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Air Box & Induction Ideas
ditchlewis - 11/4/08 at 07:32 AM

Hi Guys

I’ve been thinking (Bad Idea it always costs), about the induction system I intend to build.

I am going to build an air box with a removable top (obviously so I can fit it) with a spigot to take a filter or ducting. Unfortunately due to space issues I need to fit the spigot to the rear of the box.

I have come up with two solution and would like to know what you all think, and if you see any problems.

The easiest solution is just to fit a cone filter to the air box. The problem I see with this is that the filter will be drawing in hot air from the engine bay. I have a bec bonnet with the Air scoop on it and I done foresee the engine bay getting excessively hot.

The second option is to fit a canister filter to a support bracket I fitted some time ago and run ducting to the air box and than out through the side of the car. The flange brackets shown come as a pair, the first will be used with out mesh as the flange to the air box, whilst the other would be used with mesh to collect air from outside the car.

The only problem is that the canister filter has no bhp rating and I don’t know if this will restrict the air flow to my engine.

Looking at the burtons catalogue the diameter of the filter/ opening limits the power.
60mm 120 bhp
70mm 150 bhp
75mm 170 bhp
80mm 190 bhp

The engine I bought was rated at 165 bhp so the 75mm is pushing the boundaries. So do any of you know where I can buy bigger flanges?

Any comments and advice eagerly awaited.

ditch Rescued attachment Induction option 2.JPG
Rescued attachment Induction option 2.JPG


ditchlewis - 11/4/08 at 07:33 AM

option 2

ditch Rescued attachment airbox 2.JPG
Rescued attachment airbox 2.JPG


ditchlewis - 11/4/08 at 07:34 AM

A better idea of option 1

Ditch Rescued attachment airbox 1.JPG
Rescued attachment airbox 1.JPG


Howlor - 11/4/08 at 07:40 AM

Be careful with the side panel option, if it sets up a venturi effect then it will suck air out of the engine. Point it forwards to the front of the car alongside the rad if possible then you get a degree of ram air.

steve


ditchlewis - 11/4/08 at 07:52 AM



thanks for that i did not know about venturi effect. the problem i have at the front is space to get anything over the rad.

the side panels stop just behind the front suspension, would this be a good place to fit a bracket inside the car facing forward and connect the hose to that?

ditch


Eggy - 11/4/08 at 07:58 AM

I've had a go at this - feel free to look in my archive - I can't seem to get pictures to post on here??

(I will get round to putting some more pictures in there!)


ditchlewis - 11/4/08 at 08:24 AM



a lot better than i can manage very professional looking.

i think my rad sits a little higher than yours and so the gap at the top is much less

I've found 100mm flanges in B & Q online for use with tumble dryers.

maybe a hybrid is on the way a cone fliter fixed at the front and fed buy convoluted ducting.

ditch


coozer - 11/4/08 at 08:41 AM

Click on my blog below, I have just uploaded a picture of my homemade (rubbish) airbox, made out of an old washing machine.

Designed to fit under the bonnet it is connected to a canister air filter affair (CBS £40) it will have a hose going to the front to collect cold air and hopefully a positive pressure as well. It took AGES to make it


ditchlewis - 11/4/08 at 08:49 AM

Looks Good

the CBS filter is the one i was looking at, does it have 75mm Inside Diameter openings?

what do you think of it's quality?

ditch


coozer - 11/4/08 at 08:56 AM

The filter is a nice bit of kit, looks really nice (bling!) well worth £40 when you look at the price a BMC unit for example.

It comes with adapters, hose clips and does have 3" diameter ins and outs.


Eggy - 11/4/08 at 09:52 AM

quote:
Originally posted by ditchlewis


a lot better than i can manage very professional looking.

i think my rad sits a little higher than yours and so the gap at the top is much less

I've found 100mm flanges in B & Q online for use with tumble dryers.

maybe a hybrid is on the way a cone fliter fixed at the front and fed buy convoluted ducting.

ditch


Thanks, it turned out better than I had hoped and that's the first time I've picked up a TIG torch! (Thankfully my younger brother works at a sheet metal fabrication place so the material was FOC) cool:

It seems to run ok but it's not been on the rollers yet


Howlor - 11/4/08 at 10:03 AM

Heres what I did.

Steve Rescued attachment Ad engine 2.jpg
Rescued attachment Ad engine 2.jpg


ditchlewis - 11/4/08 at 10:08 AM

Ooooh

what size filter is that? (inlet and out let)

where did you get it, it does not look that locost

coozer it looks good and is about the right size and price. and if burtons is correct the 75mm should be enough for the engine.

ditch

[Edited on 11/4/08 by ditchlewis]


Howlor - 11/4/08 at 10:16 AM

Filter off ebay - £20, Carbon exhaust can off a KTM I think £13 off ebay, clamps alu from ebay US £15, I thinks I got the duct off ebay per metre and it was £20.

Steve


Howlor - 11/4/08 at 10:16 AM

Filter was 100mm IIRC.

Steve


Howlor - 11/4/08 at 10:19 AM

Ebay link for duct. Try this


ditchlewis - 11/4/08 at 10:23 AM



many thanks steve true locost with a hicost look

i'm at work and cant access ebay here will do it when i get home.

ditch


coozer - 11/4/08 at 10:45 AM

Sorry forgot to say the filter canister comes with 1m of duct as well.


Steve

[Edited on 11/4/08 by coozer]


Jos Fury - 11/4/08 at 11:18 AM

I have made an airbox too with remote filter for my gsxr throttle bodies. I used a green air filter etc. At this moment I am not going to use it though. I wanted to duct the air from the front of the car too, hose going alongside of the radiotor. If it is of any use just let me know.









the flange on the airbox is 80mm if I am not mistaking.


bimbleuk - 11/4/08 at 11:43 AM

I used most of the bits you have listed in option 2 to do mine. If you ignore the Rotrex supercharger and imagine the ducting curving up to an inlet plenum then that'll be option 2!

I've since fitted a shield to stop the wheel flicking stones and water in the inlet.

Filter side panel inlet
Filter side panel inlet


ditchlewis - 11/4/08 at 11:43 AM

many thanks for the offer. I'm running twin dellorto 45's on a pinto so it wont fit i'm affraid.

I'm getting depressed now, there is so much talent on this site it makes my feeble attempts at fabrication look poor

well practice makes perfect and i may have a good looking car in about 20 years

ditch


ditchlewis - 11/4/08 at 11:49 AM

bimbleuk what a star:

does it all work well???:

you obviously don't get a venturi effect?

that ingestion of water and cr*p into the filter was always a concern. i planned to put the intake as far forward / parallel with the wheel.

ditch


bimbleuk - 11/4/08 at 11:52 AM

Just takes a bit of time and patience to do a tidy job sometimes!

Here's how I fitted the filter temporarily to run the engine up on a rolling road prior to the Rotrex fitment. The small side vent in the picture is now at least 4 times bigger and shields the inlet opening as well.


[img][/img]


ditchlewis - 11/4/08 at 01:18 PM



superb looking car

i think i will go with option 2 and carefully look at the position of the air intake.

having looked at the standard of cars i'm in awe of the skills you all have and wonder how i managed to get mine built and through the SVA.

it's not bad and i have seen worse but your cars look like show cars.



ditch


mark chandler - 11/4/08 at 01:31 PM

and mine ! not a show car.

Biggest cone filter for £5 off Ebay in front of the radiator, 3" waste pipe to engine and an old turbo right angle bit of hose. Rescued attachment Inlet_plenum_Front_small.jpg
Rescued attachment Inlet_plenum_Front_small.jpg