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When do u shift?

Discussion in 'Civic and CRX - EF' started by hope801, Jun 1, 2008.

  1. hope801

    hope801 Active Member

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    ok. i have a 91 crx hf chassis, hf tranny, and 91 si motor.
    my questions are:
    when would u suggest to shift, to save gas?
    When do u shift? (ur motor, tranny)
     
  2. LS_VTEC

    LS_VTEC you get the BRAKE

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    3,000 rpm, every gear.
     
  3. eg6sir

    eg6sir Supa Mod Moderator VIP

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    x2.. thats what i told my GF to do in her GSR..
     
  4. LS_VTEC

    LS_VTEC you get the BRAKE

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  5. BrutalB83

    BrutalB83 Brutal Moderator Moderator VIP

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    The faster your motor is spinning the more gas it's going to use. For normal everyday driving in a Honda 3,000 - 4,000 RPMs sounds about right...
     
  6. INJEN78

    INJEN78 HS LEGEND

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    gas saving,shift around 3...
    racing i like to bounce it off the rev limiter a couple times before shifting:D
     
  7. eg6sir

    eg6sir Supa Mod Moderator VIP

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    just so you know, that slows you down..

    anyways.. wanna save gas? dont drive, haha..

    just stay off the pedal and shift around 3-3.5k rpm
     
  8. K2e2vin

    K2e2vin Senior Member

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    When I had my Accord; 3200-3500rpm, with my Civic; 4000rpm, my brother's Civic(CX); 4300-4500rpm.

    I just pretty much keep the accelerator steady and shift when it feels like power is falling off. Hell, my Civic does ~70mph at 4000rpm anyways(yes, in 5th gear) :D
     
  9. 99sidude

    99sidude Moderator Moderator VIP

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    2500-3000 around town here, tho I'm stuck at 3500-4k on the highway.
     
  10. hope801

    hope801 Active Member

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    k if i were to constantly be at
    35mph
    or
    50mph
    what rpm would u guys recommend to be at?
     
  11. Justin66

    Justin66 The Hondaswap Canadian

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    As low as possible. Doing 60km/h (35mph approx) im doing 2000 in fifth, i do have a J1 tranny so its tough to keep the rpms low but its decent. Depending on the movement of traffic i normally shift at 2,500 to 3000.

    Alot of it depends on torque, more torque, less rpm needed to move, but usually the engine is larger so gas usage it more. Its a bunch of factors.
     
  12. Luis998

    Luis998 Honda Enthusiast

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    :werd: :withstupid:
     
  13. |Chaz|

    |Chaz| Well-Known Member VIP

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    Doesn't it use more gas though if you lug it?
     
  14. K2e2vin

    K2e2vin Senior Member

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    From my experience, pushing the accelerator down to keep speed uses more gas than just letting it rev with barely pressing the accelerator at all.
     
  15. YBLEGAL

    YBLEGAL Regular Member w/ Cheese

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    I'd like to critique that first statement.

    I think in very general terms, you are correct, the faster the motor spins, the more gas is going to go through the cylinders.

    But, since we're EFI, not just some dumb carb, part throttle is going to be greatly improved. I'm thinking that drag, gear ratio, gravity, etc will all affect this, but possibly cruzing at one steady speed at a particular rpm higher than 'normal' could use less gas. The rotational mass of the motor's parts increase with speed. Thus, load on the engine is marginally reduced. And the ECU can make adjustments to the A/F, possibly making the higher rpm more efficient.

    For instance; I've noticed I use less gas going 90mph (approx 5k rpm in 5th) than going 80mph (approx 4.4k rpm in 5th). Very marginally so, but it adds up.

    Or if your still unclear on my concept, think back to when you've ridden a bicycle. It takes more effort to travel the same distance pedaling slowly compared to pedaling more quickly. It is more efficient to ride fast, to a certain degree (depending on wind, powerband [human powerband], etc).

    Input on my theory? I know there will be. Constructive criticism please.

    [@ OP's original Q] I've got a JDM B16A SiR-II with Y21 trans (w/ lsd) and daily town driving I normally shift at about 3,500~4,000rpm. I'd say average of 3,800rpm. Accel to highway like a normal human and not racing I'd probably shift at like 4,800rpm light throttle so you don't pop vtec for no reason (throttle pressure affects vtec crossover). Deffinatly, atleast with my current stock tune, vtec owns my gas. If I WOT just 1 gear, maybe it's just me but I can see that the gas needle drops rather quick. I probably have some issue of my own.

    I just wanna say, hitting the rev limiter is bad. That's only there if you miss shift. It's not a shift light. You might already know this OP, but I gotta say it, at least for Injen's sake ^_^
     
  16. YBLEGAL

    YBLEGAL Regular Member w/ Cheese

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    deffinatly

    deffinatly. no torque down low. dont shift under 3k if you plan on reaching 30mph or above.
     
  17. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    i shift one of my cars at 3k every gear and im in 6th gear by the time i get a 8th mile away lol,
     
  18. LS_VTEC

    LS_VTEC you get the BRAKE

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    Bouncing off the rev limiter? Holy sheep shit. When you hit the rev limiter, do you know what is actually happening Injen? Fuel cut/Spark cut. Fuel + Spark Cut = Bad news. Thats why we have two step :) Holds the RPM wherever you desire, and keeps fuel + spark to the engine. Wonderful for those 6500 rpm launches. :D
     
  19. 88B16ASiR

    88B16ASiR Light Weight Junkie

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    mine i usually rev to about 2.8 and then 3.5 at 3rd and skip 4th
     
  20. BrutalB83

    BrutalB83 Brutal Moderator Moderator VIP

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    You're right, yeah. My answer was somewhat over-simplified. Obviously the amount of throttle you're putting into it will have an effect on the amount of fuel you're burning. I was just saying as a general rule (and assuming that you're not constantly flooring it) the lower you shift the more gas you'll conserve...
     
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