i have a 280zx 2+2 (1979) i have fuel injection. and its alright but i prefer carborators. if i were to take carborators from a differnt Z would i get a HP gain.. i noticed the year Z b4 mine has around 35 more HP than mine and its the same size engine.. wat are some fairly simple and inexpensive changes or upgrades i could do to make up for HP and still be smog legal for the next few years?

 

and also i read up and i learned that the z b4 mine had 170 HP and mine is only pushing 135 and i would much rather have 150+ at least. thats y im wondering about some easy upgrades

 

Those earlier Z's were rated using SAE gross hp, not SAE net. Gross measured hp on an engine dyno with no accessories hooked up to the motor. Net measures hp at the flywheel with the accessories on the motor. That's part of the reason some of those old muscle cars from back in the day had so much hp, but their stock 1/4 mile times weren't that impressive compared to cars nowadays. Both measurements will still be higher than if you run your car on a chassis dyno (wheel hp).

 

I'm not positive but, I'm pretty sure Net measured Hp at the wheels. I was always thinking it was 145 at wheels and 180 at flywheel(For ZX's). ...and 135/170 for Z's

 

No, net hp is exactly what lifegrddude said. Gross is the engine by itself and Net is at the flywheel. I always remember it by trying to catch a fly with a net.

 

The only car manufacture that measures HP to the wheels is TVR.. Everyone else, as of today, measures at the flywheel..

 

So tell me what exactly is the difference between at the flywheel and at the engine, When they measure an engines performance, they're measuring at the flywheel. Heh....I'm almost positive it's 135 to the wheels. I started a thread about this, lots of contreversy over it. Lots of opinions..No one really agreed about it. I'm pretty sure net hp was at fly wheel, and gross was at wheels..Think about it..Net..an estimate of how much you have gross..how much you can actaully use....

But I'm not sure, like I said we never sorted it out in my other thread...let me go check.

 

So will he gain Hp from the Carb?

 

With gross hp the engine is supported by the dyno itself. None of the accessories you see in your engine compartment are on the engine like ac, ps, alternator. With net, the engine is self sustaining. It's only provided power from an outside source and the dyno is attached to the crank or flywheel. And net is the final outcome. THink of it like a paycheck. Gross=before taxes. Net= after taxes. Taxes being anything that would rob power. Make more sense now. THe reason they don't measure it at the wheels is because this way they can just measure power from the engine without having to strap into a car first and alot of engines go into more than one type of car. It's just cheaper and easier to measure the engine and not at the wheels. Nissan definitely does not measure at the wheels. The 280z and earlier cars used a different method to measure hp(gross) then the ZX and up(net). And the 170hp 280z no matter how it was measured still used the same fuel injection system as the 280zx, not carberaters. You'll probably gain some hp over the stock FI though just because you won't have the emissions restrictions built in and you can run the fuel as lean or rich as you want.

 

Oh and an easy way to net a few more hp and would probably be cheaper than converting to carbs would be to get an 81 or later L28. They made more hp than the 79 and 80 engines did. Or you could go all out and just get the L28ET!

 

A stock 280Z or 280ZX in good running order will put about 120hp to the wheels. I have several dyno sheets to prove it if anyone disagrees.

Fleaicous, putting carbs on a stock L28 with do three things for you. First, it will give you about a 10hp or 12hp increase. Second, it will give you about 15lbs of torque. Third, it will make your torque curve almost completely flat. This means that you have about 150lbs. of torque right off idle continuing until about 4200rpm when it begins to drop off. You will also notice better throttle response with carbs on the engine.


Here are some dyno sheets to prove it actually. The first one is a stock L28 with an N42 head. The second is a stock L28 with a P79 head and stock roundtop SU carbs off of a 240Z.

 

Drew,

That's a good comparison although a bit anecdotal.

Although you can initially get better performance from the carb setup given a specific set of environmental parameters, the carbs will have much worse cold start driveability as well as an inability to adapt to changing environmental conditions like cold, heat and altitude.

The carbs will need to be adjusted for each one of these environmental changes whereas even the stock fuel injection will handle these changes with little effort.

Once you start talking about upgrading the system for performance, FI is the absolute best way to get the most out of your engine.

Aftermarket FI w/ a MAF conversion and properly sized fuel injectors will deliver substantial power, driveability and fuel economy increases literally impossible for a carbureted system.

 

Haha, LWW I knew you were going to come back with something about stand alone. I was just waiting for it. You are correct though, as always. But for simplicity sake carbs are an easier and less costly conversion. Although stand alone is a much better system in the bigger picture.

 

You sir are correct!

And I do have carbs on one of my 240Z's and even one of my 280zx's! But this is purely for nostalgia reasons.

I have fuel injection on everything else.

And don't discount stand alone systems as being too expensive. You can get a pre-built MegaSquirt system now for under $250 and a MAF from a 300ZX for under $100. So, $350 and some know how and you can have a very configurable stand alone system.

Cheers,
lww

 

Simple. It's an interesting term isn't it. While carbs may seem more simplistic, and are without a doubt more simple to install; FI, while not so simple to install if wiring isn't your thing, is much simpler once it's been done right. A good FI system, with good wiring will simply give you years of trouble free performance, where as, as stated above, carbs simply are constantly in need of adjustment. I'm not looking for a response. The not so simple debate of carbs vs. FI is and forever will simply be a never ending battle between good and evil. Which is good and which is evil simply depends on which side of the fence you're on. It's that simple really First person to count all the simples gets a free paid in advance

 

What comes in the MegaSquirt system IWW

 

Information:

http://www.msefi.com/msinfo/index.html

Fully Assembled Systems:

http://www.rs-autosport.com/

http://www.glensgarage.com/

 

IWW your awsome