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Old 04-20-2009, 01:17 AM   #1
aurtini
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Default My first road dyno - stock intake vs hybrid intake

Hey everybody, I'm new here!

I've been lurking around on the forums and reading a ton over the past couple of months about tuning, in particular ECU tuning (I'm part of the research group at a semiconductor company working on software, so tuning engine management software sounded like a blast to me). So I picked up an OpenPort and decided that I'd try installing a hybrid intake as described on this forum as my first learn-the-ropes project in my '06 2.5i.

Dropping the aluminum pipe in place of the accordion was pretty straightforward; a quick hacksaw cut and we were in business. I rescaled my MAFv and everything was pretty smooth (except for some knock at low engine speeds in first gear when moving the car from a stop). After the install I learned about using engine speed logs from a road pull to generate power/torque graphs, so I figured I'd give that a shot to see if this hybrid intake was actually giving me any performance or if it was just louder

So I logged a couple of third gear pulls (below in code sections) on the flattest roads I could find and ran the data through Data Log Lab:



I was surprised at how noisy the data came out; those graphs are with a hideous amount of smoothing, so I only kind of believe the results. I logged this through a virtual machine (WinXP running in VMWare Fusion on OSX) so I'm a little suspect of the raw data quality since other road dyno graphs I've seen on this forum aren't this noisy. I'm also only moderately confident in my settings that I used for my car definition and other input parameters, but I used the same settings for both of these pulls, so the data should still be comparable.

I was a little surprised that I actually lost torque and power with the hybrid intake, but if I've learned anything from performance tuning software, it's that you can't trust your intuition at all: benchmark, benchmark, benchmark. Guess those resonators do something

Thoughts?

Here's the data:

Stock:
Code:
Time,Engine Speed (rpm)
0,1606
78,1660
156,1676
234,1720
312,1736
375,1733
468,1760
546,1790
609,1808
687,1822
765,1844
843,1888
921,1890
1000,1928
1078,1934
1171,1989
1250,2005
1328,2039
1406,2063
1484,2072
1562,2110
1640,2110
1734,2145
1812,2190
1890,2199
1968,2211
2046,2247
2125,2280
2203,2298
2281,2315
2359,2337
2437,2360
2531,2414
2656,2424
2750,2460
2828,2480
2906,2532
2984,2554
3062,2554
3125,2580
3203,2600
3281,2649
3359,2650
3437,2693
3531,2698
3593,2725
3671,2766
3750,2776
3828,2823
3906,2828
3984,2845
4062,2892
4140,2920
4234,2944
4312,2971
4390,2992
4453,2996
4531,3028
4609,3065
4687,3087
4765,3112
4843,3134
4906,3162
4984,3184
5062,3175
5156,3228
5218,3232
5296,3250
5375,3272
5453,3330
5531,3347
5609,3348
5687,3402
5765,3395
5843,3412
5906,3469
5984,3484
6062,3478
6140,3538
6218,3537
6296,3577
6359,3582
6437,3598
6500,3650
6578,3642
6656,3663
6734,3684
6812,3710
6890,3729
6953,3797
7031,3778
7109,3800
7187,3855
7265,3878
7343,3897
7406,3929
7484,3959
7562,3937
7640,4001
7734,3982
7796,4048
7875,4072
7953,4085
8031,4080
8109,4092
8171,4124
8265,4141
8328,4203
8406,4190
8484,4205
8562,4267
8640,4249
8718,4282
8796,4344
8875,4337
8953,4386
9015,4373
9093,4386
9171,4414
9250,4474
9328,4493
9437,4524
9531,4514
9593,4578
9687,4560
9765,4581
9843,4608
9921,4668
10000,4700
10078,4678
10156,4697
10234,4768
10312,4784
10375,4763
10453,4829
10531,4837
10593,4870
10687,4888
10765,4875
10828,4885
10921,4918
10984,4934
11062,5000
11140,5023
11218,4996
11281,5066
11375,5081
11453,5064
11531,5090
11609,5100
11687,5173
11750,5138
11828,5216
11906,5178
11984,5211
12062,5226
12140,5296
12218,5268
12296,5339
12375,5355
12468,5334
12546,5346
12625,5375
12703,5438
12765,5470
12843,5478
12937,5510
13015,5519
13093,5546
13171,5506
13265,5530
13343,5549
13406,5632
13484,5646
13546,5606
13625,5625
13703,5698
13781,5717
13843,5688
13921,5698
14000,5714
14078,5731
14156,5753
14218,5775
14296,5785
14375,5850
14468,5874
14546,5891
14625,5914
14703,5878
14765,5891
14843,5905
14921,5926
15000,5928
15078,5962
15140,5976
15234,5988
15312,6063
15375,6064
15453,6092
15531,6041
15609,6065
15687,6082
Hybrid:
Code:
Time,Engine Speed (rpm)
0,1362
78,1388
141,1412
219,1424
281,1428
360,1464
438,1471
500,1495
578,1504
656,1516
735,1538
813,1542
875,1574
953,1574
1031,1605
1110,1614
1188,1635
1266,1653
1328,1685
1406,1688
1485,1724
1563,1743
1625,1745
1703,1772
1781,1777
1860,1834
1922,1835
2000,1851
2078,1863
2141,1898
2219,1901
2297,1914
2375,1960
2438,1964
2516,1999
2594,1996
2688,2038
2735,2043
2813,2068
2906,2088
2985,2096
3063,2134
3141,2149
3219,2177
3281,2217
3360,2234
3438,2241
3516,2258
3594,2298
3672,2319
3750,2342
3828,2365
3906,2386
3985,2391
4063,2414
4125,2436
4203,2458
4281,2477
4344,2499
4422,2522
4485,2538
4563,2585
4625,2609
4703,2620
4781,2645
4860,2649
4938,2695
5000,2714
5078,2710
5156,2758
5235,2756
5313,2802
5375,2800
5453,2842
5516,2863
5594,2858
5672,2905
5750,2925
5828,2926
5906,2946
5985,2993
6063,3015
6141,3036
6203,3060
6281,3054
6344,3100
6422,3089
6516,3140
6594,3150
6656,3164
6735,3205
6813,3222
6891,3225
6969,3273
7031,3265
7110,3285
7172,3304
7250,3326
7328,3346
7406,3399
7469,3418
7547,3436
7625,3422
7703,3477
7781,3471
7844,3492
7922,3544
8000,3531
8063,3555
8141,3566
8219,3597
8281,3652
8360,3666
8438,3658
8516,3675
8594,3732
8656,3716
8735,3775
8813,3762
8891,3780
8969,3838
9047,3826
9125,3848
9203,3868
9266,3888
9344,3910
9422,3967
9485,3950
9563,3973
9641,3994
9735,4025
9844,4086
9938,4125
10031,4122
10110,4145
10188,4207
10250,4231
10328,4252
10406,4274
10485,4301
10563,4326
10641,4348
10719,4391
10781,4398
10860,4377
10938,4436
11000,4452
11078,4445
11156,4496
11219,4480
11297,4503
11375,4563
11438,4584
11516,4562
11594,4622
11656,4612
11735,4625
11813,4686
11891,4705
11969,4732
12047,4712
12125,4734
12188,4756
12281,4815
12344,4794
12422,4854
12500,4834
12563,4861
12641,4916
12719,4896
12781,4914
12860,4975
12922,4996
13000,5008
13078,5033
13141,5054
13219,5080
13297,5100
13360,5070
13438,5139
13516,5164
13594,5190
13672,5160
13750,5224
13828,5198
13891,5215
13969,5280
14047,5260
14110,5328
14203,5301
14281,5365
14360,5338
14438,5402
14516,5385
14594,5460
14656,5464
14735,5481
14813,5447
14891,5528
14953,5548
15047,5562
15125,5533
15188,5548
15266,5618
15328,5584
15406,5604
15485,5628
15563,5692
15641,5661
15719,5680
15813,5705
15891,5712
15969,5743
16031,5807
16110,5780
16188,5846
16266,5811
16328,5838
16422,5880
16485,5912
16563,5860
16641,5884
16703,5956
16781,5966
16860,5919
16938,5948
17000,5958
17078,5972
17156,5991
17235,5999
17313,6028
17391,6035
17453,6047
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Old 04-20-2009, 04:08 PM   #2
cmiovino
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Good info! I've been waiting for a dyno just like this forever.

When I added mine, I honestly didn't notice a thing at all. No gain in power/torque... not really any loss either though. No change in sound either.

Just from personal experience... am I doing it on my second Scoob? Nope.
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Old 04-20-2009, 04:10 PM   #3
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Yep, same results I was seeing.
http://forums.nasioc.com/forums/show....php?t=1741284

Now I feel it really depends on how the hybrid system was done. I think you could get good results if you did incorporate a resonator on the intake.

The stock intake manifold's plenum volume is quite small, so much so that it's about half of what it should be. Generally, the plenum volume is 50-60% of the engine's displacement and towards 80% if you're focusing specifically on low rpm use. The smaller size suits high rpm gearing, but the size is more specific to 8k+ rpms, something the engine never sees. The small size does benefit responsiveness though where an overly large plenum area would be somewhat unresponsive. I think because the plenum is pretty small, the intake setup does end up relying on the torque box and other intake resonators to make it function smoothly.

I played with a cone intake directly on the throttle body and played with the stock torque box with and without the stock piping. Without the torque box, air/fuel numbers were erratic. With the torque box, air/fuel was butter smooth.

With just a filter on the throttle body, I lost low and midrange torque, and the torque in the low/mid range was erratic. With the stock torque box alone, I gained some upper mid torque back, but again the low/mid torque was erratic. With the stock piping back on, the low end was restored and the torque curve was again smooth.

Can a hybrid intake work? Sure, but it will need to be tuned. You would have to at least run one resonator that you can test and dial in. A threaded chamber might be ideal since you can adjust the neck length and tune the resonance frequency. It'd be something interesting to play with at the least. The torque box is an inline resonator. I assume it essentially does what the plenum would normally do. This would have to be mimicked or reused with an aftermarket setup. Then on the remainder of the intake tract, you could add an inline resonator and through some trial and error appropriately size and tune it to optimize the power band. Then the question is, can you still beat stock? With custom tuning, you might be able to tune the inline and side resonators to shape the power band some and maybe tailor the car's tune more towards your liking. How much influence you have overall, I'm not quite certain. I guess you can sort of tell by how much you lost. In the end, stock is pretty good. It may not be a matter of beating it. It may more be a matter of making a better fit for your end goals.

The only other thing you want to try and do is get the coldest air in you can. Log intake temps and see what you have. Compare to ambient. Notice how many degrees you are above ambient when the car is warmed up. My stock setup was a solid 50F warmer then the outside air. The rough guide is:
10F drop = 1% gain in hp
If 50F = +5%, that's not half bad. This is about 5-10 lb-ft across the board. I think this is the biggest gain CAIs have over stock, not so much tuning. It would be best to retain the tuning or at least recreate it but also ensure near ambient air coming in.

On thing to think about is heat soak through the intake tract and even the throttle body and intake manifold. I don't know about you, but my manifold can pretty much burn me when the engine's warmed. Air through the intake at redline is around 3 feet per second. This doesn't give a whole lot of time to transfer neat to the air, so ensuring a cold source is more prudent then insulating the intake tract. However, insulation may ensure you cut out that last 1 or 2 degrees and maximize the system. You can look into both ceramic coatings as well as fiberglass exhaust wrap. The wrap is more effective, but places do offer coatings decently cheap too.

On and a note on the road dynoing, yes, the numbers are all over the place. You really do need to do moderate smoothing to get a relatively smooth graph.
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Old 04-20-2009, 04:54 PM   #4
Jerry Xu
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The data clearly show stock reaches higher engine speeds faster than hybrid.

That torque box provides a poll of air to cut down the rev time at lower speeds. This is likely why it is "better" because the engine is not as starved of air as much as the hybrid (missing the box).

However, a traditional dyno doesn't test how soon an engine revs up. It measures the power output at various rpms. The test allows the engine to "takes its time to rev up". So the winner here is not who can accelerate faster, but who outputs more at any given rpm. In a traditional dyno test, it's very possible that the hybrid shows an upper hand over stock.

Nevertheless, I like your test include the dynamics of acceleration to indicate the stock is better. Its more relevant to my real driving.

Last edited by Jerry Xu; 04-20-2009 at 06:50 PM.
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Old 04-20-2009, 04:59 PM   #5
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so your saying that the stock setup is better than hybrid??
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Old 04-20-2009, 06:29 PM   #6
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That's what the numbers say. Now it really does depend on how it's done. Done right, and you might be better off, but I think it would take the addition of a properly tuned resonator.

You'll also notice that stock has no problem breathing at redline. In fact, the 2.5" intake is plenty fine for the flow rate of the engine, no real need to step to a 3".

Now you may see different results if you rebuilt the engine to run at a higher rpm. You start running to 8k and want the power between 5k and 8k instead of 2k and 5k, and you'll be looking at a different setup, one that stock is not ideal for. The problem then is needing to actually run a modified engine setup in the first place to justify the need to change parts.

For the most part, leave the stock hardware or at least mimic it, and then address temps and get the intake as close to ambient as possible.
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Old 04-21-2009, 02:09 PM   #7
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damn this really sucks because i just cut up my stock air box to get a piece just long enough to fill the gap in my hybrid intake setup..... if only you had this posted a few days sooner=[
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Old 04-21-2009, 03:55 PM   #8
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BRR is correct on many accounts. Though you keep the jug resonator, the quarter resonator is removed. I didn't know, however, that the torque box was a resonator too.

As for keeping colder air. This is easily done by cutting off the turn at the end of the jug BEFORE the resonator part. I would like to believe that this does not affect plenum volume by much, if at all. Add a fender plug, and wrap the intake in pipe insulation to eliminate heat soak. That's about all you can do I believe. Although I suppose you could somehow reroute the jug to the bottom, I just left it facing the top of the fender well. I hear mixed reports about how the top of the fender is still pretty hot, and others no. I'm not willing as much to change it.

On a traditional dyno, I'm willing to believe that the hybrid would put down more power, but climb RPMs less.

Then it becomes a matter of torque/time. Or something weird like that.
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Old 05-02-2009, 02:44 PM   #9
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What about throttle response? Does the hybrid increase throttle response at all? Or is stock ALSO better in that aspect? Im mainly looking for more torque since most of the driving I do is in the city.
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Old 05-03-2009, 12:44 AM   #10
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I do find it interesting that your results are directly opposite to mine.

However, I played with road dyno software enough to completely distrust it. Honestly, I'm not certain that it's the road dyno software that's at fault. After talking with some data acquisition people, I think there's a decent chance the "weak link" is actually the ECU's reporting of RPM. They had some logging that compared the ECU's reported RPM to the actual RPM of the engine as determined by external sensors and the differences were pretty large.

Anyway, do you happen to have airflow data for both setups with absolutely perfect MAF scaling for both setups? How closely were you able to control air temperature between runs?

From the gut feeling, from logged airflow data, from timing, and from comparing the car's ability to perform certain tasks (hold a given speed on specific hills, etc), I'm absolutely sure that the hybrid breathes better on my car. I have to admit, though, that I've done zero testing on 06-07, other than to verify that they also have the resonance problem. It's entirely possible that they have something strange going on that renders the stock intake the best.

We need 06-07 people with widebands (perfect MAF scaling), to actually go to a dyno on this one.
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Old 05-03-2009, 01:26 PM   #11
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I don't have a wideband sensor so I don't have accurate airflow data, unfortunately. I'm also very suspicious road dyno data; there's just too many inferred variables from the RPM input. It really amplifies the noise in the signal to pretty ridiculous heights However, for relative comparisons on the same vehicle/ECU we should still be able to get some meaningful data providing that the difference between real engine speed and engine speed reported by the ECU remains constant.

The temperature between the runs was pretty close (I did the first run, swapped the intakes, did the second run, with the stock intake second). It's entirely possible that it had cooled down a little outside when I did the stock run, though. I'd like to redo this experiment again when I have the time and try to control the external variables a little better to try and get more accurate data.
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Old 05-04-2009, 08:18 PM   #12
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I can't wait to see the results. I have needed someone to do testing on the 06-07 because as of right now I'm keeping stock until I get some proof! Thanks for all your hard work. I will be watching this thread.
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Old 05-05-2009, 02:15 AM   #13
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I got to talking about this thread with one of my friends tonight and I actually looked at the numbers on your graph for the first time. I can absolutely guarantee you that the hybrid plot, at least, is flat out wrong. You spike 20ftlbs up in just a couple of RPM, then drop back the same amount in an equally small space. If that were really going on, your post wouldn't have looked anything like this. It would have looked like "ZOMG! Teh HyBRiDZ can has BROKED my c4r!, lulz!". Seriously, that big of a jump and fall in torque would have felt either like you broke something or you hit something.

Doesn't mean that you're not right in thinking the stock intake might be better for your car, it just means that there's no way that graph is right.
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Old 05-05-2009, 03:03 AM   #14
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Quote:
Originally Posted by williaty View Post
It would have looked like "ZOMG! Teh HyBRiDZ can has BROKED my c4r!, lulz!".


I still cant wait to see which one is better.. williaty have you thought of trying the hybrid on your womans car (she has a 06 right?) and logging it?
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Old 05-05-2009, 03:08 AM   #15
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yeah, I've thought about it. She doesn't care one way or the other and that's a lot of money to make a hybrid just for the test. The one I have for my 05 wouldn't even come close to working for an 06-07.
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Old 05-05-2009, 10:25 AM   #16
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Quote:
Originally Posted by williaty View Post
yeah, I've thought about it. She doesn't care one way or the other and that's a lot of money to make a hybrid just for the test. The one I have for my 05 wouldn't even come close to working for an 06-07.
Really?

it is virtually the same minus the extra vacuum line no?

I mean I have mine and it is pretty much the same as the 05 (went from a 05 Injen intake to the hybrid). All I needed was a T connector and some more hose, unless I forgot something...
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Old 05-05-2009, 11:50 AM   #17
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Quote:
Originally Posted by williaty View Post
We need 06-07 people with widebands (perfect MAF scaling), to actually go to a dyno on this one.
stock or with hybrid? Unfortunately I don't have the hybrid setup and it's not in my budget to put one together this year, but our local club DOES have a wideband and we have access to 2 different awd dynos.
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Old 05-05-2009, 12:29 PM   #18
Back Road Runner
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My comments are on a MAP based car. I would assume the MAF cars will behave differently for particular designs. The intakes on the newer cars are different then mine. The ECU programming is surely different. The MAF design will offer different influences. Self testing is always encouraged. The logging software is free, just need a Tactrix cable. Run several runs to gauge consistency and repeatability.

As to the throttle response question, upgrading the exhaust caused a very notable gain in throttle response. Playing with the intake did not. Stock to a cone filter right on the TB, the difference was minimal enough to not notice anything in terms of responsiveness.

My road dyno runs have generally been consistent. Absolute values vary some, but all my testing has been done with at least 4, 6, or sometimes more back to back runs for comparisons. All were very consistent. The differences in end power comes more from the flatness of the road, wind, etc. I'll note these can have large effects on the end result, so don't choose your testing area lightly. Things like MAP readings, air/fuel ratio, intake temps, timing, etc. all remained consistent for a particular setup. I agree the readings taken are horrid and jump considerably. With zero or low smoothing, it's a mountain range of data points. The graph is suitable for a Micheal J Fox joke, but I'll leave that be. A ton of points and some healthy smoothing later, the results do become quite consistent and repeatable, enough so where I don't personally question the results too much.
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Old 05-09-2009, 12:58 AM   #19
bcware
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I own a 2008, so I believe the ECU must be very similar to the 2006.

Most of us have noted some rare reports that the 2008 hybrid intake results in less low end torque, and now we have a test here that seemingly supports this claim.

Something I believe is very important and possibly the reason for this perceived loss is the act of resetting the ecu, a lack thereof, and the ECUs intelligent design.

Between playing with a handful of short ram intake designs, hybrid designs, and installing a cat-back I have reset my ECU dozens of times and I have made some observations.

First, upon resetting the ECU (battery disconnected, brake for 60 seconds) the car seems to default to a gimped out state. Even with no changes to the car at all this seems to happen. Applying the same amount of gas and the same clutch work literally stalls the car if not compensated for (more throttle).

Second, gimped out mode seems to gradually go away as the car is driven more, possible through a "drive cycle"?

Third, the ECU may (may also be coincidence) apparently adapt to your INITIAL driving habits through the first drive cycle; conservative versus aggressive.


Has anyone else noticed this or am I crazy?
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Old 05-09-2009, 01:03 AM   #20
williaty
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ECU does not adjust to your "driving habits" AT ALL.

What the ECU can and will do is to adjust fueling and timing in response to how the engine is running. When you first reset the ECU, all of the learnable parameters wake up in their default state. You need to reset the ECU, start the car without touching the gas pedal, and let the car idle for 10 minutes without touching the gas pedal. That will give the car enough time to sort out the idle timing and throttle opening. The IAM (rough timing correction) will also wake up in it's default value, which is 0.500. In other words, the car only uses half of the possible timing advance immediately after a reset. During the first few minutes of driving, the ECU is in rough correction evaluation mode and will attempt to advance the timing if it can do so without knock.
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Old 05-09-2009, 01:06 AM   #21
littlec
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Quote:
Originally Posted by bcware View Post
Has anyone else noticed this or am I crazy?
Sounds like the ecu needing to relearn. the thread in the engine management forum sticky on how to gain 10-15HP in 5 minutes might address getting it back to "normal" after the reset.
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Old 05-09-2009, 01:07 AM   #22
williaty
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The one listed in the EM forum is for turbo cars, doesn't work the same for us.
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