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Why am I losing power???

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Old 07-17-07, 11:34 AM
  #31  
caymandive
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Originally Posted by combfilter
Doesn't it take the ecu a bit of time to learn it's new increased air flow coming in? I would dyno it again next week.
I may be wrong, but typically when you start bolting parts on a car while on a dyno, you get higher gains with the additional air. (Lean condition) As soon as the ECU adjusts with more fuel, the power usually levels out. This is one of the reasons I usually drive a few hundred miles before I dyno parts and this is typically how some after market companies make power claims.

Last edited by caymandive; 07-17-07 at 11:37 AM.
Old 07-17-07, 12:11 PM
  #32  
Gernby
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As I've mentioned several times, the dyno run files would tell us a lot about what happened. The WinPEP software is downloadable, so you can view the data yourself if you have the data files from your dyno shop. I always bring a blank 3.5" floppy when I do dyno testing, and don't even bother getting paper copies.

See if the shop will email the data files to you. The things that we need to know (from the data files) is the run speed during the test (will tell which gears were used for each test), and the ambient temp and barometric pressure (will tell us if their sensors flaked out between tests and gave a bad SAE correction).

Sorry, but I don't trust your butt dyno at all for a 10 hp / 10 ft-lbs loss.
Old 07-17-07, 01:41 PM
  #33  
iizzle3fiz
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haha..i hope my butt dyno is wrong too. i may not feel 10ft-lbs but i should feel 20, right?

i will see if i can get the data file from the shop today. i think i will wait to put the stock airbox back on after i put a few more miles on it. ive been around 250 miles so far.
Old 07-17-07, 02:08 PM
  #34  
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gernby, i also meant to ask why don't u recommend resetting the ecu?
Old 07-17-07, 02:58 PM
  #35  
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We aren't talking about 20 ft-lbs anymore since the dyno wasn't done properly. By testing the way you did, the dyno operator was obviously giving partial throttle until he got to very high RPMs or the transmission would have downshifted. If you look at the plot above 5000 RPMs, you only lost about 10 HP and 10 ft-lbs. The area down below just needs to be ignored.

You shouldn't reset the ECU because you've already driven enough for it to relearn everything. If you reset it, it will have to relearn everything again.
Old 07-17-07, 10:25 PM
  #36  
LexusIS-TL
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Why is that you lose power just from getting an exhaust put on? I thought you actually "gain" horsepower, not lose them!!!
Old 07-18-07, 06:18 AM
  #37  
Gernby
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Originally Posted by TRDCorolla
Why is that you lose power just from getting an exhaust put on? I thought you actually "gain" horsepower, not lose them!!!
If you read the whole thread, you will see that this is just a strange situation, and not "normal". A decent exhaust will not reduce power, and we really aren't sure that this car really lost power, or if there was an error in the dyno testing.
Old 07-18-07, 06:27 PM
  #38  
lobuxracer
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^^and that's why I won't even guess why the OP got the result he did.

Last edited by lobuxracer; 07-18-07 at 08:01 PM. Reason: Better Gernby?
Old 07-18-07, 07:54 PM
  #39  
Gernby
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Originally Posted by lobuxracer
^^and that's why I won't even guess why you got the result you did.
Huh? Who is "you" in your statement? Sometimes the Quote button is very helpfull.
Old 07-19-07, 06:04 AM
  #40  
phatboyc
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Originally Posted by Gernby
Huh? Who is "you" in your statement? Sometimes the Quote button is very helpfull.
Well Lobuxracer did pointed up.

I believe he is basically agreeing with you Gernby. When your saying "this is just a strange situation, and not "normal"".
Old 08-03-07, 09:21 AM
  #41  
Buds
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Originally Posted by iizzle3fiz
haha..i hope my butt dyno is wrong too. i may not feel 10ft-lbs but i should feel 20, right?

i will see if i can get the data file from the shop today. i think i will wait to put the stock airbox back on after i put a few more miles on it. ive been around 250 miles so far.
What ever happened? Were you able to get the data files from the shop? Did you do another dyno run?
Old 08-03-07, 12:58 PM
  #42  
llamaboiz
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Originally Posted by TRDCorolla
Why is that you lose power just from getting an exhaust put on? I thought you actually "gain" horsepower, not lose them!!!
One dosent 'gain', one just 'free's up' the hp that was always there, removing the bottlenecks.
Old 08-08-07, 10:12 PM
  #43  
ExKoukiS14
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anything about backpressure is bull****.
the purpose of adding an intake is for more air flow. Exhausts are installed for allowing exhaust gases to escape. The faster gas escapes, then less work your engine has to do.
Old 10-26-07, 08:07 PM
  #44  
Jimmer350
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Any update on this? Did you ever figure out why the power loss. I have the HKS Hi-Pwr so am wondering.
Old 10-26-07, 08:55 PM
  #45  
iSuxeL
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Could temp be an issue?? It looks like from run1 to run8 its been about 1hr and 20mins by then the motor has gotten real hot IMO


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