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every single day it gets a little faster
you know the feeling of "ok I'm tired of xxx horsepower" that always leaves us chasing more?
I have a temporary cure. Start out with an engine at zero. For an old 'free' 5.3L V8 that would be 250rwhp and around 280ft*lbs of torque. Each day/week I take a baby step that gives me a couple hp/tq on top of that baseline, or some driving improvement. For example, today I added 1* for the first time across a fair region of the high octane timing map. I also reduced torque management around 30% AND increased shift pressure 3-5 PSI in some regions of 200-250ft*lbs of torque. This will add to the firmness of the shift and help spin the tires a little bit, but not too much. Right now they do not spin at all with just 50% TM the 1-2 shift at 250-300 ft*lbs is exceptionally FAST and SAFE even in the rain which I think is the best part of GM ecu programming honestly. That is how excited I am to tell everyone that I can't hardly stand it, all because one day I felt a shift that was so perfect, so absolutely amazing that I would never drive a manual trans again if I could get it to do that every. single. time. and now I am searching for it, for that coincidence of variables that led me to experience such a sweet shift. It was like being launched forward into the next gear, the tirespin felt RIGHT.
And it turns out, there is some percentage of tire slippage required for the "fastest car" effect. Which brings us to the two rear ABS style sensors on the Q45 differential, and a little momentary ground button on a pin added to the ECU that switches between two different transmission maps which I do. What can be done with these items is allow for variations in terrain i.e. poor surfaces. If I am going somewhere unknown or daily driving random streets I have a secondary map with alot of TM so it never spins the tires, even in the rain. It isn't necessarily for racing, its just for a guarantee of safety with such a powerful automatic transmission. I know more than on individual who wrecked a car because of a harsh 1-2 shift and this was my biggest concern of all since the beginning of time with these hydraulic monsters.
And the 4l80e is a monster, at 250lbs it IS the car. The 240sx is gone, no more. In its place I am "driving" the 4l80e, a transmission so large that you can hear its electronic box from inside the fluid filled pan, that the pump overwhelms the sound of the engine. "IS it supposed to be doing that noise?" Yes, they make that noise. Its actually kind of soothing after a while. And I've had the great question, "Why don't I hear that noise in any other 4l80e vehicle that came stock with a 4l80e" and I LOVE this question because it exemplifies just how huge this transmission is to the 240sx chassis. The reason you never hear these monsters in their intended applications is because those vehicles are usually so heavy and large themselves that the transmission is "small in comparison" and "far away from the driver". In other words, the trans looks like it belongs under the chassis of a VAN or Denali. It looks like the right size trans for the vehicle.
Not in a 240sx though. You are inches away from 13 quarts of 180*F transmission fluid. You are millimeters away from the heat coming in through the insulation you added both above and below the floorboard. The shifter is even 140*F near the base through several layers of insulation. The car needs A/C just to offset the heat of the transmission coming in through the floor after driving for an hour.
Today I recorded 20mpg on a 70 miles mixed city/highway commute with what I believe is an overloaded S14 full of parts and tools and an iron engine, stock hood, cast wheels. Literally all kinds of ways to lighten this thing up for more economy. Saturday I will be putting in the 3.5:1 ratio with hopes of touching 23-24mpg highway before I begin lightening and reducing rolling resistance, and fine tuning. I think it will be amazing to creep up on 500 ft*lbs of torque while gradually lightening the vehicle and achieving 25+mpg. Each day/week like I said it gains 3-5 torque or drivability somehow depending what doorways I can walk through.
long live 240sx platform
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