My First Attempt at Hypermiling - Can you guess what kinda of car?

[California98Civic]

Originally Posted by The Verge

California98Civic, I am new at this so what is a BSFC map? Is bump starting using the clutch in 5th gear to restart after a EOC cycle? During pulse is it better to get back up to speed quickly or better try to get good MPG while accelerating?

Here is a link that will help with the basics of what the map is. You are looking for the "sweet spot" on an island graph much like this one, with different values specific to your car. The pulse is counter intuitive because you are not trying to drive slowly for good instant MPG numbers. Instead you are quickly accelerating in order to achieve engine load that puts you in the sweet spot of the BSFC map. You burn what you burn more efficiently over a more brief period of time... then you shut off the engine when you reach desired speed and coast, key in the run position, all power on, but engine off. What gear you choose for the bump start varies with your speed. Most drivers here that I have seen offer advice have suggested bumping in a gear two above where you intend to drive. If 3 is the appropriate gear at a given RPM, bump in 5. And if 2, bump in 4. I bump start as low as fifteen RPMs frequently, very lightly friction spinning the engine. Then I engage the appropriate gear normally. You can hardly tell I have cut or restarted the engine most of the time. But it takes practice. Your power brakes will keep vacuum in them after you cut the engine, but only for a couple good pumps or so... keep an eye on brake power and don't EOC in potentially dangerous spots/situations.

I hope that helps... be safe...

[The Verge]

Originally Posted by California98Civic

You are looking for the "sweet spot" on an island graph much like this one, with different values specific to your car. The pulse is counter intuitive because you are not trying to drive slowly for good instant MPG numbers. Instead you are quickly accelerating in order to achieve engine load that puts you in the sweet spot of the BSFC map.

This definitely helps. The island graph appears to have the engine's torque graphed at the top whereas the other graph lines appear as the engine's efficiency. I can't relate to the numbers associated with the plotted lines. I would love to make this graph but I doubt I have the necessary parameters to do it without having to calculate (with rounding errors) some of the needed parms.

Based on the fact their graph is a diesel engine, and diesels' peak horsepower is made very low in rpm, I expect that the 'sweet spot' in the example is at the engine's peak horsepower since, at this point, the engine is already at its peak torque. I suspect that the sweet spot of my engine would be WOT at 5100 rpm (282.39 whp 290.82 wtq) where peak hp=286@5400 and pk tq=302@4400.

Applying this, should make for some really interesting Pulses, even terrifying on a rainy day! If all of this works I'm going to program a micro to take care of all of these tasks so I can make sure the car is pointed in the right direction during the jump to light speed. The wife isn't going to want to ride with me anymore, take that as you may.

[SentraSE-R]

That will be an interesting graph! I very much doubt your engine's BSFC will be anywhere near 5100 rpm, but it will be at a much higher % engine load than you've been using. In both my xB and SE-R, 83-85% load worked best. It's moderate acceleration in the xb, but pretty spirited in the SE-R. I'll bet it's gut-wrenching in your 4.6.

[The Verge]

Originally Posted by SentraSE-R

I'll bet it's gut-wrenching in your 4.6.

Well, that didn't work so well. Popping the clutch on a static engine followed by hard acceleration is tough on one's body and tires. I tried it in 4th then 3rd and then I really went for the gusto and tried 2nd at 40mph... this will quickly decelerate the car followed by a tire squalling blast to 60 mph. If I did manage to save on petrol, I would end up spending it all on ibuprofen.

Once I get some more practical data I will share it with you guys.

The good news for the day is that my car/data acquisition setup will still datalog during the EOC phase.

I'm planning on racing Friday night and hope to break 100mph... wish me luck.

[California98Civic]

Originally Posted by The Verge

I'm planning on racing Friday night and hope to break 100mph... wish me luck.

I was just talking about racing as a metaphor within American culture... here's a song on the themes of freedom/submission, belonging/alienation, and sin/promiseland in this song yesterday in class. One of Springsteen's best ballads from the album [i]Darkness on the Edge of Town[i]--a live performance of

Racing in the Street

in the year it was released, before a New Jersey audience in a small theater in Passaic. Listen for the audience response. The song is like an anthem to these dudes.

[jakobnev]

Originally Posted by The Verge

Popping...

Did you read this?:

http://ecomodder.com/forum/showthrea...gine-1141.html

[PaleMelanesian]

Originally Posted by jakobnev

Did you read this?:

http://ecomodder.com/forum/showthrea...gine-1141.html

Seconded. Read this and do it.

[Mustang Dave]

@ "The Verge", Before you make a habit of EOC'ing your Mustang, PLEASE read the owner's manual regarding towing the vehicle. My 2007 Mustang cannot be flat-towed (according to the owner's manual), and I presume that your 2005 is the same.
Just sayin'.

[The Verge]

Bruce Springsteen made one of the most amazing songs, capturing the spirit of my youth and many gear heads throughout America. Thanks California98Civic!

EOC can be accomplished without snapping your head off at the neck in a high-performance V8 car. "Gut wretching" acceleration is fun but not every 20 seconds.

I'll never be able to drive 1 complete tank without 'raking the coals to it' so a decent 90 day average is out of the question. I'm kinda like the guy that shows up at an AA meeting with a half empty flask, but maybe not quite as bad as the guy that gets into a fight at an anger managment group meeting.

I managed to get 101.63 mph Friday night at the track. Its amazing what a tune and some minor hardware changes can do for performance. I wish I could get that in mpgs too.

Drag radials perform poorly while driving through a monsoon (at night).