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77 l28e turbo?


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Hey everyone. ive been reading and trying to find some posts on how to turbo a motor with the N42 head, and i think ive been misled on some things and would like someone with experience to help me get my ducks in a row.. first off, I have a 1977 280Z, Bone stock motor, 4 speed manual, this is my toy, I autocross it but I baby the **** out of it, and ive been contemplating the choices on more power for the coursesicon1.png.. so I started looking and most people are telling me I NEED an p90 head to even start to turbo this engine. is the N42 head able to stand up to modest boost? 9-11 lbs for a goal.. with a few mods to stock components, is this feasible for an autocross car? or is it necessary to have many turbo ZX parts to fit on this engine? a list of what i have so far is.. : J pipe, 83zx injectors, an unknown ECU and Distrib. a turbo manifold, all this was given to me by the previous owner.. sorry for the loooong message, just wanted to give the most information i can, thanks for any help you can pass along! (I can post pictures of the distrib. and ECU if it helps identify them)
Jordan.

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I have run 10-17-21 psi on my 77 N42 for close to 85,000 miles since doing he turbo conversion in 1985.

 

Throw away the unknown ECU, get an Adjustable Aftermarket unit like Megasquirt or SDS. Depending on the type of 'distributor' it may be your CAS Trigger, or something to ditch.

 

10psi is child's play, and if you set up proper intercooler and fueling 17 & 21 psi and their accordant HP levels are easily manageable.

 

A stock turbo (euro) with the .82AR hot side, or even the stock setup should easily get you a nice round 200-215hp at that level.

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I have run 10-17-21 psi on my 77 N42 for close to 85,000 miles since doing he turbo conversion in 1985.

 

Throw away the unknown ECU, get an Adjustable Aftermarket unit like Megasquirt or SDS. Depending on the type of 'distributor' it may be your CAS Trigger, or something to ditch.

 

10psi is child's play, and if you set up proper intercooler and fueling 17 & 21 psi and their accordant HP levels are easily manageable.

 

A stock turbo (euro) with the .82AR hot side, or even the stock setup should easily get you a nice round 200-215hp at that level.

What Tony said.

 

The head is not your issue (assuming the engine is really bone stock and not modified for high compression).  The ECU is your issue.  Get something tunable and you will be MUCH happier with the outcome.

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Use those 83 Turbo injectors. There is no problem with turboing an N/A engine, just get the parts that have been mentioned and keep researching for your project.

 

Im running 15lbs on a turbo-ed 83 N/A engine, Megasquirt and it is a blast. I am going to with more boost as soon as the daily temps drop down out here in Phoenix.

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wow, after reading megasquirt FAQs and manuals online at diytune.com I feel dumb, I want to do this myself to say i did it.. but some of the stuff is going over my head.. for megasquirt do you NEED an 02 sensor? and as far as my stock distrib. I replace that with a turbo one to set up for ignition control with MS? and as far as ignition control with MS goes, does that in a way take place of an MSD box for timing control? I need to step back and look at this from a different angle to comprehend some properties of a Megasquirt install  :icon_frow

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 I need to step back and look at this from a different angle to comprehend some properties of a Megasquirt install  :icon_frow

 

Yes.  It's a steep learning curve, but it is as very good and cost-effective solution.  Reading and research is free, just be patient.  Yes, you need an O2 sensor, and probably a number of other sensors too.  There are a variety of ways to set up the tach input to Megasquirt, but the good thing about the turbo distributor is it can handle any amount of advance you will need with a turbo setup, and the internal wheel is easy to swap.

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You don't need MS, but it's a lot easier to manage the engine with it.  You'll need a MAP sensor, TPS, CAS and the O2 sensor for megasquirt.  Try not to be afraid of it. yes there's a lot to it, but it's a much newer EFI system than the L28's Bosch system.  The ZX Turbo engines can be run using a turbo ECU, harness and AFM, but that's a lot of old stuff to swap in.  DIY has everything you need including the harness. You can buy it preassembles if you're not up for soldering it together.  it's not bad, everything is labelled. Pretty easy.  The tunes you can just download based on the settings you want to use.  Search Megasquirt on here for a ton of Z related threads on it w/ pictures etc..

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MSD is a stopgap. The COP systems give you spark duration that an MSD box dreams about...

 

Not that you need it, a single fast-charging coil like from a Z31 or most any Nissan single coil application from the 84-on timeframe will work fine up to around 7,000 rpms which is your limit with cast pistons anyway.

 

Go over that, crank triggered timing is your best longevity item you can add to your engine...

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Oh you mean an MSD BTM "Boost Timing Master" 70's technology, retard per psi linear rate retard.

 

Megasquirt does that in a 3D mapping

 

I think of MSD for their multiple spark marketing. I forget they sell that BTM, I shouldn't, I used it in the early years. I got a setup assembled in 1978 ...it uses an MSD6 and Zbtm.

 

State of the art, 1975!

Edited by Tony D
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whats the degree of timing you have to set for around 11-12lbs of boost anyways?

 

That is completely dependent on your setup, which turbo, which intercooler, which engine, which head, too many things.  That is something you need to find out yourself by reviewing others' setups and testing your own.

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I woul NOT buy one! For what they want for an MSD BTM you are a big chunk of change towards a Megasquirt with programmable spark control and not a dumb. "One siz fits all" box. To get similar timing adjustment you need at least an MSD7...

 

Anybody who says they have a "good running" stock L28ET, has never driven that same car with an aftermarket EMS on it! The drivability is night and day.

 

In the late 70's we would retrofit Datsun EFI to 140HP Corvairs..that was a late model harness going into a 10 year old car at the time. The drivability change was a matter of order improvement especially when cold. Would I do that same modification today?

 

Absolutely not.

 

I would do a MS, SDS, or other modern programmable EMS (or, to be totally honest, "keeping my GM car all GM" I would adapt a current generation OBD2 at least GM EMS system to the car and useTunercat Studio to tweak the maps drivability right out of the box and the same programming flexibility to tune.)

 

What the ECCS was in 1980 is not relevant today. Yeah you can do it, but you are severely limited as to what you can do, and frankly the drivability suffers from the control technology of the day. The same engine with modern EMS just simply DRIVES better!

 

 

As to degree of retard for 12psi...I ran 24 degrees there, over 2500 but more lower and 18 where I got ping indications. That was WITHOUT intercooler but WITH adjustable fueling appropriate to the boost level, my AFR's dropping from 12's to almost 14:1 past 4,500 rpms.

 

You won't do that with an ECCS and BTM... Can't. And. The power is noticeable, as is the response to throttle inputs.

Edited by Tony D
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