Has anyone deleted the resonator in the stock airbox? or made a larger snorkel?

[StormTrooper]

Originally Posted by Nezz

I'm gonna be quick and blunt here. It's a shame Xanatos jumped out earlier, I'm pretty sure he knows what's up, too.

Race cars are not street cars are not race cars. The Griffin spends its life at full throttle and above 5,000 RPM where intake pulses start to melt into a flow, and its intake is designed to be as direct as possible for maximum flow under power. Out in the real world where we are, we're on all sorts of partial throttle and at low RPMs pretty frequently (deny it if you like, but it's true).

Resonators of about that size placed in the intake are there for more than just looks. They're somewhere for intake pulses to bounce after they come off a closed intake valve and go back down the pipe. Look at how it's placed perpendicular to flow, in the natural spot for the pulse to bounce across the airbox. As for the ones on the snorkel, I wouldn't be surprised if they're noise related, or even just to catch moisture and give it somewhere to safely evaporate. But the resonator hanging off the airbox?

S13 Silvias come with one of those in a similar (but not identical) configuration. The one on my Silvia Qs had its one fully deleted by the previous owner-- I got the parts in a box. Putting them back on did make the car quieter, but it also stopped the grab I got going from second gear to third under partial throttle and improved response (When you have a flywheel less than half of stock weight I think you can judge it fairly effectively) at low RPMs and partial throttle under load.

THIS WILL NOT, and I mean NOT reflect on a dyno. A dyno is a full power run. You'll see "gains at the top end", unaware that the 'gains in the midrange' are being eaten by the detriment of this effect. Yes, you're giving purer airflow. Is it always a good thing? Hell no.

My two cents. Don't keep up with all the "noise" crap, resonators resonate-- Resonation means more than just noise and vibration. Take the resonators out of an exhaust and watch what happens to your exhaust pulses bouncing off the muffler...

at what point with the car on does your car not flow any air? pressure waves would affect if they were large enough but sound waves would need to be huge to move air around.

now a reserve volume in the intake track, i could understand that.

[Kodename47]

Tests happening on Tuesday I've decided to change what I'm testing I'll put the findings straight on here. I still feel that 2-3k is down on power on partial throttle.

[vtmike]

Originally Posted by Kodename47

Tests happening on Tuesday I've decided to change what I'm testing I'll put the findings straight on here. I still feel that 2-3k is down on power on partial throttle.

Are you using the torque app or something that you can verify the same throttle position between runs?

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[Kodename47]

Originally Posted by vtmike

Are you using the torque app or something that you can verify the same throttle position between runs?

Dyno and full logging on ECUtek. I'll get the data into a useable format. I've decided to test with/without main resonator and with the hole open. I have my reasons and I'd like to see how each performs. I'll make sure the tests are done fairly, I'll do 3/4 pulls per config and will post all results not just the best.

[Nezz]

Originally Posted by StormTrooper

at what point with the car on does your car not flow any air? pressure waves would affect if they were large enough but sound waves would need to be huge to move air around.

now a reserve volume in the intake track, i could understand that.

Your car pulls in, in pulses, which express a bunch of energy as sound, which reflects more easily than you might think, and being as that it's a pressure wave (sound is a pressure wave, remember? Doppler effect, kinetics of sound in water?) most definitely affects your intake and exhaust.

I referred a book earlier, might blow your mind to read it-- intake and exhaust tracts are much more complex than you may think.

Originally Posted by Kodename47

Dyno and full logging on ECUtek. I'll get the data into a useable format. I've decided to test with/without main resonator and with the hole open. I have my reasons and I'd like to see how each performs. I'll make sure the tests are done fairly, I'll do 3/4 pulls per config and will post all results not just the best.

Fantastic! Looking forward to seeing the results out of blatant curiousity. Really wish I had access to a dyno where I could run programs, being as this car is TBW...

[Nezz]

Originally Posted by sierra

I agree.
It's the volume after the throttle valve that's critical and the only way it could be important before that is if there's a restriction back down the line.
Why would they engineer that in?

Because they have to meet emissions targets and noise levels? The "restriction" in this case is your entire intake tract, that's why there's midpoint volume expansions and reflection points.

[vtmike]

I think I may have some evidence removing the large resonator might be adversely effecting the low end with the car. Had this dyno done today and my a/f is all over the place at lower rpms. I also made less torque in the low point of the dip than an auto frs with only an axleback (my car is manual with axleback, front pipe with high flow cat, drop in filter, and perrin intake tube) Although this auto frs made way more power than average for its set up while every other car there was low for their respective mods.




http://www.ft86club.com/forums/showthread.php?t=35546

Richmond VA Dyno Day Results 5/4/13

[Kodename47]

Well, after a bit of a mare on the dyno yesterday and no real firm results I drove home with my main resonator back in place and it definitely feels better. It definitely wasn't my imagination. I will stress that it's only sub 3k where it feels like it makes any difference but I'm happier I've returned it.

The weather has turned today but I'll get some road tests/logging done and maybe a return to the dyno when I can.

[vtmike]

Originally Posted by Kodename47

Well, after a bit of a mare on the dyno yesterday and no real firm results I drove home with my main resonator back in place and it definitely feels better. It definitely wasn't my imagination. I will stress that it's only sub 3k where it feels like it makes any difference but I'm happier I've returned it.

The weather has turned today but I'll get some road tests/logging done and maybe a return to the dyno when I can.

Do you mind posting your results. I'd be interested in seeing how your a/f looks down low with and without the resonator.

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[wbsrazzle]

Can someone summarize what's going on here in 15 pages? I bought the AEM intake and installed it, removing the resonator/snorkel from the stock airbox and immediately felt like there was a noticeable decrease in lower end torque. What is going on here

[NickFRS]

Originally Posted by vtmike

I think I may have some evidence removing the large resonator might be adversely effecting the low end with the car. Had this dyno done today and my a/f is all over the place at lower rpms. I also made less torque in the low point of the dip than an auto frs with only an axleback (my car is manual with axleback, front pipe with high flow cat, drop in filter, and perrin intake tube) Although this auto frs made way more power than average for its set up while every other car there was low for their respective mods.




http://www.ft86club.com/forums/showthread.php?t=35546

Richmond VA Dyno Day Results 5/4/13

Well this is good news. It makes the car run richer. WAY RICHER. Once you lean out that spot it will produce more power. What did we learn from this? Needs a tune. (I have a tune and my AFR there is perfect and I have a nice pick up in the dip. Putting on my RevWorks headers Friday and getting retune on Tuesday to hopefully see no more of the dip.

(You could even say the resonator leans out the AFR's)

The only real way you will get conclusive data is

Baseline.
Dyno with resonator
Dyno without resonator
Dyno with resonator tuned
Dyno without resonator tuned

Since removing the resonator makes the car run richer. (also before my tune my car was running extremely rich)

[NickFRS]

Originally Posted by wbsrazzle

Can someone summarize what's going on here in 15 pages? I bought the AEM intake and installed it, removing the resonator/snorkel from the stock airbox and immediately felt like there was a noticeable decrease in lower end torque. What is going on here

This is about the stock airbox. Not aftermarket intakes.

[vtmike]

Originally Posted by NickFRS

Well this is good news. It makes the car run richer. WAY RICHER. Once you lean out that spot it will produce more power. What did we learn from this? Needs a tune. (I have a tune and my AFR there is perfect and I have a nice pick up in the dip. Putting on my RevWorks headers Friday and getting retune on Tuesday to hopefully see no more of the dip.

(You could even say the resonator leans out the AFR's)

The only real way you will get conclusive data is

Baseline.
Dyno with resonator
Dyno without resonator
Dyno with resonator tuned
Dyno without resonator tuned

Since removing the resonator makes the car run richer. (also before my tune my car was running extremely rich)

So your car had the same results?

After doing some data logging and more low RPM wot runs it would appear the fuel trims have gotten much better with me driving the car harder on a regular basis. This could have been some how do to my driving habits of really never hitting wot in that Rpm range before the dyno.

Sent from my Nexus 7 using Tapatalk HD

[Kodename47]

Originally Posted by vtmike

Do you mind posting your results. I'd be interested in seeing how your a/f looks down low with and without the resonator.

I'm collating the results. The dyno ones were inconclusive as I've not enough data.... a fresh re-flash seems to have been a hinderance so I'll do some AFR/MAF/MAP logging on the road.

*EDIT* - New results in the following post