launching

[Stewi]

You don't think is the AT ECU of our car. The ECU is the one that calculate the RPM for the AT to shift to the next gear. If you could tune the ECU to shift in higher RPM will be the answer to the lag. but I think is a lot of programing work. But is true more power more compression will solve the problem for AT. U notice no problem when the engine is cold it has more compression because of the cool air coming in, after 20 min the engine bay gets hot and the intake mani gets hot worming the incoming air. Or you could go 5 speed, don't know the exact improvement because i don't have 5 speed.

Your reading way too much into it and forgetting one important thing. The compression inside the cylinders is at its lowest when the engine is cold. As the engine warms up, the pistons (rings) heat up and expand causing a better seal against the cylinder wall. If you have ever done a compression test you will notice if you did it cold (which is the wrong way) your #'s usually end up about 10-15% lower than what they did when the engine is warm.

Heat soak from hot engine bay temps plays a roll in it, but its not as much as you think, maybe a 5-7whp difference on a naturally aspirated car like a stock 8g, on turbo cars air temp plays a big role since the lower the temp will allow the entire system to run more efficiently (all things considered, timing, boost, fuel) which will provide you the ability to make more power.

In regards to the transmissions gearing and trans ECU tune, you really need to focus on the original question which is just the launch. The launch is just plain acceleration from a dead stop, no consideration for gearing, shifting and the like. On an AT trans car you powerbrake when you "launch" hold the brake to the floor and hold the gas to the floor, from my experience you'll end up at about 1800-2200RPMs and the car wont move, release the brake, the car noses over like a pig, then squats in the back, then goes. If the car had lets say about another 30-50whp, it wouldnt nose over, it would squat, probably chirp the tires and go. You can get into other things like high stall torque converters so that you could leave the line at 3500RPMs which of course the car will have more power, but the bottom line is your trying to "launch" a 3000lb fwd car that makes 104 horses at the wheels.

[GmoEm2]

Why are you always talking about your Honda when this has nothing to do with it. We are talking about the auto tranny on a Mitsubishi not Honda.

if you didnt notice this was a fast and furious quote and it made me lol cuz this ricer is launching his auto. so for once i have to back cody up on this; but he is a little honda fan boy isnt he? lol

[Isaurio]

Your reading way too much into it and forgetting one important thing. The compression inside the cylinders is at its lowest when the engine is cold. As the engine warms up, the pistons (rings) heat up and expand causing a better seal against the cylinder wall. If you have ever done a compression test you will notice if you did it cold (which is the wrong way) your #'s usually end up about 10-15% lower than what they did when the engine is warm.

Heat soak from hot engine bay temps plays a roll in it, but its not as much as you think, maybe a 5-7whp difference on a naturally aspirated car like a stock 8g, on turbo cars air temp plays a big role since the lower the temp will allow the entire system to run more efficiently (all things considered, timing, boost, fuel) which will provide you the ability to make more power.

In regards to the transmissions gearing and trans ECU tune, you really need to focus on the original question which is just the launch. The launch is just plain acceleration from a dead stop, no consideration for gearing, shifting and the like. On an AT trans car you powerbrake when you "launch" hold the brake to the floor and hold the gas to the floor, from my experience you'll end up at about 1800-2200RPMs and the car wont move, release the brake, the car noses over like a pig, then squats in the back, then goes. If the car had lets say about another 30-50whp, it wouldnt nose over, it would squat, probably chirp the tires and go. You can get into other things like high stall torque converters so that you could leave the line at 3500RPMs which of course the car will have more power, but the bottom line is your trying to "launch" a 3000lb fwd car that makes 104 horses at the wheels.

Thanks Stewi for the info.