how long should i make an inlet manifold for use with bike bodies onto a 16v abf. also, i'm planning on using the injectors in the original tb location not the std 16v location. i,m going to use a 1.8t injector rail but if i use the injectors that came with the fuel rail are to short (EV6) so i was thinking about using some GM red injectors from an 2 litre ecotech as they are the same fittment but longer, code (GM90501588) does anyone have any views on this. many thanks Adam
no lengths on inlet manifolds? is it a case of the longer the better or does it need to be a certain length?
Longer the better, according to David Vizard. I expect there's a formula, but I don't know it I was chatting to a mate on this, and he had an interesting take on it... If the injectors are at the head end, you don't have the risk of fuel getting dumped on the outside of corners, so why not use the up and over design of the KR manifold - just cut off the plenum chamber and mount the TB's there? You'd need to work hard at the cold air feeds, but it's an interesting idea. The runners are even a good shape on a 42mm manifold, up near the plenum.
i did think about that but i've already cut a std manifold down to about an inch and half long. got myself some 2.25 alu pipe with a wall thickness of 3.2mm. this fits the bores perfectly when squashed into an oval shape. just planning the length of it. i read on the jenvey site that for power of around 7-9 k rpm a butterfly to valve length of approx 200mm.
these are the injectors i'm planning on using. will the be upto the job of around 200 bhp??? also i presume they'll work with megasquirt Set of 4 used GM Injectors. Part No's on injector 5KW90761 / 90501588 Vectra 1.8 2.0 Flowing around 250cc@3bar pressure. 14.2 Ohm Will be ASNU cleaned by us before sale complete with new filters, top and bottom seals. 63.25 inc VAT and UK carriage. Ring 01482 445566 to order.
Where did you get that alloy pipe from mate? Or did you work it yourself? looks like it matches up nicely! I read that the Peak Torque figure should be calculated by "total length" of the inlet runner - from the valve face to the lip of your trumpet. When i was designing my inlet manifold for my R1 carbs (which incidently never got finished) I was working to 12.5" runner length which put the peak torque about 5.5k ish.. and every inch longer would drop this by 1000rpm as a rule of thumb if i remember correctly.
hi mate. i got the pipe from ebay. just cut it to length then squashed it in a vice untill it nearly fitted perfectly. http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=400005387760 some pics of where i'm at now
