Donor debate: 240Z vs 280Z

[Guest Anonymous]

Ok, I am seriously considering a Hybrid-Z as my next project car. Being new to Z's, I have the following 3 questions. Since this seems the closest forum to asking "chassis" questions, I hope this is the right place to post this.

 

(1) Is it true that early 240's weigh a bit less than 280z's due to the 280's weight concessions for added safety? The figures I had seen were 240's being close to 2200lbs, while 280's are more like 2700-2800lbs.

 

(2) Safety aside, is there any sacrifice in chassis rigidity between the 240Z and 280Z?

 

(3) If I am planning on replacing most all of the driveline and suspension (R200 rear, Quaife diff, V8 & 5 or 6 spd trans, coil overs and aftermarket discs w/5 lug conversion), is there any advantage in going with the 280 over the 240 from a performance standpoint?

[blueovalz]

The 240 steel body is lighter than the 260 and 280. The requirements for the 5mph bumpers required a slightly thicker gauge steel in areas (if not the whole car). The weight difference you stated may be a little high. I believe that there is only about 300 lb difference in the steel, then add the much heavier bumpers (with attending shocks) and other misc stuff and the difference becomes a little larger. I've seen stress and fatique cracks on both 240 and 280 chassis', so from that point of view, I don't know that one would be any better than the other. Weight is a killer in performance because it affects EVERYTHING.

 

Terry

[Ray]

1. yes there is a difference in weight..

2. Good question we could go on for hours..

3. there is no real performance advantage in starting with a 280 as it starts out heaver and you would have to remove 500lbs of stuff to get the car back to where you would have started with a 240....

 

 

Alot of the differences in weight came from stuff that can be removed from the car... 280's had alot more wiring and under hood accessories, the dash and A/C are heavier, also more sound deadner and interior along with all the sheet metal improvements, the bumpers and shocks ..and as Terry said the weight difference isn't that great once you strip them down....

I prefer the 240 for the small bumpers and the taillights but alot of people are fitting the smaller bumpers to 280's and they look almost identical. It comes down to a mater of preference if you plan on doing a simple conversion the 280's seem to be better as they come with a r200 and more room in the driveshaft tunnel and better A/C. They are also quiter and seem to ride better. If you don't care about noise or heat then 240's are it...If you are doing a full blown caged car and are striping everything then 240's give you a weight advantage from the start. Good luck

[Guest Anonymous]

Agreed, the 240 will be the lighter car for sure. The 280's were a bit more refined not as raw as the earlier car. Both would be good candidates if smog is not an issue, with the 280 you'd just need to build a bit more power than you might with a 240, but still even at 2800 lbs, its 4-500 lbs lighter than your average modern performance car (I.E. Camaro, Mustang etc..).

I'd use either if smog wasn't an issue here (which it is) and found either with a good body with little rust, but my preference is the 240 just because its what I own .

 

Regards,

 

Lone

[Guest Anonymous]

Actually, that's a point I hadn't thought about. Smog in FL is really not an issue, they don't check it where I am. However, I may move in the future to a state where they do check it, and I know from musclecar experience, the older the car, the better. Smog aside, it is sounding like I would rather go with the 240 myself. For my 3rd point, I was just wondering if the 280 was more readily accepting of some of the modern componentry than 240's are, but it sounds like that is not the case.

[DavyZ]

Around here, 280Z's are a dime a dozen, but not so with the 240Z's. I wish the smog laws exempted the 280Z's because they feel much better, stiffer, and safer IMO. I notice a difference in just the way the doors are constructed (lock mechanism, side impact beam, window mechanism, etc). 280Zs are more rattle free and more comfortable IMO. I would do a 280Z V8 swap in a heart beat if they were smog free. I would just swap out the bumpers and go from there. I know weight affects everything--so I'm trying to stay at a relatively lean 185lbs. Shoot, consider your own weight in the equation!!!! That could be 100lbs of difference!!!!!!

 

Davy

[pparaska]

I seem to remember someone artfully and stealthily replaced the firewall area where the VIN is stamped on his 280Z with the same area from a 240Z. Of course, the VIN tag was easily swapped also. Of course, if it was ever discovered, legal problems would result.

[Guest Anonymous]

Pete,

 

What other places is the VIN listed? I have access to a 71 that is rusted out. I have the title also. Car has been striped and the seats and motor are pretty much on the ground. We have smog laws around here but that VIN plate on this 71 has always been in the back of my mind.

 

 

There is no way anyone around here would find out or care for that matter? Bumper change, take 280 emblems off...

 

Hmmmmmm

[Guest Anonymous]

Forgot to mention...I would never do anything to willingly break the law. Just want to make that clear!!!

[pparaska]

As far as I know, on a 240Z, the only places the VIN shows up are:

 

1) Stamped on the firewall, above the brake booster.

 

2) Plate riveted to bracket that's spot welded to the dash. (See it through the windshield.)

 

3) Door jamb plate.

 

I don't know but the 280Z might have a stamp on the frame rail, but my memory is gone.

 

I do not condone this, but we are all grown up girls and boys here, so we do as we see fit.

 

I also don't think this is anything that warrants more than a hand slap.

[fl327]

dont think youre the only one that has thought about that one.....

[Drax240z]

Wish I had thought it out a bit more... I parted out/crushed a 9/72 car that I had in my name, and bought another 9/72 car from out of province. Would have been nice to be able to avoid the big pain of getting it safety inspected and so on. Maybe next time.

[TimZ]

Just to defend the 280s a bit (since that's what I own )...

As others have already mentioned, some of that weight difference comes from body reinforcements, resulting in an overall stiffer body.

 

Some of the weight difference comes from the R200 (the 240s had the R180). If you are building a HybridZ, then you'll probably do an R200 swap anyway, so that weight difference is negated.

 

Also, the 280's fuel system is already plumbed for a fuel injection system - the tank has a fuel return, and there is a high pressure pump, and associated wiring for it already there. Granted, you'll have to change the pump if you are doing a high boost turbo, but the mounting brackets are already there, and the pump swap can just about be a bolt-in.

[BLKMGK]

Guys... with all of the HP we're dumping in these cars do we really give a fig about a few lbs? I mean really, an extra 100lbs is nothing to sneeze at but the power to weight on these cars is sick. I've got a 240 but now realize that the 260 had an interior console that I liked better - if I'd found one I'd have done it instead. We're goingto spend timie driving these cars, if the 280 interior is really the one you prefer I'd go for that instead and just add a few more HP to compensate. Obviously if you're doing SCCA track days and really "racing" then the weight isn't desired but most of this is fun and street driving. It also boils down to what's available. People seem to hate 260's and they carry a stigma - that works to our advantage since we replace anything that causes a problem

 

Just my .02

[pparaska]

Actually, it's that slight difference in weight (several hundred pounds) that makes me really like the 240Z over the 280Z. I CAN feel the difference in the handling of similarly prepared 240 and 280Zs exhibit.

 

There's more to light weight than just power to weight ratios. Jim, that RX7 of yours shows you that. Light weight generally goes along with lower polar moment of inertia, and ALWAYS goes along with better handling, for cars of the same design and equipment.

 

For me, I'd rather start with a 240 or early 260 and add reinforcement. I doubt the difference in the structural stiffness between the 240 and the 280 is anywhere near the difference between a 240 with and without subframe connectors and an 6 or 8 point cage (as defined by S&W).

[Drax240z]

Well Pete took the words out of my mouth. Lets say there is a 300lbs difference. With 300lbs of well thought out chassis bracing the 240 could probably be a magnitude stiffer than a stock 280 at the same weight could be. 300lbs of bracing is overkill more than likely though.

 

I certainly could tell the difference in handling between the 280zx and 240z's I've had. Granted there are a lot of other variables in there (suspension layout, wear, etc) but I'd sooner start with the lighter car.

 

However I do like the 74 and up center console better. An early 74 would be a nice cantidate for a project car if you could find one.

[blueovalz]

To add to the above, my 8 pointer added close to 100 lbs. With the engine and tranny mounted solidly at 6 points to the unibody to act as a "spine" from front crossember to the middle of the tunnel, and added triangulation at the front, a surprising amount of stiffness can be added to the car without the attendant 300 lb heavier body. Granted, the solid mounting is rarely desired, but it adds no weight.

[BLKMGK]

I know weight effects handling but is it so bad you'd turn down a more comfortable car if it was available? I don't think most of us drive 10/10ths often in these cars - at least I hope not If I wanted a 280 and folks told me it was too heavy and that I should buy a 240 instead I'm not sure I'd be persuaded just on that basis. With HP as easy to build as it is a few hundred lbs, to me, just isn't that big a deal.

 

Having said that - I'm not loading my car up with crap I don't have to. I've dropped the bumpers for glass, moved the battery, bought sort of light wheels, gone to coil overs, and chose lighter calipers than others. I almost did a cro-mo cage too! I'll save weight when I can but I'm not sacrificing things like sound deadener. We're not Hondas here - we can make power without $200 "air pipes" and $600 "headers" If a Miata or RX7 beats me through a turn I know the straighaway is just a little further away

[DavyZ]

I agree, if I was doing this again--and I may in the next few years, I'll do a 280Z or ZX with a 383 or 406. That and a T56 will be plenty fast for me.

 

However, what it really comes down to is personal preference. I wish I had the overwhelming numbers of 280Zs we have here, in another state with smog laws much less stringent than here (big sigh).

 

Davy

[Guest Anonymous]

Initially I wanted a 240z because it was the original Z. I ended up with a 76 280z because there are so many more of them available, and they are ea$ier to come by. They already have an r200, they have a wider transmission tunnel which I don't think has to be 'pounded out' like a 240's does (to fit the tranny). Even though they're not smog exempt, they can be legally converted to a V8 as long as the V8 is not older than the car, and as long as you use all of the smog equipment that came with the V8 (cats, air pump, pcv, charcoal canister, etc.) In the end I think the tailpipe emissions have to pass as if the car were the one the V8 came in (like a 95 Corvette).

Again, get rid of the heavy bumpers and you're set.

I'm happy with my 280 even though it isn't as unique as an older 240.