VZ LEO to LF3/4 V6 twin turbo conversion

[Gareth]

2014-GM-V6LF3-005-medium-850x680.jpg (65.44 KiB) Viewed 9227 times

Has anyone carried this out? I have googled this plenty but have been unable to find anyone who has.

I have an LEO V6 VZ crewman that I use to haul my race car around with and I'm starting to get bored of the lack of pulling power. I have long been looking for a 6lt doner vehicle but have not had success (mines 2007 and would require the 6lt to be EPA legal).

The LF3 & LF4 are basically LFX engines that are used in Cadillac CTS-V overseas, when I first looked at these 10 years ago the price was not attainable. Now they are over 10 years old the price has dropped to a more affordable level (I just got a quote for $1650usd for a complete engine). Power wise they are comparable to the 6lt.

Here's an extract from wikipedia - https://en.wikipedia.org/wiki/GM_High_Feature_engine "The engine is rated at 420 hp (313 kW; 426 PS) of power at 5750 rpm and 430 lb⋅ft (583 N⋅m) of torque at 3500–4500 rpm (with 90% of torque being available at 2500–5500 rpm) and helps the CTS achieve 0–60 mph (0–97 km/h) time of 4.6 seconds with an 8-speed automatic transmission.

In essence, the twin-turbo 3.6L V6 is the forced-induction variant of the popular LFX V6 found in the Cadillac ATS, XTS, and SRX, among many other GM models, with several important upgrades, including:

All-new cylinder block casting
All-new cylinder head castings
Strengthened connecting rods
Forged steel crankshaft
Continuously variable valve timing
Large 38.3 mm (1.51 in) intake valves and 30.6 mm (1.20 in) sodium-filled exhaust valves
Machined, domed aluminum pistons with top steel ring carrier for greater strength
10.2:1 compression ratio
Patented, integrated charge air cooler system with low-volume air ducts
Twin turbochargers produce more than 12 psi (83 kPa)
Vacuum-actuated wastegates with electronic control valves
All-new direct injection fuel system
Tuned air inlet and outlet resonators, aluminum cam covers, and other features that contribute to exceptional quietness and smoothness"



The Pro's I can think of are

- light weight
- bolt in swap
- factory parts
- different
- great power

The Con's I can think of are

- parts from overseas
- could end up expensive
- not sure on best way to control the engine and interface with a VZ
- may require trans upgrade

Has anyone got any thoughts on this idea?

[Gareth]

So it looks like the VZ E55 may be able to cope with boost - viewtopic.php?t=8431

[delcowizzid]

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Saab 9-3 bins might be worth a mess with e55 2.8 alloytech v6 turbo

[Gareth]

Thanks Delco, I'd forgotten about the SAAB V6 turbo

So the LF3 & LF4 are both direct injection which is beyond the E55 capability, so I'm thinking running both ECU's, the E55 to keep the car happy and the E39 to keep the motor happy, any thoughts?

[brindo]

Are you dead against supercharging? Doesn't really tick the box for being different, and hardly a challenge for you to to install, but be less heartburn if you ever have to work on it.

My brother bought a WL Statesman as a parts car. Previous owner sunk a lot of mods into it. I know not what's been done to it other than it's still NA and its a rocket.

[Gareth]

I'm not dead against it but... The top of the range CAPA kit promises 430hp for $10k, the stock LF3 (that is built to support it) has 420hp. Torque is similar too. The Americans are regularly pushing the LF3 and 4 to well over 700rwhp with seeming little problem. ZZP has a lot of great videos on this.

I'm really liking the idea of buying a half cut so I can use the 8 speed transmission too. I recon I can have one landed here for around $8k.

I love supercharging but am not keen on pushing a stock LEO or even a LY7 to those power levels, I have seen many blow up in speedway with very few mods.

[Holden202T]

watching with interest!

wonder if you could maybe make the e39 work with a custom PIM type solution ?

[delcowizzid]

There's a caddilac cts with turbo 3.6 and e39 I think so a file would be easy enough to get use the late ve/vf engine should be forged crank and powdered metal rods and forgies like the turbo one if I remember correct

[Gareth]

The other option I've been looking at is using the LGX out of the ZB commodore, they are cheaps as chips (complete low kms for $1200-$2k). It seems to be a better engine in almost every way according to wikipedia - https://en.wikipedia.org/wiki/GM_High_F ... engine#LGX

I wonder how hard it would be to buy all the hang on components from the LF3 (turbo kit) and fit up to one of these?

Anyone know what PCM the ZB uses?

Can anyone think of any issues or considerations running the direct injection in a VZ? Fuel line sizes?

[Holden202T]

from what i understand, in the VF at least, its normal fuel system up to the motor, then the high pressure stuff is all on the engine.