i took my car to get dyno tuned today and for some strange reason between 7-8k rpm i lose about 25 hp and then by 8400 rpm it comes back up to where it was right before the power loss.

does anyone have any idea why this is happening? i've had it dynoed before without any sort of problem like this. i also know its not a fluke because we dynoed it 5 times and everytime theres the same power loss at the same time.

i drive a 2k1 ITR and my mods include:
bolt ons (i/h/e)
mugen headgasket (raises 0.4 compression)
titanium retainers

i also did a compression test on it and the numbers all run about 210. anyone have any idea why this is happening?

 

possibly ignition related? did it feel at all like a "miss"?

 

hmm wats a "miss"?

 

What are the i/h/e? What you doing for fuel enrichment?

 

aem cold air
dc jdm type r
greddy sp exhaust

im using the greddy e-manage for tuning, and u can control fuel with that so im using the stock fuel regulator.

 

if this e-manage related - which i'm guessing is the problem.. either get someone that knows how to work with that piece.. or get a better managment system.. - bad or experimental tuning can mess things up..

 

its not e-manage related or ecu related. we dynoed it before we put the emanage in and had the same problem. we also tried using a obd-1 ecu and we still had the same problem. im thinking it might be mechanical....maybe valvetrain?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jsk62 &raquo;</TD></TR><TR><TD CLASS="quote">
dc jdm type r
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Are you using a highflow cat? (Carsound, random, etc.) That would be your problem.

 

Post the plot with your A/F on it, still hard to diagnose.

 

most B16 have a dip like that around 5400 due to resonance in the intake. Never seen one dip 25 hp though. usually B16 are around 7-10 hp

 

im running a test pipe, but that can't be the problem either. i've dynoed my car with it before with no such problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jsk62 &raquo;</TD></TR><TR><TD CLASS="quote">aim using the greddy e-manage for tuning, and u can control fuel with that so im using the stock fuel regulator.</TD></TR></TABLE>

Emanage DOES NOT control fuel.
It controls map sensor signal adjustment.
Not the same thing.

 

ok

 

does anyone else have any suggestions or ideas as to why im having this problem? all i know is that its most likely a mechanical problem because we've tried running an obd-1 ecu with my car but that didn't solve the problem.