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  1. #1
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    2 out of 2 members liked this post. Yes Reputation No

    What would cause jagged lines on the dyno?

    Backround -
    Car was run on they dyno a few months ago with Stock intake manifold, Intake and tune. Made solid power and had a smooth powercurve.

    Now, 3 stage manifold, car has lost power at almost every RPM point and the dyno lines are jagged.

    Stock runs 3rd gear vs 4th gear
    Click here to enlarge

    3 Stage 3rd vs4th gear (I think 3rd gear is with the tune installed)
    Click here to enlarge

    Overlay
    Click here to enlarge


    List of chances since last dyno:

    Installed 2 8.5" Style 161's on the rear (same tires) - Previous owner rotated tires on the wheels and put the back wheels in front, and the front wheels in the rear. I bent one of the wheels and picked up two replacement wheels and remounted the tires. There is a slight vibration that gets worse with speed, probably due to the sidewall being damaged when I bent the wheel.

    Installed Euro Airbox - Noticed the misfire issue around that time. Airbox is OEM and no tuner has mentioned any MAF issues with it. Cleaned MAF and installed K&N filter as well.

    Added Airscoops

    Replaced coilpack - Bought a pack, wrong part number and they didn't work. I sent them all back and bought one at Advance in the interim. Misfire is gone but sometimes the car still does surge with or without the tune installed.

    Judging by the waviness of the graph, it has to be a ignition issue - it's present on both dynos I've done with the 3 stage, as opposed to the smooth lines when I ran with my original manifold.

    No CELS, no rough idle and an occasional hiccup at WOT at low rpm.

    Has to be an ignition issue, you guys agree?

  2. #2
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    I'm not sure if it's ignition I mean that's a logical conclusion but the problems started with the airbox right? Have you tried switching the airbox back?

    Stage 2 or 2.5 E9X M3 S65 V8 supercharger kit for sale
    : http://www.boostaddict.com/showthrea...r-kit-for-sale

  3. #3
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    1 out of 1 members liked this post. Yes Reputation No
    European Airbox - and I don't have the stock one anymore.

  4. #4
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    That's tough because before ruling anything out you might want to see if the airbox switch, where the problems started, is all you need.

    Stage 2 or 2.5 E9X M3 S65 V8 supercharger kit for sale
    : http://www.boostaddict.com/showthrea...r-kit-for-sale

  5. #5
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    Hmm, I agree. But I did have 1 bad coil (I pulled the code) I don't doubt the others on the way out either.

  6. #6
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    2 out of 2 members liked this post. Yes Reputation No
    Changed the plugs recently?

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    Just the coil packs, not the plugs themselves.

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    1 out of 1 members liked this post. Yes Reputation No
    All 6 of my coils were cracked see

    Click here to enlarge
    2005 Porsche 996 TTS RWD - Eurodyne 60-130 in 6.50s
    2015 Audi A3 2.0 TFSI - Eurodyne 0 - 100 in 10.67s
    2015 McLaren 650S (RHD) - UK - 1/3rd owner yet to drive


    Click here to enlarge



  9. #9
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    1 out of 1 members liked this post. Yes Reputation No
    Click here to enlarge Originally Posted by Group.america Click here to enlarge
    I'm taking it it shouldn't look like that...

  10. #10
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    1 out of 1 members liked this post. Yes Reputation No
    So, using some nifty software, I pulled some "hidden" codes from the car.

    2a32
    2a47
    2a37
    Valvetronic, eccentric shaft sensor: Reference
    Valvetronic, eccentric shaft sensor: Plausability

    So, I guess I'll replace that sensor to start. Also, I reset the cars adaptations and WOW - did that really change everything. The car still hesitates under load, but the power came back - absolutely more enjoyable to drive.

  11. #11
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    I would think that it has to do with one or a couple of your plugs or coils, probably cant handle the load which is why it was fine on the base run but not with the tune.
    E90 335i - JB4 | DCI
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