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[05omegav6]

Following on from...

http://www.omegaowners.com/forum/index.php?topic=119902.0

I have successfully fitted a variation of the Monaro VXRs set up.

This consists of:
Monaro VXR double piston calipers with EBC Ultimax pads, modified brackets to allow for hub dimension differences.
Mercedes W164 ML 330x32 front discs, machined to fit the Omega hub spigot, 67.1mm vs 70mm.
Fresh Dot 5.1 brake fluid.

All the above are ECE R90 certified

Pad area is nearly twice that of standard pads, the discs are 34mm greater in diameter, and 4mm thicker, so should be a bit more heat tolerant.

First impressions...

Braking normally, they're a bit sharper, but not grabby. However braking from speed is simply phenomenal. The abs kicks in almost instantly when you stand on the pedal, which it only used to do grudgingly on snow. But the way it pulls up is what really impresses...

Emergency stop tests (done on an empty, dry road) from x speed to stationary, otherwise totally unscientifically:

20 mph about a car length, no more.
30 mph about 22ft
60 mph about four car lengths, 65ft perhaps.

I suspect, but can not confirm, as trying would be naughty, that it would probably stop from a ton in 100-120ft

Not sure how these figures compare to a standard 3.2, but they're significantly better than the car could previously manage, which was the principle purpose of the exercise

[martin42]

Good work 

[YZ250]

Following on from...

.....................

First impressions...

Braking normally, they're a bit sharper, but not grabby. However braking from speed is simply phenomenal. The abs kicks in almost instantly when you stand on the pedal, which it only used to do grudgingly on snow. But the way it pulls up is what really impresses...

Emergency stop tests (done on an empty, dry road) from x speed to stationary, otherwise totally unscientifically:

20 mph about a car length, no more.
30 mph about 22ft
60 mph about four car lengths, 65ft perhaps.

I suspect, but can not confirm, as trying would be naughty, that it would probably stop from a ton in 100-120ft

Not sure how these figures compare to a standard 3.2, but they're significantly better than the car could previously manage, which was the principle purpose of the exercise

Best make sure none of us get too close behind you at speed then Al. 

Nice work. 

[cem_devecioglu]

Good work Al.. next step test with several tyres

[Rods2]

Well done, it looks like you have had a good plan that has achieved what you set out to do.

Thread bookmarked for future reference.

[omega3000]

With all that braking G force its going to be ...




 

Well done 

[05omegav6]

Good work Al.. next step test with several tyres

I shall let them bed in a bit before really pushing them, but the Goodyears currently fitted seem to be upto the task... as do the polybushes

Re the stopping distances/following traffic, I might need to get it decorated sooner rather than later... any one rear ending a marked car, in service or not, deserves shooting... well perhaps not shooting, but it should help encourage people to keep back

[05omegav6]

With all that braking G force its going to be ...




 

Well done 

Well the seat belt definitely works

Joking aside, the total cost so far is about £300, so certainly not a bank braking (boom, boom) mod
 
Whether they'll meets Chris' V8 needs is a different question... but that'll be answered soon enough

[chrisgixer]

Good work Al. Might fancy a "quick feel" of those.

[chrisgixer]

Do you think the back needs an upgrade to match? Or is that in the pipe line? So to speak.

[tigers_gonads]

Do you think the back needs an upgrade to match? Or is that in the pipe line? So to speak.

My thoughts Chris 

Does the back end go light or any movement when you brake hard Al ?

[05omegav6]

Was always a bit squirrely under very heavy braking, feels no different now

But yes options are being considered

[tigers_gonads]

Any pictures or a "How to do" in the pipeline ?

[chrisgixer]

Do you think the back needs an upgrade to match? Or is that in the pipe line? So to speak.

My thoughts Chris 

Does the back end go light or any movement when you brake hard Al ?

I didn't intend the pun originally. Too late.

Been looking at 365 discs for the v8 project. Or even just for my own car. These would be a good pointer if 365 is needed, as they ain't cheap off an rs6.

[05omegav6]

 Reminds me, I shall try to remember to grab one of the Monaro rear calipers and the removed fronts to bring with me tomorrow, along with a rear hub coming straight from work...

[Kevin Wood]

I wonder what has happened to the brake balance. What is the ratio of piston area between old and new calipers?

Might be worth taking it to a "private test track", pulling the ABS fuse and trying a little braking on fast turns to see how well balanced it is.

[chrisgixer]

Yes braking in a bend is the next test. IMO.

Where's that airfield.

[05omegav6]

Aldermaston any good
good?

[chrisgixer]

Aldermaston any good
good?

Ditches are a bit close round there.

[Kevin Wood]

Aldermaston any good
good?

Ditches are a bit close round there.

The blokes with rifles are a bit of a distraction too.

[tigers_gonads]

Might be pishing in the wind here but is there a adjustable brake bias valve on the omega ?

If not, could something similar to what my old astra estate had on the back end work but you would need 2 since the facelift is 4 channel 

[05omegav6]

Had a bit of a play on the twisties on journey home... hitting the brakes mid corner doesn't seem to bother it any if anything, it turns in more readily/progressively as the speed drops, no complaints from the rear even with a bit of weight in the boot

[elvin315]

Had a bit of a play on the twisties on journey home... hitting the brakes mid corner doesn't seem to bother it any if anything, it turns in more readily/progressively as the speed drops, no complaints from the rear even with a bit of weight in the boot

My Catera is equipped with Monaro/GTO front calipers with C5 Corvette brake pads on OEM sized slotted discs. I've noticed improved straight line stopping and nothing untoward while braking in mid-corner. Granted, when I brake in turns it's nowhere near as forceful as when braking before the corner.

Is your suspension stock or is it fitted with polyurethane bushings? That might account for your car's improved turn-in under braking. My car has Powerflex front/horizontals and anti-sway bar bushings but still using the GM rubber rear/verts. While on the topic, any progress on a poly rear/vertical bush? I know you've been working on one as well as chrisgixer and hoping for some news.

[05omegav6]

Hi Elvin, I'll drop you a pm later with my set up

But basically I think the front brake set up is the same as the stock C6 Corvette. Not to be confused with the monsters on the Z06 though

[minifreek]

Have you also upgraded the front flexi's too....?

I's be inclined to change the flexi's for braided hoses to cope with the extra load that the 4 pots will require....

[05omegav6]

The flexies are on the list, but not of immediate concern... More about proving the concept the rears may need some custom plumbing so Omega specific braided hoses may prove to be a wasted purchase. The joys of upgrading on a budget

[05omegav6]

Any pictures or a "How to do" in the pipeline ?

This is a rough guide to record a basis of what's what. There are pics in the thread linked in the opening post, and some in the 'What have you done today' thread.

This all currently only applies to the fronts. The rears are in hand, but still some detail work to do

Shopping list:
1 set of... http://www.ebay.co.uk/itm/Vauxhall-Monaro-LS2-VXR-HSV-Brake-Callipers-Hawk-Pads-CV8-Pontiac-GTO-Holden-/191134598749?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2c8082865d Must be later 6.0 VXR ones
1 set of... http://www.ebay.co.uk/itm/EBC-FRONT-ULTIMAX-BRAKE-PADS-VAUXHALL-MONARO-6-0-2005-2007-DP1162-/310432717746?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item48473b5bb2
1 pair of... http://www.ebay.co.uk/itm/190670543926?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Key points to note... the calipers should include an L shaped bracket to enable them to be bolted to the hub. This extra bracket positions the caliper carrier to fit the discs. The caliper carrier needs to be spaced out from this bracket to fit the above discs. One side on mine needed spacing 2mm, tother 4... go figure Longer bolts to suit the spacing would be well advised too. Once spaced, you can go 5mm longer without protruding from the back of the bracket. The bracket itself is a lump of steel, about 15mm thick.

This spacing is simply to offset the caliper slightly as the hub depth of the disc used is 4mm shallower than the Omega one. The centre of the disc hub requires machining from 67.1mm to 70mm to enable it to fit the Omega hub. The wheel bolt holes can be left untouched, as the PCD of the disc is 112 vs 110 of the Omega. Original wheel bolts fit without any issues, the disc hub faces are the same thickness.

Budget also for the brake hose banjo bolt holes to be machined/helicoiled, as the calipers are aluminium, and the threads strip a little to easily. Mine were fitted with M10 x 1.5P x 1.5 D helicoils, which match the banjo bolts already fitted to my Omega. Worth checking what is fitted currently... ideally get the bolts supplied with the calipers.

That's about the size of it

If you simply want bragging rights down the pub, then you can get the calipers from a base 2004 Monaro. These will bolt straight on, no disc issues. Base Monaros have the same sized discs as the Pre/mid facelift Omega... 296x28 vented fronts, and 286x12 solid rears. Fitting these might be a slight improvement, as they are also twin pot sliding calipers, with a slightly larger pad than the Omega standard.

Monaros have very different hub dimensions to the Omega, and the discs reflect this... the ones used provided the closest match to the Omega hub, whilst still providing the correct diameter/thickness. It is worth noting that you cannot go deeper than the Omega hub, as the disc would then foul the track rod ball joint/track rod. Equally, too shallow, and the caliper would foul the wheel. So although it might seem a bit bastardised, it is the most cost effective solution without going down the fully custom machining route, (£££££).

More to follow in due course...