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Old 07-27-2012, 10:17 PM   #1
NH8991
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Default 08+ N/A Hybrid Intake Testing Graphs Inside

Searching the forums indcates that the jury is still out for the hybrid intake on the 08+ N/A cars, some like 'em, others have reverted back to stock due to diminished performance. However, i've never seen any actual data posted to back either side up.
I figured I would try the mod on my 09 4EAT, it's a cheap (and supposedly relatively safe) mod so why not? Originally I bought an ebay SRI to hack up and tide me over, but I wasn't happy with the fitment so I had one fabricated for that 'professional' look. Here's the intake in question during fitment (and for those with eagle eyes no the clamps weren't all done up at this point ):



After many trials at various stages of mods i.e. relatively stock (catback & crank pulley only), modified (EL headers, mild cams, initially no tune), modified with a tune (including a MAF rescale on the stock intake), the results have always been similar, whether it be from logging or my calibrated butt dyno.

- Engine related details for those interested: EJ253, Group A crank pulley, stock OEM paper air filter, Delta 1000 cams, Lachute Performance EL headers/HFC/2.25" exhaust, 91 octane, OS tuned.

So, GRAPH 1 - 100% throttle, RPM along the bottom, MAF (g/s - the numbers are roughly equivalent to WHP) up the side. Stock intake profile in red, hybrid intake in blue.
Note that the car was running the stock tune (on 91 octane) at the time, the graph only shows the results before/after the hybrid install



Observations:
Above 4000rpm, MAF is increased, but from the data only by up to about 2-3g/s by 6000rpm, not exactly mind boggling, but an increase nontheless.
Below about 3800rpm, the hybrid loses out big time to the stock intake, up to about 7g/s, and that dip is really noticeable. The butt dyno felt a real kick around 3800rpm which initially made me think that that the hybrid was having a major effect at this point, only to realise that it's because the car was pulling a lot less prior to this and I was just feeling the difference when it finally woke up.

GRAPH 2 - same parameters again.
Note that the car had now been tuned for the stock intake, including a needed MAF sensor rescale, but was not tuned following the hybrid install, the graph only shows the results before/after installation.



Observations:
Above 4000rpm, MAF is higher, up to about 5g/s by ~6000rpm, so running the engine higher in the rev range reaps benefits.
Below about 3800rpm, the hybrid is still losing out to the stock intake by up to 7g/s.

General Notes:

- It's more difficult to log the comparisons at part throttle so I haven't bothered to really try, I just don't have the time. However, the butt dyno feels a noticeable loss from around 1500-3500rpm, and the torque converter unlocks earlier (another good indicator) on inclines because the engine has less grunt.

- Because the car is a 4EAT the results may differ from a manual, especially lower down in the rev range where the torque converter may be unlocked and 'diluting' the power delivery. The TCU also sets the shift points at 6000rpm so I can't run the extra few hundred rpm to redline as with a manual.

- The hyrid does seem to give a little better initial throttle response compared to stock.

- This is not a performance observation but i'll throw it in anyway, with the hybrid the engine sounds marginally more thrashy, though some people may not notice.

- Although the MAF sensor was rescaled (with the stock intake) prior to the hybrid install, I haven't tried a specific tune yet for the hybrid intake.
I'm a little sceptical that a tune can recover all the loss low down, but I guess there's only one way to find out. If it can't then I'm going to keep the stock intake, the car is a DD/family runabout so i'm not willing to sacrifice the everyday driveability for the bit extra up top that I will rarely use.

There you go, i'll let the experts pull it all apart
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Old 07-28-2012, 01:14 AM   #2
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Thanks for the info. You pretty much confirm what i thought as for the low end. I figured the surge i felt around 4k was because it was being robbed at the low end and finally picked up. Living in the city, i need low end more so I'm probably reverting to stock. On a strange side note, my parking brake light has been coming on and staying on intermittently since the hybrid install. Probably unrelated, but a strange observation.
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Old 07-28-2012, 09:33 AM   #3
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Nice write-up. Do you have any wide band data to compare afr from one to the other? I suspect you could improve the curve of the hybrid in that dip and below the range of your graph (1500- 2500) rpm
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Old 07-28-2012, 02:25 PM   #4
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Thanks.
Unfortunately no wide band data, only what was being output from the stock sensors via the OBDII. I'll take a look at the AFRs, though i'm still a noob at tuning. While i'm beginning to understand what the data is telling me, i'm not yet comfortable enough yet to start altering the tune myself.
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Old 07-28-2012, 02:36 PM   #5
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Quote:
Originally Posted by NH8991
Thanks.
Unfortunately no wide band data, only what was being output from the stock sensors via the OBDII. I'll take a look at the AFRs, though i'm still a noob at tuning. While i'm beginning to understand what the data is telling me, i'm not yet comfortable enough yet to start altering the tune myself.

The a/f data in your log from the stock sensor is probably not accurate at wot but the 08+ ecu is different than what I am most familiar with. Would be interesting to see it graphed with the g/s comparison graph you posted previously
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Old 07-28-2012, 08:43 PM   #6
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The hybrid is nicely done. If you decide not to keep it shoot me a pm, I'd be interested.
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Old 07-28-2012, 08:59 PM   #7
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Good job!
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Old 07-28-2012, 10:40 PM   #8
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Quote:
Originally Posted by bidaci View Post
The hybrid is nicely done. If you decide not to keep it shoot me a pm, I'd be interested.
Willdo.

Quote:
Originally Posted by RaceFaceXC View Post
The a/f data in your log from the stock sensor is probably not accurate at wot but the 08+ ecu is different than what I am most familiar with. Would be interesting to see it graphed with the g/s comparison graph you posted previously
Let me know what you think:


Last edited by NH8991; 07-31-2012 at 09:08 AM. Reason: Keeping it on topic
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Old 07-29-2012, 12:27 AM   #9
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Glad to see someone took the initiative lol.
So do you think their will be a bigger difference when you get a tune for the 91 octane and the hybrid intake? I know just a stock tune with no mods only gains a few HP/torque pounds but throttle response is greatly improved...
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Old 07-29-2012, 12:42 PM   #10
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wouldnt timing charts be needed as well to get the whole story? For a given airflow and A/F ratio for example, octane rating might influence timing advance, and thus the torque output
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Old 07-29-2012, 01:58 PM   #11
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Quote:
Originally Posted by KartRacer3 View Post
Glad to see someone took the initiative lol.
So do you think their will be a bigger difference when you get a tune for the 91 octane and the hybrid intake? I know just a stock tune with no mods only gains a few HP/torque pounds but throttle response is greatly improved...
Maybe, though i'm happy enough with the gains up top. However, i'm not willing to take the hit lower down the rev range.

Currently i'm running the stock intake though I will get a tune for the hybrid at some point, I want to see this through, I just don't have the time to invest right now, plus I have to pay for the tune.

Quote:
Originally Posted by Bluefoton View Post
wouldnt timing charts be needed as well to get the whole story? For a given airflow and A/F ratio for example, octane rating might influence timing advance, and thus the torque output
Just to clarify, i've always been running 91 octane, it was actually one of the first changes I made to the car. Even on the stock tune 87 (and to a lesser extent 89) made the car run like arse, though i'm pretty sensitive to how it runs.

Looking at the data for Ignition Total Timing, values are practically identical, with the hybrid there was an increase by 1 degree maximum between about 3175-3600rpm, the rest of the time it was identical to the stock intake.
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Old 09-02-2012, 06:29 PM   #12
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NH, great write up and food for thought. I think I am going to stay with my stock intake setup with the Perrin Foam air filter instead. I bought my NA Impreza as a daily commuter with fuel economy and cost in mind and while I do want a little more pep and the boxer rumble out of it, going 91 octane would defeat that purpose.
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Old 09-02-2012, 11:38 PM   #13
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Cheers.
The cost for, say 87 versus 91 is not necessarily as straightforward as just comparing prices at the pump.
I know that my car (and others) ran much smoother on the stock tune with 91, though whether there was any real benefit to the mpg (to offset the extra cost) I don't know. Maybe a tune for 91 could not only eek out more power but also improve fuel consumption.

I can say that i've just come back from a 1300 mile round trip with a fully loaded car, 2.5 people on board, 2 bikes on the back, lots of 75mph highway stretches and some serious hills along the coast, and returned an average of 29mpg. This is at least as good as I used to get on road trips when the car was stock running 87 octane, and currently the car has slightly heavier wheels, wider and stickier tyres, more drag from the larger hatch spoiler, cams (which don't normally go with better fuel consumption) etc. etc.
More food for thought...
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Old 09-02-2012, 11:54 PM   #14
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How would one get a tune for running 91 octane? It would only be worth your time and money if this was done in association with a SRI or CAI?
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Old 09-03-2012, 12:31 AM   #15
NH8991
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Quote:
Originally Posted by pkL View Post
How would one get a tune for running 91 octane? It would only be worth your time and money if this was done in association with a SRI or CAI?
If you have a 2012 I don't know, i'm not sure if the opensource tuning world has looked at the new cars And you certainly don't want to pay for Ecutek or similar.

I know that even with the stock intake, my MAF sensor required rescaling to be more optimal, plus the tune can take care of other aspects to just engine performance, e.g. throttle mapping.
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Old 09-05-2012, 03:42 AM   #16
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Quote:
Originally Posted by NH8991 View Post
If you have a 2012 I don't know, i'm not sure if the opensource tuning world has looked at the new cars And you certainly don't want to pay for Ecutek or similar.

I know that even with the stock intake, my MAF sensor required rescaling to be more optimal, plus the tune can take care of other aspects to just engine performance, e.g. throttle mapping.
I guess I'll just have to wait and see.
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Old 09-10-2012, 12:12 PM   #17
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I run my 2.5i on 89 octane, figured it's playing it safe on a totally stock car.
NH, where/how did you tune yours? Also, can you elaborate on the MAF rescaling?
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Old 09-10-2012, 11:04 PM   #18
NH8991
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Quote:
Originally Posted by Bluefoton View Post
I run my 2.5i on 89 octane, figured it's playing it safe on a totally stock car.
NH, where/how did you tune yours? Also, can you elaborate on the MAF rescaling?
Opensource 'e-tune' - i'm not savvy enough yet to tune myself but i'm learning (my wife bought me a Tactrix cable for Christmas bless her ).

MAF rescaling - when I was collecting data we could see some relatively big spikes/values in the fueling corrections (on the Romraider logger there's a handy tab that shows A/F correction vs MAF voltage via a scatter chart).
So even though i'm using the OEM intake, the MAF scaling needed some optimising. Not sure if this answers the question fully?
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Old 09-10-2012, 11:23 PM   #19
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It does, thanks. You're waaay ahead of me, I just enjoy my TorquePro app
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Old 09-11-2012, 12:45 PM   #20
NH8991
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Quote:
Originally Posted by Bluefoton View Post
It does, thanks. You're waaay ahead of me, I just enjoy my TorquePro app
I'm not sure about that, I consider myself old school. What's an 'app'?
Seriously, never owned a smart phone, my 3 year old son understands the workings of an iPhone better than I do!
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Old 09-11-2012, 04:10 PM   #21
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It's a cheap way to get all the readings from the OBD2 port displayed with a gauge-like graphic interface on my smartphone. Costs less than having a ton of dedicated gauges, and is arguably. less cumbersome that screwing a laptop instead of your sunblocking visor. We should meet up for a beer when I zip by Montreal...
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Old 09-12-2012, 09:06 PM   #22
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Absolutely neighbour, drop me a line when you're gonna be in town
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