Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: flexbuttcheck1 on 11 July 2012, 22:58:27

Title: rear vented discs?
Post by: flexbuttcheck1 on 11 July 2012, 22:58:27
while looking for new brake discs and pads for my car i found some rear vented discs listed for omegas, did any omegas come with rear vented discs? i dont want them i just wondered because ive not seen a car with them on  :)
Title: Re: rear vented discs?
Post by: zirk on 11 July 2012, 23:11:58
Believe the late 3.2 had them, not sure about late 2.6.
Title: Re: rear vented discs?
Post by: Darth Loo-knee on 11 July 2012, 23:18:00
2.6's too :y

At the York Meet a couple of years ago, The Master found that someone had fitted none vented rear discs to Mike Dundee's car. His pads were low which were fitted into their vented disc calipers.... the pistons if I remember correctly pushed out :o
Title: Re: rear vented discs?
Post by: noel on 12 July 2012, 13:21:35
my 2.6 is fitted with them :y
Title: Re: rear vented discs?
Post by: martin42 on 12 July 2012, 15:21:34
my mv6 2.6 also has vented,different calipers as well which are wider than the solid  :y
Title: Re: rear vented discs?
Post by: TheBoy on 12 July 2012, 19:17:14
Post 2001 V6 (ie, 2.6 and 3.2) have vented rears
Title: Re: rear vented discs?
Post by: b4ndit on 12 July 2012, 20:04:06
Is that all 2.6's had vented rear disc's? :y
Title: Re: rear vented discs?
Post by: 2woody on 12 July 2012, 21:15:17
calipers also had bigger pistons at the rear, too.
Title: Re: rear vented discs?
Post by: flexbuttcheck1 on 12 July 2012, 22:57:33
is it the same caliper as the unvented, just wider?
Title: Re: rear vented discs?
Post by: kcl on 13 July 2012, 06:20:56
Is that all 2.6's had vented rear disc's? :y

Yes. All 2,6 and 3,2 have vented rears. Oddly enough, have seen one or two instances of 3,0 car having vented rears, cars were made late 2000. Very strange ones.

But, generally and with more than 99,9% odds vented discs only on 2,6 and 3,2 :y
Title: Re: rear vented discs?
Post by: venom on 13 July 2012, 09:40:30
Can the discs & calipers be retro fitted to 2.5/3.0 ?
Title: Re: rear vented discs?
Post by: kcl on 13 July 2012, 11:38:42
Can the discs & calipers be retro fitted to 2.5/3.0 ?

Yes, but what would be to gain? Solids give well enough of braking power
Title: Re: rear vented discs?
Post by: venom on 13 July 2012, 14:41:32
Just a though so when I rebuild the rear end it would just be a nice upgrade as there's so many 2.6/3.2's scrapped it wouldn't be an expensive job
Title: Re: rear vented discs?
Post by: 2woody on 13 July 2012, 16:59:08
Can the discs & calipers be retro fitted to 2.5/3.0 ?

Yes, but what would be to gain? Solids give well enough of braking power

nothing on Omega gives anywhere like enough braking power. The braking performance I find truly shocking.

the vented rear setup is of the same dimensions as the non-vented, with the following exceptions :-

wider disc
wider spacing between the two halves of caliper
bigger diameter caliper pistons ( 42mm instead of 40mm )
Title: Re: rear vented discs?
Post by: biggriffin on 13 July 2012, 23:39:45
ive found if the system is looked after. bleed correct and pads/discs all good stops fine.  if your compering it to a large performance saloon then it is a bit woefull. the police found them ok but they had new pads about every 6weeks and discs every year.
Title: Re: rear vented discs?
Post by: sjc on 14 July 2012, 07:50:31
Regarding the braking "power"... I've had 3 x 3L V6s, a '95 Elite, a '98 MV6 and my current car is a '99 MV6.

The perception of braking power on the 2 earlier cars was poor - i.e. compared to other cars, it felt like you had to stand on the pedal to get it to stop, but when sufficient effort was exerted, it would pull up swiftly.

On the current one, the brakes "feel" much more powerful but I'm convinced it's the efficiency of the brake servo that is the difference.  Why do I say this?  Because I swapped the disks and pads between them all at various times (initially expecting this to be a factor) and found that it made no difference to the individual car.

Don't know if the later servo has been improved, or if it is a case of the earlier ones being faulty in some respect but there were no air leaks or other obvious problems.
Title: Re: rear vented discs?
Post by: TheBoy on 14 July 2012, 11:11:47
Can the discs & calipers be retro fitted to 2.5/3.0 ?

Yes, but what would be to gain? Solids give well enough of braking power

nothing on Omega gives anywhere like enough braking power. The braking performance I find truly shocking.

the vented rear setup is of the same dimensions as the non-vented, with the following exceptions :-

wider disc
wider spacing between the two halves of caliper
bigger diameter caliper pistons ( 42mm instead of 40mm )
I single, one-off stops, I'd have to disagree.  However, the discs clearly aren't big enough, or able to dissipate enough heat quickly enough, for sustained abuse.

I'd say the standard setup is OK for road use. But would last about 1 lap on a track.
Title: Re: rear vented discs?
Post by: Brikhead on 14 July 2012, 11:14:52
Can the discs & calipers be retro fitted to 2.5/3.0 ?

Yes, but what would be to gain? Solids give well enough of braking power

I guess Vx. thought differently otherwise they would have stuck with the solid rears.
Title: Re: rear vented discs?
Post by: Andy H on 14 July 2012, 13:06:38
My perception is that the front brakes are OK but the front wishbones & bushes are too puny to cope with serious braking.

Going to polybush mine, hopefully that will stop the front wheels flopping about under braking.

Raised painted bands on the approach to roundabouts are what I hate.

I don't understand the switch to vented rears, if they were going to change anything they should have changed the front discs to 320mm diameter IMO.

Eureka moment...... facelift V6 2.6/3.2 can apply the rear brakes as part of the traction control. That would explain why they need to be vented :y
Title: Re: rear vented discs?
Post by: TheBoy on 14 July 2012, 14:07:06
My perception is that the front brakes are OK but the front wishbones & bushes are too puny to cope with serious braking.

Going to polybush mine, hopefully that will stop the front wheels flopping about under braking.

Raised painted bands on the approach to roundabouts are what I hate.

I don't understand the switch to vented rears, if they were going to change anything they should have changed the front discs to 320mm diameter IMO.

Eureka moment...... facelift V6 2.6/3.2 can apply the rear brakes as part of the traction control. That would explain why they need to be vented :y
Tyres can seem to cause that as well... ...cue gayboy gixer and a Falken rant....
Title: Re: rear vented discs?
Post by: b4ndit on 14 July 2012, 15:38:24
My discs on the rear are solid. car is a 2003 is this normal or have they been changed at some time. its a 2.6 :y
Title: Re: rear vented discs?
Post by: Kevin Wood on 14 July 2012, 15:47:15
My discs on the rear are solid. car is a 2003 is this normal or have they been changed at some time. its a 2.6 :y

Make damned sure that it has the caliper for the unvented disks! At 2003 I'd expect it to be vented.

If someone has scrimped on the disk and fitted unvented disks with the wider caliper, the pistons will pop out of the caliper once the pads have worn down and your brakes will fail. :o
Title: Re: rear vented discs?
Post by: TheBoy on 14 July 2012, 15:57:55
Yeah, what Kevin Wood says.  We've seen it before where a garage had skimped, and fitted the cheaper discs, and the resultant drama a few weeks later...
Title: Re: rear vented discs?
Post by: b4ndit on 14 July 2012, 17:04:08
Thanks for the heads up, have been driving the car for about 7 months and not had any problems yet but will check on monday at work. how can i tell if the calipers have been changed? what is the difference between vented and solids thanks?  :y :y
Title: Re: rear vented discs?
Post by: 2woody on 16 July 2012, 22:42:29
the only calipers fitted to rear vented cars as standard will have a "42" cast into the outer face of the caliper.

Other Omega B calipers will have a "40" instead.
Title: Re: rear vented discs?
Post by: Andy B on 16 July 2012, 22:49:42
..... how can i tell if the calipers have been changed? what is the difference between vented and solids thanks?  :y :y

Solid discs are around 3/8" to 1/2" thick and err ............ solid  ;) Vented discs are nearer an inch thick & are like two solid discs fastened together with a web in between. If you have vented calipers with solid discs there'll be enough room to get your fingers inside the caliper along side the disc.  :y
Title: Re: rear vented discs?
Post by: Elite Pete on 17 July 2012, 12:15:41
I fitted some to my mini facelift estate a few years ago, can't say I noticed any great improvement in the braking but they look good ::)

(http://i61.photobucket.com/albums/h64/pickledpepper/DSCF0096.jpg)
Title: Re: rear vented discs?
Post by: Kevin Wood on 17 July 2012, 12:48:44
..and in Pete's picture above is the key to identifying calipers designed for vented disks. The caliper is in 2 parts, sandwiched together. You can just see on that photo, where the 2 halves meet, that there's a spacer between them. Calipers for solid disks don't have it.
Title: Re: rear vented discs?
Post by: Elite Pete on 17 July 2012, 12:51:28
Standard disc and caliper

(http://i61.photobucket.com/albums/h64/pickledpepper/DSCF0095-1.jpg)
Title: Re: rear vented discs?
Post by: b4ndit on 17 July 2012, 17:50:25
Oh dear i have solid discs and vented calipers will get them changed asap thanks guys :( :o
Title: Re: rear vented discs?
Post by: paulg on 18 July 2012, 09:35:29
I am currently converting my rear brakes to the 3.2 set-up, as they were siezed up anyway, has anyone got any calipers (42's) for sale?  :y
Title: Re: rear vented discs?
Post by: Brikhead on 18 July 2012, 10:26:34
I am currently converting my rear brakes to the 3.2 set-up, as they were siezed up anyway, has anyone got any calipers (42's) for sale?  :y

I have vented rears on this car...
http://www.omegaowners.com/forum/index.php?topic=103796.0
Yours for £25 each, includes discs and pads if required.
Title: Re: rear vented discs?
Post by: paulg on 18 July 2012, 20:22:32
P.M sent :y