View Full Version : DCOE Carbs - A few questions
My twin 40s arrived today. I'm really chuffed with them and cant wait to get them fitted, but I've been wondering about what filter(s) to get for them.
I've been looking into getting a pipercross PX600 dome filter, mainly because it seems like good value for money and my local rally shop sells them so I won't need to pay for delivery.
Does anybody know if this filter will fit in my car without cutting out the fire wall? The externel height of the smallest dome filter they do is 90mm. I've measured up behind the engine and the numbers say it should fit (just), but we all know life isn't usually that simple.
Any help appreciated.
And here's a pic of my new toys :D
http://i40.photobucket.com/albums/e230/Miko_Gethinsky/DSC00068.jpg
Tbh it shoyuld fit on. As ive seen a few T40'd nova's with the big pipercross filters on and they fit fine like
andymac
01-09-06, 05:48 PM
i wouldnt use foam filters as i have herd of carbs spitting flames out and setting them on fire
i wouldnt use foam filters as i have herd of carbs spitting flames out and setting them on fire
Lol we managed to do that to a single carb on an old fiat at college, timing was well out, my mate was leant over it at the time, it was a short burst of flame, singed all of his hair and eyebrows, good thing there was a hair and buety course round the corner!
The carbs will spit back , you'd be unlucky to set something on fire, but obviously more of a chance with things like Socks or a foam element.
You can buy 2 slimline K&N filters, that fit comfortably ! They're still cotton. but it's not anything to worry about.
(it's a 1600, but same amount of room)
http://img.photobucket.com/albums/v626/j829nick/IMG_2226.jpg
where did you get the k&n filters from?? they look good wanna get a set for mine when there finished being rebuilt
Nick,
What height filters are they?
K&N bolt ons have always been my second choice due to the fact that I have to buy two and that is a little more expensive than the PX600. I run a K&N on my current DMTL and am very pleased with it's performance so would have no worries running them on DCOEs.
I think maybe my best plan would be to get the smallest (45mm) filters, run them for a while and see where I can go from there.
Thanks for your help guys.
Bassboy
decwasere
02-09-06, 11:29 AM
The carbs will spit back , you'd be unlucky to set something on fire, but obviously more of a chance with things like Socks or a foam element.
You can buy 2 slimline K&N filters, that fit comfortably ! They're still cotton. but it's not anything to worry about.
(it's a 1600, but same amount of room)
http://img.photobucket.com/albums/v626/j829nick/IMG_2226.jpg
I'd stay away from filter's like that.
Notice, one of the filter's are rubbing on a coolant pipe leading to the heater matrix. That could lead to a bit of disaster.
Go for a set of trumpets and sock filters that will not rub on the coolant pipe.
i was thinking of getting bolt on k&n's for mine, but then thought about socks, am unsure now! lol
I'd stay away from filter's like that.
Notice, one of the filter's are rubbing on a coolant pipe leading to the heater matrix. That could lead to a bit of disaster.
Go for a set of trumpets and sock filters that will not rub on the coolant pipe.
Erm, nope it isn't "rubbing" , and it wouldn't cause a disaster if it was
They are 44mm (IIRC)..
I wouldn't go for socks, after all the opinions i've had they're by far the most restrictive. "go for trumpets and socks"... you should run trumpets regardless.
Well, Countless caterhams run these filters, they're fine for midley tuned engines. And the back-plates create a pulsation effect which is good for highly highly tuned engines.
i was thinking of getting bolt on k&n's for mine, but then thought about socks, am unsure now! lol
At the end of the day, your going to be running them on a 1400SR or something, not a Technology breaking peice of kit.
The type of filter will make very very very little difference, if any at all. Without, and with filters, mine made EXACTLY the same BHP on 2 consecutive runs on an RR.
If anything, i was warded away from Socks, by various people, all of whom own or build/tune older 8v engines, frequently on 40/45's
Just go for an irmscher airbox instead then with a K&N panel filter :thumb:
Look mint, was originally designed to fit in a nova so space isnt a problem
mad-driver
04-09-06, 06:36 PM
only if you have weber carbs though i think, plus what are the chances of stumbling across one now? very slim.
Eurocarb do the filters Nick has, they're about 40 odd quid and do the job, i've just got trumpets on mine at the minute
womble sri
04-09-06, 08:00 PM
i wouldnt use foam filters as i have herd of carbs spitting flames out and setting them on fire
yeah mine done that and i didnt realise untill it sucked a lump of foam in! gutted all i did was take it out but it was not good. just keep your bay plenty clean and run it on the trumpets or you can get these mesh ones from egay get it set up once you have got your filters though because the slightest air flow change can upset your carbs.
Yeah, I saw eurocarb's filters on ebay and was put off by a few minor details.
1). They cost ?40 for 2 filters, there must something up there :wtf:
2). From their eBay advert
Good quality brand new chrome plated steel air filters, the same size as K&N small oval units.
In other words, they aren't K&N, they are cheap immitations! Not worth the paper they are probably made out of.
Anyway, I bought two K&N bolt-on filters for ?85 at Peter Lloyd Rallying on my way from work today. Almost bought a facet fuel pump too but decided to wait until next payday.
:Bank manager sighs with relief:
because the slightest air flow change can upset your carbs.
:roll: . When the car is setup on a r/r the filters are off when they check the balance etc, and get replaced when the final verdict has been reached. They are not left on during the tune up. next you'll be telling us they knock out of tune really really easy and are very bad on fuel etc lol
Nick summed it up perfectly and i fully back up his results. Trumpet size is only needed at 16mm, with this small size you can get a filter ideal for the nova bay with the firewall still in place, or if this is removed you have the scope to go slightly bigger, here's a pic of my old gte bay and small 'nova' filter and my present bay with larger filter
http://www2.novaload.net/files/dan/engine1.jpg
http://www2.novaload.net/files/dan/fil2.jpg
This whole trumpets only thing seems daft to me. It only takes one little stone to get kicked up into the bay and sucked in by the carbs to destroy an engine and set you back ?100s, maybe even ?1000s when you get as far as Dan. Spend about ?90 on some filters and there's no problem.
Talking to the guys at fast road cars, the trumpets won't make much difference at the kind of power we run. Although they did stress that if I am going to run filters, 19mm between the thrumpet and the inside of the filter is a bare minimum. So with 45mm K&Ns and 16mm trumpets I am happy that I am well beyond that (that's 29mm for the mathematically challenged).
^ RUN TRUMPETS, underneath the filters. only a fool would permanently run trumpets only; on a daily driver ! Fair enough on a hill-climb or sprint car. but as you said, it's a bit risky !
Infact, i'd not seen a filter like dan's up untill now ! i'd only seen the HUGE piper-x boxes, that would barely fit.
Your trumpets are pretty much identical to mine.
On a stupidly tuned engine, i.e more than what me and Dan run (and we both run reasonably well tuned lumps) the length/size/shape or trumpet will make a difference, also which filters you use.. but that's so that you can squeeze the last extra 1/2hp, or get that tiny weeny bit more torque , which will give you an "edge" over competitors. but as you've realised, it's completly fcuking pointless on a 1300sr with a kent cam !
Just realised you've got the filters ! Hope it all goes well !
get them on, and get them Set-up ASAP, i made 25hp just by having the carbs set-up. Also the K&N elements are Cotton based. When the carbs run under full load you'l get misting appearing outside the trumpets (cool to watch on the RR - Just like what happens when they test F1 engines) so your filters will get doused in fuel internally.. Fuel + Cotton based elements = hmmmmmmmm.
it's perfectly fine once they're set-up, as they shouldn't Bark/spit. Mine do very occasioanlly, but Pre RR, it sounded like i had left a socket in my bottom end !
Also, loctite the K&N bolts in, they're fiddely to do, and get tight !
and finally, dan will probably disagree with this... but if your runing it off the Mech Fuel pump, and your on a budget. it'l run fine without a electronic pump, or even a fuel Pressure regulator !
Mine made absolutly perfect power + torque curves, with no Pressure reg. I am going to fit one, but it's not a neccesity for a cheaper set-up likes yours !
womble sri
04-09-06, 11:33 PM
i figured that gas flow would make all the difference my car was setup with the filters on and i seem to remember pete saying it would affect the perfomance but not drastically. mine was like that and gained 28 ponys when it had been tuned and rejetted i ran mine without trumpets but tried to avoid driving in the rain and did always TRY and take care through dusty lanes ect think it is definetly best to use filters for instance if you look at the state of the filters after a few thousand miles youll be pleased to see the crap you have stopped gettin into your engine my bad!
the effect is insignificant !
what power did you make, just out of interest ?
johnnynova
06-09-06, 12:26 AM
dont bother with filters unless you are driving around a dirt track all day, even then....
i have had my 40's for over a year now and done a good 2500-3000 miles on them, with no filters through a manor of roads/conditions.
I wouldnt want to do aything thing to them which would interfer with the beautiful sound they make! ;-)
they are the dogs!
end of the day its personal preference. You spend all that money tuning the car, then take a risk due to being to tight to get a 60 quid filter that wont affect performance or muffle the sound at all. I have always ran one and always will, but then my engine has covered just over 50k miles on carbs.
womble sri
06-09-06, 09:21 PM
dan that is quality your engine must have been well built mine is hust a cheap(ish) load of bits that i slapped together until i can afford to convert all the bits to a 1600 which hopefully will be complete by next year i only built my sr this christmas. nick if you were reffering to me about the power i slapped the sri head on after hving it skimmed, a 300 cam with the followers springs and lifters pulley and a pair of dellortos whoch havbe seen better days. on the rr before any fetting it put out 96 then around 115 then after a lot of tiny adjustments to the pulley dizzy and carbs it made 125 apparently the rollers are oout its the same bloke who set up jim kellys nova, Peter baldwin, i wasnt really bothered about the figure it was so quick nearing in mind it was all on an 80k sr with no work i was impressed then i hit my manifold on some stupid things in a car park and it blew like a bitch and really lost power it was very noticeable so i bought an ashley system and manifold and the car ran ropey as fook so after another trip to the rr it put out 134 which was good enough for me the rollers are however from ww1 but the power increase was immens. hence why also thought taht filteres would effect the balance due to the effect on my car when the flow was altered.
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