| Author | Topic |
|---|
Location:
Toowoomba
Registered:
May 2002
|
|
Re: Fuel usage at same RPM levels in different gears
|
Thu, 19 June 2003 23:25
 
|
 |
Lets look at this from a slightly different perspective. Say you are travelling 100km on a straight, flat road with no wind, first at 3000rpm in 1st gear (25km/h, 240mins) and secondly at 3000rpm in 3rd gear (60km/h, 100mins). This will give you about 720,000 revolutions for the whole trip in 1st or 300,000 in 3rd (not really acurate, will differ between cars, good enough for an example).
Now, we know how many revolutions for the trip (about) so now work out how much fuel pre revolution. In 1st you will use less pedal, there fore more vacume, less and and less fuel, so we will say 2ms injector timing in 1st would give you about 15L for the trip, now at about 3.5ms for 3rd gear would give you around 14L.
But if you take into account resistances like road, mechanical, wind, weight of car, variations in road condition and incline, how much stopping/starting/overtaking/blah blah blha. You'll see there is no real difference.
As you can see I have used alot of guestimation, estimate, aproximation, and talkcrapimation. So take what i've said with a grain of salt, there is some sense in my calculations but I don't have enough accurate figures to work it out properly. If some one could give me exact speeds at 3000rpm in 1st and 3rd, injector flow rates for that duty cycle at that speed, it would be much more accuate but still would not simulate real world conditions. You could however at take 1sec intervals the injector duty cycles and take an average of that for a trip but it's unlikely you could stay at 3000rpm in either gear for much of a time.  I'd say hope this helps but I don't think it would, so if you actually read all of this you have as much spare time as me .
|
|
|
| | Subject | Poster | Date |
|---|
 |
Fuel usage at same RPM levels in different gears
|
BlackSupra | Mon, 16 June 2003 11:21 |
|
Re: Fuel usage at same RPM levels in different gears
|
manipulate | Mon, 16 June 2003 11:59 |
|
Re: Fuel usage at same RPM levels in different gears
|
Norbie | Mon, 16 June 2003 12:13 |
|
Re: Fuel usage at same RPM levels in different gears
|
BlackSupra | Tue, 17 June 2003 10:34 |
|
Re: Fuel usage at same RPM levels in different gears
|
manipulate | Tue, 17 June 2003 11:00 |
|
Re: Fuel usage at same RPM levels in different gears
|
draven | Tue, 17 June 2003 11:42 |
|
Re: Fuel usage at same RPM levels in different gears
|
oldcorollas | Tue, 17 June 2003 12:23 |
|
Re: Fuel usage at same RPM levels in different gears
|
kingmick | Tue, 17 June 2003 12:08 |
|
Re: Fuel usage at same RPM levels in different gears
|
manipulate | Tue, 17 June 2003 12:09 |
|
Re: Fuel usage at same RPM levels in different gears
|
SUPRAGTE | Tue, 17 June 2003 13:21 |
|
Re: Fuel usage at same RPM levels in different gears
|
oldcorollas | Wed, 18 June 2003 04:05 |
|
Re: Fuel usage at same RPM levels in different gears
|
SupraPete | Tue, 17 June 2003 23:29 |
|
Re: Fuel usage at same RPM levels in different gears
|
GIN51E | Wed, 18 June 2003 07:59 |
|
Re: Fuel usage at same RPM levels in different gears
|
Remedy | Wed, 18 June 2003 08:40 |
|
Re: Fuel usage at same RPM levels in different gears
|
jza70-mel | Thu, 19 June 2003 17:04 |
|
Re: Fuel usage at same RPM levels in different gears
|
Nark | Sat, 21 June 2003 01:59 |
|
Re: Fuel usage at same RPM levels in different gears
|
willwal98 | Thu, 19 June 2003 23:25 |
|
Re: Fuel usage at same RPM levels in different gears
|
manipulate | Fri, 20 June 2003 09:48 |
