Transmission options.

[pgfpro]

Here's what I would like to discuss.


As you can see in this example BSFC map, the 25% load has a very tight vertical curve to it. So the sweet spot is much narrower then the 50% and 100% load lines.

Just moving up or down in rpm a little can take you away from the sweet spot.
At 2800 rpm you have the most efficient BSFC number of 0.70 lbs/hr.
At 2000 rpm you have 1.0 lbs/hr.
At 4000 rpm around 0.95 lbs/hr.

Food for thought???

[some_other_dave]

Where's the new thread?

-soD

[California98Civic]

Originally Posted by some_other_dave

Where's the new thread?

The new thread was a suggestion I made when Mista Bone suggested taking-on a challenge to build a 68mpg engine/tranny combo that would prove a point he has wanted to persuade people of. Pgfpro was endorsing the idea, but not for himself, I thought.

pgfpro, I don't know for certain the BSFC chart you offer should be thought of as representative. I think different gasoline cars can be quite different. Take these two for example, posted by betasniper and ever green in the http://ecomodder.com/forum/showthrea...tml#post397134 thread:

Toyota/Lexus 2GR-FSE




In this second one it looks as if 80% engine load may get you into the "sweet spot" at 1500 rpm.

Cars vary.

james

[Mista Bone]

Originally Posted by Old Mechanic

The real mileage I get on my vehicles, here, not just claims, real mileage, every day, every fill, every mile.

regards
Mech

I prefer REAL numbers to the number some dohickey on the dash gives out, they are easy to make them lie.

Originally Posted by pgfpro

Here's what I would like to discuss.


As you can see in this example BSFC map, the 25% load has a very tight vertical curve to it. So the sweet spot is much narrower then the 50% and 100% load lines.

Just moving up or down in rpm a little can take you away from the sweet spot.
At 2800 rpm you have the most efficient BSFC number of 0.70 lbs/hr.
At 2000 rpm you have 1.0 lbs/hr.
At 4000 rpm around 0.95 lbs/hr.

Food for thought???

pgfpro, we both know our Hondas, which MAY not carry over to ALL other cars, That I understand. I'm also privy to some Honda testing after some of my suggestions that the engineers played with at TRC in Marysville, OH. I know the "sweet spot" for the 16 valve Honda D series we so love. I also know how to move the sweet spot around with in reason.

Old Mech, about the mileage logs, two issues right now.

1) I haven't dug into how to get it setup in my profile yet, for a reason, see #2

2) Due to some court issues with a mix up of paperwork, I haven't been allowed to drive since November.

As most know, hte CRX HF is a PITA to get a proper fill when filling up. for this very reason you need a "home" pump and to park in the same location and have same filling procedure. IMHO to get a true average mpg number that has to cover atleast 1000 miles, 3000 miles is better.

When I switched to the LLR tires I selected 175/65/14's to correct the Honda Speedo error. I will verify the speedo reading with GPS app on cell phone when allowed. I will then compare it to odometer reading as well.

Also last night I was running on lack of sleep, so if my posts here were more scrambled than normal, now you know.

[pgfpro]

Originally Posted by California98Civic

The new thread was a suggestion I made when Mista Bone suggested taking-on a challenge to build a 68mpg engine/tranny combo that would prove a point he has wanted to persuade people of. Pgfpro was endorsing the idea, but not for himself, I thought.

pgfpro, I don't know for certain the BSFC chart you offer should be thought of as representative. I think different gasoline cars can be quite different. Take these two for example, posted by betasniper and ever green in the http://ecomodder.com/forum/showthrea...tml#post397134 thread:

Toyota/Lexus 2GR-FSE




In this second one it looks as if 80% engine load may get you into the "sweet spot" at 1500 rpm.

Cars vary.

james

I agree with what your saying. The charts you gave are not plotted low enough power wise for what I want to talk about. I will have to start another thread. Also it will be much much more involved.

[California98Civic]

Originally Posted by pgfpro

I agree with what your saying. The charts you gave are not plotted low enough power wise for what I want to talk about. I will have to start another thread. Also it will be much much more involved.

Yeah, new thread. This is still "transmission options" related, but only loosely. I gotta say, though, I am getting food for thought about my shift points. But another caution: as I understand it BSFC maps are created using a dyno and when no accessories whatsoever are attached to the engine. So these maps represent "ideal" conditions" in which none of us really drive. I'm not saying that I think the maps are meaningless, but I'm not certain how precisely they predict what we'll see on the road. For that you'll need well-calibrated gauges in your car.

[pgfpro]

Originally Posted by California98Civic

Yeah, new thread. This is still "transmission options" related, but only loosely. I gotta say, though, I am getting food for thought about my shift points. But another caution: as I understand it BSFC maps are created using a dyno and when no accessories whatsoever are attached to the engine. So these maps represent "ideal" conditions" in which none of us really drive. I'm not saying that I think the maps are meaningless, but I'm not certain how precisely they predict what we'll see on the road. For that you'll need well-calibrated gauges in your car.

Your one step a ahead of me.
This is what I want to talk about in another thread. Dyno built BSFC maps verses road fuel usages with power output maps or optimum load shift points.

With today's ability to monitor data and collect in logs, I think we could have a great discussion about the vehicles we drive. I would also like to give praise to all the people taking advantage of utilizing load when up shifting thru the gears on this forum. The numbers don't lie and a lot of you are already increased fuel efficiency.