Where'd the extra LBS come from?

[mikewags]

I was reading this write up today:

Though it lacked originality, the 240Z was immensely attractive and, with 150 horsepower pushing just 2,320 pounds, decently quick for the era. Sports Car Graphic stirred the four forward gears of the first 240Z to go from zero to 60 mph in just 8.2 seconds and complete the quarter-mile in 15.5 seconds at 86.5 mph. And it only cost $3,500 — a screaming bargain. "We think Datsun has a real winner," wrote Road & Track at the time, daring to state the incredibly obvious.

With sweet handling and an undeniable star presence, Datsun had no problem selling 16,215 Zs that first year. So for 1971, the company didn't mess with it, and sales more than doubled to 33,684 units. Again essentially unchanged for 1972, the 240Z saw its sales rise to 45,588. Changing practically nothing for 1973 resulted in another 46,282 Zs hitting this country's fair shores. But with new bumper regulations (and more weight) coming and emissions regulations threatening to strangle output, there would have to be some changes.

Changes arrived in the form of the 1974 260Z. The name was earned as the straight six was stroked to displace 2.6 liters while it still inhaled through two SU-style carburetors. "It's an updated version of the 240 that includes the required safety equipment," wrote Motor Trend, "yet continues the virtues of its forebear." But the extra displacement couldn't keep engine output from dropping to 139 horsepower with the new emissions equipment and the federally mandated 5-mph bumpers' weight helped push weight up to 2,580 pounds. So zero to 60 now took 9.9 seconds according to Motor Trend.

The 260Z coupe was now but one model in the Z family as a new 260Z 2+2 joined it in Datsun dealer showrooms. With a wheelbase 11.9 inches longer than the two-seater's, there was now room for a tiny rear seat under an awkwardly shaped roof. With a three-speed automatic transmission available as an option, the heavy and relatively slow 260Z 2+2 was hardly a sports car — and a harbinger of the direction the Z car's evolution would take.

The 260Z lasted just over one year, as the 280Z appeared late in 1975 with a new 2.8-liter version of the SOHC six now running with Bosch fuel injection. The extra displacement and fuel injection system bounced engine output up to 149 horsepower, but the two-seater now weighed 2,875 pounds

and Road & Track could only manage a 9.4-second 0-to-60-mph time. Buyers still scooped up the Z, however, with almost 52,000 coupes and 2+2s getting to American buyers during '75. So Datsun didn't change anything for 1976 and sold nearly 60,000 of them over here.

I'm curious. If the bumpers (which seem like the biggest weight addition) were added in 1974 to the 260z, where did the extra weight come from in 1975, making the car go from 2,580 lbs to 2,875 lbs. Thats just shy of 300 lbs, which seems like an awful lot.

Could this be the engine (2.8 vs 2.6)?

Edited August 11, 2008 by mikewags

[mikewags]

I came across this link regarding 240z - 280z weight.

http://forums.hybridz.org/showthread.php?p=917651

FYI in case anyone else was curious as well.

[Danglybanger]

...I've heard lighter quoted for the 240Z...

But it seems like a vast amount of the weight gain had to do with revised weighing techniques, gross vs. net etc...

That said, 300lbs though doesn't sound like an implausible increase for the heavy bumpers and additional bracing.

I think more drivers would benefit from going on a celery diet over cutting bits off of their cars to achieve weight loss though I'd personally rather keep the safety gear on my car...

[John Coffey]

I never weighed a S30 that was anywhere near 2,800 lbs. I corner weighed a stock 1977 280Z with AC and it came in a 2,671 lbs. (with fuel, spare tire, aftermarket stereo, etc.) I've weighed racing 240Zs that came in a just over 2,000 lbs (no fuel) and street 260Zs that came in at 2,556 lbs. with fuel, spare tire, stereo, etc.) A racing 260Z with a SR20DET swap almost weighed exactly the same as my old racing 1970 240Z with an L6.

The preparation level of the car has a lot more to do with its weight then what the factory listed 35+ years ago.

[m4xwellmurd3r]

2671 sounds more reasonable the 2800 is the maximum weight for the 280z (meaning, vehicle weight PLUS maximum cargo weight)

close to 100lbs is in the bumpers and even more in all the extra bracing in the doors, and in the body.

[bigoak]

Possible myth alert:

I think I recall reading somewhere that the 280Z had thicker gauge metal? Is this possible?