i want info on turboing the non turbo engine

[Guest mrcow]

Over the last two days i have read every thread i could find about putting a turbo on a non turbo engine. I went through every page in this section.

 

The reason i am interested in this is pretty much the same reason all of yall that have done it were... i have a strong non turbo engine that i trust more then something i would find in a junkyard. I am also not looking to max out the boost but just get more zip.

 

my question to yall is, how has it been? have yall run into any problems since installing it? would you go that same path if you had to start all over? most of the posts i found yall were in the process of installing the turbo and i never found any follow up posts.

 

thanks

[Guest bastaad525]

there are guys on the forum here driving motors that were N/A and just added the turbocharger... it should be fine you just have to keep in mind your threshhold for detonation will be a bit lower... so you need a bit more fuel and a bit less timing advance, but really I dont think its a very big deal at all... the hard part is just finding all the necessary parts... But really even the usual N/A L28's compression levels are not so high that it's just so bad to run a turbo on them, and if anything you benefit by having a much more resposive throttle off the boost. If you're aiming to just keep it mild, I'd say there'd be no worries at all.

[Guest mrcow]

well i am definitely going for a mild boost. i am not going to try and crank out 350 hp. i want to keep this car as my daily driver. In all of my searching not many people seem to turbo the N/A engine. I guess many of the people are trying to get excessive amounts of power therefore the n/a engine wont work. Also, the other big catch is what the price difference is going to be. I am guess when looking at the big picture the price difference probably isnt worth it, but thats what i am trying to figure out.

[Clifton]

N/A top ring land is thinner. That's the only weak link. Just don't let it knock.

 

I'd have to disagree with more fuel. Too much and it just lowers power. May as well run it at 12-12.5:1 and lower the boost. I never run richer than 11.7:1 regardless of octane or boost, I aim for 11.8-12.2:1.

[(goldfish)]

N/A top ring land is thinner. That's the only weak link. Just don't let it knock..

 

 

Is that just for the dished n/a pistons, or does it apply to f54 flat tops also?

[fl327]

yes flattops too.

[Guest 260ondubs]

Well, I am one of those people who are 'presently finishing it up'. Mine isn't on the road just yet, but I can tell you about some of the problems you'll run into from my experience.

First of all, is the car a 280ZX or a 1st Gen?

I have a 260Z, so I had to do a lot more with the actual chassis differences (fuel tank and stuff etc...) but otherwise we can go from here with the same situation.

I have left my block alone for the turbo swap. It is an F54 with dished pistons. Something I am still in the dark with even today is whether dished pistons were only for the turbo motors or if they put them in the N/A's as well OEM. I'm in Australia too so parts for a L28ET are non-existant.

I changed the head over to E88 and had it machined and prepped for fuel injection. Plus, all the valve stems and the like were replaced with better items. I'm not sure on my camshaft, but it is either a E88 or L20ET.

I lowered the compression via a 1.5mm headgasket AND a metal head shim. If you are going to turbo a N/A motor, you might as well do it correctly... If you leave the CR at stock you are just inviting detonation or some kind of failure right to your door.

Also, fuel is another important area. I've gone all out with programmable engine management and huge injectors, multiple fuel pumps and custom fuel rail..... but the stock won't cut it, so at the minimum get bigger injectors and another pump. My engine when it was N/A was leaning out at 6000rpm when it was stock and that was without a turbo!

Of course you must intercool it.

I think though (and here is the good news) the basic inherent strength of the two motors (N/A and turbo) are about the same. Just alter the compression and fuel and it should be okay.....

 

And by the way, can anyone answer my query from above? Did only the turbo L28's come out with dished, or did they make dished with N/A motors too? Surely then it would need a different head (such as P90 for turbo..... hmmm)

 

EDIT I think my question jsut got answered.... there IS dished pistons for N/A L28's..... from factory.

[Clifton]

And by the way' date=' can anyone answer my query from above? Did only the turbo L28's come out with dished, or did they make dished with N/A motors too? Surely then it would need a different head (such as P90 for turbo..... hmmm)

 

EDIT I think my question jsut got answered.... there IS dished pistons for N/A L28's..... from factory.[/quote']

 

You are right, there are dished N/A pistons. The turbo pistons have P90 stamped on the tops.

[Guest 260ondubs]

Okay Clifton, then can you tell me how they kept the CR high in the N/A motors when they put dished pistons in? Is it all in the head?

 

We didn't get the factory L28ET's here in Australia. I have an F54 block with dished pistons. I have to assume that it originally from an Aussie delivered 280ZX. So now that the piston-thing makes sense, it just the head thing that i'm concerned about.

 

I have some numbers from my block if that helps anyone solve this for me.

 

It has: 821887 on it.

 

and: 3708A

 

I know they are serial numbers but do they define if the motor is turbo or not from the order produced. Can it be worked out from these numbers?

[yo2001]

I lowered the compression via a 1.5mm headgasket AND a metal head shim. If you are going to turbo a N/A motor' date=' you might as well do it correctly... If you leave the CR at stock you are just inviting detonation or some kind of failure right to your door.

[/quote']

 

Dropping the compression with a head gasket is not a correct way to lower the compression. You'll be alternating the quinch of the engine which can cause poor mixture and more prone to datonation.

 

I ran a pretty odd combo of L26 bottomend with P79 head with stock N/A ECU with MSD BTM. I kept blowing out the head gaskets until I got Z31 ECU with better timing and fuel control. The bottomend ever gave me any problems though.

[Guest 260ondubs]

Dropping the compression with a head gasket is not a correct way to lower the compression. You'll be alternating the quinch of the engine which can cause poor mixture and more prone to datonation.

Quote ^^^^^^

 

I have a Haltech E6X with a very expensive fuel system, I think i'll be fine when it comes to detonation and mixtures.

[akeizm]

Yep the na turbo conversion engine I have was a dished pistoned n/a in a n42 block.

[Clifton]

Okay Clifton' date=' then can you tell me how they kept the CR high in the N/A motors when they put dished pistons in? Is it all in the head?

 

[/quote']

 

Yes,

The early dished piston motors had 8.3:1. They had smaller combustion chamber than the P90 turbo head so it keep the compression up. The turbo uses the same dish but the combustion chamber is alot larger and the valves are .100" shorter also. I don't know what the numbers on the block mean but I do know every turbo piston I have seen has P90 stamped on it. As longe as you don't let it knock hard you shouldn't have a problem. I have broke L26 and L28 pistons but only from hard detonation.

 

 

Dropping the compression with a thicker gasket is not the best way but it works. I stacked 2 on my Toyota 3VZ and run a 3mm on my 7M.

[fl327]

NA motor can be turboed and make power, but its often cheaper, better, and stronger, in my opinion and experience to just do the whole l28et engine, unless you have this parts list on hand..

Turbo oil pump

oil pan

injectors

eccs efi harness and sensors

dp

exh manifold and turb0

 

piecing it together costs more than the turbo setup if you can get one complete, which ive seen anywhere from 150-500.00 and last two parts zxt cars ive had cost me less than 500.00 each, selling parts of the t5 car actually net me a small profit which I used to add a few fresh sensors and parts to the conversion.

Not trying to crush the dream, but it sounds like you want a car that has good zip and is reliable, the stock zxt setup in a z can do that easily, wheras turboing an NA engine opens up more variables that must be addressed due to the car not being initially setup for turbocharging and the addition of a turbo. Not saying it couldnt or shouldnt be done, but this isnt what ive heard, this is what I know.

[GrayZee]

I agree with FL327 that it is easier to just buy a complete 280zx turbo car and swap everything over. However that is not always possible. I've never tried to turbo a N/A engine (yet) but if I did, this is how I would do it..

 

You pretty much HAVE to get your hands on a turbo exhaust manifold

(unless you have the skill to make one)

 

Of course you need a turbo (buy a new one if you have the cash)

 

I wouldn't worry too much about the turbo oil pump (as long as you aren't running a oil cooler or something) However it certainly couldn't hurt to get one either.

 

The n/a oil pan can be modified easily enough to accept a drain port for the turbo.

 

I would get all my injectors, ecu, sensors, ect. straight from a z31 car (better setup and likely alot easier to find)

 

and lastly I would seriously look into getting a intercooler for anything other than stock boost to make up for the higher CR

[Sean73]

From my own observations, the top ring land on the flattop L28 piston is the same thickness as the L28 turbo dished piston:

 

 

I know of at least 3 people running this setup, including myself, pallnet, and Tony D.

 

I have about 900 miles on my 8.8:1 CR L28ET, running about 10 psi normally. Dynoed at 232 HP @10 psi.

 

Soon I will be upgrading to 460 cc injectors for more boost.

[mobythevan]

nice picture, so does that settle the thin ringland issue?

[Guest mrcow]

those pistons are lookin pretty similar. so basically the differences are the CR and the better swirl characteristics of the P90 head.

 

what if i was aiming for 250RWHP by turboing the N/A engine, do yall think that can be reached safely? How much boost and resulting HP can the stock 280zx turbo provide? it seems lots of people are around the 230 RWHP range, so maybe the N/A engine cant be pushed to 250.

[Clifton]

You can make the same rwhp with n/a dished pistons as with turbo pistons. It's just that the chances of breaking a ring land from detonation are greater. As long as you don't let it knock you're ok. I wouldn't try 18 psi on 91 octane.

[yo2001]

I say you can do 250WHP on N/A bottomend with a right turbo and good tuning. I don't know pushing a stock turbo will get you there since you have to run alot of boost to get the airflow you need but with bigger turbo I think it can.