc. However, be warned that if you put the VT discs/calipers on, you're going to have a spongy pedal with a fair bit of ineffective travel (free pedal) as the Master Cylinder is too small and won't push the appropriate flow through.

The VS Booster is the second problem. Being a plastic single diaphragm unit, it also doesn't generate the required pressure for the larger twin piston calipers.

You have two options:

1. Run VT Discs, VT Calipers, VT master cylinder and use a Master Cylinder adaptor from Race Brakes Sydney which will sit between the base of the VT M/C and the VS Booster. This will improve pedal feel but will still have a fairly spongy pedal with a tiny bit of free travel at the top of the pedal.

2. Run the above setup but with a VT Booster with a custom mounting bracket to fit the VT Booster onto the firewall (different mounting style) these can be sourced from fellow JC member MarkoVR. The pedal mounting point on the Booster pushrod also needs relocating which is a fairly simple task of welding up the old hole and re-drilling it.

Believe me, I've gone through all the possible VT upgrade setups on my VS and I never recommend anyone do anything but the full system upgrade including the VT Booster.

[Not_An_Abba_Fan]

Or an easier option is to sell your rotors and buy the VE spec upgrade.

298 or 322mm curve slot and dimpled rotors, VE calipers, VE pads, brake lines, brake fluid and all mounting hardware. $795 shipped to your door.

No need to change the master cylinder or booster as the pistons are a smaller diameter than the VT calipers so they displace less fluid.

[scvs6]

Ok all that makes sense

If I was to get the VE brake upgrade would everything still bolt up the same? I found a kit on eBay for $880 brand is RDA. I would post up the link but I'm on my iPhone and I'm not sure how to.

[Not_An_Abba_Fan]

I do that exact same kit for $795 shipped.

Everything bolts straight up, there are brackets that fit the calipers to the existing mounts, and the calipers actually mount the opposite to what is cast into the caliper as they fit on the rear of the rotor instead of the front like the VE, this is to put the bleeder at the top where it is supposed to be.

[scvs6]

I do that exact same kit for $795 shipped.

Everything bolts straight up, there are brackets that fit the calipers to the existing mounts, and the calipers actually mount the opposite to what is cast into the caliper as they fit on the rear of the rotor instead of the front like the VE, this is to put the bleeder at the top where it is supposed to be.

What about the wheel hub? When I bought the WM Caprice wheels, I had to get them machined to fit over the hub, will the rotors fit over the hub? Also do you have the rear brakes and rotors as well? I was thinking of changing all brakes.

[Not_An_Abba_Fan]

Yes, the rotors will fit straight over the hub, they are specially made to suit the VS hub and VE calipers.

I can do the rear rotors in the same pattern and pads for $225.

[scvs6]

Yes, the rotors will fit straight over the hub, they are specially made to suit the VS hub and VE calipers.

I can do the rear rotors in the same pattern and pads for $225.

Ok, I am interested in buying the front and rear sets off you but I wouldn't be able to do it until January or February.

Is that $795 for the 322mm or 298mm? (I would want to get the 322mm). And how many mm is the rear rotors? I already have 18 inch rims so there shouldn't be any problems with wheel to caliper clearance.

[RX25SE]

FYI

VT discs have a 71.5mm center bore.
VS is 70.0mm.
VT discs require a shim to center the disc on the VS hub.


After all that, I would go VE as I have VT's on my VS and personally, I wouldn't bother.

[scvs6]

FYI

VT discs have a 71.5mm center bore.
VS is 70.0mm.
VT discs require a shim to center the disc on the VS hub.


After all that, I would go VE as I have VT's on my VS and personally, I wouldn't bother.

Yeah thanks for that mate, I have decided i'm going to get the VE upgrade instead of VT. Like Not_An_Abba_Fan said, with the VE upgrade, you don't have to change the brake master cylinder or brake booster so that saves some time and money

[HamaTime™]

FYI

VT discs have a 71.5mm center bore.
VS is 70.0mm.
VT discs require a shim to center the disc on the VS hub.


After all that, I would go VE as I have VT's on my VS and personally, I wouldn't bother.

*Slaps myself on wrist I completely forgot about the hub shims

[scvs6]

Oh, I forgot to ask, what happens with the backing plate? Can you still use it? Do you remove it and leave it off? Or do you have to get a VE backing plate?

Not too worried if I do have to leave it off, BA and BF Falcons don't have front or rear backing plates, just the metal plates that sit between the rotor and wheel.

[ephect]

just trim it to clear the calipers and rotors.

another option which could be cheaper down the long run and if its needed, change your front wheel hubs for the VT ones then you wont have to run shims..

[Not_An_Abba_Fan]

just trim it to clear the calipers and rotors.

another option which could be cheaper down the long run and if its needed, change your front wheel hubs for the VT ones then you wont have to run shims..

But then you would be running VT brakes, thus the need to change the master cylinder and booster remains.

The VE upgrade doesn't require this and is a direct fit with no need for the shims. The rotors will always be available as well at the same price as the special slotted rotors.

To superchargedvs6, the rear rotors are the same size as the stock ones, no need to go bigger. The fronts are the 322mm.

[scvs6]

But then you would be running VT brakes, thus the need to change the master cylinder and booster remains.

The VE upgrade doesn't require this and is a direct fit with no need for the shims. The rotors will always be available as well at the same price as the special slotted rotors.

To superchargedvs6, the rear rotors are the same size as the stock ones, no need to go bigger. The fronts are the 322mm.

Thanks very much for your help (and everyone else), I will let you know when i'm ready to buy them off you, just need to pay off a couple of things first before I spend anymore money.

Just have another question, most of the rear rotor upgrades are vented and not solid. Are the ones your selling vented or solid? I know that the front brakes are the most important because they do most of the work.

And do I have to modify the backing plates for the front and rear or change them?

[VS_Pete_1]

super please let us know how they are after u fit them.

[Not_An_Abba_Fan]

The rears are solid, but they are the same curve slotted and dimpled design as the front.

Yes, I think there is a small bit of the backing plate that has to be trimmed off to suit the larger caliper.

[scvs6]

super please let us know how they are after u fit them.

Yeah no worries mate, will definitely let you know what they are like.

The rears are solid, but they are the same curve slotted and dimpled design as the front.

Yes, I think there is a small bit of the backing plate that has to be trimmed off to suit the larger caliper.

Ok no worries, at least they will look the same through the wheels. I think thats all the questions I wanted to ask and thanks for your help and answering them. Looking forward to buying them off you

[Not_An_Abba_Fan]

I have the same pattern rotor on our Senator and they look good as well as perform really well.

[walesy]

hey abba does that mean with the VE upgrade you need a minimum of a 16in wheel for the front? ie:no 15in front runners?

[Not_An_Abba_Fan]

Yes, the 298mm needs 16" and the 322mm needs 17". I was told that the 322mm will fit under stock VY 16" steelies, but after having tried it, they don't fit.

[flanker]

Will this VE upgrade bolt over to the VN as well? (no idea if VS/VN is the same)

[Not_An_Abba_Fan]

PM answered.

But to anyone else that reads this, the kit is basically the same except that the VB-VP requires a hub that is included in the kit for the earlier Commodore. Slightly dearer at $850 shipped.

[flanker]

If I get a brake shop to fit the kit, would they need to muck around modifying anything?

all I've read is to swap around the calipers (left to right, fit to back of rotor) and to either remove or cut the dust plate.... Why does the dust plate need to be cut/removed?

[ephect]

the calipers are physically bigger so you need to trim it to fit.