Max power from a 4.0 Litre engine

[DailyDriver]

This might be an obvious question, but since the Falcons have a 4.0 Litre engine, shouldn’t the max torque/power to be gained from the engine be higher than it is? I mean if I change the exhaust/headers and free up the engine completely, why am I only producing 10-15kw more at the rear wheels? Is something else restricting the max power/torque of the engine?

Other car companies produce as much power (like the Lexus 2.5 Litre) or more power (like BMW) from smaller engines. From a 4.0 litre engine you should be able to get over 180kw easy, shouldn’t you??

[Casper]

Its a long stroke, high Nm engine. Have a look at the Nm from the Lexus engines, it is usually less than the Kw. In the Falcon the Kw may only be 110rwkw or so but there is close to 400Nm of torque, thats more then some turbo's put out.

Its a lazy, high torque, towing sort of engine. Not a high rpm power engine.

[parawolf]

Depends on a few factors here:

a) how long do you expect the car to last - most people want 300,000km with minimal issues - some people couldn't care if it lasted 100,000km
b) cost of parts
c) cost of servicing
d) the Ford inline 6 4.0 litre is a longer stroke engine so it produces that good torque. Try and see what that torque figure is on the Lexus 2.0 or 3.0 IS200/300 inline 6 engine - not even close to the 380nm @ 3000rpm of the BA/BF falcon.
e) R&D, the inline 6 4.0litre is only used in Australia, therefore it doesn't really have global view for parts manufacturer or cost benefit through larger target audience.

The answer is yes you should be able to get more kw, however true performance comes from torque, kw is merely a function using rpm and torque output.

These other engines you talk about produce bugger all torque - but just rev quite high compared to the 6000rpm of the inline 6.

[DailyDriver]

So due to the type off engine, Ford will never be able to get as much power out of it as it does with the Turbo version (hence why they had to use a turbo to give it a power boost). A pity, since 4.0 Litres is alot of engine…looks like a XR6T will be my next future purchase…

[parawolf]

Originally Posted by DailyDriver

So due to the type off engine, Ford will never be able to get as much power out of it as it does with the Turbo version (hence why they had to use a turbo to give it a power boost). A pity, since 4.0 Litres is alot of engine…looks like a XR6T will be my next future purchase…

You will never be able to match a forced induction variant against a NA.

The NA motor could make 240kw, however it would have trouble idling, it would be expensive to build and power delivery would be really peaky and as soft as a sponge down low.

Generating a big bang inside the engine requires two things, ample oxygen, ample fuel, good compression, good valve timing and good spark.

With NA there is always limited oxygen you can feed the engine, particularly with the head on the I6. As a result too much fuel and you will flood the engine which will reduce performance. Increased compression during firing stroke is also important as the more compressed everything is the bigger the bang due to denser air. However more compression requires high octane fuel which means increased running costs.

So therefore it makes perfect sense to turbo the engine to "FORCE" more air into it, which means good fuel and slightly reduced compression you get a car which produces far more power than NA, and is far more civilised and streetable in delivery.

Just look at the rotary in the Mazda RX8. It is a 1.3Litre engine, produces ~170kW but only about 210Nm (numbers are a guess). However the torque peak is over 5000rpm and power over 7000rpm. So between idle (say 1000rpm) and peak torque (5000rpm) there is going to be a real soft spongey no performance region.

Also as a final comment, the XR6T is still a 4.0Litre engine, just with a turbo. So it is still a whole lot of engine, it just have gobs of power with it.

[DailyDriver]

Thanks Parawolf for your insights.

[AWD Chaser]

Dude, you try towing a heavy as trailer load (caravan or horse float or such) in the Falcon - 383Nm @ 2500rpm - thats almost max torque taking off (almost but not quite) which also makes it great for towing up hills too..

whereas the Lexus is250 producing 252Nm @ 4800rpm mean you have to really wind up the car to get this max output going - lol love to see a comparison of the two doing a hill start with a caravan - lol :

But as with any car, they all (as previously mentioned) have their target audiance.

The Lexus isn't targeted for the Aus. Market, or even designed for it, thats where Ford Aus. have their competative edge (sometimes).

(BTW - the Lexus IS250 needs 95RON or higher any ways - higher costs yet)

If you want a high power output car, buy one, if you want a car that can pull 5 ppl, a full tank of fuel, luggage and a big *** trailer, get a falcon... (or other inferior brand... god forbid).

If Ford wanted their I6 4.0L to produce more then what it does now, they could do it... (What a day that would be _ )

I might be wrong with the above information anyway so please don't hound me