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My notes on the N/A L28 to Turbo swap.


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These are my notes on doing a turbo swap on a N/A L28 using L28ET parts off of a 1981-1983 280ZX Turbo car. Use them at your own risk.

 

***This is most likely adequate for a T3 Turbo on stock boost, if you have a bigger turbo or want to turn up the boost it is STRONGLY recommended that you get a lower compression motor [i.e. L28ET] and have spark timing and fuel control as the L6 is incredibly sensitive to detonation.***

 

Obviously there are alot of options when turboing an S30, I'm basically just trying to get all of the basics down for reference. This is what I did, it might not the "best" way, just the one I preferred. This will document the swap without using the stock ZXT harness. It has already been beat to death and I strongly recommend against using the stock computer, especially with a N/A L28. I went with MegaSquirt, which you can buy from DIYAutotune.com, as well as other reputable websites.

 

Here is the ‘bare bones’ list taken from BumbleZee's yadamnfool website, and should be obvious if you've ever looked at a turbo L6. You may not need all of these things, especially if you are using a stand alone ECU.

 

"First off, this swap is very straight forward and does not require a great deal of modifications to an S30 to install.

 

To get started you are going to need these parts off an S130 ZXT

 

* Turbo

* Turbo exhaust manifold

* Most of the sensors [if you have the L28E you already have most of these]

1. head temp sensor

2. knock sensor [i am not using one currently]

3. water temp sensor

4. crank sensor (81 mounted down by the crank, 82-83 mounted inside distributor)

5. ignitor (mounted to the coil bracket) [i've seen a GM HEI unit work in place of the ignitor on a stock EFI setup, but haven't done it myself]

6. oil pressure sensor

7. If you need to run all the sensors and emissions then I suggest you get those also

* Coil bracket (has ignitor mounted on it)

* Downpipe

* Injectors [stock are 260cc, there are many other options if you are going standalone]

* Turbo clutch (if you are going with a manual) [The Turbo clutch is 240mm, I was initially running a lightweight 225mm clutch, see below for more info]

* Turbo TPS (Throttle position sensor) [This should be the same as the N/A L28E, again, if you are using a standalone you will need a Throttle position sensor, not switch. The most commonly used is the 240SX KA24 Throttle Body]"

* J-Pipe - This goes from the Turbo cold side outlet to the Throttle body, if you are using an intercooler this obviously isn't needed. You will need a 2.5" coupler to go from the Turbo to the J-Pipe, and I used a reducer [2.5"-3"] to go from the J-Pipe to the 60mm KA Throttle Body.

* Oil Pan - The Turbo is oil-lubed so it needs to return the oil it uses back to the motor. You can try to get a L28ET pan, but they are hard to find by themselves and are usually relatively "pricey."

 

I 'tapped' an N/A L28 pan I had laying around. To measure where to drill the hole, I measured 9 and 3/4" from the back of the block, and 1 and 3/4" down from that point. This worked for me, but I'm not responsible if yours doesn't line up right :D You can mock the turbo up and measure yourself if you are worried about it.

 

Here's a picture representation... http://i254.photobucket.com/albums/h...280/l28ZXT.jpg

 

I can't remember what the Inside Diameter was for the length of pipe I used, I measured the Inside Diameter of the outlet for the T3 and then went to Lowes, got a pipe connector about 2" long with the appropriate ID, and cut the threads off then welded it to the pan.

 

Worth mentioning: I ended up cutting the 90* off of the outlet pipe and using a longer soft line [no kinks] because my flange that I welded on was a bit long if your home-made pan doesn’t line up perfectly you can make it work.

 

You're going to want to do this with the Oil Pan off the car so you don't get shavings in the motor from when you drill out the inlet hole. I replaced ALL of the 30 bolts for the oil pan, it was $3 for all 30 at Fastenal. I would recommend replacing all fasteners if you are working with a virgin L28, trying to dig old bolts out of the L28 is a pain.

* Oil Pump - You will need the turbo oil pump from an L28ET to increase the pressure to adequately oil the turbo. You can try to find one from a parted out turbo motor, but there are other places to get them. MSA has a "high capacity" pump here: http://www.thezstore.com/page/TZS/PROD/17-8021

 

* Oil Feed Lines - You can use the stock L28ET lines and distro block - the "T-Fitting" [This is the easiest route] but I got stainless steel lines for my car. You will need a T-Fitting at the Oil sending unit to get oil for the Turbo. I used these parts from Pegasusautoracing.com [THANK YOU CHRIS a.k.a TRUMPET RHAPSODY for the part numbers!!]:

- A 1/8 NPT Female T-Fitting

http://www.pegasusautoracing.com/pro....asp?RecID=895

- A 1/8 NPT Male Fitting to 1/8 BSPT Male fitting to connect the T Fitting to the stock hole for the oil sender

http://www.pegasusautoracing.com/pro...s.asp?RecID=56

- A 1/8 NPT Male Fitting to 4AN Male fitting to connect the T Block to the 4AN SS lines.

http://www.pegasusautoracing.com/pro...p?Product=3208

- I got the 4AN stainless steel "44 inch Size 4 TFE Hose, Straight Swivel to 90 degree Swivel"

http://www.pegasusautoracing.com/pro....asp?Product=4

- 1/8 BSPT Male fitting to 4AN Male fitting. [The Banjo bolt is a 1/8 BSPT] This is to connect the 4AN SS Line to the turbo, I used a restrictor plate and haven't tried this myself.

 

* T3 Gaskets - I tried to get just the T3 turbo inlet to Exhaust manifold gasket and they wanted $25 for an Edelbrock gasket. You can order a mid 80s Merkur XRTi gasket kit from O'Reilly's for about $8. It comes with all of the necessary gaskets [Oil inlet and outlet gaskets and the Turbo to downpipe gaskets], not just the Exhaust manifold to Turbo gasket.

* Intake Exhaust Head studs - I ordered a long rod from Fastenal that was the same pitch as the stock bolts, and made my own "stud kit." Two of my stock bolts were broken off in my P79 head and I had to helicoil them so I wanted to do studs instead of bolts.

 

* Intercooler – I am using a Volvo 740i front mount intercooler. I cut off the 180* bend in the J-Pipe and used it to hook it up to the rest of the IC piping. My 2.25” piping goes from the turbo into the intercooler on the LHD Driver’s side, then comes out and goes behind the fan. I was able to run the mechanical fan for a while but eventually it started hitting my piping. I’ve since then converted to an electric fan and would recommend doing that. Because the J-Pipe has that large opening right after the cold side of the turbo, I have mounted a 20 PSI Volkswagen recirc valve as a Blow Off Valve. You can’t do that with the stock Turbo EFI or any other AFM/MAF system without recirculating it back into the intake manifold.

 

* Clutch/Flywheel – Do not cheap out on this. You WILL buy twice. I was running a 11.5 lbs 225mm flywheel off of a KA24DE from a 240SX. I installed an OEM replacement Exedy clutch a year prior to the swap as I was not planning on being turbo at the time. It was prefect for my N/A setup but it began slipping shortly after I had my first tune on the turbo swap. The clutch was only a year old. Since I knew the 240SX flywheel would fit I searched for other options, hoping the 240SX guys had figured something out but realised the best way to go was with the Fidanza for the L28ET [Part #143281]. I heard good things about South Bend Clutches, and found that their clutch was the best offering for the price and fit my power goals perfectly. I have their K06032 ‘Rally’ Clutch that is rated at 390WTQ. This clutch is the same as the 84-86 300ZX Turbo clutch [later 87-89 Z31T ‘W Block’ Clutches were 250mm] They use a 350Z pressure plate and an organic disc. They claim pedal effort will increase by 15-20%

 

**Just to remind you, if you haven’t found it in other threads, the L28ET Fidanza only uses 6 bolts on the Pressure Plate when the stock flywheel uses 9. It is fine to only have 6. I’m not sure why they still haven’t fixed it.**

***IF you are using a S30 tranny and go with a 240mm Clutch, you will need the Throw Out Bearing Collar from the 81-83 Turbo 280ZX as it is shorter than the S30’s. You can get the TOB assembly at O’Reilly’s which includes the collar. It’s about $40. [Would probably be best to use the TOB that comes with the clutch ***

 

* 82-83 CAS [Crank Angle Sensor] Turbo Distributor – If you get the 82 or 83 CAS Dizzy you have to get the “star shaped” shaft as well. It is different from the N/A dizzy shaft and the N/A shaft will not work.

Also, people are having a hard time finding a dizzy connector so I drew up this cheesy diagram of the top side [Not the wire side] of the 82-82 Dizzy connector, the one that plugs into the bottom of the metal housing.

 

http://i254.photobucket.com/albums/hh81/flatblack280/NWAMS/dizzyconnector.jpg

* Downpipe - I am using a MSA 2.5” Down Pipe, I chose to move the bung for the WBO2 sensor further down the pipe to get better readings. My wideband sensor bung is about 3” from the end of the DP and has plenty of clearance in the transmission tunnel mounted at the top.

-------------------------------------------------

Hopefully this consolidated most of the information that is out there, this is not meant to be a comprehensive "swap guide" but hopefully a good jumping off point for doing this swap. As in any motor swap you are going to do much research.

Please don’t ask if the R200 diff will stand up to your power goals, or if the N/A transmission can handle the power.

 

Here is my build thread if you are interested in what motor/other swap specific parts that I used, and what I did with Megasquirt using the stock ZXT Turbo coil and 83 CAS Dizzy to control spark:

 

http://forums.hybridz.org/showthread.php?t=150722

 

 

Feel free to ask me for Fuel/Spark maps if you are using MegaSquirt. I have got the fuel tables down pretty close but I can’t properly tune spark until I get the LT4 knock sensor hooked up for knock retard. I plan on doing that soon. If you are using an N/A motor, and especially the Flat Top F54, be careful with the spark advance. Proper spark control is the best method of preventing detonation.

Edited by RTz
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- I have a special Male 4AN "oil restrictor" plate that bolts on to the oil inlet on the T3, I'm not sure what you would need to convert the 4AN line to the stock oil inlet

Technically he's using the undrilled version of the following link, with a .080" drilled hole to serve as a restrictor... here is the normal version that is pre-drilled:

 

http://www.atpturbo.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=tp&Product_Code=ATP-FLA-020&Category_Code=BCS

 

This is probably the easiest way to go. AFAIK the threadpitch and size for the stock feed flange is unusual and hard to find adapters for. Maybe someone else can chime in that knows the specs.

 

You'll also obviously need a feed flange gasket if you go that route, and that site sells them as well.

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Eeep! I had it at .060 when it got clogged by that chunk of RTV. Opening it up to .080 for you was almost exactly simulating the stock feed line size IIRC. I guess it'll be alright though... As I recall 240hoke was running unrestricted for awhile to no ill effects.

 

Either way, as long as you don't have chunks of RTV floating around in your oil, you'll be fine! :D

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Edited accordingly letitsnow, thanks. And Chris, I didn't make the restrictor hole any larger than the stock lines.

 

You'll also obviously need a feed flange gasket if you go that route, and that site sells them as well.

 

I threw in a note about the Merkur gasket set, which has everything for a T3.

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The inlet thread on a stock turbo(or any normal t3 or t4 chra that I've seen) is 1/8" BSPT, british standard pipe tapered. You can get them from most online hardware stores like mcmaster, haven't seen any at local places though.

 

I don't know about the OEM Nissan turbos, but just about any other Turbo I have used has been NPT, not BSPT, That goes for the Garrets I've installed, knock offs, the Borg Warner I have on my Datsun currently, and a few others I've had my hands on.

 

FWIW, I am running a turbo on my "N/A" L28, I've had it upwards of 14 PSIG non-intercooled and not had any problems. I am currently running 10 PSIG, until I get my FMIC built and installed. I'm running Ford 30 lbs/hr Injectors which at the 44 PSIG base fuel pressure I'm running works out to about 32 lbs/hr. N47 intake, ZXT manifold, full 3" exhaust, Moroso Spiroflow muffler, no cat or resonator, 2.5" intake plumbing, 56 mm TB, which I will be swapping to a 52mm, running on a GM ECM with GM DIS. Runs great and already has more than enough power to get into trouble. LOL

 

Before swapping to the DIS, I ran an N/A dizzy, from a '77 or '78 IIRC, with a GM ignition control module, to interface to the GM ECM and provide ECM controlled timing. It worked well, the DIS is just more accurate and is much smoother than the dizzy set-up was.

 

Flatblack280, you forgot to mention the "TURBO" cam cover, that's required. LOL ;)

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I just checked 3 of the CHRA's I have around, one was a ford t3, one was a 300zx t3, and one was an air research t4. The t4 didn't have threads and my bspt fitting threaded perfectly into both the ford and the nissan. NPT and BSPT are very similar, there is only one thread difference. The BSPT seems to be a little smaller, but you can cram an NPT into one if you try hard enough.

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Flatblack280, you forgot to mention the "TURBO" cam cover, that's required. LOL ;)

 

Haha Only if you're a ricer. I am going to grind the "TURBO" off of mine so that it just says Nissan. :D [Notice in my build thread I still have the OHC cam cover]

 

Shooter what block were you running? N42 or F54? I'm running 30# Ford EV1 Injectors as well.

 

Thanks for all of the contributions, guys!

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I just checked 3 of the CHRA's I have around, one was a ford t3, one was a 300zx t3, and one was an air research t4. The t4 didn't have threads and my bspt fitting threaded perfectly into both the ford and the nissan. NPT and BSPT are very similar, there is only one thread difference. The BSPT seems to be a little smaller, but you can cram an NPT into one if you try hard enough.

 

BSPT will thread into NPT fairly easily, depending on size, but not the other way around. The Ford T3, being off a Turbo Coupe or SVO mustang definatly has NPT threaded inlet and coolant port threads. I've had a couple. ;)

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Haha Only if you're a ricer. I am going to grind the "TURBO" off of mine so that it just says Nissan. :D [Notice in my build thread I still have the OHC cam cover]

 

Shooter what block were you running? N42 or F54? I'm running 30# Ford EV1 Injectors as well.

 

Thanks for all of the contributions, guys!

 

I guess I'm a ricer then, not that I needed it per-se, but I got a good deal, and I like how it looks. ;)

 

Block is F54, head is P90, from an '81 or '82 280ZX, that's as narrowed down as I could get it. I'm sure if I talked to enough 280ZX owners I could narrow it down to one year or the other, from the number stamped into the block. The engine came in the car when I got it. Truth be known, I would have turbocharged an L24 if that was what was in the car. ;) The extra displacement was just a nice surprise. :)

 

I have some 42 lbs/hr low-Z injectors to go in once I get the IC in and am able to turn up the boost a bit. :)

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  • 1 month later...
All this talking and no progress pics?

 

Hope to see some soon. I will be getting a turbo parts car for my '71. :D

 

Ummm.....

 

 

Here is my build thread if you are interested in what motor/other swap specific parts that I used' date=' and what I did with Megasquirt using the stock ZXT Turbo coil and 83 CAS Dizzy to control spark:

 

http://forums.hybridz.org/showthread.php?t=150722

 

[/quote']

 

Maybe read the thread ;)

 

heh just playin. I've been updating that as I go along. The car's been on the road for several weeks now.

 

This was supposed to be a writeup that you could post in newb's threads who were asking about turbocharging their Z. It's got common knowledge that we all know, but it's probably nice to be a newcomer and see all of it in one place.

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