LC4 vs LC5 : Launch Control Test

Bill from Spray It Racing, put the latest versions of the Nissan GT-R launch control to the test and reported his results on the NAGTROC forum.

What is LC4?

First used on the 2012 Nissan GT-R. In 2012(US), the launch control was again revised. This time it is an actual advertised feature, called R Mode Start, with limits. LC4 allows for four launches prior to it requiring a mile and a half drive to cool the transmission down. The quick numbers are generated with the setup switches in R- Comf - R.  4000 rpms comes up, and 0-60 times happen in anywhere from 2.8- 3.2 seconds. Check out this video of a drag race between a 2011 GT-R with LC3 and a 2012 Nissan GT-R with LC4. Videos like this, plus 0-60 times in the 2's made the early Nissan GT-R owners lust after LC4.

What is LC5?

Used on the 2013 Nissan GT-R. For 2013, there may be a further improvement in the launch control.  Nissan says that 0-60 mph has dropped to the 2.7 second range. From Nissan's own charts, it looks like there is not as much of a dip in RPM after launch. User impressions say that the car holds gears a little longer in auto mode, but no huge differences between LC4 and LC5.

LC4 on the Left, LC5 on the Right. Let me first say LC5 is a slightly revised launch strategy compared to LC4.

My interpretation of the launch data. LC5 the Initial clutch drop is harder. This gets more wheel speed. I put my cursor on the peak wheel speed on the initial clutch hit. LC4 went to 14.7km/h and LC5 went to 18.4km/h.

Next point I want to look at is Clutch Slip A data point at the peak initial wheel speed. LC5 is slipping the clutches more. LC4 has 2113 rpms of clutch slip, At the same point LC5 has 2529 rpms of clutch slip on the A (1st gear) Clutch. And continues that trend until the clutch is released. If you look at clutch temp, Peak is similar but the graph on the left (LC4) the temp goes down faster (10 degrees C lower), due to less slippage. Comparing Clutch pressures tells that story, LC4 is using more clutch pressure,

Also LC4 dropped to a lower launch RPM after the clutch came out. LC4 went down to 3027rpms and LC5 went to 3229rpms.

Now your results may vary due to engine tuning, tires and conditions.

Controlled slipping of the clutches is not a bad thing, however the issue presents itself is clutch slipping in higher gears. I have recorded clutch slipping data and LC5 does create more clutch heat, And that can make the clutches slip in higher gears, usually 3rd and 5th gears. (Max Clutch temp for LC4 256 Degrees C, Max for LC5 268 Degrees C)
Head over to the forum for the full discussion and feedback on LC4 vs LC5 on the Nissan GT-R.

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Item Reviewed: LC4 vs LC5 : Launch Control Test Rating: 5 Reviewed By: Sean Morris