Conversion of an L28 to L28 turbo.

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Brock365
Posts: 233
Location: Auckland

Conversion of an L28 to L28 turbo.

Post by Brock365 » Fri Nov 17, 2006 7:34 pm

Is this an easy thing to do?
I am reasonably mechanically incompentant, so would get someone to do this.
I have spoke to various members of the Z club, and some reckon NA is the way to go. My brother and several of my friends, reckon turbos are better, just due to the newer technology.
Opinions people?
Owner of a Nissan 280ZX, a Toyota WiLL VS (yes its spelt with capital Ls) for the missus and a 2005 Nissan Skyline 3.5 litre manual sedan

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nzeder
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Post by nzeder » Fri Nov 17, 2006 8:36 pm

Easy - yes/ish
Cheap - no

I was thinking about doing this to my zed - purchased a Nissan Laurel L20ET for $100 was going to take the L20ET out - take the turbo manifold (same as the L28ET manifold that was fitted to the 280ZXT in the US) in the end I took the front cover (mint) turbo dizzy, rear discs and 3.9 R200 and gave the rest to pick-a-part.

Since then I have purchased a L20ET for under $160 for a guy in Australia - I have stripped the manifolds off, turbo oil pump, dizzy and sump and will be shipping these to him as this is cheaper than picking up the L28ET parts from the US for him.

Given you have a L28 you car is already EFI so it will a bit easier than a 240z/260z. Things to remember to do this type of install - I would recommend looking at brakes and possible upgrades. I know the 280zxt had the same size brakes so you could get away with the stock setup. Personally I would upgrade them. The 280zxt also had a CV alxes setup (these types of setup can also be found on the late 82/83 280zx so I would try and find one and get those part = bolt in) also these later cars also had a power rack and pinion steering setup. The earlier cars were either rack/pinion non power assist or recirculating ball/box power assist. So I would go with the later model car as a base for these reasons. If you 280zx is not such is model does not matter - just a personal thing as if had one of these = you have all the parts that the turbo cars came with just minus the turbo engine (they also had the turbo type bonnet with the larger intake on the pass side)

So that is the car choice out of the way. Next pick up a L20ET from a C31 Laurel 81-83 (cheaper than the skyline but the same floor/chassis) or a R30/R31 Skyline (some R31 are RB20E powered to be sure it is L20ET). This assumes you want to turbo a L28. Other option is RB25DET - depends on your budget but a powerfull L28ET conversion might cost almost the same as stock RB25DET conversion.

If you go the L28 turbo path here a few things you can do that will keep the cost down (most of this info is what I learnt from the Hybridz.org Forum over the years)

1. Pick up a L20ET - take the exhaust manifold, turbo dizzy (there are a few different model - if you want a hand to ensure you get the right type just yell out - I did have 3 of these but sold these to the guy in Australia), turbo oil pump (could use the secondhand one if you are on a low budget or buy a new one) and don't forget the oil pump/dizzy drive shaft. You will also want to take the turbo rocker cover, get the loom and AFM maybe the ECU.
2. Then pick up a 300ZX Z31 turbo and dizzy and manual ECU. Then you want to install the option dics from the Z31 Dizzy into the correct optional L20ET dizzy and then you can use the Z31 ECU (I am sure there might be a bit more to it but again this is what I read at hybridz and I am going by memory)
3. Install the Z31 turbo on to the L20ET manifold and install this on your L28 - the stock L28 with Dish pistons and N42 head will be fine for low boost which is what all this stock kit will give you.
4. Install the turbo oil pump/dizzy setup the ECU/loom/AFM (if using the Z31 ECU you might need the Z31 AFM also)
5. Install larger injectory hose tail = no fuel rail mods (or purchase my spare 14mm o-ring injector fuel rail :) and pick up some RB25DET injectors to match my fuel rail)
6. Install a surge tank (not required if you don't drive hard in the corners but recommended for turbo setup as you don't want detenation....spelling?) and a higher HP fuel pump. Use the stock EFI pump to lift to the surge tank then the new pump to push the fuel to the engine bay - don't install the surge tank or fuel pump in the engine bay better to have both as close to the fuel tank as possible. If you see these installed in the engine bay = lazy and not doing it correctly.
7. Now drive hard and start to break things, gearboxes, universal alxes etc. Then upgrade these in the future to CVs, stonger type gearbox - do the RB/SR/Z31 ie FS5W71C to L6 conversion - see the tech section on this forum.
8. Spend $$$$$ and then some more $$$$$
9. Don't forget to get the mods certed :)

That is the basic setup and I am sure a lot more can be said - google is your friend and visit sites like Hybridz they have a complete section for just this question :wink:

Also pm DJZ on this site he has done this conversion on his 280zx 2 seater.

Hope this helps.
Cheers
Mike

PS I decided to go NA with triple throttle bodies = cost is getting up there and I could have turboed for the same $$ but it would not have the triple induction noice 8) + I have never owned a turbo car so don't know what I am missing.
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nzeder
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Post by nzeder » Tue Nov 21, 2006 7:45 am


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djz
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Post by djz » Sun Nov 26, 2006 1:37 am

You can use the Z31 computer, but I think its a bit trickier than that, the ECU itself will plug into the ECU plug on very late model Zs (I think they use 2 or 3 plugs instead of the normal 1), if you've got an earlier Z than about 1982 then you'll need the loom from the Z31 aswell, which needs bit of chopping to make it fit.

Don't forget you'll have to weld a oil return from the turbo onto the sump - the engine will have to come out to do it properly.

Be careful about which exhaust manifold you get, there is more than one style, one of mine (a C31 one) has the flange for the turbo further forward that all the others I've got (R30 ones) so you can't fit a big turbo on it without the compressor housing hitting the engine mount on the LHS.

If getting new injectors make sure the impedance matches the original injectors that go with the computer you are using. Standard Z injectors are low impedance (from what I remember), alot of new cars are high impedance (ECCS RB20s, RB25s etc). And some RB25 injectors are side feed aswell I think. If you use an original L series computer or an earlier Z31 computer you can use VG30ET, FJ20ET or NICS RB20DET injectors for a start. I've wondered what would happen if you took out the injector ballast resistors and tried to run high impedance injectors straight of the computer, if I get another stock ZX to play with I might give it a go sometime.

A surge tank shouldn't really be needed for a ZX as the tanks are already baffled, but I would definitely get a bigger fuel pump if you are going to run more than 8 odd psi. But if you were doing autocrossing or something like that, the surge tank might be a good idea.

Turboing a Z is easy to do, doing it properly so it runs well isn't so easy :)
Nissan 280ZX 2 seater RB26 powered.

85_z31
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Post by 85_z31 » Wed Dec 20, 2006 10:48 pm

hi there

Im not really very helpfull to this but there is some good information on www.redz31.com/forum about using an L28 and a Z31 computer you have to join the forum, but this is a very informed crowrd of guys and they will not get all pissy when you ask a question like on hybridz.org (been there done that myself) You will be welcomed even though you are not a z31 guy. Also i have a Z31 parts car its a rusty old boat of a thing body wise but it has a sound wiring loom if you decided to go this route, and the early Z31 used the same T3 turbo as did the US 280ZXT i also have a spare turbo once i pull the engine from the car if you happen to need a turbo or need turbo parts.

Edit:forgot to note z31 turbo injectors and a z31 dizzy are floating about also i don't intend on selling all my spares but if you needed something from a z31 dont hesitate to flick me a pm.
1985 Z31 Slicktop Turbo

85_z31
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Post by 85_z31 » Wed Dec 20, 2006 10:56 pm

Hi there again

I also had another brain wave , if deciding to go with a z31 ECU you may consider using nitune for tuning and making serious hp
It basically makes a stock ECU full programmable and as good as a standalone unit. There are a number of Z31's in the USA making 500HP+ using stock ECU's that have been rechipped and re programmed here is the link

http://home.aanet.com.au/nistune/
1985 Z31 Slicktop Turbo

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Tony Edmeades
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Location: Waitakere

Post by Tony Edmeades » Sun Aug 19, 2007 10:28 pm

Hi there,

I've turbo'd my L28 with relative success so far. I decided to run a low boost level (8psi) into a completely stock engine, and over engineer the whole set up to try and ensure absolutely no detonation and thus a reliable engine.
It ran 280horse at 6k on the torque performance dyno, which isn't huge numbers but the 600Nm rear wheel torque is the real kicker, FUN !!!
If you want more details just sing out, or call me to talk over what I did. I do have to say at this stage though, it wasn't cheap !!.
Cheers
Tony
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Josh
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Post by Josh » Thu Nov 01, 2007 9:53 pm

Has anyone had any success with putting an L20et setup into an L28? There are some Skyline R30 parts on trademe which I was considering. Just interested in knowing how compatible they are and if there are any pitfalls I need to be aware of, ie is it just a case of bolting on the bits and switching ECU's? or is it going to take a lot more time, money and effort than that?
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nzeder
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Post by nzeder » Fri Nov 02, 2007 9:00 am

I believe the L20ET exhaust manifold is the same unit used on the factory (US and Europe only) L28ET (why would Nissan make two different manifold's keep the manufacturing cost down if the same unit is used). The L20ET dizzy is the same too (well depends on the model as some have the optical trigger others have a hall effect setup, were as the US L28ET only had the optical setup but I believe both generate the same signal). You could get away with the L20ET ECU but I would recommend replacing it due the larger cc and different size injectors that would be required etc. Here is a heap of info on turbo'ed L28 on hybridz.org so search there too.

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Tony Edmeades
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Post by Tony Edmeades » Fri Nov 02, 2007 10:10 am


Yea, I'd say parts should bolt on without too many dramas. Biggest issue will definitely be getting the fueling correct.
You would want to use the largest injectors out of the two (and they may not be big enough any way), and the computer out of the skyline as it will recognise positive manifold pressure (boost). Unfortunately with the larger engine capacity the fueling will be wrong and you will need to run a piggy back unit on the computer that is adjustable to tune the fuel map. I believe some guys have mucked around with the air flow meters some how to adjust fueling but your playing with fire.
The other option is maybe a cheap second hand programable ECU such as a link or whatever.
One other potential downfall is the size of the turbo. If it is too small it will restrict the exhaust gas flow and also may over speed if the internal wastegate can't release enough gas to control boost levels. That website mentioned will have some usefull ideas though.

A lot to think about huh.

Good luck.

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