MY02 RX Wagon - Resonectomy?

[Fez]

Hi Guys,

Stumbled across the site only recently and am glad I did. Using the "Door Lock Actuator Repair" thread as a rough guide I was able to finally fix my my front passenger door lock. The MY02 is a slightly different setup than the model used for the demonstration but I was able to make it work. If anyone has a MY02 Lib and needs a hand let me know and I'll be happy to help!

The next thing I'm interested in doing is a resonectomy on my wagon. Again, I've taken a look at the excellent howto guide by Smythie, but his setup is again different to mine due to being a later model.

I've taken a few pics of the engine bay and if you guys can take a look and tell me what I need to do it would be appreciated. There appears to be 2 separate "devices" hanging off the air intake pipe enroute the filter box (one considerably larger than the other) and I don't really know what each is. Other than those being something to do with the resonator I really have no idea what they are.

Your input is appreciated.

Regards,

Fez

DSCF2536.JPG (145.01 KiB) Viewed 4355 times

DSCF2537.JPG (117.33 KiB) Viewed 4355 times

DSCF2538.JPG (113.17 KiB) Viewed 4355 times

DSCF2539.JPG (99.49 KiB) Viewed 4355 times

DSCF2540.JPG (117.04 KiB) Viewed 4355 times

[Robbks]

1) unbolt the intake duct from the airbox to the scoop
2) drill out the rivets holding the resonator onto teh pipe
3) remove resonator
4) block off the hole in the intake pipe with suitable rubber cap and hose clamp/ glue/ tape
5) refit

alternatively, you can replace as much or as little of the intake with silicone/ alloy/ stainless/ rubber piping

[Rome_BRZ]

Doesn't blocking off the hole defeat the purpose of removing the resonator?

[Robbks]

not on these.
the resonator is a disturbance to airflow
you can either block it off or add another duct,
but you don;t want to be sucking in the hot engine bay air.

so totally replacing the intake (pre-airbox) with a large bore, smooth walled cold air feed from tehinner guard or teh factory duct is the best option

[Nottage969]

Doesn't blocking off the hole defeat the purpose of removing the resonator?

+1. I have the same intake set-up and have left the hole unblocked. Otherwise you barely notice any sound difference whatsoever. Also, there are two smaller resonator's further up the intake pipe (toward the intake manifold). Drill out those rivets and take those off two, you'll notice more sound difference from those two than just taking out the main one believe it or not. Leave all holes un-capped

[Rome_BRZ]

not on these.
the resonator is a disturbance to airflow
you can either block it off or add another duct,
but you don;t want to be sucking in the hot engine bay air.

so totally replacing the intake (pre-airbox) with a large bore, smooth walled cold air feed from tehinner guard or teh factory duct is the best option

But where's it gonna suck the hot air from? As the car's driving there will be cold air making it's way in, the hot engine bay air isn't going to travel around and into the hole?

[Nottage969]

not on these.
the resonator is a disturbance to airflow
you can either block it off or add another duct,
but you don;t want to be sucking in the hot engine bay air.

so totally replacing the intake (pre-airbox) with a large bore, smooth walled cold air feed from tehinner guard or teh factory duct is the best option

I agree that's the best option. But i guess it depends whether the OP is after a sound difference, or whether he wants to get an extra 0.999999kw out of his engine.. Cause for $1,000+ for a custom induction, i think i'll stick with holes left open for a nice air intake noise.

[Robbks]

But where's it gonna suck the hot air from? As the car's driving there will be cold air making it's way in, the hot engine bay air isn't going to travel around and into the hole?

why do Subaru bother with the duct that comes over the top of the radiator then?

[Rome_BRZ]

Yeh but the intake and radiator are two completely different things. the whole point of the resonator is to reduce sound on factory isn't it?

[Robbks]

Yeh but the intake and radiator are two completely different things.

yes.
but teh duct over the top of it is the Cold Air Feed to teh intake system...????

[Fez]

Thanks for the input guys. Interesting conversation going on about the pro's and con's of the procedure.

To be honest, all I'm really after is a nice little lift in the intake sound, a less restricted airflow and if I get a micron of a kw boost to go with it then all well and good.

Perhaps I'll try removing the resonator(s) and giving it a run with the holes covered and without to see what I get.

[Nottage969]

Perhaps I'll try removing the resonator(s) and giving it a run with the holes covered and without to see what I get.

sounds like a good plan mate. Post back with your results because I would be interested to hear your thoughts also, what you use to plug up the holes

[Robbks]

Thanks for the input guys. Interesting conversation going on about the pro's and con's of the procedure.

To be honest, all I'm really after is a nice little lift in the intake sound, a less restricted airflow and if I get a micron of a kw boost to go with it then all well and good.

Perhaps I'll try removing the resonator(s) and giving it a run with the holes covered and without to see what I get.

for the best intake note, while keeping teh stock airbox
use some large bore alloy piping to the inner guard and enlarge the inlet hole in the airbox.

[Fez]

Ok. Finally got a chance to post about my tinkering and findings.

Step 1

Method: Removed stock piping to access and remove 3 x resonators, refit system leaving original resonator holes unplugged.

Result: No real discernible difference in intake sound or engine pickup.

Step 2

Method: Removed stock piping to access and plug 3 x holes left from removing resonators. Holes were covered with multiple layers of duct tape.

Result: Engine revved a little more freely. When accelerator buried could hear a induction "sucking" sound, but under normal acceleration engine was as normal. Would have been tempted to leave it like this if it weren't for a terrible vibrating sound from the engine when the accelerator was buried. My thoughts were it was the duct tape vibrating over the resonator holes due to a certain amount of give in the tape.

Step 3

Method: Removed all stock Subaru air intake components and refitted with 63mm purpose specific air intake pipe from Clark Rubber. This intake rubber piping was fitted to the OEM airbox by utilizing the existing rubber flex joiner before running down into the front guard into a pre-existing hole in the panel. I didn't like the look of it just hanging in the hole so to make an oversized grommet I got a rubber plunger base from Bunnings. I then cut the appropriate sized hole in the base to accomodate the 63mm piping before fitting the new "grommet" to the guard. Then it was just a matter of routing the pipe from the airbox to the guard.

From the pics you can see I made sure my air intake hung through into the guard by a couple of inches and is tucked down under the headlight loom.

Result: Really happy with this setup. No chance of water getting in due to CAI in the front guard and the path being all uphill to the airbox. Also, under normal acceleration there is absolutely no difference from the stock setup however under heavy acceleration there is a nice intake sound and the engine revs considerably more freely. You can really hear the air sucking when you bury the accelerator!

Overall I think it looks pretty neat and tidy, has really opened up the engine compartment and given the use of the original flex connector and the flex of the 63mm piping to the guard there is plenty of give for engine torque under load.

DSCF2580.jpg (121.25 KiB) Viewed 4286 times

DSCF2581.jpg (92.51 KiB) Viewed 4286 times

DSCF2585.jpg (73.72 KiB) Viewed 4286 times

DSCF2586.jpg (130.13 KiB) Viewed 4286 times

DSCF2587.jpg (128.58 KiB) Viewed 4286 times

DSCF2588.jpg (118.87 KiB) Viewed 4286 times

[hamish_023]

LOL