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Questions about 78' 280z turbo build


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So I've been forum lurking for a while here now, and reading up on turbo L28 builds,

and I was wondering if you guys could help me out with some questions I have as I have 

never really done much work on my own cars before and I'd like to start. 

I'm basically gonna copy and paste what Gollum wrote in response to another

post to let you guys know where I'm starting at. I'd just like to get some recommendations

and definite answers on what I need/should purchase and in what order.

I don't think my goals are to outrageous I'd just like my care to be moderately fast.

 

Is this a street car? Daily driver

 

Will it see track use? It's possible

 

What kind of budget are we talking about? I'm hoping to spend less than $3000

 

What kind of level of performance are we talking about? I'm trying to get around 

230hp to the wheels.

 

 

Fast as a new mustang? Fast as a Corvette? Fast as an enzo? 

Looking to hit 0-60 around 6 seconds

 

What's your experience level? Basic

Have you done engine swaps before? No

Can you weld? No

Rebuilt a motor before? Yes

 

What access to tools do you have? A pretty good variety

Have a cherry picker? Yes

Welder? No

Grinder? No 

Decent Bench? Yes

Assortment of jacks and stands? Yes

 

Basic list of parts I'd suggest:

 

Was wondering if you could give me some pricing on what I should pay for these 

parts used or new Gollum suggested.

 

Turbo manifold

Turbo (T3/T4 hybrid works well for a street setup)

300cc+ injectors, 400+ preferred

Any 'ol intercooler that fits

Turbo intake will make integration with HVAC easier

36-1 Trigger wheel + Sensor

MS 2, or 3

Coils (LSx work great, or EDIS-6 is fine too)

MS Wire Harness

Laptop with serial port

Manual Boost Controller

 

I'm getting my car dyno'd soon to see where I'm starting at.

 

Do I need to do a head swap on my L28 to turbo it or can I just slap a manifold 

on with a turbo? 

 

Are dished pistons required? 

 

Do I need a turbo downpipe and exhaust?

 

Do I need a stronger rear end or anything else? 

 

I know my questions  will probably sound overly simple to you, I have a tendency 

to over think things.  I'd appreciate any help you guys can give me. I think I have

some pretty reasonable goals with a pretty decent budget. I'd prefer to avoid a

head swap if I can as I'm low on time due to my work schedule.

 

Thanks 

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Rather than telling you what you should expect to pay for each part (that's your job to figure out), I'll tell you that you can easily do the whole thing for under $3000.

And if you're looking for 230WHP you won't need a T3/T4 hybrid to get there, although that would be a nice setup. The stock T3 turbo will get you to your power goals and will be easier to source, as well as be more straightforward to install (no spacer needed).

No, you won't need to do a head swap but like the T3/T4, it would be nice. That leads me to ask, do you know what block and head you have on it now? You imply that you have flattop pistons, but do you know that for sure? The OE engines in the 280Z came with dished pistons. You should check the stampings on your block and head to see what you've really got. To check your pistons, pull out a spark plug and shine a light in there to get a look.

Yes, you will need a downpipe. Motorsport Auto (MSA) sells them. They do have a O2 sensor bung welded on them but many feel, me included, that they are too close to the turbo outlet. If you get one you may consider getting an additional bung welded on further downstream. On mine I put it at the other end of the downpipe, close to the exit flange. For exhaust on a turbo car, the bigger the better. Many people choose to go with 3" tubing which works great. 2.5" tubing will also work fine but it's not ideal.

Whether you need a stronger rear end or not will greatly depend upon how abusive you will be to it and how much traction your rear tires will be capable of. If you plan on drag racing it and/or slamming gears you might get into some trouble. If you treat it nicely with smooth shifts and avoid shocking your drivetrain, it should be okay. Remember that if you have big and/or sticky rear tires capable of creating a lot of traction, that force will be transmitted into your drivetrain. Depending upon what clutch your car has in it now, that may be one of your weak points that needs attention. You may want to consider a clutch from a turbo car or other suitable unit. Plan accordingly.

For injectors you have a lot of options. I ended up using 440cc Supra injectors and I think I paid $180 for 6 of them, used.

For intercoolers, again you have a lot of options. Certainly you can pick a good used one up for $100 or less.


Your intake manifold you have now should work fine. No need to switch over to a turbo intake manifold, although I'm not sure what the HVAC concerns are.

MS2 is the tried and proven solution for these cars. You should be able to get all the MS stuff you need (ECU, relay board if you want, wire harness, etc) for about $500 or so.

You don't need to go with a fancy EDIS solution for spark, but of course you can if you want. It's a nice way to go, but not necessary. The stock distributor and single coil setup out of an '82-'83 ZX turbo works pretty well. Any good quality coil will work.

Laptop prices vary greatly. Mine cost $0 (a hand-me-down), but you should be able to get something that works fine for not much more than that.

Manual boost controller you can make yourself with parts from your local hardware store. Search for "grainger valve" and "threaded rod" on these forums and you should find what you need to know. If you want something that's adjustable from the driver's seat (not needed nor advisable), that's a different story.

The more reading you do on this subject the better. Plan things out and know what you want before you dive into it. Get as many parts as you can before you start ripping the current parts off your car.

Some things to research that you didn't mention in your post are turbo oil drain, turbo oil feed, fuel pump, oil pump, fuel lines, fuel rail, fuel pressure regulator, wideband O2. Not saying that you need to upgrade all that stuff (you will need the turbo oil feed and drain though), but you should learn as much as you can before you get started.

What is your time frame? You sound a bit in a hurry due to your work schedule. Are you working now? Can you only work on your car in the evenings and on weekends? Keep in mind this is not a project you can rush through and get done in a week, or two, or three, or likely four. It will take thorough planning, the acquisition of all your parts, identifying parts that need to be modified or fabricated, fabrication and assembly time, acquiring the parts you didn't think you needed, troubleshooting, tuning, etc. My turbo conversion took longer than most (~ 2 years) but I had very little time to work on the car, just a handful of hours every month.

Good luck with the project.

Edited by OhBilly
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Thanks for the reply this is pretty much what I wanted I really appreciate it. I'm not so much in a rush as I work a lot so I can only work on my car on the weekends. I found a full fuel setup out of a 90s supra I'm going to purchase this weekend for around $160 fuel pump rail an 440 injectors, I also found a set of ls1 coils for $60 I found a 3" turbo exhaust for $275 as well I'm really glad for the info you've given me this makes it a lot easier on me as I can piece together everything I will actually need to get right away.

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Ohbilly, your ECU prices are a tiny little bit off...I just finished helping a buddy with his MS2 purchase and he went as cheap as he could get away with. You might find the parts needed used or on ebay for the 500$ mark

 

To include the ECU KIT, not preassembled, 8' wiring harness pigtail, the two temperature sensors, all new connectors for the engine, and a wideband O2 sensor, the total comes to about 680$ delivered. MS1 is about 530$ delivered.

 

The fuel components you've gotten will work fine...but you need to get the correct connectors for those injectors...they aren't a stock-type EV-1 connector, some toyota connector.

 

The supra fuel rail won't fit, and the stock Z rail won't work with the supra injectors...you'll need an o-ring rail for those injectors.

 

The stock, factory assembled N42 blocked-N47 headed engines have pistons with a 10CC dish in the top. F54 block N/A engines had flat-tops, and F54 block turbo motors had 10CC dished pistons. Anything is possible if it's a rebuilt engine, though...

 

The N47 head has the steel exhaust liners in it that are not really capable of handling the heat of the turbo exhaust. There are a few members here who ran them, and more than one (I can only think of two, so not sure exactly how prevalent this problem is) found out when he pulled the manifolds that the liners were nearly burned completely out. That means metal flakes and rust being blown through the turbine housing, which some feel may damage the turbocharger. Other than that, the head should work fine, you'll have a compression ratio about 8.3:1 instead of the stock turbo compression ratio of 7.4:1. There are varied opinions on what is ideal and what is too high, or too low.

 

Like OhBilly said, alot plenty of time for this. If you've done this exact swap before, it can be done in a weekend. I've pulled an engine, and re-installed it, in 5 hours. I've also, on a separate occasion, installed an MS-1Extra setup on an L28ET in a car that had unknown electrical problems and had the car running in 48 hours. (continuous...not recommended...)

 

It's plausable that it could be done on a three-day weekend...but if you've not done this swap before, count on at least 85-100 man hours of work.

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Thanks for the clarification on current prices Xnke. In my pricing I wasn't including wideband or any other assorted connectors needed. I bought my MS1 kit about three years ago, along with the 8' harness, relay board and IAT sensor and I think it came up to about $420.

 

Bigfat280z, Xnke pointed out some excellent things that emphasize the details that need to be considered, like the exhaust liners, injector connectors and the different fuel rail needed for the Supra injectors. Pallnet makes a popular Z fuel rail that a lot of guys use for that style injector, and I think there is at least one other guy who is making them as well but I don't remember his name.

 

I don't know the specifics on the Supra fuel pump, but my guess is that it is an in-tank pump. I don't know if it could be modified to work as an inline pump or not, so you might want to consider a universal inline pump. Lots of people go with Walbro pumps but there are others that work too.

 

Keep at it and have fun.

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If you have some time to do some reading check out my build thread. (link in my signature)

 

I go through the majority of questions you asked. With lots of pictures. It may help you. (Start on page 3 for turbo motor related stuff)

 

You can see my process in converting my n42/n42 setup. And I'm diving into megasquirt in the next couple weeks. So those updates will follow.

 

Best of luck with the project!

 

Keep us posted on progress!

Edited by OldAndyAndTheSea
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It's amazing how when someone posts a thread with QUALITY input they get QUALITY responses. So far all the advice given is GREAT!

 

Regarding the dizzy versus coil packs: The reason I usually skip recommending the turbo dizzy is that #1, they're more prone to signal noise/jitter than a crank trigger. #2, the stock dizzy/coil setup doesn't offer near the spark energy coil packs can, and with the price of a MSD add-on you might as well just get LS1 or EDIS coils. #3. The only "new" or "reman" dizzy out there at stores will cost you over $200... Even if you can find a used one for $50 or less, if it ever fails guess what? You're getting towed home. If a LS1 coil fails, find the nearest parts store and start walking, they'll have it in stock. All in all the turbo dizzy is FINE, and I run one currently. I plan on going COP with LS or similar coils, but right now my car hasn't left the garage in the last 1.5 years, so I'm not in a rush...

 

The HVAC comment: Was more directed towards the fact that the turbo intake has a LOT of stuff on it that's turbo-specific. There's a fun little do-da that prevents BOOST from reaching your HVAC controls. If you use your stock intake with no modifications, if you have the AC on then anytime you're under boost you'll have a heater inside the cabin instead.... Careful study of the turbo FSM will show you EVERYTHING you need to know about the turbo specific systems that you can choose to replicate on your own.

 

Also, even though 230whp is easy as pie, you'll also want a BOV and I recommend a recirculating type, which is super easy to plumb considering the throttle body is right near the turbo inlet. 

 

The N42 head has liners. Yes, they "can" disintegrate and go through your turbo. Yes nissan obviously REMOVED them for the turbo head, since the NA head at the time had the liners. But there's little documentation that I've seen as to the real reason why they did it. If they wanted to they could had made the liners thicker to take the heat better. We know the liners are intended to get hot and help reduce emissions, maybe nissan thought that the turbo would already be creating PLENTY of heat so that the liners just plain weren't needed? We don't know for sure, either way. But what we DO know is that the guy who have seen issues turbo'ing a liner head certainly weren't running "mild" setups. IIRC one was running close to 300whp. And if IIRC the other guy was running non-intercooled. There's been probably hundreds of guys to turbo a liner'ed head, and we have only a small handful that have had bad results. If you want to remove them, go ahead. It's a PITA but can be done with any die grinder. Expect that to add 4+ hours to your build as you'll want to be VERY careful, take your time, and not get any shavings back towards the exhaust valve.

 

For 3k this is a realistic swap. You should have enough loose change at the end of this build to sort things out nicely and really "finish well" as I like to say. Many times with tight budgets guys get 90% done and run out of cash, and just force the rest of it to work and the results, even when they work, are usually not ideal.

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Removing the liners without re-working the ports (involves a lot of welding of dirty, corroded aluminum deep in a hole and is not easily done) will murder your exhaust port flow. Don't do it unless you intend to go all out on a very, very expensive project.

 

E30, E31, E88, N33, N42, O5L (turbo L20A), P90 (turbo L28), and P90A (turbo L28) heads have no liners. N47, P79, Y70, and the Maxima's N47 all have the cast-in-place exhaust liners.

Edited by Xnke
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"murder your flow" is a bit overboard don't you think xnke? The data is out there for those that dig, but yes it will hurt flow to remove them.

 

If it were me, I'd run the liner'ed head with a cheap T3 and not worry about it. If it blows the turbo, oh no, i'm out a whopping $100 and I've actually DRIVEN the car in the meantime. Then I can worry about sourcing a different head and turbo.

 

The reality is that at 230whp just about ANY T3 should do fine, and on a stock longblock that should only take around 12-14 intercooled PSI which shouldn't get THAT hot. As long as it's tuned well the EGT shouldn't be crazy and shouldn't cause the liners much issue.

 

But hey, if you find a non-liner head for under $150 these days, go for it! 

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Last head I removed the exhaust port liner from, before re-welding the port floor and working the roof to match, went from 112cfm at 0.420" lift to 79cfm....So yes, I would call that "murdering the port flow". This was an L16 head, with a very small exhaust valve, but a similarly sized exhaust port to the L6.

 

I like to fiddle with old datto heads....the L6 guys say don't remove the liners...the L4 guys say it has to be done...I needed to know.

 

Now I know what *I* can do with a roundport head, but just cutting out the liners is a huge step backwards. To remove the liners, weld up the floors, reshape the port and then work it for best flow, it is a very large amount of work for a not very large increase over a well ported squareport head. If I had ready access to the flowbench I use occasionally to check things, I would have more detail than I am willing to put forth here.

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Had you removed the entire liner, as cast in? Or did you just remove the part the protrudes from the casting? I seem to remember some flow bench test showing before and after just the protruding liner material removed on a L6 head and the numbers weren't THAT bad.

 

But hey,you're speaking from experience with never lies, even if it's not true for everyone in every context.

 

Right now the price for a non-liner head isn't very cost prohibitive, but at the rate prices have been rising it might soon be cheaper to weld up a liner head!

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For a stock port, stock cams are fine. People really like the "a" cam for the turbo. Even though it's NA and has more overlap, which some anal bench racers swear against, the extra duration does a lot to improve the powerband.

 

The second half of that bit of info is that the stock ports are fine until you're trying to get to 400whp, and at that point you've got to be running the RIGHT turbo, with the RIGHT tune, with all the RIGHT parts to complete the SYSTEM to get to those levels and beyond on a stock head. Not saying it can't be done. On the contrary I'm sure it has, plenty of times.

 

On the other hand, a mildly prepped street head by robello, braap, yourself in your garage, etc can make WORLDS of difference. Matching mild port work with careful port match work done with a custom intake/ported intake, matched with the right cam can make 350whp a breeze to make. I can't remember his username on here right now, but if you go through Big-Phil's youtube videos you'll see a friend of his (who is on here I believe) who (if memory serves correctly) put over 400 to the wheels at LESS than 14psi.

 

Think about it this way, if "all things were equal", which I'll tell you they wont be, a motor running 1 bar of boost (14.7) should make double it's NA HP. That doesn't happen exactly, but it's in the ballpark. If the stock L28E makes around 175 crank HP, then you'll need about 2.75 bar of boost to have enough power at the crank to make 400 to the wheels. That's a LOT of boost! It makes everything complicated in all reality. On the flip side you can modify a L28 to make 200whp, 250whp, or even 300whp. For simplicity sake lets say 200, lots of people manage that around here. That's around 235 at the crank. So now you're only running about 1 bar of boost to reach 400whp.

 

And THAT is why it's complicated to answer the simple question of "what cam is good for X horsepower". It's all about the application of how you get there! In the end it all comes down to what I started this post with. The cam should match the SYSTEM. The port, the intake, the chamber, the valve size, etc. Sure in every setup there's a "range" of cams that will work fine and you can fine tune the torque curve to some extent with difference choices, but in the end you will always want to match a cam to a SYSTEM, not just throw a cam in a stock or unknown head and expect power.

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Think about it this way, if "all things were equal", which I'll tell you they wont be, a motor running 1 bar of boost (14.7) should make double it's NA HP. That doesn't happen exactly, but it's in the ballpark. If the stock L28E makes around 175 crank HP, then you'll need about 2.75 bar of boost to have enough power at the crank to make 400 to the wheels. That's a LOT of boost! 

Right idea, but I think your math is a little off.  It appears that you were assuming 20% driveline loss for your 400hp to the wheels number, which would require a boost _ratio_ of 400/175 =~2.75.  So, you would need 1.75 atmospheres (not bar) of boost to reach 400rwhp on your otherwise 175hp engine.

 

1atm = 14.7psi

1bar = 14.5psi

 

...so somewhere around 26psi of boost.

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Tim ~ I was assuming 15% and then I rounded a few numbers because I was just in a hurry to make a point. Obviously I was in such a hurry I had a typo or two. But thanks for the clarification for those trying to not crunch the numbers themselves. :wink:

 

I just figured out what happened...

 

175 * 2.75 = 481 crank hp

 

481 * .85 = 409 wheel hp with 15% loss

 

But 175 * 1 = 175.  The 2.75 number would be 1.75 * atmospheric pressure equivalent and I just forgot to subtract the 1 for "normalizing" the equation/formula.

 

But now everyone can see just how easy it is to figure out! :-) And just as important, 1 bar is NOT perfect atmosphere, but 14.5 psi while standard atmospheric is 14.696 psi or commonly rounded to 14.7. So keep that in mind when calculating BAR pressure required versus PSI pressure for a given output.

 

And then remember that calculating boost requirements this way is just to give you an IDEA of requirements. Real world application will require factoring in YOUR altitude, average outside temperatures, intercooler plumbing losses, actual intake air temps under boost, size of compressor/efficiency under use, etc.

Edited by Gollum
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