[alexdavis]

I don't have my texts in front of me. Perhaps someone can verify (or adjust) what I think I read:

As the car (2012) is warmed up from a cold start, I think the LC4 is disabled until a certain oil temperature is reached...perhaps 140 degrees.
Is this correct or not?

Second question, if applicable: Are any other "disabling minimum conditions to be met" from a cold start-up, also in effect?

And lastly, besides the programmable gauge info such as oil temperature, and of course just trying/testing a launch, is there any other observable feature "declaring" that the ECU will allow full LC4 launch?

I'm asking these questions because of the possibility of long delays at a drag-strip...and coming to the "line" without the car being ready to go. (cold drag-strip; waiting an hour or more!)

Alexd

 

[FikseGTS]

the transmission retains a lot of heat, you will be able to wait an hour, pull up to the line and run the car.....

 

[ancalagon]

From the owners manual:

- When the temperature of the engine coolant and transmission oil is high or low, the function cannot be used.
The temperature range in which the R mode start function can be used:
- Engine coolant: 140F - 212F (60C - 100C)
- Transmission oil: 140F - 266F (60C - 130C)

 

[alexdavis]

From the owners manual:

- When the temperature of the engine coolant and transmission oil is high or low, the function cannot be used.
The temperature range in which the R mode start function can be used:
- Engine coolant: 140F - 212F (60C - 100C)
- Transmission oil: 140F - 266F (60C - 130C)

Thank you both!

So, the 140F that stuck in my mind was correct...but it was a requirement for Transmission Oil, not engine oil, as well as additionally coolant temperature.

I forget, is transmission oil temperature part of our options for display? (And, repeating my last question, does any OTHER display phenomenon show up as an indicator the car is "ECU-enabled" or still cold and "disabled" for full-tilt launch?)

Alexd

 

[MC]

in addition to all of the temp stuff you shouldnt hold the launch at 4K more than 4-5 secs... if you do it will bog down and not launch

also you only get 4 in a row on the 4th launch it wont let you stay in 1st or 2nd gear and will automatically shift to atleast 3rd

and the part i havent figured out is how long of a gap inbetween them still counts at 4 in a row...

for instance i did 2 at the drag strip...let the car sit for about 30-40 mins.... did 2 more and the transmission light came on

but then the other day i did 3 launches at a autoX... went home for about 3 hours then came back and i expected the next launch to throw the light and ..it didnt i had a fresh new 4 count

 

[Davin]

and the part i havent figured out is how long of a gap inbetween them still counts at 4 in a row...

for instance i did 2 at the drag strip...let the car sit for about 30-40 mins.... did 2 more and the transmission light came on

but then the other day i did 3 launches at a autoX... went home for about 3 hours then came back and i expected the next launch to throw the light and ..it didnt i had a fresh new 4 count

Isn't it just 1.5 miles of driving to reset the count for LC4?

 

[MC]

Isn't it just 1.5 miles of driving to reset the count for LC4?

yeah but thats after the light comes on.....

what im not sure about yet is say you do 2 or 3.. and you dont get to the transmission light... when does it reset?

i need to test this.... i need to do a couple then drive the 1.5 miles without the light on and see if it gives me a new 4.......

 

[jaspergtr]

^ That was my understanding of it.

 

[ehyman]

yeah but thats after the light comes on.....

what im not sure about yet is say you do 2 or 3.. and you dont get to the transmission light... when does it reset?

i need to test this.... i need to do a couple then drive the 1.5 miles without the light on and see if it gives me a new 4.......

I beleive it resets every 1.5 miles, though I haven't tested exhaustivly. What I do know is once its tripped, the only way to reset it is to drive, power, battery , clear codes have no effect. Thats what I'm working on now.

Eric

 

[MC]

Im curious about time...like if i do 2 then let it sit over night...do i only have 2 more before the light or a full 4

 

[ehyman]

Im curious about time...like if i do 2 then let it sit over night...do i only have 2 more before the light or a full 4

I didn't test that exact case, but based upon how the reset worked for me, I'd bet the answer is yes. I'm also pretty sure if you hit the launch limit. Parked the car for a year and restated it, you'd still need to drive 1.5 miles to have fun again

 

[alexdavis]

I'm guessing from the continuing thread that apparently no know is aware of any independent way of telling if the LC4 is "enabled' or "disabled," short of the obvious of trying it out.

But, I'd like to ask a tangent question: For a LC4 launch, the brake must be applied and the throttle floored. Has any experimentation been made as to how much pressure has to be applied to the brake? Obviously it can't be feather-touch with the car slipping forward...but do we need to "stand on it" or more softly press on it. What I'm looking for is an advantage (if there is any) to light brake pressure during LC4.

Alexd

 

[MC]

the brake needs to be firmly pressed all the way down

if not it wont start the LC process and the car will feel like is trying to move forward like brake loading an automatic...

 

[alexdavis]

the brake needs to be firmly pressed all the way down

if not it wont start the LC process and the car will feel like is trying to move forward like brake loading an automatic...

I suspected as much. I wonder if anyone has pressed down hard enough to start the LC4 process (4000 RPM holding), then within the 3-4 seconds, easing off the brake slightly, for possible faster reaction response, both for the driver and the car's various processes, before totally jumping off the brake.

(Looking for any incremental drag-start advantage...)

Alexd

 

[ehyman]

I suspected as much. I wonder if anyone has pressed down hard enough to start the LC4 process (4000 RPM holding), then within the 3-4 seconds, easing off the brake slightly, for possible faster reaction response, both for the driver and the car's various processes, before totally jumping off the brake.

(Looking for any incremental drag-start advantage...)

Alexd

You *do not* want to do that unless you value likly imaginary "Drag start advantage" over the life of your clutch.

One of the advantages of the LC4 style launch is the Revs come up immedietly, whereas in older versions it crept up slowly...the later building more heat which is bad for your clutch and tranny in general.

Eric

 

[MC]

yeah you want to be all the way on the brake the quickly all the way off.... no in between...

but speaking of drag strip advantage one thing you can do is learn strategy with when to engage the launch.... one tip i usually tell people is if you can always let the other lane stage first so you can be in control of when the tree countdown starts.... so when you see their 2 staging lights lit and you roll up and light yours.... you can usually get away with starting the LC4 rpm hold right then but on the other hand it revs up to 4K fast enough so you can actually start the process as you see the first yellow light ( this is obviously on non pro tree) and you still have time to release the brake right when your brain acknowledges the 2nd yellow... thats how i do it but i still struggle with reaction times with LC4...

so i would say if your looking for a edge at the strip... getting timing down on LC4 is gonna pay off more than any sort of pedal technique and the LC program makes all of that straight forward

 

[alexdavis]

yeah you want to be all the way on the brake the quickly all the way off.... no in between...

but speaking of drag strip advantage one thing you can do is learn strategy with when to engage the launch.... one tip i usually tell people is if you can always let the other lane stage first so you can be in control of when the tree countdown starts.... so when you see their 2 staging lights lit and you roll up and light yours.... you can usually get away with starting the LC4 rpm hold right then but on the other hand it revs up to 4K fast enough so you can actually start the process as you see the first yellow light ( this is obviously on non pro tree) and you still have time to release the brake right when your brain acknowledges the 2nd yellow... thats how i do it but i still struggle with reaction times with LC4...

so i would say if your looking for a edge at the strip... getting timing down on LC4 is gonna pay off more than any sort of pedal technique and the LC program makes all of that straight forward

Thanks...I had figured that out (from prior non-GTR drag experience). I acknowledge the desirability of "ON or OFF" the brake/clutch, but I still ask this:

A firm pressure on the brake is necessary to start the LC4 process...but no one including Nissan says how firm, nor how much less firm keeps the process going (without creeping). So...just speculating...if 50 pounds of force (for example) starts the process, does a lessening of pressure to 25 pounds really do any harm (or stop the process)? I maintain as a clear fact that one can get one's foot off something FASTER, when the foot is pressing with less force, compared to the same situation with more force.

Not arguing...just looking for micro advantages without increasing damage.

Alexd

 

[bobel]

You would imagine it has to be hard coded somewhere the exact brake % that is required to disengage the clutches, however you would likely fry your clutch pack trying to ease off at 4k rpm during staging!!!! However I wonder if you could roughly gauge it by looking at your braking force MFD readout when at a junction and working out at what stage your clutch appears to engage, I assume that it is probably workin on the same logic, although I imagine the R-R-R or your favored launch method would need to be set? It's also pretty obvious from adjusting you tp settings that you can dial in creep with + settings I also imagine if you were to increase your tp setting you will marginally gain a faster clutch engagement off the line, but again at what cost to the clutch pack and the gains may not even be noticeable.....that GR6 sure is a complex mofo

 

[alexdavis]

You would imagine it has to be hard coded somewhere the exact brake % that is required to disengage the clutches, however you would likely fry your clutch pack trying to ease off at 4k rpm during staging!!!! However I wonder if you could roughly gauge it by looking at your braking force MFD readout when at a junction and working out at what stage your clutch appears to engage, I assume that it is probably workin on the same logic, although I imagine the R-R-R or your favored launch method would need to be set? It's also pretty obvious from adjusting you tp settings that you can dial in creep with + settings I also imagine if you were to increase your tp setting you will marginally gain a faster clutch engagement off the line, but again at what cost to the clutch pack and the gains may not even be noticeable.....that GR6 sure is a complex mofo

We "Park our cars in the same garage." Thanks!

Alexd

 

[ehyman]

So quick question:

Would folks prefer that the number of launch limit jsut be removed, or is there a preference to allow the number to be changed. For my use, I would liky jsut disable it, but know others might have different opinions.

Eric