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Link G4+ Launch Control - New turbo setup

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Hi all

I have recently changed the turbo on my 1JZ 2.5 engine and now I am having issues getting it back onto 2step for the drags.

I called my transmission guy and he suggest I install a dump valve, this has been done and is working but it is still not enough to get it back onto 2step

I have attached my tune, this mornings data log of what it does when activating 2step and also the data log of the dyno run last week

The plan is to try and get the car to launch at around 15psi at 4000rpm that is the stall converter speed, I am having doubts that my converter stall speed it too low and I might need to increase it to 5500rpm

Any information/help on this issue will be great, racing season kicks off on the 7th of March and I am trying to get the car ready by then

Attached Files

It looks like your converter starts to grab pretty hard at about 3000 and by 3600 is absorbing all the torque your engine can produce and the RPM has plateaued. Since your launch limiter is set to 4000 with a 200RPM control range (ie will start to limit at 3800) it is never going to touch the limiter.

To me it seems your stall may be a bit too low but I havent played with many auto cars.

One thought I have which may be worth a shot is a "3 step". So say we set it up so something like 95% or less throttle you have an aggressive limiter come in at about 3400 to bring boost up quicker and make more torque, (so you initially stage with your foot not all the way to the floor) then after a second or so of it banging away at 3400, you then press it all the way down and the limiter jumps up to 4000...

I have attached your tune with this set up if you wanted to give it a try. I still might be off with some of my assumptions so it may need a couple of reiterations.

Attached Files

Hi Adam

Thanks for the reply, I will try this tomorrow morning when I get into the shop and report back with a log file


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