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[geoffr70]

Hello, if one were to employ forced induction on a V6, could the rear multiram be rendered inoperative by merely removing the plug? Or would it need removing?

As the ecu meters fuel based on airflow, could this not need remapping/replacing as it would meter more due to forced induction? Or does it only meter upto a set parameter?

Thanks

[feeutfo]

One for Kevin this, interesting to see what he says, but I'm guessing the maf will read whatever within the confines of over powering the engine to destruction, as the will the injectors deliver enough fuel perhaps?

They don't take much more before bottom end issues rear their heads. Did you see the ad in piston heads for a v8 omega that was born of that very reason. Supercharger destroyed the stock motor.


Multi rams and supercharger...? Leave them in I guess  :-/

Stick a v8 in it! 2woody is taking orders as we speak i believe. 

[TheBoy]

I've seen turbo'd omegas. Usually accompanied with a big end knock, but thats another story.

The ECU will need to electrically see the rear multiram, but won't be fussed about whether its actually doing anything.



Though do bear in mind, before starting this project, every single one I've seen with modified intake has been disappointing.  I think with 2.5/3.0, there is more to be gained by looking at exhaust manifolds to be honest...

[Kevin Wood]

The engine has 10.7:1 compression, so not a lot to be gained with forced induction unless you're going to rebuild it with lower compression at which point you might as well do a proper job with a mappable ECU, so everything else is then answered. Not sure disabling the rear multiram would make any odds. Certainly wouldn't be the first of my concerns.

Everyone looks at the induction system on the V6 and thinks they can do better. I've yet to see any evidence that anyone can.

Kevin

[2woody]

I'm sure that no-one can.

the "standard" fuel injection sensors would probably compensate for extra power, but only up to about 2% extra power or so. Even then, you'd need a specific fuel map really.

four ways to make extra power.

one. Reduce parasitic losses - remove a/c, slow down water pump, lighter weight flywheel (works under acceleration only) low back-pressure exhaust.

two. forced induction.

three. engine spec - go for the cam/compression ratio combination first and work from there.

four. different engine.

fully agree with the comments about bottom ends - the 54degree V6 sems incredibly fragile there.

[geoffr70]

I have seen the v8 omega, but with space at a premium with the v6 and having done most of the most horrible and tightest jobs on the beasts already, I don't want to lose anymore space!

I hadn't considered the bottom end, it's quite surprising how fragile people say it is! As for exhaust manifolds, I'd considered getting new ones fabricated from scratch which would obviously cost alot!

If I am to start a project I would got the whole hog including mappable ECU.

As for 2woodys methods of reducing parasitic power loss, I doubt slowing down the water pump would gain much if any, surely with increased power you'd want more cooling, and having a lighter fly wheel would be detrimental to acceleration once the car is actually moving reducing torque which is the whole point of a v6.

Lots of things to consider here, I might just lpg them instead!

Thanks all.

[Kevin Wood]

A lighter flywheel won't make any difference to torque. It's just a lump of metal bolted to the back of the engine so it doesn't affect the engine performance at all.

It might make a larger car very slightly more tricky to pull away from rest due to less stored energy in the flywheel. On the other hand, you aren't accelerating a huge mass of metal to 6500 RPM through each gear, so, in the low gears, where the rate of change of engine speed is high, it does make a small difference to the acceleration. It can also help you make quick gearchanges as you haven't got to decelerate that mass again to match the revs for the next gear.

I think forced induction on a V6 would make for a much more cluttered engine bay than a V8. Remember that most V8s are pushrod engines so they have much more compact cylinder heads than the V6. More importantly, it's a path that's rarely been trodden, so you will be finding and fixing snags all the way along. Just dropping in a tried and tested larger engine, however...

If I were looking for a substantial power hike in an Omega, I'd be fitting a V8, no question.

Kevin

[geoffr70]

I might just get a holden!!!

[2woody]

I might just get a holden!!!

 I did !

the flywheel thing - basically, although it doesn't increase the engine power at all, it does have quite a large effect on acceleration. in first gear, the car will accelerate as if it's lost maybe 25kg for each one lost in the flywheel with the effect reducing with higher gears. So, for example a flywheel which is 10kg llighter (such as aluminium) will in effect shave 250kg off the car weight in 1st - an effect not to be sniffed at. Only down-side is idle stability, but you'd be hard pushed to notice.

have just fitted an aluminium flywheel to the Holden and will report back the acceleration difference.

[feeutfo]

I might just get a holden!!!

More expensive than v8ing an omega, depending on your donna car,a high miles example brings costs down considerably, and the v6 will be coming out anyway obviously.... and very few toys in a Holden. To few for my taste anyway. 

[Martin_1962]

Parasitic losses.

I suppose that could include cats.

Need power steering
Need water pump
Need alternator
Need air con compressor

Nothing else to remove

[2woody]

there's all sorts of parasitic losses, granted some you can't do anything about, but coolant pump, aircon and exhaust back-pressure you can.

coolant pump is sized to pump adequately at idle in the worst possible conditions, so is way over-sized for 3,4 or even 5000 revs in the UK.

aircon can use 20hp to drive, so removing that is an instant power boost, not to mention the weight you've lost as well (100kgs or so). Different people have different ideas on this, some can't bear to be without aircon, whilst some (like me) can't bear to cart round 100kgs of unnecessary lard for those three days of the year it would be useful.

exhaust pumping losses can be quite high. I've never measured an Omega exhaust, but I wouldn't be surprised to gain 5hp at max power by reducing the back-pressure IF the fuel map were adjusted to suit.

there's a lot to be gained in the bodywork, too. removing the boot spoiler and fitting a large under-tray would also be effective.

As an example, my Omega Evo500 is quite a bit slower in a straight line than a standard Senator, despite having 30BHP more - it's all lost in drag (the body kit)

[TheBoy]

some (like me) can't bear to cart round 100kgs of unnecessary lard

Thats why people never give me a lift