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Old 11-25-2009, 04:14 AM   #183 (permalink)
RH77
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(since the lockup has 3 stages, the abbreviation is S-1 for Stage-1, to make it easier)

I like the brake switch idea and keeping 1st gear out of the mix, but I noticed something on the route today that can be used as an advantageous example of full lock with gently angled grades and no throttle input...

There's a residential street with a 25 MPH limit that has a very gradual descent. I can EOC it, but it scrubs considerable speed (and is now a busy reroute for a detour). With 4th + S-3 at idle, I was getting around 80-90 MPG @ 27 MPH on a segment that normally is set to 3rd + S-1 lock at around 45 MPG and barely 25 MPH. Having that "Direct Connection" is amazing.

The stock setup uses lock on decel above 35 mph anyway (which is a real drag for most Honda-based autos, pun intended )

Another observation: once it gets into S-3 lock, it hangs there. If I disconnect it with the switch, and then re-engage it, the TC defaults to S-2 and needs the throttle back into 21 TPS to allow enough fluid pressure to engage it again from S-2 to 3. So, I'm hesitant to implement a trip disconnect when at idle. I don't have a whole lot of compression braking at 1500-2000 RPM, so rolling terrain with velocity at those engine speeds are rather efficient.

I could go back tighten the kick-down cable, so that it wouldn't take so much throttle to engage S-3 -- it's tricky because then kick-down is more sensitive. By and large, downshifting with the TC at S-3 is very hard shift (and really should be avoided). I can play with the cable and see what develops.

Ideally, I need an RPM-based trip. Decel is good until about 1050 RPM (only in 4th) and then theres a lug and vibration with odd noises (probably the worn exhaust, but not sure). I really can't think of an easy way to use RPM without hacking an electronic output (and is likely beyond my skillz) or some crazy tach-needle trip

Starting out with it on reminds me of a CVT or Diesel Truck/Bus with an Auto Trans -- first is short with immediate lockup (then manually lift-shifting keeps the RPMs down through the gears). Honestly, I don't crack 2-grand unless I've got my foot in it.

This is great discussion, many thanks for the input! This torque converter has been the most frustrating part of this car. Having any control over it is a step in the right direction

RH77

Quote:
Originally Posted by Christ View Post
As I mentioned earlier, I'd likely use a NC momentary contact above the brake, so that when you touch the brakes, it unlocks.

A more elegant/time consuming solution would be to wire the switch so that it only gets power from the 4th gear solenoid's supply, and once you're out of 4th, it unlocks. I think you'll see even more gains if you can find a way to stay fully locked as soon as you're out of first gear, though, and just unlock for EOC or slowing down. Engine braking isn't likely to save you anything anyway, since you're a more efficient driver than many, so the ability to have full lock on decel isn't as necessary as it would be for someone else.

I think the way I'd work it, if possible, would be to power the solenoid with 2/3/4 gear, and add a momentary NC switch to the brake pedal, since you're probably in neutral any time you're purposely decelerating without the brakes anyway, or in my case, EOC any time you need to slow down when it's not a reaction to some unexpected environmental change.
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