rogerguzzi Posted January 20, 2017 Report Share Posted January 20, 2017 Hello All As some of you may know I am in the process of converting my Triumph Spitfire 1500 to EFI (Microsquirt) Well I have built an air box and have 2 x 48mm bore tubes coming out of it down to cold air. I was thinking what air filter to try and fit on the end and was looking a the usual K&M and I came across this article on the nissan site. http://www.nicoclub....oem-filter.html So now I will have a rethink and perhaps make a box to take a CHEAP paper filter? Roger ps how much filter surface area do I need for a 1500cc engine of say 100/120 bhp Or pehaps I can fit one inside the air box? Link to comment Share on other sites More sharing options...
Clive Posted January 20, 2017 Report Share Posted January 20, 2017 Roger, don't forget you want some nice long trumpets in there too, makes the idea of a OE filter harder. I started modifying a dolly sprint airbox by attaching a 3" pipe. A single large pipe is more efficient than twin even if total area is the same (boundary effect) Anyway, for my money (!) I would still use a K+N cone filter, If you want an alternative, the sprint airbox should be fine, just respace the back with fresh metal with appropriate holes. But no space for trumpets.... That filter is fitted to TR7, Sprint (127bhp) and stags (not much more bhp!) As to size of filter, not sure! I will undoubtidly end up with a foam sausage filter on my new setup, purely because it is easy compared to the alternatives, and as I am using bike ITBs attched via silicone hoses, I want to keep it light as possible. I know, I have just waffled on and been no help...... Link to comment Share on other sites More sharing options...
rogerguzzi Posted January 20, 2017 Author Report Share Posted January 20, 2017 Hello Clive I am thinking of fitting a set of these in the air box the 25mm ones http://www.ebay.co.uk/itm/Weber-DCOE-40mm-Velocity-Stack-Carb-Trumpet-IDF-Dellorto-DHLA-DRLA-Solex-ITB-/272400841050?var=&hash=item3f6c5af95a:m:mFWCgugmwx_eUSCzQCuYMiw Or how about some of this built into the air box? http://www.ebay.co.uk/itm/Ramair-Universal-Large-Foam-Pad-300-x-200-DIY-Make-your-own-air-filter-/351167961002?hash=item51c33dd7aa:g:hK8AAOSwRLZUEGEG I think I will stick with the 2 x 48mm i/d tubes for now as they fit nicely. I made a new engine breather today similar to the one on my TR2 engine I have yet to chamfer the end of the tube so the leading edge is longer. Roger Link to comment Share on other sites More sharing options...
rogerguzzi Posted January 20, 2017 Author Report Share Posted January 20, 2017 Hello All Or how about these? http://www.ebay.co.uk/itm/2-x-RAMAIR-Carb-Sock-Air-Filters-Double-Trumpet-Weber-DCOE-Dellorto-DHLA-/271581092161?hash=item3f3b7e9941:g:uzYAAOSwA4dWGuxe Roger Link to comment Share on other sites More sharing options...
Clive Posted January 21, 2017 Report Share Posted January 21, 2017 What diameter trumpets do you need? I may have some 45mm types in a couple of lengths. And somewhere I have a new, but missing some fixings and "garage soiled", K+N filter, the DCOE type which handily has a pair of 48mm holes in the backplate. I can measure its depth if needed. I would avoid sock type filters, not enough/any free airflow around the trumpets. So really only a solution if nothing better will fit. Link to comment Share on other sites More sharing options...
rogerguzzi Posted January 21, 2017 Author Report Share Posted January 21, 2017 Hello Clive The trumpets I need are 40mm bore and I was thinking of 25mm long which would leave 40mm to front face of the air box which from what I read is about right(same as choke diameter) In K&N filters I was thinking of perhaps this one http://www.knfilters.co.uk/search/product.aspx?prod=R-0990 But still thinking of making a box to hold a cheap modern car one? If I look for one that fits a 1600/2000cc engine should be big enough and cheap? Roger Link to comment Share on other sites More sharing options...
Clive Posted January 21, 2017 Report Share Posted January 21, 2017 Do you mean make a separate box for a filter? Have a look at the triumph PI filter box? the offer of that K+N is open. About 80mm deep. If you can find full radius trumpets, they should be best. Certainly on carbs, I don't see why injection would be different. Link to comment Share on other sites More sharing options...
rogerguzzi Posted January 21, 2017 Author Report Share Posted January 21, 2017 Hello Clive Like these? http://www.ebay.co.uk/itm/Dellorto-Weber-40-DHLA-DCOE-DCOM-full-radius-trumpet-velocity-stack-30-or-50mm-L/262119245060?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40762%26meid%3D70a1b4062bf2419eb0c94e7e83c5f4b6%26pid%3D100005%26rk%3D1%26rkt%3D1%26sd%3D262114425349 Will they be worth the the extra £35 What are the dimensions of the K&N filter? Thank's Roger Link to comment Share on other sites More sharing options...
rogerguzzi Posted January 21, 2017 Author Report Share Posted January 21, 2017 Hello Clive This is interesting and confusing to me! http://www.pjmotorsports.com/velocity-stacks.html Roger Link to comment Share on other sites More sharing options...
Clive Posted January 22, 2017 Report Share Posted January 22, 2017 Yes, full radius gives best airflow, there is a comparison on the web somewhere, pretty old but informative. Will nab the filter later. It looks similar to the one you posted earlier, but just has the holes in the backplate. pm me an email addy and I will send a pic or 2. Here is some more research for you, actually this stuff IS well worth a read, as it is proper research done on a rolling road so gives actual results. http://www.emeraldm3d.com/articles/emr-adj-length-intake/ Link to comment Share on other sites More sharing options...
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