Hi guys, I'm in the process of building an efi L20b manifold for my 200b which will be turbo also. I was making a one off aluminium inlet manifold but if anyone here was interested, I could possibly make a few extra. Would have bungs welded in for standard Bosch injectors, and provision for 60 mm or larger throttle body if needed, 38 mm ID runners too. I'd hate for people later on to say, "I wish I had on of those", that's all. Let me know what you guys think.

All comes down to $$$, would be some labour in making them. Out of interest where are you mounting the injector bungs? close to the head or in the runners?

I'd be interested in some inlet flanges if you are getting them cnc'ed, I'm guessing water jet or laser might not give the straight edge you'd want if using 10mm etc.

Will be mounting them in the runners, close to the head. Yes they will be sent to Jet Cut to be done after the template is sent to them after being drawn on the computer. Not sure how clean it will come back as yet.

I would be very interested in what you are proposing - for me, however, it not just about the dollars, it is a performance vs. packaging vs. price equation.

There are so many factors that are dependent on what are the performance goals (eg. operating range - is it going to be for a max effort HP, or good broad torque and response through out the RPM range; what about runner length and shape, manifold volume, injector(s) location) and packaging (ie. are you locating the throttle bodies centrally or at either end of the manifold, will it clear or work with my existing turbo, will it clear my bonnet, do I need to make a new exhaust manifold, what chassis is it intended for ie. 1600, Bluebird, 200B, Stanza, 180B, etc or something else, fuel rail)?

Really appreciate your offer on this - would be great to hear what you have in mind?

At the moment, I will set it up for 200b. Basically, it's what you would use for a stock to mild engine to give it a bit more go and more drivability from efi. I was given an SR20 turbo(t25g) to use . My car is a daily driver, so I'm not after the fastest in Oz, but something to go better with reasonable economy. I realise the runner length will always be a compromise in each engine bay, but being boosted should get away with a shorter runner. Throttle body will be single on the front end of plenum facing front of vehicle. I'll do some research on plenum volume but it will be set up for the standard/mild engine for now. I will document the build and fab, which should give people some ideas or feel free for people to make suggestions. Thinking it may be better for everyone to see end product but can get some extra manifold flanges cut for now. If people like what comes out, we can go from there.

Use the factory injection mounting positions. most heads can be drilled and tapped to suit. you wont then have injectors in the way of nuts and studs. Run 40-42mm runners reduced down to 36mm at the head so can be enlarged if need be. CPC on facebook make a mani I think $3500 could be wrong he may do a group buy. If using turbo you wont be running a 76deg cam so slightly shorter runners arent that much of a problem. Keep turbo extractors as short as possible with 3' works wonders 2'1/2 is probably big enough

t25 will yield a very drive able car 120-140 rwkw @ 5000 rpm on an L20b in stockish fourm

Cheers for the input. Was looking at 38 mm ID, 44 mm OD for runners. I think next size was 50 mm OD and 38 mm ID. So factory injectors were in the head?

I still havent worked out how to put pic up

https://www.google.com.au/imgres?imgurl ... mrc&uact=8

These are itb but will be similar concept. He only made one run of these 10 of I think

Here are some pics of the factory setup too give you an idea on injector position, note the larger stud hole tapped in the middle of the two smaller holes either side above the ports so that they clear the injectors. I wouldn't have a clue if this is a good or a bad way of building an injected manifold but it's what Nissan did in the 70's. The only down side of this setup is that a head would need modifying too run this setup where as if the injector was located a bit further away from the head.
Ps I stole these pics off google

_________________
Chris Thomas

1971 1600, mild L18, 5 speed

All I want is less to do, more time to do it and higher pay for not getting it done.

Some good pics and info there for sure. I will probably make it similar to Nick Diggles Turbo Stanza manifold although not as powerful for now. But using 4x440cc injectors instead of the 8 he used.
Theres always a $3500 manifold for if you win the lotto! https://m.facebook.com/photo.php?fbid=1 ... 7534277242

Just a quick update guys. The manifold flanges, throttle body mounting flange and turbo mount flange are getting cut at the laser cutters. I've purchased a 17/32" reamer for the injector bungs, some 20 mm aluminium bar for the injector bungs. A mate gave me a length of aluminium pipe , 38 mm id,1200 mm long to use for the inlet runners. I ended up purchasing Bosch 550cc injectors from the US, a Bosch 070 efi fuel pump with an Ecotec 60mm throttle body. The manifold 'L's (thick wall pipe ) have been purchased too. My mate started welding the collector today.

Had to do some searching, but this is the best L series efi manifold I have seen yet in terms of shape, just chucking it in the thread in case you hadn't seen it yet

Thanks for sharing, that's pretty neat, I like the nice shape into the runners also . Will build something similar but longer runners. My mate is a pretty handy guy, he's a sparky who's handy with a tig. Owns a VL with RB25 turbo and a 07 Hilux with LS1, which he fitted. I'm a fitter/machinist by trade who does panel and paint on the side for some spending money, or in this case to trade labour(I painted my mates work trailer ). I'm sure I'll be running out of hours owing soon though lol.A lot of work in doing this set up! End product will be worth it though, I'm too old to put up with carbys anymore and I love a fast and reliable daily driver. The future has a GT28 and forged bottom end after I get the Z20 long rods. First things first though!

From what I understand you can actually buy those curved aluminum sections from the states, haven't seen anything locally yet, but then again I'm not exactly in the industry, so rely on the internet to find stuff.

I like the sound of your setup. I also agree carby's are getting to the end of their time in some respects since efi costs are slowly coming down as people learn more.

What ecu and timing things are you planning on running? Crank and cam triggers? Or just modified dizzy?

I'll have a talk to my mate about the curving sections, will do our best to mimic what you've shown but I'll post when we start fabbing, hopefully this/next week. I'm going for a budget ecu, whatever I can afford to run 4 LS coil packs , so doing away with the dizzy. Will look at either crank or cam trigger depending on whether we decide it's worth running batch fire or sequential injection or wasted v timed spark ignition. I think the main benefit is economy so it might not be worth the extra expense or effort. Trying to keep it budget , I've got 3 growing boys and a mortgage lol. Oldest lad just got a Gemini to fix up, so it's a juggle of time between my full time day job, my side cash paint jobs , helping the son with his car, boosting the Datsun and the usual family time lol. But not complaining, all part of the fun.