scoober101

For a while Ive searched the net and this forum to upgrade the stock air intake on a Scooby, looking at the pros and cons of different variations, eg, induction kits, cold air feeds etc.

I came to the conclusion of combining different parts whilst avoiding methods that "could" have a negative effect. I say "could" because many people on here that have opted for methods such as cold air feeds from the front bumper have had no problems with rain and debris shooting up the pipe at all. However, Ive avoided this by keeping the stock intake scoop in place but change other things in the intake route on my 2005 PPP WRX.

First off, heres the parts I used to make the intake...(parts not shown is a length of 80mm ID Silicone Hose and Jubilee clips)

* K&N Apollo Induction Cone Kit
* GP Moto Intake Elbow
* ATP Turbo 80mm MAF Housing
* 70mm ID, 45 degree bend Silicone Hose (3 in total)

I bought the 'Universal' K&N Apollo kit, I would recommend buying the WRX/STI specific one as it comes with a MAF Housing. MAF Housings made for the Denso MAF Sensor on Newage Scoobys are not easy to come by. (not sure if Classic Scoobys use Denso MAFs?) A US company ATP Turbo sell them but after cost, postage and customs charges it works out very expensive, my advice, buy the slightly more expensive Scooby specific Apollo Kit. (from Scoobyworld and Revolution for example) There are other 'unclosed' cone filters on the market also.

The GP Moto Elbow replaces the stock intake 'snorkel' or 'silencer' in the front wing of the car, the airflow into and out of the stock snorkel is very restrictive as the air flowing into the snorkel has to travel up the same route to exit it and into the air filter box. This elbow does away with the snorkel entirely and creates a simple direct feed tube for the air coming into the car.

I also drilled a small drain hole in the lowest point of the GP Moto Elbow, as you can see from the photo its a 'U' shaped bend. Similar to the stock snorkel a small drain hole is ideal incase any moisture becomes trapped in the elbow.



A common problem with induction kits is that they draw warm air from inside the engine bay, Id argue that induction kits infact worsen the cars performance, even if there is an air feed pipe leading up to the induction cone, its not a sealed system so under acceleration, all the warm air around the engine is being sucked in. Fresh air traveling into the cars intake is cold and must be preserved as best as possible its entire journey into the intake manifold. With this in mind rather than route the end of the cold air feed pipe down inside the front wing or even to an opening in the front bumper, I connected it to the existing intake scoop. (via the GP Moto Elbow in the wing)

Heres a pic of the setup...




I had to use 80mm ID Hose to seal the connection between the MAF Housing and the 70mm Hose on each side as 45 degree reducer hose from 80mm to 70mm is impossible to find, besides after trimming the hose lengths to fit, hardly any of the hose on each side of the bend was left anyway. As luck would have it, the external measurement of the 70mm ID hose was 80mm (5mm wall each side) so 80mm hose fit snuggly over the 80mm MAF housing and the hose, held in palce with jubille clips. Something not to worry about if the WRX/STI specific Apollo kit is bought, as the MAF Housing supplied with it is not 80mm, Im guessing its 70 or 75 mm. The only reason that stopped me from re-buying a Scooby Apollo kit was the other parts in the kit I wouldnt use, after looking at photos of the kit fitted, the hose supplied with it would be the wrong length as a lot of 'custom' hose trimming was involved in making the whole setup fit correctly.





Now, the part that alot have probably been wanting to hear...has it made a difference in performance? Before I go on, bear in mind I havent done any kind of 'technical' measuring to find results at all. However....................with the combination of using the stock intake scoop, a direct feed route through the GP Moto Elbow, a sealed link into the cone filter, through the MAF and into the pipe leading to the Turbo...I have to say yes I noticed a difference in turbo spool-up. Noticeably in the 2nd and especially 3rd gear, the climb in acceleration was definately quicker. Was I telling myself there was a difference? No, I did notice a positive gain. And when you look at the change in the intake route, cold air is more direct through the wing without the snorkel, through a sealed cylindrical filter and through very shallow bends into the turbo intake pipe.





Even when looking at the stock air box after removing it, once air is inside the air box it isnt a direct route straight to the MAF and on, it goes without saying air traveling through a cylindrical path is the most efficient way for it to travel.

With all that said, only the driver of his/her own car "feels" the difference in performance after making a modification. Without proper testing with equipment, only the driver can tell if there has been a positive or negative change in the way the car drives.

Was an enjoyable mini-project to do, any comments welcome!

jonny_693

iTrader: (5)

To be honest I can't see how it can be any different from using a resoator delete with a panel filter. Be carefull though, that bend before the maf could make the car run lean as air will stick to the outside of the curve if that makes sense. Nice tidy job though!

scoober101

Yeah, that was a concern of mine also, theres not much room to play with inside the bay, I did try mounting everything a bit differently to reduce the bend but I couldnt get it too all fit, had to settle for this. Fingers crossed running lean wont be much of an issue, time will tell.

frayz

iTrader: (7)

Nice job

joz8968

iTrader: (13)

Simple - but expensive - sloution... Go Simtek!