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A lotta potential with LF3/LF4 engines, particularly if you're not into emissions like GM has to be or you pick different turbos.
Lag isn't a massive issue anymore, modern turbos are ruthlessly efficient, particularly if you pick a turbo that is correctly sized, but advances in valve and cam timing technology also make a big difference. Roots chargers are difficult to do on 60 degree V engines because of the narrow valley, and the intake manifolds end up being large and complex and hang off the side (e.g. you have to take the charger off to do spark plugs etc...) - exhaust manifolds are generally a lot easier to fabricate than intake manifolds that require precise alignment if a cast one doesn't exist. Centrifugal chargers exist, but are way less flexible than turbos (most of the centrifugal's boost comes on mid to top) can be and there's generally only so much boost you can get from them because they're tied to engine speed. Other big advantage for turbos on the LLT onwards engines is the integrated exhaust manifolds make it much easier and much cheaper to do, as far as I know the turbos that GM used are just bolted directly to the side of the heads, no manifold in between. Going turbo is also a lot more achievable at home when there's not many aftermarket kits around too.
Single or twin turbo is the least of your problems. 2 questions:
Yes there can be huge potential if reliability and emissions are sacrificed for dyno sheet bragging rights… and a lot of sitting by the side of the road waiting for a tow truck…
These days, exhotic road cars are pushing upwards of 200hp/litre, some nearing 300 But such stuff are dreams to us financially limited mortals I like the LF3 Yeah i Don't no what i was thinking about that hp but i am just trying alot of things for this projectYes there can be huge potential if reliability and emissions are sacrificed for dyno sheet bragging rights… and a lot of sitting by the side of the road waiting for a tow truck…
In the case of F1 turbo BMW M12/13 engines of the mid ‘80’s, reliability was heavily sacrificed to get to the front of the grid during qualifying. But these weapons were lucky to get 4 laps out of those turboed 1.5 ltr engines pushing 1400hp @ 930hp/litre
In the real world, cost limited reliability and emissions ain’t easy which is probably why GM only gets 420 reliable and clean horsepower from their 3.6l turbo LF3 . But OP wants 580 hp from a NA Holden 3.6 litre, thats 38% more than GM’s LF3. That’s a lots more and not easy down under when the aftermarket isn’t well known for doing such V6 builds (or is it?)…
And such projects ain’t just the engine since you need other driveline, brake and suspension updates to keep the car reliable, safe and legal which requires even more $$$..
Interestingly the LSA pumps 580hp and one just needs to look at the drive line and cooling system of the HSV’s containing such engines to realise it ain’t just an engine mod to a V6 to get 580hp…
Really, if one has to ask such engine build questions on a forum without specifying their budget and their desired goals, for stuff like reliability, drivability, emission, legality, etc, etc, etc, for me it is just dreaming…
Good luck to him though… sometimes dreams come true
PS: if the LSA had the same specific power as the LF3, it’d pump out 720hp so I guess that shows how effective the LF3 individually variable intake and exhaust cam timing can be
Maybe on what not to do?
