How to Accelerate?

[azraelswrd]

Yep, BSFC map is your friend in visualizing it.
I couldn't find one for my own car but I know there was a topic about them here. This is an article from Autospeed about them with a few example maps:

Brake Specific Fuel Consumption

[badaz907]

I know I have the more powerful engine at 127hp vtec, but i find that while looking at my vacuum gauge the best vacuum occurs at 2500-3000 rpm, so you guys always talk about driving under 2k rpm but when i do in my civ vacuum remains low in or around 0-5 full throttle because it doesnt seem to have enough torque to move. what I'm asking is how to drive my civic in the city its a 5 speed so light throttle to get moving and coasting at 3000 to obatian best vacuum is this correct. I need a clear answer , most posts are a bit confusing please help.

[pumafeet10]

well most cars are different but most of us with one of the d16 varieties have seen the best results staying between 1500 and 2500 at most but someone like me has gotten best results shifting at 2000rpm that way you also can keep your speed down easier, you just need to see what does best for you accel and shift at 2k, 2500, or 3k and then report back. Since i have a scangauge i use engine load which i keep at about 75

[badaz907]

I can use the vacuum to see engine load, basicly lower the vacuum the more throttle im giving it, I would get a scan gauge but I find that they are too costly, the vacuum gauge was 20 bucks however on this tank with the spoiler removed new dist, 40 psi in the tires and grill block i think i am currently getting 36-40 mpg city

[bbjsw10]

I get roughly 18-20in. hg. at idle and accelerate at 10in. on vacuum gauge where would that fall in load %'s. Just to give me an idea, I tried reading the link posted but got lost over my head I guess.

[pumafeet10]

from what i have seen that you want too see the most amount of vac for the least amount of fuel used, higher vac means the throttle is closed hte most there for creating a vac in the intake manifold

[Vince-HX]

Minimize pumping losses while accelerating.

Accel - least amount of vac without going into open loop
Cruise - highest amount of vacuum @ efficient rpm

imo

[PaleMelanesian]

I like to accelerate at about 50% throttle at lower speeds, working up to about 80% at higher speeds and gears. Something like this:
1st gear: just to get moving. Shift before 5mph.
2nd gear: 50% throttle
3rd: 60% throttle
4th: 70% throttle
5th: 80% throttle pulse, then glide, then pulse again

Watching the scangauge, these throttle points roughly correlate to 70-80% load in each gear. At low speed and rpm, there's less power available, so it takes less throttle to reach the same load %.

80% load is about 12 on the MAP gauge, so near WOT but not quite there. I find that my Honda will go to Open Loop at about 90% load.

[sickpuppy318]

Originally Posted by Vince-HX

Minimize pumping losses while accelerating.

Accel - least amount of vac without going into open loop
Cruise - highest amount of vacuum @ efficient rpm

imo

wow, thanks for putting it so simply
And i think i'd take your oppinion anyday because for a while there i was a tuner mag junkie and always loved the full race stuff. I don't generally "like" hondas but, well, you know, you work there.

i dont have any instrumentation (gauge cluster doesn't even work), but just driving my three speed tercel to work today with that little tidbit in the back of my mind, i think i've "modded" my technique for the better.

thanks for the insight.

[pumafeet10]

so in watching lod on the scangauge you want 70-80% of the maximum out of your engine therefore keeping it in its maximum bsfc atleast that is where it would be for the honda guys here with the 1.6l engines