SIDI TT powers new Caddie

[AirStrike]

All I am saying is your average person who buys a GTS/Clubsport will not want a bar of a turbo 6cyl.

 

[lmoengnr]

Impressive horsepower, but that's one very fugly car...

 

[mad mick]

seen a write up on them a while ago would be a sweet conversion . Engine is different to the one here its a 4 litre block not 3.6 or 3.0 can go out to 4.4 litre heads are totally revised for turbo charging and larger displacement

 

[PIR4TE]

seen a write up on them a while ago would be a sweet conversion . Engine is different to the one here its a 4 litre block not 3.6 or 3.0 can go out to 4.4 litre heads are totally revised for turbo charging and larger displacement

Bracketed by the ATS-V’s front wheels is the car’s twin-turbocharged 3.6-liter V-6. The six started life as the LF3 found in Cadillac’s larger CTS Vsport model, where it makes 420 horsepower and 430 lb-ft of torque, but is overhauled for ATS-V duty by way of new crankshaft counterweights, titanium connecting rods, and stunted intake runners. The oil pan features unique baffling to better manage flow during high-g cornering (it’s still a wet-sump design), and the turbos are unique, too. Peak boost sits at 18 psi—6 higher than in the LF3—and higher-flow fuel injectors deliver appropriately more go-juice to match the extra air being forced into the combustion chambers. This results in a new engine designation: LF4.

More about the LF4.

 

[AirStrike]

18psi and it makes like 310kw........................................:s
I was impressed with the setup till I saw 18psi.

 

[PIR4TE]

18psi and it makes like 310kw........................................:s
I was impressed with the setup till I saw 18psi.

Why is that a let down?

 

[AirStrike]

Why is that a let down?

Not a lot of power for that high a boost level in a largish 6 cyl. Doesn't leave lots of room to move if you want more out of it.
Depends if you would modify it or not I guess.

 

[PIR4TE]

Not a lot of power for that high a boost level in a largish 6 cyl. Doesn't leave lots of room to move if you want more out of it.
Depends if you would modify it or not I guess.

Very good point. The LF4 has 10.2:1 compression, plus 18 psi...

I'm sure the explanation for the output discrepancy has to do with an emissions compliant stock tune (EGR / LIVC, etc).

Because LF4 has strong potential given greater IMEP than stock R35 GTR, plus the 0-100 time, I think it must have safeguards and emissions provisions in the tune up the wazoo.

I reckon, like Nobuhiro Tajima (dude who owned Pikes Peak in a SIDI TT 4wd for years) that the engine has huge potential, but on release in stock form is like Ford's GT-F - the potential is there but the chastity belt needs a lock pick (ECU fully hacked).

From the data I've read, more appropriate camshaft calibration (via ECU) will be the key to healthy performance in the tune.

Will be interesting to see LF4 parts trickle down for the 6es as per LSA / LT1 is for the 8s.

 

[AirStrike]

Quite a high comp ratio as well. FG XR6T is 8.8:1, R35 is 9.0:1, 2JZ Supra is 8.5:1, etc, etc
It's one of two things, they threw some turbos on as an after thought or (I hope it's the or) they have gone a higher static comp so it has plenty of low down torque and pull out of the hole.

 

[PIR4TE]

Yeah, but those engines are all port injection. Direct injection can do a lot more with the injector pulse at different timing, in fact the total effective compression is exactly the same as the AMG A45 (direct injection):

Difference is as you say no lag, significantly more potential than any of the port injected turbos you mentioned.

It's a beautiful thing: