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[anV6]

Hi,

I have always liked the Omegas, including the A. I have finally decided to buy an Omega B.

I would like to do some tuning to the engine and performance. So I'm undecided what is my best option between the 3.0 and 3.2.

I have heard and read conflicting info with some saying the 3.0 has more potential for tuning and can make more HP than the 3.2 because of that. While others saying while true it may be easier to increase power in the 3.0 you would be basically only increasing to as much as is also possible with the 3.2. Meaning you would not pass it.

Now I'm not thinking of turbo charging or super charging or anything crazy. I want to keep it naturally aspirated. If I could squeeze about 50hp more I would be very happy.

So what should I buy, 3.0 or 3.2?

It has to be a manual gearbox. But I guess both were available in manual if I'm not wrong.

Thanks in advance.

[Andy B]

....
It has to be a manual gearbox. But I guess both were available in manual if I'm not wrong.
 .....

Fortunately both are few & far between 

[anV6]

Hi,

I'm not sure what you mean? I guess you mean there are not so many manuals? But then why fortunately?

[Andy B]

Hi,

I'm not sure what you mean? I guess you mean there are not so many manuals? But then why fortunately?

Tongue in cheek ..... sorry, it's your first post.  Manual was a no cost option, auto was the default gearbox. Some obsess over wanting to be in control with 3 pedals while others just put their car into dive 

[Migv6 le Frog Fan]

The engines aren't particularily suitable for tuning, and I cant see any way of getting another 50bhp out of one without spending a lot of money.

[ted_one]

Possibly one or two people on here,would be able to give some pointers for your project,HooverMig is currently going down the supercharging route and I think NickW is pretty up on what's involved.Alternatively just get yourself a supercharged VXR8,bit bigger than the Omega and frigg me does it get down the road if that's what you want or driven sensibly it turns in a comparable fuel consumption figure to the 3.2.

[Diamond Black Geezer]

The 'most tuneable' is the 2.5, on the grounds that it has the least power - you can get close to (some say a fraction over) 200bhp with some relatively low-cost mods. Though the argument is 'just buy a 3.0/3.2 in the first place' - which is a fair argument. But you'll not be able to tune it very far, as said, keeping it naturally aspirated. And they don't like forced induction very much either!

NO idea how people manage to get 300bhp out of the old C20XE, yet struggle to get more than 220bhp out of the 3.2!

[Omega VT3000]

In the UK, the 3.2 wasn't available with a manual gearbox to the public although I think the Police may have had manual 3.2 cars.

I haven't seen any packages for the 3.2 but Courtenay Turbo did a turbo conversion for the 3.0 V6 although it didn't dramatically increase power but gave more torque.

Steinmetz did a supercharger conversion for the 3.0 V6 but for left hand drive cars only that took power up to around 272PS I think.

[Kevin Wood]

There are pros and cons with both engines. 3.2 has a forged crankshaft and more cubes, but lower compression. 3.0 shares the same geometry as the C20XE, meaning potentially more tuning parts available.

Neither engines have any sort of track record in tuning, meaning it will be a very lonely and expensive road to travel. There is folklore of the bottom ends not handling significant power hikes well, and of cooling problems with tuned V6s.

It's a case of "I wouldn't have started here". The Omega has a decent sized engine bay and conventional layout, so an engine swap for something with better tuning pedigree would be my first step.

[ted_one]

One of my 3.2's has had a remap and is claimed to be putting out 241 bhp,and comparing it to my other 3.2 there does seem to be a difference in performance and fuel consumption but hey they're 3.2's a nd they'll get you down the road to a driving ban quick enough in standard guise.  :oAlso there's another view that the 3.0 is a bit quicker than the 3.2 albeit the way it delivers the power,so it would be advised if possible to get a drive of both and make an educated choice for the basis of your project

[anV6]

Thanks for all the replies.

Yes, I heard that the 2.5 and 3.0 are more tunable and I suspected that was on the grounds that they start with less power. But if the limit is about the same as the 3.2 might as well go with the 3.2 and not bother with upgrades, right?

But the question of how people manage to get 300bhp out of the old C20XE, yet struggle to get more than 220bhp out of the 3.2 is a good one. I would like to know that too. Is the V6 just a bad design or what is the issue?

The VXR8 is a good idea, except it was never sold in LHD and I currently live in the continent. So I need a LHD car. The good thing is Omegas seem way more available in continental Europe than back in the UK. And I'm glad to find out the 3.2 is available here with a manual. The reason I asked is because I had heard the 3.2 was auto only. But now I know that is for the UK. Here 3.2 manuals are available.

The reason I would like to avoid turbos and superchargers is because they are complex, expensive and I really dislike the sound that both make. I want the natural grow of the engine and want power also available at lower RPMs. I also read the V6 doesn't cope well with neither turbos or superchargers.

As for just doing an engine swap, I'm not really interested in that. Before doing that I would just buy another car then. Too much work and money.

I'm a bit surprised that it seems so hard to tune the V6 to get a mere extra 50hp without a turbo or supercharger. I have seen remap packages claiming an extra 27hp which would get me past half the way to 50hp extra. Then I thought it wouldn't be a problem to get the other 23hp on the exhaust, chip and other small mods. I also found some tuning info over at the Cadillac Catera forums which claims to add about 30hp. It's for the Catera but we all know it's the same car. He says he got the advice from this forums, which is how I got to there. If it's ok to post a link, I can post it. But he is a sum of what he said:


   "1. 3.2 Liter - Engine Block w/ all its internal parts, Exhaust Manifolds, Fuel Pressure Regulator, and Head Gaskets

   2. 3.0 Liter - Intake Plenum, Velocity Stacks, Fuel Delivery System, Throttle Bodies, TPS, Intake & Exhaust Cams, Exhaust Valves, Oil     Pan, ECU, Sensors, Ancillary Components, and "Front Pipe" (modified flange)

   3. 2.5 Liter - Saab 900 Cylinderheads (intake passages require porting)

After all this we end up with a 200cc displacement increase, a stronger crankshaft, a higher compression ratio, the best camshafts, the best fuel delivery set-up, freer flowing "factory headers", and an increase in horsepower anywhere from 20 to 30HP over the 220 HP of the stock 3.2L V6 plus more useable torque, all with stock GM parts. Sounds easier than swapping in an SC3800 V6 or an LS1 V8, doesn't it? True, not as powerful than either of those two but with them you'd have to do lots of custom fabrication, and maybe install a stronger transmission."


So I thought the above mods plus a remap should be good for around 57HP more. But I guess it's not really that way?

The reason I'm looking at the Omega is I want a 4-door saloon with rear-wheel drive and a somewhat powerful engine. It would be better if it was European, but not a definitive must.  But I don't want to go BMW or Mercedes. As I always liked the looks of all the Omegas I thought they would be a good option. I also don't want to spend a lot of money buying the car. So not many other 4-door saloons with rear-wheel drive, a somewhat powerful engine, relatively modern, readily available in Europe and not very expensive.


Thanks again.

[Diamond Black Geezer]

Nice amount of information. I had to google the Saab 900 heads - had no idea that engine went in the 900. It would certainly be interesting to see what difference there is - though one possible thought I'd had - was the Omega every available as a Catera in 2.5 guise? If not, perhaps this 'Saab 900 heads' thing is simply a way of (for Americans) acquiring the 2.5 heads easily, rather that try and source some from a European motor? Presumably this is a way of raising compression, but I theorise only.

I think initially, what you might want to do, is get yourself an Omega, in whatever engine size presents itself, have a drive. Next step would be a manual conversion, ans possibly change the diff (two things which will unleash a fair amount of 'oomf' without doing any engine work), then see how the car feels, you may well find it plenty good enough for your needs. 

[anV6]

I don't think the Catera was sold with the 2.5. But I think the reason for the Saab heads is because they are stronger. Because the Saab engine version was turbocharged. So the engine had to be modified and made stronger to cope.

What do you mean with a manual conversion? Omegas are readily available with a manual transmission. Unless I'm wrong? So I would be buying a manual already.

[Diamond Black Geezer]

Well, as a rule most (and I think the number was around 75%) of Omega are Autos. The only reason I say 'manual conversion' if that when you find 'the' car, that's top condition, well looked after, lots of servicing, and all the other things you should search for when buying an older car... it's probably going to be an automatic. If you wait until a manual car comes along you may be waiting a long time. You might get lucky, but don't be afraid of passing up mint Auto 3.0/3.2 cars, until you find a car that's got a few problems, but you buy it just because it's a manual. That's all 

This same argument comes up every now and then with people waiting for an Elite, they only want to buy an Elite. I say - buy yourself the first mint, low mileage Omega you see - all the toys and niceties can be bought second hand for very cheap, it's easier to install a gearbox, or heated seats, than it is removing some hidden chassis rust the MoT man finds 

[anV6]

I see your point and it's definitely a good one. 

But I believe you are speaking from the perspective of buying in the UK right? Speaking of the Vauxhall Omega?

Because the Opel Omega seems to be readily available in manual. At least this is the impression I get while looking at local classifieds here.