280zx question

[natepriest]

So I recently picked up a 1973 Datsun 280zx and had a few questions. One of the first things I want to do is replace the air intake and the exhaust system. Unfortunately I'm only able to find stock intake for 1973 280's. The closest I can find is for a 75 and I'm wondering if it's at all possible to fit it on a 73 with a little fabricating. I couldn't find the dimensions of the intake I was looking at so I'm unable to take a guess by looking at my car. If anybody has any experience dealing with this issue that would be much appreciated.

[natepriest]

I also had a more general question. I'm not the most mechanically literate person out there and I was just wondering where most of you gear heads would start when throwing some money into a z car. I'm pretty sure exhaust/intake are on the top of the list, but what are the things you would generally repair/replace first to get it running as well as it can?

[Bleach]

well, first get to know the linage of the Z.

 

1970-73 240Z - 2.4L twin carbs

1974 260Z

1975-78 - 280Z first Z with fuel injection

1979-83 280ZX

 

Your 1973 is a 240Z and probably has carbs if it is the factory engine. If you have a fuel injected engine then either your engine is swapped or you have the year wrong. The intake you speak of is just a K&N type cone filter, right?

 

First thing is to put new distributor cap and rotor, spark plug wires, and plugs. Oil change, new fuel filter, check the timing.

 

Then add your filter and a 2.25" exhaust (done by a shop)

 

Depending on the condtion on the engine, the tune-up will get you 10 or more hp.

The air filter and exhaust will get you 10hp total if you're lucky.

[Icehouse]

well, first get to know the linage of the Z.

 

1970-73 240Z - 2.4L twin carbs

1974 260Z

1975-78 - 280Z first Z with fuel injection

1979-83 280ZX

 

Your 1973 is a 240Z and probably has carbs if it is the factory engine. If you have a fuel injected engine then either your engine is swapped or you have the year wrong. The intake you speak of is just a K&N type cone filter, right?

 

First thing is to put new distributor cap and rotor, spark plug wires, and plugs. Oil change, new fuel filter, check the timing.

 

Then add your filter and a 2.25" exhaust (done by a shop)

 

Depending on the condtion on the engine, the tune-up will get you 10 or more hp.

The air filter and exhaust will get you 10hp total if you're lucky.

 

 

What about the turbo engine and the 18's?

[Bleach]

well ya. 18 inch wheels add about 100hp but for some reason that 100hp doesn't work against an SR20DET powered 510. :D

 

Turbo is the way to go. NA mods have very little results. But that's not what this guy is asking. If this is his first time working on a car, the NA engine will be easier to learn basic auto mechanics with.

[natepriest]

You were right about me having the wrong year. The guy I bought it from told me it was a 73, but it's actually a 79. He sold it to me for $500 and seemed pretty gittery, think the guy needed some rocks. Anyway, almost every electrical component in the car was replaced in the search for an illusive problem. I'm sure the oil was changed recently. The best site I was able to find for parts was thezstore.com which had a cold air induction with K&N filter for $130, a billet fuel filter for $100, performance exhaust for $145, and a 3" into 2" header for $235. Do you know of anywhere to get a better deal or a better variety of parts? Do you think these would be the best things to replace as far as getting more power? I did also plan to have the timing checked. Thanks a lot for your help, any feedback's appreciated.

 

Nate

[Bleach]

ok! so it is a 280ZX with fuel injection.

 

As for getting more power you have to realize that any of those bolt on parts will do almost nothing for your car. You'll hardly be able to tell a difference.

 

For sure you do not want to get a billet fuel filter or headers.

 

You can buy a K&N or cone filter separate for much cheaper and run your own pipe off the front of the air flow meter. If you want the fancy powdercoated pipe then get the kit from MSA.

 

If you're keeping the enternal engine components stock (which is a good idea if you want to drive the car) then just keep the factory exhaust manifold and have an exhaust shop put on a new 2.25" diameter pipe all the way back with a freeflowing muffler. What kind of muffler is up to you. Depends on how loud you want it.

Then change out your 3.5 differential for a 3.9 from a 1981-83 non-turbo 280ZX.

 

Keep an eye out for a cheap timing gun if you don't have one.

[speedgato]

NA mods have very little results.

 

 

I don't think I would be so quick to say that..........

[Bleach]

I don't think I would be so quick to say that..........

well then tell us how you can bolt some parts from MSA onto a stock L28 and get a lot of results. This guy is new to mechanics and isn't going to tear the engine apart or run race gas on 12:1 compression. Even then, a stock turbo would do more for him.

[natepriest]

I realize that anything easy enough to swap out with a few bolts probably isn't going to give me a huge jump in power. I was mainly wanting to replace exhaust because it sounds terrible right now, and the air intake just didn't look real efficient I guess. If I were to look into some slightly heavier mechanical work that wouldn't take a long time what would be a good bet? Right now I do need to be using the car pretty frequently, but I'm moving to San Francisco and it'll have plenty of time to spend in the shop then. I saw that the website I was looking at discontinued their bigbore kit for the L-28 engine, what might some other options be that wouldn't require a ton of hours/money. I know none of it is cheap or easy, just trying to get a feel for the stages of restoring these cars. Basically just wondering what somebody wiser than myself would do with it. Thanx again for the help.

[natepriest]

So Bleach since you seem to be the z car guru would you mind if I continue to consult you from time to time on what the hell I'm doing. I've kind of been looking for somebody with your kind of knowledge to help me with the questions that I'm sure will arise as I delve into this project. I'm sure you probably have a lot of other shit to do, but I doubt I'll be needing advice very often seeing as I don't have a real abundance of money.

[speedgato]

well then tell us how you can bolt some parts from MSA onto a stock L28 and get a lot of results. This guy is new to mechanics and isn't going to tear the engine apart or run race gas on 12:1 compression. Even then, a stock turbo would do more for him.

 

You're saying just bolt-ons, agreed, to a point. You can bolt on a turbo, but you won't take advantage of it's full potential without some engine work to lower the compression to allow for higher boost. Either way, more work than "bolt on" needs to be done.

[datzenmike]

Lowering compression will make it run like a pig during everyday driving or anything below 'turbo'.

[Bleach]

So Bleach since you seem to be the z car guru would you mind if I continue to consult you from time to time on what the hell I'm doing. I've kind of been looking for somebody with your kind of knowledge to help me with the questions that I'm sure will arise as I delve into this project. I'm sure you probably have a lot of other shit to do, but I doubt I'll be needing advice very often seeing as I don't have a real abundance of money.

The general idea for your basic NA mods if you're willing to tear apart the engine are to do some head work.

Port intake, bigger cam, shaved head (higher compression), new timing chain advanced to #3 position, and then headers and exhaust.

Otherwise, if you don't do that head work headers are pointless.

If you want to go turbo, I'd highly suggest an engine swap to a factory 280ZX turbo engine. The whole thing, not just a turbocharger.

You can consult with me but even better would be to find a forum specific to Zcars. There are a lot of archived info on mods you can do, their difficulty and cost, and what the results are.

zdriver.com / zcar.com /hybridz.org

search through those websites and you'll find way more to read than you have time to read :D

 

oh, and if you end up doing head work, you might want to first do that work to one of the newer 280ZX engines. The 1981-83 engine had flat tops, closed chambered heads and higher compression stock. (F54 block P79 head)

You can do that work and then swap out just the block/head while maintaining your cars factory fuel injection. (no wiring!)

The P79 head will have round port exhaust. If you use that head, don't forget to order a header for that year of engine. 1982, or 83 ect. Not for 1979 as it may not fit the newer head.

[speedgato]

The general idea for your basic NA mods if you're willing to tear apart the engine are to do some head work.

Port intake, bigger cam, shaved head (higher compression), new timing chain advanced to #3 position, and then headers and exhaust.

Otherwise, if you don't do that head work headers are pointless.

If you want to go turbo, I'd highly suggest an engine swap to a factory 280ZX turbo engine. The whole thing, not just a turbocharger.

You can consult with me but even better would be to find a forum specific to Zcars. There are a lot of archived info on mods you can do, their difficulty and cost, and what the results are.

zdriver.com / zcar.com /hybridz.org

search through those websites and you'll find way more to read than you have time to read :D

 

oh, and if you end up doing head work, you might want to first do that work to one of the newer 280ZX engines. The 1981-83 engine had flat tops, closed chambered heads and higher compression stock. (F54 block P79 head)

You can do that work and then swap out just the block/head while maintaining your cars factory fuel injection. (no wiring!)

The P79 head will have round port exhaust. If you use that head, don't forget to order a header for that year of engine. 1982, or 83 ect. Not for 1979 as it may not fit the newer head.

 

Dead on! Nice.

Seriously, Bleach isn't kidding, for Z cars, Hybridz.org is just awesome.

 

As for running like a pig, the stock turbo motor has less compression from the factory. It doesn't run like a pig at all. Unless you have a huge turbo installed with huge lag, all the lower compression does is allow for higher boost more safely. My brother runs a 77 with an 82 turbo engine installed it's no pig at any range.

[datzenmike]

As for running like a pig, the stock turbo motor has less compression from the factory. It doesn't run like a pig at all. Unless you have a huge turbo installed with huge lag, all the lower compression does is allow for higher boost more safely. My brother runs a 77 with an 82 turbo engine installed it's no pig at any range.

 

Agreed. But lowering compression lowers power output which means you have to step into it more and have the turbo put back what was taken away. Higher compression risks detonation, true, but this can be controlled (limited would be a better word) by using an intercooler and perhaps some kind of ignition retard as part of a fuel management system. I know they aren't cheap, but neither is taking it apart to lower compression. Just an opinion.

[speedgato]

That is exactly the point of a turbo. You loose initial compression and then add artificial compression with the turbo. That is why some of those turbo'd sr20s can have such high horse under boost. There is no way you can have that kind of hp with high compression and intercooler, meth injection, nothing.

 

My point is, with anything you do to increase hp, you need to figure on doing some work. Turbo does not necessarily make it easier or less expensive. It really depends on the intent of the build.

[Bleach]

dont' forget the stickers!

[speedgato]

dont' forget the stickers!

 

 

:lol:

I was just giving a guy in our club a bunch of crap about his stickers!! Yes, you must have a grip of stickers to go faster!