DCOE Carbs - A few questions

[Nick]

i was thinking of getting bolt on k&n's for mine, but then thought about socks, am unsure now!

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

[Mike]

Just go for an irmscher airbox instead then with a K&N panel filter

Look mint, was originally designed to fit in a nova so space isnt a problem

[mad-driver]

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]

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.

[Geth]

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

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:

[Dan]

because the slightest air flow change can upset your carbs.

. 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

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

[Geth]

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).

[Nick]

^ 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 !

[Nick]

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 !

[Nick]

Also, loctite the K&N bolts in, they're fiddely to do, and get tight !