VN/VP Brakes

[8rody]

Okay i'm having alittle confusion about the factory brake changes/upgrades between series 1 and series 2 VN's. Furthermore, the difference between VN and VP brakes.

expressed as.. [Front] | [Rear] [Brake System]

VL
L6:
L6 Turbo: 289mm - Finned Caliper |
V8: 289mm - Finned Caliper | Double Booster, 1 inch Master

VN
V6: 270mm |
V6 FE2: 289mm - Finned Caliper | Single Booster, 1 inch Master
V8: 289mm - Finned Caliper | Double Booster, 1 inch Master

VP
V6 S1: 270mm | Single Booster, Stock Master
V6 S2: 289mm - Finned Caliper |
V8: 289mm - Finned Caliper | Double Booster, 1 inch Master


I assume this is correct? Commodore factory spec web pages seem to be disappearing from Google, its getting harder and harder to find info on VP/VN.

The calipers on the VP V8 (have fins on them) look the same as the VS Calipers (upon physical comparison). Is this true?

[greenfoam]

Yes from VP series 2 they all run the finned caliper and all FE2/V8 and Series 2 VP (everything) onward cars run the bigger rotors and finned calipers. Also the V8's got the double brake booster (unsure if anything else got that)

[Not_An_Abba_Fan]

the reason they are better is the pads will have more surface area to grab the disk with to stop the car."

No, this is not correct, the pads are the same from VB to VS regardless of rotor size. (Not including HSV) the reason the rotors are larger is to do with leverage. The further you get from the centre of a rotor, the less clamping force is required to slow the car, thus making the brakes more efficient.

Oh, and the VL is not a V6.....

[8rody]

Yes from VP series 2 they all run the finned caliper and all FE2/V8 and Series 2 VP (everything) onward cars run the bigger rotors and finned calipers. Also the V8's got the double brake booster (unsure if anything else got that)

Thanks greenfoam, i've updated accordingly! V8's Double brake booster?... As in 1" Master Cylinder? I didn't know the Brake booster was different...

No, this is not correct, the pads are the same from VB to VS regardless of rotor size. (Not including HSV) the reason the rotors are larger is to do with leverage. The further you get from the centre of a rotor, the less clamping force is required to slow the car, thus making the brakes more efficient.

Oh, and the VL is not a V6.....

Woops. Sorry about the VL mate, got a bit lazy ..copy/paste, didn't realize till now. Its now corrected. So all the pads are the same VB to VS (surface area wise)?

I did some measuring at the Junkyard, and the contact wear patch on the disc rotor was less between VN S1 and VP S2 (270mm and 289mm rotors). I didn't check the pads though *slaps forehead*... I assumed they would be different.

[Not_An_Abba_Fan]

The pads are all the same, yes DB1085. The only difference is some manufactures put slightly more friction material on the pad, a good example of that is the QFM "police spec" pad which have the total backing plate covered by the friction material.

[8rody]

Heh. Well there you go! Thanks mate.

[Cheap6]

There was also a change in the calipers sometime around late VN or early VP to allow an increase in disc new thickness (22-23mm) and a decrease in disc scrap thickness (21-20mm) while still allowing the caliper to fit over and not have the pads fall out. The pad backing plates were thicker too: 6mm? from 5.5mm?.

[Not_An_Abba_Fan]

The only change was when they went to the finned caliper. The pads remained the same throughout all the models form VB to VS.

[greenfoam]

That's right the pads are the same size right through. But you can run the HQ-Z? pads with a notch ground in it and they are a bigger pad. The _Booster_ on the V8's is a double diaphragm unit the V6 is a single. I think all the FE2 cars run the 1 inch master but unsure if they get the big booster. In fact I suspect most of the guy that complain about their VN-P V8 brakes and go for the VT setup no longer have the right booster because it does make a difference.

You will have to ask someone with a factory S model to confirm the master and booster on those FE2 V6's

[centy]

the vp's got the bigger brakes a little before the series 2 was release.
mine is a late 92 just before series2 but has much of the series 2 gear on it.

[greenfoam]

I had a look at some of the S packs on the forum, seems they run the single booster. I did have the rotors/calipers and master from a VP S on my VN and that was a 1 inch master so you can pretty safely say the "S" pack run

VN-VPS1 V6
270mm rotor, non finned cailper, single booster, stock master

VN-VP S
289mm rotors, finned caliper, single booster, 1 inch master

All V8 VL-N-VP
289mm rotors, finned caliper, double booster, 1 inch master

Just out of interest the VS V8's run a single booster and don't run a 1 inch master (they don't have brakes anywhere near as good as a VN-P V8)

[greenfoam]

the vp's got the bigger brakes a little before the series 2 was release.
mine is a late 92 just before series2 but has much of the series 2 gear on it.

It would have been the October cars like my VP

[Not_An_Abba_Fan]

Didn't all the VP's have the larger rotors and finned calipers? I thought they changed with the VN 2.

[8rody]

That's right the pads are the same size right through. But you can run the HQ-Z? pads with a notch ground in it and they are a bigger pad. The _Booster_ on the V8's is a double diaphragm unit the V6 is a single. I think all the FE2 cars run the 1 inch master but unsure if they get the big booster. In fact I suspect most of the guy that complain about their VN-P V8 brakes and go for the VT setup no longer have the right booster because it does make a difference.

You will have to ask someone with a factory S model to confirm the master and booster on those FE2 V6's

Thanks. I've updated list above.
Hmm... might look into running HQ-Z pads, did a quick google/search here and cant seem to find any info on this. How much needs to be notched out of the pad/backing plate?

[8rody]

Didn't all the VP's have the larger rotors and finned calipers? I thought they changed with the VN 2.

Not that i've seen at the wrecker... (open to be proven otherwise)

[Not_An_Abba_Fan]

Just had a look in the catalogue, the smaller rotors were used on the VP V6's non FE2 up to and including chassis No 569902.

There was also a limited run on the VP V6 that used a 23mm thick rotor in 1992, as well as the V8 and V6 that started 10/92.

Up to the chassis No above they used a 270 x 22mm rotor, after that they used the 270 x 23mm rotor.

VN V6 FE2 and all V8's up to 9/92 used 290 x 22mm rotor, after 10/92 they used the 290 x 23mm rotor.

[8rody]

Now there's some technicality. The change in rotor thickness, still had the same brake caliper i assume?

Had a quick call to the junkyard, double booster / master cylinder 1inch's are quite expensive. :|
Must be a very common upgrade.

[Cheap6]

The revision to the thicker front disc was made in June '92.

Both standard and heavy duty calipers new thickness went from 22mm-23mm, scrap stayed at 20mm. That was revised earlier from 21mm - I don't have a date for that.

Both standard and heavy duty calipers use mounting brackets with a wider slot to maintain clearance to the thicker disc.

Standard and heavy duty used a common pad with the backing plate reduced from 6.0mm to 5.0mm thick with 'joggle' ends = 1mm dog leg => same outside dimension as 6.0mm at caliper bracket. The pads could (can) be used in all VB-VP/VQII(VS) vehicles. Friction material thickness was increased from 7.5mm-8.5mm.

The friction material also covered a greater area of the backing plate.

Vehicle break points for the thicker front discs:

VP V6 std: L569902

VP V6 H/D: L569013

VP V8, VQII V6 and V8, not ABS: L570556

VP, VQII with ABS: L569988

VP BT1: L569013

There was later service bulletin stating 6mm or 'joggle' backing plates are OK in all calipers but 5mm backing plates are not OK in later type caliper brackets. I'm guessing that to avoid confusion all (aftermarket only?) backing plates are now at least the 6mm dimension with the friction material thickness reduced to ensure clearance.

[hemi01]

I found (and bought for $35) a double diaphram booster that also had the 1" MC attached at my local wrecker. It was fitted to a VN S2 BT1 equipped V6 Exec. Still had the altered lines and unique front bracket.

Made a huge difference.