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[456lbft]

Does anyone on here know if the manual gear ratios in a 2.2DTi Diesel differ from the 2.2 Petrol manual box, or 2.5/3.0V6 etc. Officially the 3.2 only had autos behind them unless you were in uniform and driving a "special", but did they just use the same gearbox as a 2.2Petrol? I realise that because diesels don't rev, they tend to have longer final drive ratios in the diff, but wasn't sure if the ratios in the box differed too.
Thanks.

[Doctor Gollum]

From the 2003 Edition 1 Sales Brochure...

2.2 16V (ALL)

Clutch diameter: 229mm
1st: 3.81:1
2nd: 2.11:1
3rd: 1.34:1
4th: 1.00:1
5th: 0.76:1
Rev: 3.40:1
FD: 4.22:1

2.2 DTi (ALL)

Clutch diameter: 241mm
1st: 3.81:1
2nd: 2.11:1
3rd: 1.34:1
4th: 1.00:1
5th: 0.76:1
Rev: 3.40:1
FD: 3.45:1

2.6/3.2
Clutch diameter: 241mm
1st: 3.95:1
2nd: 2.19:1
3rd: 1.39:1
4th: 1.00:1
5th: 0.84:1
Rev: 3.53:1

So the only difference IS the diff. Sport and Elite models with the factory 17" wheels/tyres are a smidge slower per 1,000 rpm, but the diesel is 5 mph faster per 1,000 rpm due to the diff ratio.

The 2.6/3.2 have the 241mm clutch, but a completely different ratio set to the four cylinder cars. 2.6 manual FD is 3.90:1, 3.2 manual FD is 3.70:1.

Autos 2.2 16v/2.6 FD is 4.22:1, whereas the 3.2 FD is 3.90:1. The 2.6/3.2 share gearbox ratios.

So there's scope for increasing the top end on the V6... Scratches chin wondering where the 3.2 would get to with a 3.45:1 diff and how much difference the 3.90:1 diff would make to an 2.6 auto 

[456lbft]

From the 2003 Edition 1 Sales Brochure...

2.2 16V (ALL)

Clutch diameter: 229mm
1st: 3.81:1
2nd: 2.11:1
3rd: 1.34:1
4th: 1.00:1
5th: 0.76:1
Rev: 3.40:1
FD: 4.22:1

2.2 DTi (ALL)

Clutch diameter: 241mm
1st: 3.81:1
2nd: 2.11:1
3rd: 1.34:1
4th: 1.00:1
5th: 0.76:1
Rev: 3.40:1
FD: 3.45:1

2.6/3.2
Clutch diameter: 241mm
1st: 3.95:1
2nd: 2.19:1
3rd: 1.39:1
4th: 1.00:1
5th: 0.84:1
Rev: 3.53:1

So the only difference IS the diff. Sport and Elite models with the factory 17" wheels/tyres are a smidge slower per 1,000 rpm, but the diesel is 5 mph faster per 1,000 rpm due to the diff ratio.

The 2.6/3.2 have the 241mm clutch, but a completely different ratio set to the four cylinder cars. 2.6 manual FD is 3.90:1, 3.2 manual FD is 3.70:1.

Autos 2.2 16v/2.6 FD is 4.22:1, whereas the 3.2 FD is 3.90:1. The 2.6/3.2 share gearbox ratios.

So there's scope for increasing the top end on the V6... Scratches chin wondering where the 3.2 would get to with a 3.45:1 diff and how much difference the 3.90:1 diff would make to an 2.6 auto 

From when sales brochures were written by Engineers, for men!! Thanks very much. We have squeezed a slightly bigger clutch disc onto a  billet lightweight flywheel on my 3.2 with a 2.2DTi gearbox.  I am going to go with a 3.9:1 final drive ratio for spirited driving on track...one day when it finds a home in a suitable car.  (also have some ITBs with lovely curved air horns which are said to fit under a standard bonnet, but that's even further away atm)

[Doctor Gollum]

As an indicator, in 4th, you'll be seeing 18.8-19mph/1,000 rpm depending on tyre choice.

The factory 3.2 manual with 3.70:1 diff is a sub 8 second car with a top end of over 150mph. RWE in an estate, saloon is a smidge faster. As a benchmark, 80 mph in the same car was around 2,800 rpm (from memory).

The 3.2 manual with 3.90:1 diff is a smidge quicker off the line, but you're changing gear sooner and the top end is substantially reduced. The 2.2 ratios will exacerbate this. The lower mph/rpm will also impact economy.

I appreciate that that's not necessarily what you're building, or why, but it might matter to someone considering similar. 

[456lbft]

As an indicator, in 4th, you'll be seeing 18.8-19mph/1,000 rpm depending on tyre choice.

The factory 3.2 manual with 3.70:1 diff is a sub 8 second car with a top end of over 150mph. RWE in an estate, saloon is a smidge faster. As a benchmark, 80 mph in the same car was around 2,800 rpm (from memory).

The 3.2 manual with 3.90:1 diff is a smidge quicker off the line, but you're changing gear sooner and the top end is substantially reduced. The 2.2 ratios will exacerbate this. The lower mph/rpm will also impact economy.

I appreciate that that's not necessarily what you're building, or why, but it might matter to someone considering similar. 

Thanks for that. A friend has a factory 2.5 V6 manual (estate) and wants a taller gear for economical cruising, but the only diffs I have are 3.9:1, so no good for him, I was given a CWP from a Carlton, but I'll have to count the teeth to establish what that one actually is.  Interesting that the 2.6/3.2 manual ratios are different, do you know what the code for that gearbox might be?
I have only ever seen a couple of manual 2.6 civilian cars, the only 3.2 manuals I know of were police specials.  You are right, that is the sweet spot for a road car gearing, but there aren't many times where you'll see much over 140mph on British circuits in a Omega.  Maybe on those long straights at the Nurburgring, but maybe the rev limit could be raised for that . All hypothetical bench racing at the moment, but fun anyway!

[Doctor Gollum]

A 2.2Dti diff would be a good choice if he does alot of distance motorway work...

I suspect that the 2.5/2.6 would run out of puff after 130 anyway, but it might get alot nearer 40mpg on a steady cruise.

Cruise control is a pretty easy retrofit on any Omega if it doesn't already have it. 

There was a 3.2CDX manual estate of reportedly Royal provenance on Ebay a few years ago, but the 3.2 manuals were a factory option via special order. That's to say nothing particularly special about them beyond the fact that they were built to order.

You or I could have walked into the dealer and ordered one after a bit of a debate... Retail price of a 2003 V6 Special, 3.2 manual with xenon, self levelling and 16"wheels was £18,500.

[jb]

The  2.5 v6 and 2.6 v6 manuals had an R25 GETRAG box, the 3.0 an R28 and the 3.2 special an R30 box. The R value being safe max torque.

[Doctor Gollum]

The  2.5 v6 and 2.6 v6 manuals had an R25 GETRAG box, the 3.0 an R28 and the 3.2 special an R30 box. The R value being safe max torque.

True, but the ratios are as above difference being a hardened gear set.

[456lbft]

The  2.5 v6 and 2.6 v6 manuals had an R25 GETRAG box, the 3.0 an R28 and the 3.2 special an R30 box. The R value being safe max torque.

True, but the ratios are as above difference being a hardened gear set.

I assumed that the 2.2DTi had the hardened gears to cope with the torque of the diesel, so presumably are the R30.

[Doctor Gollum]

The  2.5 v6 and 2.6 v6 manuals had an R25 GETRAG box, the 3.0 an R28 and the 3.2 special an R30 box. The R value being safe max torque.

True, but the ratios are as above difference being a hardened gear set.

I assumed that the 2.2DTi had the hardened gears to cope with the torque of the diesel, so presumably are the R30.

Possibly R28, but it will be cast on the casing, so no ambiguity

[VXL V6]

The  2.5 v6 and 2.6 v6 manuals had an R25 GETRAG box, the 3.0 an R28 and the 3.2 special an R30 box. The R value being safe max torque.

True, but the ratios are as above difference being a hardened gear set.

I assumed that the 2.2DTi had the hardened gears to cope with the torque of the diesel, so presumably are the R30.

Possibly R28, but it will be cast on the casing, so no ambiguity

The casting in the casing of the box on my old DTi said 'R25 R28' But then I guess the casing will be the same and there is a plate attached somewhere that tells you what's inside.

[Doctor Gollum]

Presumably said plate is a code on the build sheet. 

[omegod]

The  2.5 v6 and 2.6 v6 manuals had an R25 GETRAG box, the 3.0 an R28 and the 3.2 special an R30 box. The R value being safe max torque.

From what I was able to decipher after some research many years ago all the boxes marked R25-28 are identical, the near mythical R28 has shot peened internals so it could take more of a battering. I sold scores of the R25-28 gearbox kits to kit car builders and the like who were putting 350-400 bhp through them and I've never had any feedback regarding problems or request for replacements..... they really are a tough box !