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Discussion Starter · #1 ·
Hello everyone,

This is my first post since my membership back in October so bear with me.

I recently bought a used (only slightly) ST airbox from Ebay for £9.50 (thank you whoever decided to buy a Dreamscience Induction kit by the way).
Now I've seen how the ECU spacer works, obviously creating a larger gap between the ECU and the intake cowl increases airflow and therefore throttle response. The only thing I'm not so keen on it the fact that with the ECU spacer on, you can no longer put the cover back over the top of the ECU.

So my project is to keep the airbox looking stock on the outside and change how it works on the inside. So I've removed the intake cowl from inside the box and cut the tubing back a little towards the MAF housing.

So do you think this is going to work, or am I barking up the wrong tree?

You can see from the image below, that there is now a massive gap between the tube and where the ECU will sit. Is this going to keep the ECU cool enough?
I cut the tubing back to the height of the back of the airbox, so that the air wasn't hitting a flat surface.
How does the K&N Gen II keep the ECU cool?


You can see here that I've also removed 2 x 30mm tabs that were sticking up inside the airbox to increase air flow.


The intake cowl has a upper and lower clip inside the tubing itself, using a long thin flat-head screw driver you can pop it off.


My plan is to put a K&N panel filter into the airbox to aid airflow.

What do you think? Am I just wasting my time?

Cheers guys
 

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QUOTE(Dennis @ 11 Feb 2010, 08:57 PM) <{POST_SNAPBACK}>This may be a mistake as you appear to have cut off the ram pipe
.

I've cut the ram pipe back (not off), so that it's further away from the heatsink of the ECU. Giving it more room to breathe.

QUOTE(stingy @ 11 Feb 2010, 09:14 PM) <{POST_SNAPBACK}>you can still fit the ecu cover with the spacer. theres a how to on here somewhere.


Yeah I found that earlier.


The only thing though is that with a spacer fitted, air still has to go up and over the top of the Cowl through a small gap between the rectangular shaped hole of the ECU and the round intake cowl. Also if the incoming air hits the neck of the cowl, it has to travel to the top before it can enter the intake. With the pipe cut back the air has a path of less resistance.

Correct me if I'm wrong, but I believe the K&N Gen II internally works in the same way. It doesn't have a cowl 1cm away from the base of the ECU does it?

I experimented earlier and hooked a vacuum cleaner (Dyson) up to the MAF side of the airbox using some Gaffa tape. I then blocked the hole where the ECU sits (again using gaffatape). Stuck a K&N panel filter in the airbox and tested the airflow. The vacuum cleaner didn't have any trouble sucking air through at all (obviously, it's a Dyson). I then made a small hole through the Gaffa tape (where the ECU sits) to check whether or not air was flowing there. I licked the tip of my finger
and could feel the air flowing past it rather nicely. So maybe it will work how I think it will.
 

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QUOTE(techieboi @ 11 Feb 2010, 10:25 PM) <{POST_SNAPBACK}>I've cut the ram pipe back (not off), so that it's further away from the heatsink of the ECU. Giving it more room to breathe.

Yeah I found that earlier.


The only thing though is that with a spacer fitted, air still has to go up and over the top of the Cowl through a small gap between the rectangular shaped hole of the ECU and the round intake cowl. Also if the incoming air hits the neck of the cowl, it has to travel to the top before it can enter the intake. With the pipe cut back the air has a path of less resistance.

Correct me if I'm wrong, but I believe the K&N Gen II internally works in the same way. It doesn't have a cowl 1cm away from the base of the ECU does it?

I experimented earlier and hooked a vacuum cleaner (Dyson) up to the MAF side of the airbox using some Gaffa tape. I then blocked the hole where the ECU sits (again using gaffatape). Stuck a K&N panel filter in the airbox and tested the airflow. The vacuum cleaner didn't have any trouble sucking air through at all (obviously, it's a Dyson). I then made a small hole through the Gaffa tape (where the ECU sits) to check whether or not air was flowing there. I licked the tip of my finger
and could feel the air flowing past it rather nicely. So maybe it will work how I think it will.

you go for it mate. cant see there being any problems. ecu will be fine. let us know your results.
 

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Discussion Starter · #7 ·
I think I could possible adapt the Ram pipe to be a bit shorter. If not maybe get hold of and aftermarket air funnel to fit inside the 70mm neck of the remaining pipe.
 

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Ah ha, I think I've found the right tool for the job!

The funnel inside the standard box is too wide (130mm wide at the head) to fit this deep in the airbox, so I need a slightly narrower one.



This should do the trick! 120mm wide at the head, 70mm at the neck and only £7.48
 

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Airbox Modification Update.

I've now fitted an Alloy Air Horn to the intake pipe in the airbox. There is now a 75mm gap between the bottom of the ECU cooling fins and the Air horn.





I need to do a little bit of polishing to get the surface of the horn a little bit smoother, so that the air can flow in with less resistance.

It also needs a proper clean out so that none of the filings get dragged through the intake system into the engine.

Anyone have any other ideas that I could try while I'm at it?

Cheers
 

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I know that opening is where the ECU sits.

Where does the air come in? Can you post a pic of that?

This could be a good mod but how restrictive is the air path from the filter to the trumpet?

PS does the MAF fit inside that, is it not 78mm diameter?
 

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Discussion Starter · #12 ·
No problem, camera batteries about to die!


Air enters the airbox through the bottom left corner (as you probably already know). It then passes through the panel filter and up through the roof of the box to the right. It uses the entire surface area of the Panel Filter as well. See Below.



Then looking through the hole of the ECU you can see the air enters to left. It would normally have to go up and over the top of the intake cowl, passing the heatsink of the ECU, but as you can see there is a lot more space to move.



Cheers
 

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Might still be worth having an ECU spacer as the ecu cooling fins would obstruct air entering through that small channel on the left.

PS does the MAF fit inside that trumpet, is it not 78mm od? Whereas the trumpet is 70mm od?
 

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QUOTE(mitchst @ 15 Feb 2010, 10:16 PM) <{POST_SNAPBACK}>Might still be worth having an ECU spacer as the ecu cooling fins would obstruct air entering through that small channel on the left.

I could move the ECU back, but I think it will take it completely out of the airstream and not cool it enough. Besides there is loads of room in there now, the pictures really don't do it justice. I'm sorry.

QUOTEPS does the MAF fit inside that trumpet, is it not 78mm od? Whereas the trumpet is 70mm od?

The MAF sits beyond the airbox, it is attached to the rear with 2 fixing screws.
 

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QUOTE(techieboi @ 15 Feb 2010, 10:21 PM) <{POST_SNAPBACK}>I could move the ECU back, but I think it will take it completely out of the airstream and not cool it enough. Besides there is loads of room in there now, the pictures really don't do it justice. I'm sorry.
The MAF sits beyond the airbox, it is attached to the rear with 2 fixing screws.

I think the ecu cooling issue is a myth. Look at the RS ecu its not in the airbox nor is it in most CAIS kits.

The MAF have a sleeve on the end after the flange which locates inside the airbox AFAIK.
Take a look at your very first pic. Is the pipe not stepped for the MAF to locate in thus keeping a smooth bore?
 

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Discussion Starter · #17 ·
QUOTE(mitchst @ 15 Feb 2010, 10:29 PM) <{POST_SNAPBACK}>I think the ecu cooling issue is a myth. Look at the RS ecu its not in the airbox nor is it in most CAIS kits.
I believe the RS ECU is cooled by the air flowing through the radiator. The RS ECU cover has a slight air scoop located on the the left hand side to flow a small amount of air. The Lid and Base of the ECU cover also have vents cut into them. Obviously it not being cooled sat in traffic, unless the radiator fan is on. But at least it has some form of dedicated cooling, even if it's just a precaution.

QUOTEThe MAF have a sleeve on the end after the flange which locates inside the airbox AFAIK.
Take a look at your very first pic. Is the pipe not stepped for the MAF to locate in thus keeping a smooth bore?
The stepped part you speak of still exits behind the back lip of the Alloy intake horn. It should flow air smoothly into the MAF as it did with the stock air horn.
 

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Discussion Starter · #20 ·
Of course...

It's still looking a little rough back here I'm afraid. I'm waiting 24hrs for the glue to set completely before I tidy this up and polish the horn.

 
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