LUJ (1.4 Turbo) Torque Curve?

[the_yellow_dart]

I was able to find a torque curve graph for my engine previously on Google. Now I can't. Can anyone help me out?

Also, does anyone know what the minimum engine speed for boost is?

[Cory Wolfe]

Don't know who made it, but...

[dwightlooi]

I was able to find a torque curve graph for my engine previously on Google. Now I can't. Can anyone help me out?

Also, does anyone know what the minimum engine speed for boost is?

Here's the official one straight from GM Powertrain

If you have an LUJ, here answers to some questions you may want to ask...

What kind of turbo is in the 1.4T engine (LUJ/LUV)?

The Turbo is a Garrett MGT14 (MGT1446 to be precise). It is most similar to a Garrett GT15 if you want a generic reference. The "M" in front of the model designation indicate that the turbocharger's turbine housing is a custom casting that is one with the exhaust manifold. The "46" indicates that it has a 46mm compressor wheel which is between that of a GT1544 (43.9mm) and a GT1548 (48mm). This turbocharger can support up to ~175hp in airflow before falling off the map and becoming highly inefficient.

How much boost does it run?

The Stock Boost level is about 12.8 psi on a static compression ratio of 9.5:1

How much boost can be run if the ECU is reprogrammed?

You can probably run about 15 psi on regular 87 octane and about 18 psi on premium 91 octane on the 9.5:1 stock compression.

How much power can the engine make?

On 87 Octane, using 15 psi of boost an estimated 150hp @ 5000 rpm and 165 lb-ft @ 2500 rpm can be made on stock compression. On 91 Octane, I estimate 175hp @ 5000 rpm and 180 lb-ft @ 3000 rpm. In all cases, peak torque will arrive later and the engine will be somewhat less linear, although probably not objectionably so.

Will a new intake, filter or exhaust help make more power?

The biggest issue is the intake manifold. GM has molded into the intake a set of tumbler dams* just ahead of the intake ports. These obstruct the lower 1/3 of the intake ports creating a tumbling effect on the inducted air. This is good for emissions, probably in an effort to get it to ULEV or some preferred rating. They can be removed if you pull the intake, then Dremel and sand paper them out. Removing the dams is worth about 5~7% more torque across the board, assuming ECU is retuned to account for the increase in volumetric efficiency.

How fast will a Cruze be if you run 18 psi and do the intake runner mod?

About 7.0 secs to 60 mph.

*Tumbler Dams

[Cory Wolfe]

The Cruze Turbo has alot of potential to be a fun little car.

[hyperv6]

I was able to find a torque curve graph for my engine previously on Google. Now I can't. Can anyone help me out?

Also, does anyone know what the minimum engine speed for boost is?

The torque curve is more of a plateau. The Turbo VVT DI engines hit max torque low and generally hold it through most of the range. To anyone who has not driven one of these engines it will suprise them. This is not a performance engine but still has good power and torque.

Boost comes in early and fast so there is little lag.

It will be interesting to see if GM Performance Division will make a Turbo Upgrade like they did for the 2.0. Gains of 55 HP in the Auto HHR SS and in the case of the 5 speed Kappa 70 FT LBS were added with only two 3 bar map sensors and a computer flash. Mods will be easy but they need to be well sorted as if the tuner misses the mark damage can and will happen.

What has been given so far is just a basic package with the 1.4 and I suspect better versions are to come that will better take mods to advance power.