[cowboy]

Just got my 80 280zx coupe put toghter and took her for a ride. she runs good but at 68-70mph iam pulling 4000rpm .. Why is this? Did they gear the zx low that year? And does anybody know what gear raito this may be ?? To low for me.. I do have a 81 280zx2+2 that i used for parts, is this rear end geared higher , it should bolt right on right? what are my options? Need more highway legs.
Thanks

Z on brothers

 

[SlickZ]

Is your 280 an automatic?

 

[cowboy]

Yes this is an automatic

 

[JJG]

My 1979 280ZX is an automatic and has a 3.545 final drive. My engine is turning 4000 rpms at 80 mph. Is your transmission slipping??

 

[cowboy]

JJG
Transmison feels good, shifts good. Just feels like it needs onther gear. What do you think about the 81 to 80 swap is there something differnt iam not seeing.
Thanks

 

[davtylav411]

some 80 models came with a 3:70 81 non turbo had 3:90

 

[240 Al]

The "80" GL and 2+2 5spd models had 3.90's.The others were 3.70's
the autos were 3.54's.I've had wrecking yards say that they only had 3.70's in the 5spd version but it ain't so. 240 Al

 

[SlickZ]

My 80 2+2 automatic does the same thing. I'm sure it's the transmission. When I get on the highway It feels like it just needs another gear, but it still feels solid and shifts smoothly. I think it is because the auto's are 4 speeds. My also would guzzle gas like mad cause I wanted to go faster and would have to rev it up to 4 grand on the highway. If you want the most performance and economy out of your z I suggest getting a manual tranny.

 

[szlash280z78]

arent the ZX autos 3 speeds? That would indicate they have no overdrive and therefore higher revs right?

 

[Lee Smith]

215-70-15s fill the fender hole nice & should give better milage.

You will need to check speed with mile markers to know how fast your going.
I am gessing, add 10% to speedo reading.
You don't need $$$ to try, go to tire shop, ask for tires from discard pile, they are good enough for a test run, don't try 100+mph, they may kill you.

 

[Drewfen]

i've got a 80 280zx with an auto, and it is about the same, 70mph ish is about 4000 give or take a few hundred. but yea it is a 3 speeds for the auto, no overdrive.
I havent changed my fluid in the transmission in a very long time, and i know it has been well over 30000 miles since the last change.

drewfen