Any given sunday....

[Jayme]

3.6 .... buy yeah ... ive got a 1.9 tonne adventra with a 3.6 alloytec 190 in it... its damn revvy. the 5 speed auto seems to make good use of the power but all it wants to do to get anywhere is REV... I can only imagine how well it would go in a 1.2 tonne VL or VN. I reckon the ecotec has a better bottom end feel to it than the alloytec, even tho its got its fancy cam phasers...

[HQ355]

Take a 3.6 sidi for a spin, better again than alloytec, would love to put one in an LC or LJ torana

[Jayme]

ive always wanted to know.... can you imagine in an SIDI how big the injectors are.... think of it this way, an ecotec has all 4 strokes of the cycle to inject its load... at 80% duty cycle its injecting at the back of a mostly closed valve across the compression, power, exhaust and inlet strokes and is what, 19lb per hour injector.... imagine in a direct injection, its got give or take, 25% of the time to inject its full load as it can only inject during the inlet stroke and mayyyybe a little bit of the compression stroke (unless they have insane fuel pressure like a deisel) so the injectors in theory would be 4 times the size.... so 80lb per hour?? and how much room does that give to modify the engine. where are you going to buy as set of injectors to handle boost and at the size they need to be how crap is the low pulsewidth delivery going to be given they have to be 4 times the size as an equivalent non-direct injector.

[Gareth]

This point came up in a previous post, the best answer to that was to use a set of staged injectors??.. EG: not direct injection but rather mounted in the inlet tract.

[Jayme]

oops im good at forgetting things..... I swear ill get alzhimers later in life

[slewinson]

oops im good at forgetting things..... I swear ill get alzhimers later in life

I used to have Alzheimers, but then I forgot all about it!

[Gareth]

The trick is to think of it as a whole, know all of these things, and design the package to do what you need.

Unfortunately for us, finding out the original reasons for the design would be hard if not impossible. In general I suspect more thought has gone in to these things than poeple realise, but the only way to verify that is to do our own tests.

I agree antus, but how is it that a Ferrari can make awesome torque from zero to redline on pump fuel? How is it that the engineers of higher end cars can get so much more from their engine/intake design? I agree that intake design dictates torque curve, I just don't understand how other engines can perform so differently in the same environment.

I can only imagine how well it would go in a 1.2 tonne VL or VN.

I campaigned a VH commodore with a heavily modded Ecotec in Speedway Mod sedans for many years very sucessfully, Light weight + great motor = lots of trophies

[Holden202T]

ive always wanted to know.... can you imagine in an SIDI how big the injectors are.... think of it this way, an ecotec has all 4 strokes of the cycle to inject its load... at 80% duty cycle its injecting at the back of a mostly closed valve across the compression, power, exhaust and inlet strokes and is what, 19lb per hour injector.... imagine in a direct injection, its got give or take, 25% of the time to inject its full load as it can only inject during the inlet stroke and mayyyybe a little bit of the compression stroke (unless they have insane fuel pressure like a deisel) so the injectors in theory would be 4 times the size.... so 80lb per hour?? and how much room does that give to modify the engine. where are you going to buy as set of injectors to handle boost and at the size they need to be how crap is the low pulsewidth delivery going to be given they have to be 4 times the size as an equivalent non-direct injector.

aren't they injecting directly into the cylinder just as the piston is coming up ? I thought that was the go, and obviously needs a shiz load more pressure to offset the cylinder pressures! and having it work this way is why they can run more compression without knocking as there's no fuel in the cylinder to knock!

and I can vouch for how well an ecotec in a nice light Torana goes

[Dylan]

I read somewhere they have a high pressure mechanical fuel pump driven off a camshaft.

[immortality]

I too am fairly certain the Sidi engines run a lot more fuel pressure.