on turbo f1 engines, they were able to measure the inlet pressure at up to 10psi above the exhaust manifold pressure, that was 20 years ago.. just imagine how they would go now with the advances in turbo design, wheel profiles.

that being so

consider, both turbo / s/charger shafts are requiring 20kw to drive them

the s/charger is drawing 20kw from your crankshaft (forget belt losses etc)

the turbo, on the other hand, even if it drew 17kw from your crank via piston backpressure, it then gets fed the missing 3kw from your hot exhaust gas.....

therefore, making the turbo a more effiecint device, only sucking 17kw vs 20kw from the crank...

it is very well known that a turbo is much more effiecent than a s/charger at increasing engine power output

Agreed! what I had a problem with was this statement "super charging uses power 2 make power, torbo is free grunt."

There is no such thing as free grunt/power.

Seeing as you've got the 6, turbo it, if you had an 8 and wanted to stick to a budget, you would have to supercharge it.
The same reason mine isn't twin turboed, is the cost. It would have been more of animal, i'll grant that, but it would have cost a s**t more.
Turbo the 6.

Thats what I thought. Im a bit of a fan of the supercharger, and I dont know if its my imagination, but dont superchargers give imediate strong boost? whereas turbos, no matter how modern give even a little lag?

For acceleration from a standing start wouldnt supercharging be better than turbo? Im probably wrong but the only stupid question is the one you didnt ask.

The low down grunt of a supercharger that you are speaking of only applies to a certain type of supercharger.

The kits readily available for falcons - powerdyne and vortech- are not like this.


If you correctly size your turbo you can have boost from when you leave the line.

IMO a turbo has everything over a supercharger except for the heat it puts out.

The few people I know with supercharged 6's always have belt troubles where it slips at high rpm's and doesnt deliver boost.

These days a turbo setup can be done for the same price or even cheaper if you can fab your own stuff.

You mean a roots type SC that give the good grunt? or the screw type? Im not to sure what the screw type are called... only read a sentence or two on them. Are those powerdyne and vortechs centrifical? Dont like sidemount superchargers, seems to be a bit of a compromise.

I know I ahouldnt mention the holdens lol, but what about the supercharged sixes that peter luxton did for holden? they were pretty streetable wernt they?

I dunno... when your at idle, do turbos add to your volumetric efficiency, or not?

and as for turbos being as good low down as supercharging- then why did Volkswagon do the 1.4 litre twincharged engine with a super doing the work from 0- 3500 rpm, and then the turbo taking over from there? I mean having 200+ of your 260 Nm of torque available from 600 rpm sorta speaks of the "low down" grunt of the supercharger.... and peaking at 1700 rpm all the way to 4500- the whole 260 all that time... sounds like a good supercharger.


Heres how I can put it simply- and its my burning question. Put a turbo or a supercharger on my AU, all things remain equal- same max boost, same day same temp same fuel used etc etc. what would give better torque (coz KW is a dud figure unless you want to race) at 2000 rpm?

That all depends on the sizing of the turbo! if you put on a huge turbo for the displacement then you will not havew boost until late in the rev range, and if you fit a tiny turbo for the displacement you will have huge boost down low, but it will choke badly up top. Look at fords XR6T specs, peak torque of 480Nm at 2000rpm, speaks for itself really.

get a supercharger boost comes on real low in the revs which is good

After a lot of debate with people with more knowledge than myself, Id guess that a correct sized turbo would be best. Simply because of the engine config. If it were a V6 then a screw type SC would be the ducks nuts, but being inline means the best bet is a turbo. The turbo is much better than the centrifuge from what Ive gathered, and I havnt seen any roots/screw type setups for inline 6's.

Depends what you want and how you define "better". A centrifugal SC is geared to achieve full boost at max revs, so you get a linear increase in power as you rev it out. I'd guess that a 9PSI unit on an AU redlined at 5600 would make 4.5PSI @ 2800 and just over 3PSI @ 2000 rpm, for example?

A turbo will deliver full boost from lower revs right through, so will have a flat torque curve and solid shove, once the turbo spools up. I've heard of 6 PSI turbo's giving similar RWKW to the 9PSI Powerdyne. The turbo comes on-boost with a rush however, so may be harder on your tranny & diff.

A positive-displacement SC is theoretically possible on an I6, just difficult due to space and the need for a custom plenum. You're right, those V6 ppl are spoiled. Not only are there plenty of positive displacement SC kits to choose from, the V configuration is also much better for gripping the ocean floor