Age-Old Battle! 240Z vs. 280Z

[zguitar71]

The light weight of the 240 is the selling point for me and because, I know I am not supposed to say it, it is the original. The feel of the lighter wieght is awesome. I have done some modifications to the car, but if I did the same suspension work and got the same power to weight ratio in a 280 as my 240 and used the same tires the 240 would win in an autox (autoxing is the reason I drive a Z) due to the weight difference. Lighter weight cars handel better and feel better.

[chickenwafer]

I have a 260, which combines a little of both (but mainly the 240 with a stroked engine). The Z car is all about weight. Not power. If it was power Nissan would have stuffed some oversized V-8 it and called it a muscle car (okay, Nissan probably wouldn't go with an 8 cylinder, bu let it run). In my eyes, the Z was all about handling. It isn't going to win any straight-line drag races against cars of the similar era, but in the twisties it will run circles around, say a '73 Camaro. Those things used arcaric suspension and soft steering. The Z is what I like to call "pure". Just driver, engine and road.

But the 280 is a great machine as well, that goes without saying. It's more refined, not as raw. And it's much better for a daily driver because of the fuel injection which makes it more reliable and gets it better fuel mileage (although a set of well-tuned SU's aren't too shabby in the MPG, espically when you have only 2.4 liters). The 280 is slightly bulkier, and I think doesn't have the same lines and body as the earlier Zeds.

I think the best of both worlds is an L28 in a 240. The L28 weights much more than the stock L24, but the 240 has a more nimble chassis. Needless to say, this is a debate that will never be solved.

Dave

[Alfadog]

I put a 240z exhaust on my 280 ( just straight pipes from the manifold back then a nice muffler) to get rid of the catylitic converter because it was a california car. Now since i did this did i get much of a HP increase? I know when you take off the cats ( or cat. in this case) it adds some but i was wondering how much.

I have heard the catalytic converter doesn't really restrict that much. But I guess on an older car when they were first being used it may be different. Anyhow, it's illegal to get rid of your cat, if your car came with it.

[zman525]

oops......

[zman525]

any way of uhh... gettin away with that in massachusetts?

[zguitar71]

But the 280 is a great machine as well, that goes without saying. It's more refined, not as raw. And it's much better for a daily driver because of the fuel injection which makes it more reliable and gets it better fuel mileage (although a set of well-tuned SU's aren't too shabby in the MPG, espically when you have only 2.4 liters).

Dave

I prefer the rawness of the 240 (to each their own). I do wear ear plugs on the free way though, at 80 the noise gets kinda loud. Around town the raw feel of the car is great. I have a much stiffer suspension and an L28 block so I guess it is not a "real" 240 but it does have the 240 feel only a faster one.

The SU's on my 240 are never touched. I got them from Ztherapy, put them on and tuned them and have not touched them since. I get nearly 30MPG at 75 (with an 83 ZX 5 speed and a 3.9 R 190) on the free way and about 20 in town. The intown milage can go down fast though if I "drive" the car. Even though the SU's are not as frugal as fuel injection the light weight of the car counter acts that in the world of fuel economy. I think the diference in the 4 speed and 5 speed transmissions in the 240 and 280 make more of a difference in milage than the type of fuel delivery. When I had the 4 speed in the car (3.54 diff, low gearing) the milage was terrible on the free way.

[hls30.com]

I would like to know why the 280 has more suspension travel than the 240. I know that the rear strut housings are 1" taller on the 280 vs the 240, but I thought the fronts were exactly the same length. I was also under the impression that the stroke was the same on all of the Z struts, front or rear. Same stroke = same amount of travel unless there is something that I'm missing.

Geometry is slightly different in that the 280 has a higher cg and higher rear roll center as far as I can tell. Above and beyond that I see no major difference in geometry, and I'd prefer the 240's geometry if it was to remain stock.

Sway bars are easy to install on a 240 or a 280, FWIW.

What you have not taken into consideration is that the shock in a 240Z is a) shorter than that in a 280Z, and not mounted within the strut to maximize its available rebound, both of which lower its travel.

It is true that the sway bars are easy to mount it is also true that the 240Z came from Datsun with only one, while the 280Z, and a few 260Zs came with 2.

Don't forget 50 lbs added at the far ends of the 280Z also adds a good bit to its turning moment of inertia, and then there is all of the other added mass-no wonder the COG moved up and the performance went down!

I have owned bone stock versions of both 240Zs and 280Zs, and when tuned equally, the 240Z leaves the 280Z every time, but the 280Z starts every time, runs exactly the same every time, and is less persnickety when the weather changes-not that the 240 is horrendous by any means.

regardless of the state of tune, weaving through traffic, cones, or a dotted line on a deserted highway is much more fun in a 240! The 240Z is simply more responsive-just shy of a street legal go-cart.

Will

[agemeansnothing]

2222222228888888880000000000. Fuel injection all the way I don't like the 240's because everyone has one. Can someone tell me if this is good. I found out that the head on my 280z is a N42??????

[Pennyman]

It'll say N42 on the passengers side of the head stamped into the metal.

280z's certainly LOOK a little more muscular than 240z's. For some reason, they almost appear wider even though the track is the same. It's also true that when it comes to enthusiasts, more people go for the 240z than the 280z, which means there;s WAY more spare parts for 280z's in the average junkyard.

[jmortensen]

What you have not taken into consideration is that the shock in a 240Z is a) shorter than that in a 280Z, and not mounted within the strut to maximize its available rebound, both of which lower its travel.

I could be wrong, but I don't think so. The 240Z front strut is the same length as the 280Z front strut, of this I am 99% sure. I know the 240 and 280ZX front struts are the same length.

The rear is a little tricky. If you buy an aftermarket 240Z strut like a Tokico Illumina for instance, you get a 240 front strut with a 2" spacer on the bottom. My understanding is that the 280 strut is a 240 front strut with a 3 inch spacer on the bottom. I don't have a 280, but I've read that quite a few times on threads where people are trying to figure out how much to section their strut housings.

Your comment about the spring perch being mounted differently also doesn't make sense to me. I know Nissan raised the spring perch on the 280, but I assumed that they moved it up 1" to fit the new taller strut. Otherwise the spring would have to be shorter, or else it would just be that much more preloaded than a 240 spring. I thought they were the same length.

Just did a little checking and I came up with spring lengths for 240s and 280s. Looks like the 240 had a free spring length of 15.19" and the 280 has a free spring length of 15.43". So there is a .24" difference in the length of the springs. The springs are not the same rate, but the 280 is heavier. So again, either the springs on the 280 are preloaded a whole bunch more, or else the spring is basically in the same position as the 240, just 1" higher on the strut.

Again, all of this is contingent upon the struts have the same stroke, which I believe they do. If that is true, then the rest of it is pretty clearly going to be similar. The reason the 280 sits higher than the 240 is the bigger insulators on top of the struts, and because of the 1" taller strut in the back and the relate 1" raise of the spring perch.

I tried to look up stock spring specs to see if I could find out how much preload they have on them, wasn't able to find it. If we had the spring rates, we could figure out the rate to weight ratio and see what kind of a difference there is there, I would venture a guess to say they're pretty similar in this respect as well.

[Fun_in_my_z]

2222222228888888880000000000. Fuel injection all the way I don't like the 240's because everyone has one. Can someone tell me if this is good. I found out that the head on my 280z is a N42??????

The only 240z i every seen around here is parked in my yard...

[hls30.com]

I could be wrong, but I don't think so. The 240Z front strut is the same length as the 280Z front strut, of this I am 99% sure. I know the 240 and 280ZX front struts are the same length.

The rear is a little tricky. If you buy an aftermarket 240Z strut like a Tokico Illumina for instance, you get a 240 front strut with a 2" spacer on the bottom. My understanding is that the 280 strut is a 240 front strut with a 3 inch spacer on the bottom. I don't have a 280, but I've read that quite a few times on threads where people are trying to figure out how much to section their strut housings.

Your comment about the spring perch being mounted differently also doesn't make sense to me. I know Nissan raised the spring perch on the 280, but I assumed that they moved it up 1" to fit the new taller strut. Otherwise the spring would have to be shorter, or else it would just be that much more preloaded than a 240 spring. I thought they were the same length.

Just did a little checking and I came up with spring lengths for 240s and 280s. Looks like the 240 had a free spring length of 15.19" and the 280 has a free spring length of 15.43". So there is a .24" difference in the length of the springs. The springs are not the same rate, but the 280 is heavier. So again, either the springs on the 280 are preloaded a whole bunch more, or else the spring is basically in the same position as the 240, just 1" higher on the strut.

Again, all of this is contingent upon the struts have the same stroke, which I believe they do. If that is true, then the rest of it is pretty clearly going to be similar. The reason the 280 sits higher than the 240 is the bigger insulators on top of the struts, and because of the 1" taller strut in the back and the relate 1" raise of the spring perch.

I tried to look up stock spring specs to see if I could find out how much preload they have on them, wasn't able to find it. If we had the spring rates, we could figure out the rate to weight ratio and see what kind of a difference there is there, I would venture a guess to say they're pretty similar in this respect as well.

There are pictures in the archives here comparing both struts side by side, while you said the strust are the same length, what I said was the 240 has shorter front shocks.

If you take a 240Z front strut apart, and hold the shock beside its mounting lpocation, you will find the shock is not in a position to allow full travel-that is a shortcoming with the geometry of a 240z front suspension. Many people section the strut(shorten it) about 2", and use MR2 of VW Rabbit shocks-that allows the front suspension to have greater travel.

Will