I did the air box mod earlier this week - ie removing the resonator from the inner wing.

Took it for a quick spin, and as reported in other threads you can hear the induction more and also the standard dumpvalve.

I replaced the plastic trunking to tidy the engine bay back up



Just a quick couple of questions though:

1. Should I blank off the hole where the trunking leads to, and if so what would any one recommend.?

2. Should I run some pipe from the vent under the indicator into the air box?



Car is pretty much standard My00, just running scoobysport decat centre and back box, plus ITG panel filter.

James

 

Waste of time what youve done mate, youve only made matters worse, you must blank the hole to the engine bay and yes you should run some ducting to the box.

It will be drawing hot air from the engine bay now and your charge temps will go through the roof on full tilt...this isnt any scaremongering either. I have carried out this mod on an 02 sti and datalogged the timps.

Only get rid of the resonator if you plan to run a ram air duct from the front like this.

 

i did the same mod last week.
what i cant understand is why people are removing the box and the attatched piping as this leaves a whole where the cold feed should go into the airbox.
i chopped the box off but left the piping into the airbox thus sealing the intake from hot engine air and still taking in cool air from the wing/ram air thing. i can also add a cold feed from the front also.

 

if you are just getting rid of resonator box you could try to get this not sure if it sells over here http://www.xcceleration.com/itemdetails.cfm62.htm its about half way down the page called intake elbow.

 

Hope that ducting isn't one long piece from bumper to airbox?

Mac, buy some thin s steel sheet from ahradware shop and cut it to size to cover the inner wing hole. Glue it in place with silicon and ditch the trunking.
You really need some piping to go from the airbox and into the wing to give a cold air intake.
Another variation of trunking is grey 3" drainage pipe elbows (45 & 90 dgree) They make a tight fit into the air box intake.

Nick

 

Why???


If youre going to tell me how much it will fill up with rain water... thats not even an issue, ive been through some torential rain recently and checked my airbox at the destination.. Dry as a bone mate

 

on the my99/00, subaru sell a blanking plate to fill the hole.

subaru part # 46059FA000
£7.23 inc vat.



dp

 

Rain -no.
standing water -yes
Plus its a nice tube for mice to run up and make a cosy nest in the box.

Nick

 

Thanks for the replies guys, couple of things tho,

Frayz - what piping did you use on your car? - looks like a really good fit

Dogpole - thanks for the info on the subaru part, saves cutting metal to shape to block the hole, looks like it just clips in.


James

 

When I removed the resonator and jointed up the air inlet I found that :
1) AFRs were badly affected, probably due to unstable air flow past the MAF sensor.
2) Power output was down 10 bhp.

This was done carefully over two consecutive afternoons, along with other induction work on a Dyno Dynamics RR.

The louder induction roar gave the impression of more power but the figures told the real story.

 

That is till you map it mate, The ram air affect has made a massive difference in inlet temps.

Before i would have say 14 deg ambients and be seeing over 45 deg at the maf, the stock system was robbing hot air from the bay all over the place.

With the ram air pipe fitted i get -2 to +1.5 deg at the maf with the same ambients and similar conditions.

Map it properly and rescale the Maf and you will be laughing.

My hose is 3" spring reinforced neoprene race spec stuff, its expensive for what it is but very very nice kit imo

 

As mentioned by Fraz whilst the airflow will be changed as far as the MAF is concerned if mapped to suit it should provide better breathing. Andy F advised me to remove mine along with the box between turbo & MAF (95 WRX) before I get it mapped again.

 

There's a lot of b*ll*x being talked above, but here's my experience with removing resonator, somewhat in contradiction to Harvey I suspect (Harvey - which model/year car did you test with?);

Classic - no problems; improves throttle response; doesn't mess with AFR's
Cautions;
- Watch for water ingress (make sure inner splash guards are correctly fitted)
- if you link a pipe from front up to airbox, make absolutely sure the pipe is fixed securely at entrance to airbox - if not secured, pipe can end up resting against the filter severely screwing up both airflow and MAF readings!
- makes things pretty noisy - can use drain pipe elbows to reduce this effect (by moving inlet closer to front of car)

New age STi; forget about it, seems to mess with airflow readings

New age WRX; never tried

Richard

 

The above was done on a 97 STi 3 Wagon with standard turbo, injectors and ECU. There is no facility to remap the ECU. With the snorkle, the car produces 335.5 bhp and without but with the last 2" of the snorkle retained to bud up to the inner wing it produced 325 bhp.
After replacing with another snorkle, as 2" had been cut out of the O/E, the car produced 335 bhp. No other changes.
Removing the Snorkle on its own will not increase power when retaining the O/E air box on a classic car and this is what Mac was referring to above.

 

Hi Harvey - all my testing was done with phase 2's. Didn't detect any power difference, just throttle response improvement (both with decat d/p, and stock d/p). Difference between phases is interesting, related to type of MAF I assume.

Richard

 

Mine was all done on a newage STI,

Big improvement!!! providing its mapped properly to suit

 

so what about removing the box between turbo and maf?? what will this achieve? (uk 95)

 

frayz - is there any benefit to this if you do not plan to increase the boost?