New Zealand Datsun Club

I did some research some time ago, and looked into inlet tube lengths, and injector location for optimum power etc. some cars ie Hondas & 4AGE's have injectors quite close to the inlet valve, where as some inject even outboard of the ITB's! also most aftermarket generic ITB's have the injector pocket moulded into the inlet side of the body assembly.

With custom EFI / ITB setup there is obviously a bit of "suck it and see" , in hindsight my ITB design, might be a bit wrong, as I have used quite narrow inlet runners, which flare out at the end where they meet the 43mm throttle bodies, but I have to contend with quite small oval inlet ports on my A series, as well as angled runners, due to non-cross flow head design. however I thought 43mm bodies might be a bit large for 1500cc, so thought I would choke the inlet tract down, much like dellortos run a venturi of 28mm-32mm generally for 1400-1500cc. I guess I will find out in a month or two when I finish my inlt manifold fabrication and run the old girl up.

Mark I agree that ITB's must have trumpets open to atmosphere!! the sound of them is just pure pornography. The whole reason I have gone down the EFI / MS2/ EDIS / ITB path, is due to some idiot patching a youtube link to some ITB's on a Lexus V8.

However, its not cheap, depending on how you do it, I have spent about $2.5K to date on my setup (with EDIS kit & O2 sensor setup), and will be $3K all up by the time manifold & fuel system is complete and its wired up....

cookie what you have said is quite right and its mostly to do with inlet air speeds as i under stand it. the closer you have the injector to the port the less air speed you need to get that fuel into the port with out it de-atomising giving a shitter burn. hence most factory applications i think putting the injector as close as possible. you dont get so much up top but better low down. you can use outboard injectors to get more HP up top on top of the inboard injectors, you just phase them in near WOT and these injectors are usually quite big in CC rating to get all the fuel you need in, hence placing them outboard so they take maximum advantage of intake air speeds to get the excess fuel into the chamber.

now as the L series doesnt rev hugely high this setup of injectors as close as i can to the port i think will suit it quite well. my intake diameter is governed entirely by the N42 port size on the head and the 45mm GTR throttle body. being the original triple carb manifold i copied was a 40mm carb, which seems very common on L series i figured a 45mm throttle body was more than enough and the length well i wanted it to behave similarly to the carb manifold also as being made by cannon they should have been well tested so i copied this in regards to the length.

as for cost kitch i guess it depends on what you have at hand. it looks like you have brought new most of your gear where as i made most of my stuff. i think all up my setup has cost me approx $1100, the megasquirt and wide band at $300 each was quite a fair chunk of it, then $250 for throttle bodies, bout $100 of materials for the manifold and $100 for my trumpets. the rest i had on hand. im using heaps of gear from old RB's ive scrapped, like 260cc rb25de neo injectors (these are a nice new small injector so looked to be good), i had an old fuel rail from a RB20DET i chopped up to suit, i made all my wiring from an R33 look i had about. so i had plenty of stuff on hand to use. i kept my optical dizzy setup from a L20e i had so i was lucky there as you probably dont have anything available for an A series like that.

but yeh the more you can do your self at the end of the day the cheaper stuff gets.

Since seeing the pics you posted I've been having wild dreams of lost foam casting an aluminium intake manifold and plenum in my backyard and using RB26 ITBs.
Here's a video which has this car injecting before the butterflies. Looks really crazy. I saw the same setup on a large strait six and it idled like a dream which blew me away as the fuel was hitting the butterfly and it seemed it would require much more fuel but apparently not.
http://www.youtube.com/watch?v=OIxdRqcI ... A3D272CD5E" onclick="window.open(this.href);return false;

Thats gonna be fricken cool when its running. I hope you have the facilities to video it when its going.

so i have been doing heaps on this but its all just small boring things to take pictures of like finishing of all my wiring, throttle cable, reassembling stuff after painting it, putting in oil catch tank, tidying up fuel lines and so on, all those small jobs to make it tidier which wasnt needed for track day haha.

i probably wouldnt have had it track day anyways as i have been having some spark issues which i have all but solved now. my distributors clearances i had modded it to were a bit tight and it was driving it mildly eccentricity causing some dizzy rotor issues and giving me cross firing and so on. but thats all fixed now.

so i can prove it does in fact run haha here is a small video of throttle butterflys moving...



i am probably at the point where i would feel happy to start road tuning it now but i have no doors on it yet and i am yet to still finish painting all the bolt on stuff (i wasnt going to paint this for track day) so im looking to get the bits acid dipped as the inside skin of my bonnet is rusting from the inside out and i dont want to de stitch it all so im going to dip it and blast rust treatment all up in there.

but yeh its getting close

also if any one wants a write up on how to make a L series optical dizzy fit into an engine with a non optical dizzy drive hit me up.

Couldnt find your Youtube vid, had a search for '240k' in recent vids, all I found was this poor bugger, who has appreciated your car more, by exterminating one more classic Datsun..
http://www.youtube.com/watch?v=IPRdcEHgR50" onclick="window.open(this.href);return false;

whoops didnt realise youtube embed wasnt on here.

link: http://www.youtube.com/watch?v=zGv98ltY4Tw" onclick="window.open(this.href);return false;

thats the tits .Great work

Congrats Mate, awesome work

I particularly like the wee rev you give it at 1:32

Superb work ten5!
You must be quite elated to have made it this far.

yes i am quite stoked to have it all up and running. all mine and dads fabrication has worked! really cant wait to drive it, cellphone video doesnt quite do it justice, lets just say it should be very aurally pleasing on song.