D14A1 Dual Carb cone filter mod

91Hatch · Post by **91Hatch** » Sat Sep 25, 2010 12:08 pm

Hey guys, got idle hands this mornin so decided to whip off the standard airfilter/hosing/induction pipe. Gunna pop down to the shop to look for 2 cone filters... Just a quick question as I am 1/5 mechanic skill level..
Is the pipe coming from the head the only one I need to put a breather on the end of? Can I "tape up" the inch wide one coming from the manifold cover (heat wrapped) or even just point it towards the bumper for its own air feed? and do away with the tiny black one as well? (bout 5 mm)
Also im going to run some ducting for some cold air!

Advice greatfully received as always!

HONDAB88 · Post by **HONDAB88** » Sat Sep 25, 2010 12:19 pm

yep breather filter for the pipe on the rocker cover or you can make up a custom breather box for it, the heatwrapped pipe to the mani heatshield can be dumped. have a read through the engine / help sections a few of the lads here have done this mod

91Hatch · Post by **91Hatch** » Sat Sep 25, 2010 3:34 pm

AAAAGH! Spent all day driving round trying to find a couple of cone filters to fit, epic fail. One bloke said something about ordering a specialist ram type set up instead of just a couple of filters...not quite sure what hes goin on about... oh well, back on goes the old filter, at least I can remove that silly air flow thing inside the filter housing while its off!
Cheers for the info anyway dude

mattj · Post by **mattj** » Sat Sep 25, 2010 3:39 pm

I'm running mine open mate, just got the little oem sieve type metal mesh on for now.

91Hatch · Post by **91Hatch** » Sat Sep 25, 2010 3:43 pm

Sweet music to my ears mate! how does that run? it wud be my first mod, everything else is standard as of yet... perhaps wrapping some ladies tights(clean!) around the mesh guards wud do ok for now then, to be sure?

joe f · Post by **joe f** » Sat Sep 25, 2010 4:10 pm

mattj wrote:I'm running mine open mate, just got the little oem sieve type metal mesh on for now.

Brave man!
Haha I'm too scared to run open filters, to many tractors and S*!t covered roads round here.

My airbox is just drilled to feck, more holes than metal. And I cut off the whole intake thing (drilled out spot welds where it mounts).

91Hatch · Post by **91Hatch** » Sat Sep 25, 2010 4:53 pm

Sorted just stretched a bit of tights behind the mesh covers and bolted em up! The sound is really noticable at top end, sounds really good actually! Cant wait to get it sorted permanent tho and couple it with a nice exhaust. Have a good saturday lads! if playing in Bury in my band 2nite, the 4g is awesome for fitting drum kits in!

mattj · Post by **mattj** » Sat Sep 25, 2010 5:38 pm

runs fine, doesnt have any problems starting either. Think i may have to put the air box back on for winter tho, i'll see if i have any issues. Roads are pretty good up here to be honest, lots of industry back in the days means most of our road network is dual carriage way a roads, all well maintained.

Has a brilliant intake noise, can here the carbs sucking air in, sounds alot like my turbo on the rst actually lol. Has a pretty good growl after 5k, sounds like barry white chewing wasps.

Oldskool J-EDM · Post by **Oldskool J-EDM** » Sun Sep 26, 2010 1:09 pm

91Hatch wrote: the 4g is awesome for fitting drum kits in!

x2

....although it does get tricky with C-pillar and rear strutbraces, subs and amps

With regard to the breather on the rocker cover.....it is for your PCV system:

Oldskool J-EDM wrote:Vents positive crankcase pressure from the head and sump area. This helps to prevent pressurised gases blowing the sump off or knackering seals.....and generally stopping oil leaks. The PCV is a way of maintaining a constant 'lower than ambient' air pressure from within the head/block relative to RPM, which in turn helps to eject the unwanted gases. These gases then should be re-routed/recycled back into the air intake system to help lower emissions and obviously allow for the constant 'lower than ambient air pressure' to be maintained. A simple filter on the PCV exit spout from the head is not going to maintain this required low pressure (i.e. it's not going to 'suck' the gases out)....and is therefore not recommended.....I have also heard that this can result in an MOT failure...although not sure how true this is.

Incidently, a baffled oil catch tank (fitted between the PCV vent and air intake point) is designed to condense the oil from the gases and hence collect it in the tank rather than reintroduce the oil laiden gases back into the air intake...theoretically allowing for a more oxygen rich/pollutant free intake system.

IMO....I would keep the original airbox, drop in a K&N filter and drill holes around the outer edge of the case to let more air in. Running without an airbox can play havoc with your AFR's and knacker your emissions and generally loose low-end torque....plus you will have the PCV issue. Anyone running without a filter is prone to scoring the cylinder walls, killing the piston rings, clogging carbs, etc...generally not good practice.

Rams/trumpets/velocity stacks fitted to bike carbs in this example.......these will allow cylindrical foam filters to be simply pushed over the top. Have a look for Harley Davidson and Honda Blackbird parts....some are direct bolt-on to OEM GL Keihin carbs

The heat wrapped pipe that comes from the manifold is to send heat from the manifold upto the dashpot on the intake pipe. The pot opens to allow warm(er) air into the intake upon intitial/cold startup to allow better atomisation of fuel & better running when in cold, damp conditions. It is ok to remove this pipe from the manifold...but be aware that the engine is likely to run quite rough, even stall in the aforementioned conditions....but all will be good when the engine is upto temperature.

jonny f · Post by **jonny f** » Sun Sep 26, 2010 1:37 pm

+1 to the above!

Just do what joe did. I have a nice big book on engine tuning (david vizard, mini related) and of the worse things you could possibly fit in front of your carb or intake is mesh or tights! Although it may not look restrictive, it certainly is.

Just remove the orginal mesh, run a uprated panel filter and drill your airbox.

91Hatch · Post by **91Hatch** » Sun Sep 26, 2010 9:32 pm

Cheers for the replys guys, I shall stick the old filter back on tommorrow!
My impatient actions are going to land me in bother one of these days!

Oldskool J-EDM · Post by **Oldskool J-EDM** » Sun Sep 26, 2010 11:11 pm

No probs....now order one of these:

http://www.knfilters.com/search/product ... rod=E-9071

91Hatch · Post by **91Hatch** » Mon Sep 27, 2010 7:30 pm

Another quick question, how do those sock and trumpet things work, as it seems the 'sock' just wraps round the trumpet, which appears to just be a hole with nothing inside....??

Like this one http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT

Oldskool J-EDM · Post by **Oldskool J-EDM** » Mon Sep 27, 2010 8:41 pm

They are just filters that stretch over the top of the trumpets.
The idea behind trumpet design is to achieve a better control of the air mass moving into the engine and the speed increased by Venturi effect. It also can utilise standing wave resonances inside the intake columns and trumpets to achieve a very mild 'supercharging' effect.....inlet and trumpet lengths tuned to the harmonic length of the resonance frequency (at apprx.peak power) in that inlet can enhance cylinder filling.

rasta4life · Post by **rasta4life** » Tue May 10, 2011 8:38 am

hello guys what size trumpet and filter fits the da14 ? help anyone !!!

4GUK

D14A1 Dual Carb cone filter mod

D14A1 Dual Carb cone filter mod

Re: D14A1 Dual Carb cone filter mod