DIY Short Ram Air Intake (The Heath Robinson Method)

Ok, so this should have been a comprehensive and simple guide. However it's going to be more an example of how to bodge a short ram intake as opposed to one cleanly and nicely :lol: .

So at the weekend I took the air box and measured up. I'd taken a measurement of 70mm apparently of the air intake pipe. So I ordered a K&N filter with a hole of 70mm and piece of 70mm metal pipe to act as a go between to the rubber hose of the existing air intake pipe.

So it all arrived today:



I quickly set about putting the components together. I had the K&N filter, a heat shield and a metal pipe. It was shaping up very nicely.





Then I went to the car and took the airbox out. It's simply two screws that are easy to get to. One is visible in this picture. It's at the end of the fusebox and is clearly attached to the airbox. Simples.



The other is down low by the bottom of the batter near the positive end of the batter.



Which left me with this:



I took the little wire spring thing off the end of the intake hose, popped a hose clamp on, went to bung the metal pipe into the intake hose and it swallowed it up :unsure: . Turns out the hole I measured to be 70mm was 80mm. Major "D'oh" moment!

So I go back inside and sulk. But then the old grey matter starts thinking...

Ok, so after I'd sulked a little I first considered returning the filter and other parts for a refund/exchange. But K&N don't do an 80mm holed filter. They do an 79mm . But I realised that its dimensions were too big and wouldn't fit inside the heat shield. I actually had about the biggest filter I could given the heat shield I was using and wanted to keep using.

So the filter and heat shield were keepers. Maybe a downsizer piece of pipe to go from 80mm to 70mm would be better. Indeed it would but their like £17 on eBay . I've already spent a reasonable amount and also want to fit the filter now .

I measured things up and realised that the outer diameter of the K&N mounting hole was almost 80mm. I just needed to reinforce the rubber of the mounting hole some how. Cue the 70mm piece of pipe .



I cut a short piece off the pipe, filed the sharp edges off, washed it thoroughly and dried it (don't want any metal shavings or water residue finding there way into the engine).



I then I squeeze this piece of pipe into the K&N's hole.



I now have a K&N filter with a solid mounting piece of about 79mm diameter to put in my 80mm rubber hole, which with the aid of a hose clamp should lock things down nicely.

First of all I couldn't mount the heat shield properly as intended as it simply isn't big enough to go over the outside of the Accord's rubber intake tube at the filter clamping position. So I slid it down the pipe a little, left it loose so I could twist it round and work around it. I clamped the filter on good and tight. Then I slid the heat shield into place and realised I didn't have a sufficiently big enough hose clamp left . I zip tied it for this evening and will pick up a hose clamp first thing tomorrow.





Haven't had a proper drive yet so will report later, but did take it round the block. It felt and sounded nice and could drive at ridiculously low revs thanks to the increased flow. Will obviously give a more thorough performance review in a few days.

Great write up Steve a well deserved rep point there mate and it looks very good indeed.
When you fit the extra intake duct let me no mate as it looks like yours will be done before mine.
Im thinking about taking the front bumper off and taking out the resonator.This will free up the hole where the stock tube comes through and then find a suitable place for the other end.

Nice one Steve! Hope this inspires more of us to get it done too.

brett said:

Great write up Steve a well deserved rep point there mate and it looks very good indeed.
When you fit the extra intake duct let me no mate as it looks like yours will be done before mine.
Im thinking about taking the front bumper off and taking out the resonator.This will free up the hole where the stock tube comes through and then find a suitable place for the other end.

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Cheers Brett, I was thinking similar things regards the resonator but don't know if I can be bothered :lol: . I may find some time tomorrow or over the next couple of days to mount the tube. Obviously, I will add pics etc.

As for anyone else thinking of doing this, I don't actually recommend you do it the same as me. My method was a bodge because I messed up my measurements.

But, I found this place for various things like the tubes and heat shield. They're cheap and have great customer service.

As for the K&N filter, I ordered this filter and to be honest, it's about as big a filter as you could mount in the heat shield I brought. But just do some measuring for yourself as clearly mine ins't up to the job :lol: . If you do get a filter like mine, I'd suggest just buying a 80-70mm piece of downsizer pipe. to go between the Accord's hose and the K&N Filter. I don't think it would really have much of a noticeable impact on flow rates.

Steve, now you have completed the job, my concern is how you attach the accord hose to KN filter, what is the best method?

ok, re reading this again, the KN filter was 70mm, the honda pipe was 80mm. ( am I correct so far) So the silicon pipe of 80>70 would fit over the top of the honda pipe and need clamping down and then it would fit over the kn filter inlet rim? thats all I need to know and I am good to go

Very nice pal and great writeup. Bet it does sound good though.
Do report back mate.

Is there a simple ECU reset procedure for the 7G? If so, may be worth doing, so the ECU can learn the new set up quicker and get the most from it. It will learn in time, but on the 6G, everyone resets the ECU each time they fettle with something.

I reset the ECU with the Honda Diagnostic System on my brother's after fitting his Typhoon kit, I guess you could disconnect the battery for a few hours.

Good writeup Steve B)

A short-ram should give y ou very good low end power, but you'll loose a bit in high revs. Hope I'm wrong.

Cheers Guys.

Simon, the silicone hoses aren't rigid enough to clamp to, you'll be clamping rubber to rubber and it will just fold up and warp. You will need a piece of metal piping.

Option 1: get a filter with an 79mm fitment (there's no 80mm fitment option with the K&N) and an 80mm pipe - but seriously check the space you've got to work in. I don't think a much bigger filter could fit in the space there is and the 79mm options are all quite a bit bigger than the one I've got. Also, if you're going to go the heat shield route like I did, you really can't go any larger than my filter.

Option 2: get a filter like mine with a 70mm fitment then get a piece of metal downsize/upsize the goes from 80mm to 70mm. I think I'm going to buy one and replace my heath robinson effort soon, just for piece of mind.

Shabz, I've only collected the Mrs from work and driven round the corner in it so far. But yes it sounds lovely. When in a high gear at very low revs it positively gurgles and you feel it in your chest. I shall take it out on a dual carriageway tomorrow and spank the VTEC and report back .

F6had, do you seriously recommend I reset the ECU? If so, how long should I disconnect the battery for? Is it that simple?

Joooe, I think you're right mate. I shall go google it now, but I vaguely remember reading something along those lines. Quite honestly I'd rather have more power in the low end. I'm on a little mission to become the TA Petrol Pin Up Boy For Good Mileage :lol: so more power in the low revs suits me just fine. I'm determined to one day reach 500 miles on a tank of regular Sainsbury's petrol, exactly double of my worst ever tank of 250 miles :lol: .

Steve it'll learn anyway but resetting it might be a good idea anyway.. leave it off overnight to be sure.

F6HAD said:

Steve it'll learn anyway but resetting it might be a good idea anyway.. leave it off overnight to be sure.

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Cheer mate, I shall do that now.

cheers steve will do ( ps my name is Rob lol) :lol:

whereami said:

cheers steve will do ( ps my name is Rob lol) :lol:

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:lol: :blush: Sorry Rob

Ok, hose clamp on the heat shield to replace the temporary zip ties.



Still not had chance to spank it yet and now the car's in the garage for some bushes and the tracking. But I will hopefully spank her this afternoon once I have the car back. Then I will report back on the filter mod.

Give her a good run down the Hailsham bypass, good bit of road that so long as the federalés aren't hiding up on the bridges the dual carriageway past Shinewater leading up to the bypass isn't too bad either I always go in and out of Eastbourne that way so I can give it some in VTEC lol

Ok, well I've just got back from proper drive. No stereo, no air con, window open half the time, closed the other half the time for listening pleasure and comparison. Just nice driving pleasure. So what's the difference with this DIY short ram?

Performance wise it feels smoother under acceleration across the revs. It also seems to accelerate a little quicker on the whole too. Gets up to the red line a little quicker. It's undoubtedly an improvement on the stock intake as far as performance is concerned, especially in the lower revs. Nothing major obviously, but a result!

Also, it doesn't feel like a modded performance car (which for me is a good thing), but just more like you'd expect a 2.4 petrol to feel and deliver the power. It's also more responsive in the lower revs. You can keep the gear high and revs extremely low, which is great for potential fuel consumption. Where the engine used to feel like it was going to stall, it will now just keep gently pulling you along. So performance wise, the car feels better.

Sound wise, it is simply and obviously (as it's the air intake) directly linked how much you open the throttle. So very gentle normal round town driving it's almost the same as before, just a touch deeper and smoother sounding. You occasionally hear it deep grunt when in a high gear at very low speeds and touch the throttle. Which in my opinion is a nice reminder of the pretty new filter you've added to your pride and joy. But on the whole the gentle and quiet driving remaining quiet is great as it keeps it civilised, especially as I spend a lot of time driving the Mrs and boy around.

Spanking it, frankly, is AWESOME!!! . It bellows with a chest shaking deep tone. But it's still smooth, civilised and deep, nothing whiny or boy racer sounding, which I guess is because of the larger, naturally aspirated engine size. I'd imagine a smaller engine would whine more. My first comparative thought was not of another car, but like the car equivalent of Paul Robeson's singing voice :lol: . Seriously deep, but mighty fine .

But on a serious note, the increase in noise might not be to everyone's taste. When you floor it, it is deep and loud (I liked it though ). But what is very important to stress is that the engine talks to you more. Ok, it's a little louder and deeper, but you feel much more engaged with your drive, like the car is talking you through every gear change and every feathering of the accelerator.

Now, regards my bodge job. I've spent too much £££ on the car this month with a few garage visits and this mod, but next month will get a proper 80mm to 700mm metal pipe made up, fit it and obviously take some more pictures. Partly for peace of mind regards the fitment at present and partly just for a tidier looking job. Also, I want to mount this feeder pipe somewhere, but have no idea where I'll mount it yet. It's looking ominously like a bumper off job .

I hope this has been helpful to people unsure about whether or not to do this. As far as I see it, providing you don't mind a little more engine noise it's an all round improvement in driving experience, cost less than a tank of fuel and will get you from the order window to the collection window at KFC just that little bit quicker . Game on!

Good job buddy, the VTEC will really sing now! As for the cold air feed, whip the bumper off, rip the resonator box out and you'll find a path easy to take a feed from the centre bumper grill right up to the filter B)

Nice response writeup pal. Really impressed with the quality of install. after hearing Fahads brothers car it sounded so amazing and the roar was nice.
I remember on my bros civic I had to reset the Ecu as it would not idle properly. Disconnected the battery for 30 mins and all was well and has been fine ever since.
Items like these really need an Ecu reset after being installed. You'll get the full potential then.

Great write up steve im glad you like it expecily the rore lol

Cheers Guys. I actually clean forgot to do the battery thing, but will sort that this evening. I will have a crack at the cold air feed next monday when the Mrs is at work and the boy is in Nursery and write up that too with pictures.

Stevearcade said:

Cheers Guys. I actually clean forgot to do the battery thing, but will sort that this evening. I will have a crack at the cold air feed next monday when the Mrs is at work and the boy is in Nursery and write up that too with pictures.

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Steve as you might no my car is at HH this week for a few warranty claims.So i rang Steve yesterday and asked them to take out the resonator for me
This involves the front bumper to come off so it saves me a lot of work and it frees up more options for my cold air feed.

Result! I had the front bumper off on mine a little while ago for a headlamp fix. It's relatively straight forward and provided it stops peeing down I'll get and get stuck in on it. If you manage to get yours done first though, please stick some pictures up, as I imagine our engine bays are pretty similar really.

Stevearcade said:

Result! I had the front bumper off on mine a little while ago for a headlamp fix. It's relatively straight forward and provided it stops peeing down I'll get and get stuck in on it. If you manage to get yours done first though, please stick some pictures up, as I imagine our engine bays are pretty similar really.

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Will do mate but im going to be flat out this weekend so you might beat me to it :lol:

steve, i must ask, you are going to add a 80mm- 700mm pipe, BL00DY BIG, You sourcing the part from AIRBUS :lol: :lol: :lol:

Well, the stock inlet hose is 80mm, which is pretty awesome really. But then it is a Honda, so stock should be pretty good anyway . The 80mm fitment K&N's I think are all too big or the wrong shape to fit quite right in the space where the airbox once was. They certainly won't fit within that style of heat shield I bought. And I think the heat shield's a must. I've read things about the drawbacks of running these types of filters within the warm air of the engine bay. In fact without the right shielding I've read they can provide an overall drop in power over the stock air box.

So for ease of sourcing parts etc, I reckon a K&N with 70mm fitment stepped up to the 80mm inlet is game on. Lots of nice breathing for the K24 .

Some considerations for heat shielding if you want to put a bigger filter in could be maybe cutting a sheet of aluminium to size, to completely cover the whole area where the filter is and then cover it in the type of heat proof stuff used in kitchen fittings etc. You know the flexible adhesive stuff they mount around cookers and stuff. Put extra cold air feeds in and game on. Something for future tinkering perhaps.

Sounds good mate, impressed to see what can be done with just a few parts and a bit of ingenuity I need to get a heat shield sorted in the lude myself as it's just drawing warm air at the moment.

Have you had any ideas for a cold air feed yet? I found it difficult to find the space behind the from bumper on my 6th Gen, the slam panel and radiator surround made it hard to get a nice bend in the pipe leading to the filter, it always kinked. I'm kinda tempted to bore a hole in the side of my bumper and mount a feed there :lol:

I had a quick look the other evening and was shocked at how little space there is in the bay actually. The only clear way through was into the front passenger wheel arch, but I wasn't sure about heat from the brakes and possible water spray being chucked up their in the rain, so have ruled that out. The radiator is massive man , definitely no easy way around that. But I've seen in other cold air intake threads that there should be space in front of the wheel behind the bumper, as that's where they were mounting their filters. I don't have the money for that kind of proper pipe work and I don't have the balls to go putting my filter that close to the ground, but I have a fairly rigid, cheap as chips flexible pipe and will fashion something. in that area I reckon. Just waiting for some down time without hassle from the Mrs and the boy to get the bumper off and get stuck in .