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Discussion Starter · #1 ·
G'day Noel, and guys. I posted this on "the other forum" and am sharing it here too.

Well yesterday afternoon I had two power runs on the same dyno as my baseline run a few weeks ago. Both were with the Injen CAI, the first run (05) on the plots was with the BMC twin cone filter, and the second run (08) used the Injen/K&N air filter that came with the intake.

From here's where I started to get frustrated, and will display my limited knowledge on the matter of dyno's (this dyno in particular) for the customer:

(1) They didn't calibrate the dyno and car so the plots can display torque/power vs RPM
(2) Didn't record tyre pressure or gear (not too significant as I know the runs are all in third.
(3) Didn't print out the maximum outputs and atmospherics for each run in digits for easy reference and comparison.
(4)Torque output is plotted against obscure units that have no resemblance to any accepted unit of torque, thus rendering the plot almost useless. (Unless someone can enlighten me?)
(5)Speed on X-axis isn't particularly useful (anyone know the Euros gear ratios? - on a TSX site probably not )
(6)K&N filter appears better than the BMC much to my disgust and the difference is the exact opposite to what would be expected.
(7)And adding further insult to injury.....the max gain over stock is a piddly 2.8kW or 3.75HP. After seeing dyno results for this combination on a TSX, that nets at least twice this value at the wheels I'm most disillusioned not to mention disappointed.

The driving experience suggests that the increase in power is much greater than these dyno results indicate. And I must begrudgingly confess that I drove home with the K&N filter fitted and it did feel stronger, sounded slightly deeper, and less resonant (tinny) than the twin cone. Maybe a twin cone filter on this reasonably small engine provides an increase in air mass flow that the engine is unable to utilize. Maybe that's a placebo effect no-thanks to the dyno. I'd love to reinstall the BMC for the "bling factor" but I'm not sure if I will.

I'm also not sure if I should read anything into these results or throw them in the bin and forget about them.

I think I'll find another dyno place and approach them with the list of things
I want to be able to see on the dyno output.

In summary......

Stock = 115.2kW (154.5hp)
Injen CAI + included filter = 118.0kW (158.2hp)
Injen CAI + BMC filter = 117.5kW (157.6hp)

Power and Air Fuel Ratio


Power and torque


Maybe I'm a whining bitch, but I was honestly hoping for more......ie 123kW (165hp)(Oh if only to have a K24A2 not an A3). Sure it made a great noise that impressed the guys in the shop office, but I'd like verifiable gains to accompany that noise.

Another thing I noticed that I’ll have to RTFM for the Apex'i RSM I've installed is it registered max RPM before the limiter as 7490rpm, and max speed of 147kmh (3rd Gear). I know it's accurate at lower speeds as it confirms with the tacho and gpsGPS respectively, but doesn't seem to agree with the dyno speed.

Yesterday was a little hotter and more humid than when the first run was done, but not enough I wouldn't have thought to rob 5hp+. Maybe I shouldn't have topped up the oil this morning. I'm going to assume yesterdays conditions on the dyno were simply crap.

By no means do I doubt the gains of the Injen on the K4A2, my butt dyno tells me they're much the same on the K24A3, if only these results suggested the same I'd be chuffed. Hence I'm looking for another dyno that might stroke the ego some by giving me a higher result
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2004 Honda Accord Euro (Shaved Accord), GP/CG, Full OEM Body Kit
--->Installed: Injen CAI, Comptech Short Shift, Apexi RSM+G Sensor
--->To Install: BMC Twin Cone Air Filter, when I decide if it's worth putting back on, K&N Drycharger (when the weathers crap)
--->On it's way: Comptech Rear Sway Bar
--->Looking to buy (again!): Hondata Heat Shield Gasket, Comptech Rear Sway, Cusco CL9 Strut Tower Bar
--->Mods Performed: Throttle Coolant Bypass,
--->Mods to be performed: Oil Catch Can
 

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Your results itself is showing a poor indicative of "standards" across the board. I'm not going to point fingers to how the dyno reading was intepreted. While even on the AT CL9, the power gains for the Injen alone is consistently showing 9-10bhp let alone the MT.

Ambient temperature, engine temperature, water temperature are 3 effects without considering ECU management that can significantly affect dyno outputs. Since I run much more different modifications and the most significant difference of my ECU that has different fuel and ignition mappings along with a 1000 RPM raised redline, comparing my power gains would not be fair with yours especially when the ECU could be raising the bhp more than anything else.

But the BMC twin filter is designed for mid-high RPM power gains, the low end power will be rob but is compensated in the mid-high powerband instead. Because of the increased air suction/flow, heat soak occurance will no doubt cause more power loss as well. If you feel that this product is not good enough for you, I'd suggest you go with what you feel is a better filter to match your driving style/condition. I should have mentioned that when I made a recommendation for improving the Injen CAI. It was based in reflect of performance gains primarily used with constant hard driving or competitive scenarios.

No doubts, I too am disappointed to see such poor results.
 

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Discussion Starter · #4 ·
Joe I've honestly got no idea what units of torque they're meant to be (makes me wonder at the skill of the people running the dyno) and has had me scratching my head and pawing through my old engineering texts since I saw it.

G'day Noel thanks for replying. It wasn't a personal affront to you for your recommendation or a bagging of the product. I'm certainly not going to get rid of the filter, or rule it out as a waste of money.

I'm very new to car modification, and have a very strong technical background, but interpreting automotive dyno's is something new to me. I'm always eager to hear pointers and tips from others with more experience.

It just dawned on me that I have a photo of the monitor from the original baseline run that yielded 115.2kW not to mention the temperature wire was in the same location for both baseline, and CAI runs. Not sure how much of a source of error that would be, but I know that with stock air box the air is NOT drawn in from under the resonator where the guy placed the probe wire.Hmmm.....but I digress.....

Anyway the atmospherics are as follows:
(Assuming BP=Barometric Pressue, RH=Relative Humidity, AT=Ambient Temperature, IT=Intake Temperature.)
Baseline(sock)
BP: 101.1
RH: 37
AT: 31
IT: 30
RR: 010 (not sure what this value could be)
TM: 3.544 (ditto)
CK: 181 (ditto)

For the run I've scanned in the cars configuration was CAI with K&N, throttle body coolant bypass, (still awaiting Hondata gasket)
BP: 101.3
RH: 60
AT: 25
IT: 30
RR: 010 (not sure what this value could be)
TM: 3.544 (ditto)
CK: 976 (ditto)

So that's a +23% difference in humidity, -6C difference in ambient temperature, and identical intake temperatures which is very curious. Also I know the ambient temperature as I drove there was 34C, and it certainly didn't feel like 25C in the dyno cell. Questions are starting to come to mind now about the setup and calibration of the dyno.

I also noted that the end of the intake temperature probe was very close to the roller......hmmm. Maybe I should ask for them to export the results for all my runs in a data format so I can analyse the actual numbers for discrepancies. I'm sure dyno-dynamics designed that ability into their product. I would also think a dyno should also interface into the vehicles OBD port....but that’s digressing again!....it sucks being an engineer and over analysing, and scrutinising everything. :jeffy:

As I mentioned I honestly feel subjectively that the performance gains from the Injen CAI are much greater than indicated. I'm calling these results "an aberration" where this theory will hopefully be proved when I repeat the test between the two filters on another dyno. I was going to stick with the K&N initially after these results, but I'm going to switch back to the BMC this weekend and continue to run it.

It was pointed out on another forum that the engine was also running excessively rich in comparison to other AFR readings people have had from dyno's. It was suggested that maybe the ECU hadn't "learned" and optimised to the new airflows, but I don't think that's an issue as I've had the intake installed for several weeks now, and have done almost multiple daily trips to flirting with the fuel cut-off on my long drive to and from work.

I guess I'll know more once I've taken it into a very experienced dyno shop and replicated these tests.

Please Noel if you've any thoughts or ideas no matter how objective, feel free to PM me.

Cheers,
 

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Your dyno calibrations or measurements definitely show inconsistency and are itself subjective to question, yes running rich is the primary principal especially with my experience on how OEM Honda ECUs are setup. I noticed the ambient temperature to be relatively high as well, and that could be a serious contributing factor to power outputs when the ECU runs rich.

If you want my definition of a dyno expert or see their thoughts on how to improve your readings, visit Centrax Auto - In MacGregor. Steve and his brother are the owners of the business and a good friend, I never miss an opportunity to go down and visit them and discuss technical improvements and we share a strong Honda knowledge on tuning and improvement.

I wouldn't exactly suggest you to take another reading until you have more mods because even if you do end up proving that the initial calibration is not accurate, the money is better well spent investing in vehicle improvements. I'm sure there are other stuff or changes in your mind now that you have the intake in place. Feel free to continue on this thread, I endevour to do my best to improve your vehicle's power output.
 

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Discussion Starter · #6 ·
Thanks again as always Noel,

My next, and probably last engine mod for the time being will be an item of questionable value to some, aka an intake manifold heat shield gasket. Then it'll be a little while before possibly headers and exhaust a long way down the track.
You're dead right about using the money saved on other improvements, this weekend I'll install a Comptech rear sway, and also place an order for a Cusco strut tower bar.

Strangely when driving home this afternoon the throttle felt completely different. Almost like the ECU had leaned the mixture out somewhat and the CAI had become more effective. I'm not sure exactly what happened but it feels markedly different and more responsive than when I drove to work this morning. I'm certainly not complaining! :)

I'll organise a time to stop by Centrax and have a chat to them with these dyno's in hand, I'm glad I'm not the only one who could see a few unexpected values. Meeting up with the guys there is something I've been meaning to do for a while. I might pick up some new fluids while I'm at it, and see if they can acquire for me above said bar ;) I'm very much a novice at this so I'll look forward to learning things from guy's who've gained many years experience improving Hondas.

Thanks!!! :thumbsup:
 

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Headers/Exhaust Manifold and Catback ... Will re-learn the driving experience. As for the the strut bar/brace ... I don't really see a need for it, I really don't. There are other handling aspects that can be dramatically improved.
 
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