putting a stock 83 turbo on a stock 78 na engine

[MaTTSuN]

Im not sure if anyone has when over this, but ive done allot of searching and have come up empty handed. I want 2 used a stock turbo with a stock 78/NA engine with the NA electronics, has anyone done this or have any tip's exluding putting turbo computer or allot of money. since i have the turbo and turbo manifold but not the electronics. thanks allot guy's....or gurls?

[Pyro]

You can do that. But you will need a FMU to increase fuel pressure under boost conditions. Bell Engineering sells a pretty good one. You will need 50 or 60 psi of fuel pressure at 6 or 7 psi of boost. The stock fuel pump will not flow enough volume after 50 psi. So, use two stock pumps in series (one pump feeding the other pump) to get the flow you need. Then, 26 to 28 degrees of ignition timing is about all your engine will stand under boost.

 

If you used a P90 or P79 head on your 78 block (dished pitions) then you can turn the boost up to 10 or 12 psi. This head/block combo will make the stock turbo compression ratio.

 

I'm using all stock 76 efi on a turbo long block with two fuel pumps, FMU set to 80 psi of fuel at 12 psi of boost, spearco IC. I also reduced the amount of timing from the dist. by welding the advance slot just a little. I used 20 degrees initial timing with 28 total.

 

235 hp at the wheels, 13.7@ 106 mph, 3.90 gear, later model 5 spd, and 2+2 clutch.

 

But, a FMU is not a good way to control fuel. It works but just barely. If I drive hard anound town, the car will get very bad mileage because the FMU is overly rich at low boost and low rpms. Sub 10 mpg is easy to get around town. Megasquirt or the like should be used as soon as possible.

[Pyro]

repeat (how do you delete a post????)

[jkube]

I'm about to do a similar turbo upgrade to my N/A motor.

I'm currently using an 83 N/A motor with an N42 head, and 2mm steel head gasket and have just installed FI system onto it (Was running '72 240 carbs before)

 

I have a Walbro 255 ltr/hr fuel pump, AN6 lines & Megasquirt installed and running. Its sort of tuned, but I want to add a sump to the bottom of the gas tank before finalizing the tuning

Running with turbo injectors installed already, seems to idle fine. It has lots more pull then the carbs.

 

For ignition control I'm planning on switching to the Crane XR3000 with the add on package they have for boost retard control.

 

For the turbo, I picked-up a 300zx (single) turbo, had it rebuilt and had to have the cooler side snail reclocked to fit under the intake.

 

I suspect with the N/A motor setup, I'll have to dial in a lot of ignition retard, keep the boost reasonable and install an I/C to keep it from blowing up.

[naplesZ]

Would it be possible to run a turbo computer on an NA motor? I have a 78 NA with a N42 head. I don't have access to a turbo motor because I live overseas,but I could possibly peace one together.

[Kennysgreen280zt]

Four years ago I ran a turbo on my 75 NA motor, NA electrics, NA AFM, and a rising rate FPR. It was non-intercooled and I broke 4 ringlands within 2500 miles of 7-9 psi boosting. I would say just do the turbo swap and run megasquirt & spark, but that is just my advise.

 

~Kenny

[Guest bastaad525]

Someone just posted a very similar question to this a few threads down. I typed up a long answer to that one, which I'll just copy and paste here Forgive me if any info is repeated or doesn't seem to apply:

 

"Hmm... just read the first post here so pardon me if I ask or say anything that's already been said.

 

One important thing to know is which pistons and head you are running, and therefore what compression you're running? I've seen N/A combinations have CR's of about 8:1 all the way up to 11:1 +. If you're at the lower end that will be very helpful. However, with the right fuel setup and a good I/C people HAVE run boost on 10:1 + compression engines.

 

Things I would consider necessary to do turbo your rebuilt motor, assuming you are on the lower end of the compression.

 

1. The exhaust manifold and turbo from a 280zxt, and downpipe as well unless you plan on fabbing one

2. The distributor from a zxt

3. The entire ECCS system from a ZXT... important to try to get all components from the same year (also try to get a same year distributor). You will want the ECU, AFM, wiring harness, injectors

4. A good intercooler

5. A good blow off valve, which you should recirculate back into the intake

6. A good fuel pump to replace the stock one. While the stock one handled 200rwhp fine on my own setup, it is just good insurance to upgrade to a new one

7. An adjustable fuel pressure regulator to help supply some extra fuel for extra safety margin and add some tuneability.

 

Alternately, you MAY be able to take the route that lots of honda guys do when adding turbo's to their normally N/A cars, but wanting to keep their mostly stock EFI setups. While not as tuneable or flexible, you could conceivably keep your stock N/A EFI setup, and run a rising rate adjustable fuel pressure regulator (quite a mouthful eh?). The RRFPR will supply extra fuel pressure ONLY when boost is present. It is adjustable for how much extra fuel you want per psi of boost, and at what point you want it to start affecting the pressure (usually, at 0hg's of vacuum). You would probably still want to run the turbo injectors, at least, as well, but this way you wouldn't have to rewire the whole darn thing. There are a few guys out there running turboed motors on N/A ECU's. If you did decide to try that, you will also want something like the MSD unit that retards ignition timing under boost, as well.

 

I've seen or read about guys running lots of boost on even relatively high compression, normally N/A motors, with setups like this. As long as you can cool the intake charge enough, supply enough fuel, and pull enough timing... also the best octane fuel you can get helps. I could easily see you running enough boost to put 250hp or so to the wheels and still be safe."

[77280]

ive been running a fresh n42 dished piston bottom end and a p79 head and stock n/a ecu at stock boost for about a year and no problems and it runs very strong! the boost will be going up a little once the tranny gets replaced

[Guest Reeebuuk]

If u put turbo on stock N/A motor and u want to tune it. Like about 350 hp can u do that like on stock turbo engine or it's to weak???

 

sry for bad english

[MaTTSuN]

wow thanks for all the info guys, now i have a better idea of what 2 do. I cant wait 2 dig into my car. good thing i got an extra block if anything goes wrong i think im going with the sto k setup with the rrfpr like Bastaad siad it sounds like the best way 2 go.

[Guest bastaad525]

noooo no definately not the BEST way to go! heheh but it can be made to work. Remember you will also REALLY want some way to pull timing under boost (MSD makes a boost-timing-retard unit that works perfectly).

 

Just dont expect a perfectly running car with this setup... an RRFPR can't 100% replace even the factory stock turbo EFI... you will probably have a few little bugs in how the car works, but it will be drivable and should have a decent safety margin from blowing anythign up with boost.

[MaTTSuN]

oh kool thanks for clearing that up. As soon as i get my car up and running and make sure everythings solid then on goes the turbo and MSD and all the other things i need NOT 2 blow up the motor. If i do make a mistake i have a 82 N/A motor that has been off the road for 10 years so the bottom end should still be good. But thats worst case. I wanna take baby steps and make it nice and solid so i dont blow-up when im chewin up some lame honda or drifting in the middle of nowhere 8)