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Poor Gas Mileage After Tuning

Discussion in 'General Tech and Maintenance' started by turbo99, Jul 12, 2005.

  1. turbo99

    turbo99 Member

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    Ok, I noticed a significant difference in mpg after I got my car "Chrome"-tuned. My bro's friend did the tuning on my B18B Greddy turbo. At the same time, we also swapped out the RC 330cc injectors with some DSM injectors and the resistor box. We only tuned to 7psi and was supposed to tune to 10psi, but it was late. I can't get a hold of the guy who tuned my car so I'm asking you guys.

    For a week, I tried to keep my car under 3000 RPM with no AC to see if the mpg would improve, but it only got worse. What's up with that? I was running the crappy blue FMU before tuning, but I got way better gas mileage with that. I'm using 91 octane as before. Also, my spark plugs need to be upgraded to some colder ones. The guy who tuned my car also bridged the gap closer on the plugs since it wasn't firing up at times I guess.

    Do you think it's the tuning, the spark plugs, the DSM injectors or a combo of all that dropped the mpg? I'm pretty sure that it's one of them. 20 mpg on a freakin Honda is ridiculous especially why I didn't boost that much. I would appreciate your thoughts and suggestions. Thank you.
     
  2. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Lots of guys don't do a very good job tuning part throttle and engine speeds below 3000rpm.... they're the hardest part of the tuning process. Get it checked out- I'll bet your timing is way off and that you're spraying too much fuel down low.
     
  3. turbo99

    turbo99 Member

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    Thanks for your feedback. So you're saying if I want to conserve mpg, I should drive my car over 3000rpm in the meantime? Does spark plugs, DSM injectors, contribute to the problem or is it just tuning? You know, I did notice the smell of my fuel more since the tuning.
     
  4. reikoshea

    reikoshea HS Troll...And Mod Moderator VIP

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    He didnt say it would conserve fuel, but i am pretty sure that the fuel map down low might be just as bad as up high. So you wouldnt change your fuel consumption by going faster.
     
  5. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Yeah, don't drive above 3000 to save fuel. That's not the logic I was shooting for. Get it tuned again by someone who knows what they're doing- you're just running way too rich.
     
  6. B16CRX

    B16CRX Senior Member

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    I went from avgng. 31mpg stock to ~25mpg tuned with my turbo on 450cc DSM. Part of that is because my e-brake it too tight and causing light braking while I drive...

    Your ECU may be stuck in closed loop also. That would cause a decrease in mpg.
     
  7. turbo99

    turbo99 Member

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    I'm sure it's not my e-brake. 25 mpg sounds more reasonable. Well, I'm in the SF Bay Area. Does anyone know of anybody that tunes well? Chrome tuning or uberdata maybe? Would it be a good investment to upgrade to a hondata maybe? Thanks for you help. I was pretty sure that the tuning messed me up.
     
  8. formby

    formby learning in progress

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    i dont live in cali but calesta knows his shit...and more than likely its the tunning...and keep the chrome ive heard nothing but good things....specially from B
     
  9. B16CRX

    B16CRX Senior Member

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    oh, its definitely the tuning. my friend with a boosted d series on 450s avgs 38mpg.

    unless your fuel filter is absolute shit....
     
  10. MikeBergy

    MikeBergy Blah blah blah....

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    Definitely the tuning. Register with PGMfi.org (it's free) and see if you can find someone in the bay area that knows chrome. I'm sure you'll find dozens of people. And make sure they tune it with a wideband and datalog. You'll get your best tune tuning on a dyno.
     
  11. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    :werd:

    Someone in Cali can help you out.
     
  12. turbo99

    turbo99 Member

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    I checked pgmfi.org. How do you register on there? Anyway, I spoke to someobdy that does Chrome Tuning and he said that if you want to tune mpg, it's better to street tune it for about two hours, not dyno tune. Is street tuning better for mpg or dyno? I need to get this fixed soon. :(
     
  13. MikeBergy

    MikeBergy Blah blah blah....

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    It's always best to tune on a dyno, it is all in HOW you tune it. If you want to tune for max power, then you do that. If you want to run as lean as possible and still be safe, then you do that. It's only possible to tune for max power on a dyno, because otherwise, how are you going to know if what you are doing is helping (butt-dyno is not accurate ;) ) ? Street tuning is a good way to get a clean running car if you have a WB O2, but that's about it. Dyno tune the car to get the best tune, regardless of how you tune it.
     
  14. MikeBergy

    MikeBergy Blah blah blah....

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    Register Here for PGMFI.org
     
  15. B16CRX

    B16CRX Senior Member

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    street tuning gives actual load on teh engine and more accurate (daily driven..hot..cold) O2 readings etc...
     
  16. integraslut78

    integraslut78 Stylus DJ Extraordinaire

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    Modacar in Pleasanton/Dublin they know what they are doing out there they may be a little pricey though. If you are down come down to So. Cali and my tuner will hook you up but you probably don't want to drive 350 miles for a tune :)
     
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