How many HORSEPOWER vroom roooom!

[skunkbud280Z]

Okay I know this has been brought up and discussed before and I read the old threads and talked to different sources through the years and I'm as confused as ever.

Let me see if I can put some supposed puzzle pieces down that I've heard about regarding 280Z's horsepower (and generally all the classic Zs).

1975 the 280Z came out. Sources speak of the engine having 149 HP. Okay. 1976 some online sources don't speak of anything different with the engine. I have a metal plate under the hood that says 170 HP. I was talking to the owner of one Z shop locally and he was saying "oh yeah we can completely rebuild your engine brand new to 200+HP for xxxx dollars". Another owner of another Z shop laughed and said "there's no way that engine is going to produce 200-220 HP and still be pleasant streetable". I retorted "Oh c'mon, my engine has 170 HP already!" And he replied back "That engine does NOT have 170 HP!"

So, Nissan was pulling a fast one here (no pun intended)? They're using a different unit of measure that happens to share the same name? Samurai, like vikings, ride hobby horses? Or WTH is going on?

Then I read on a lot of online sources that in 1977 280Z's HP is upped to 170. I also saw a sticker that still says it has 170 HP, just like mine. Then based on the discussions here and elsewhere, I read that the HP difference between these 280Z cars is non-existent and they're all the same or about the same???!

I found this information in another forum which seems realistic, mentioning an old convention for measuring HP vs. the new convention for measuring it:

BHP- Brake HP measured at flywheel

HP- 1BHP=.986HP so for most cars the difference would only be off by 1, also measured at flywheel

Gross HP- old way, HP of motor only-no accesories and out of car, also measured at flywheel.

http://www.zcar.com/forums/read/2/854050

But is this right?

So how much HP does a '76 really have? A '77 really have? A '70 really have 150? 151? A '74 really have 139? Etc.

To add more dizziness to the discussion, an old friend was telling me the virtues and drawbacks of mounting weber carbs onto my L28: Sounds mean, FAST, difficulties starting, etc. How much of a HP boost would this move make? If I keep the EFI and just go for different options on a rebuild, what gains would we realistically be talking about here? Any good bang for the buck wisdom from any of you fellow Z-heads?

I'd rather keep my original engine and EFI than install a V8 so am more interested in L28 EFI alternatives. I don't want to stifle the discussion though. Hearing someone's V8 stories would be fun too. I saw a 240Z on youtube with a big V8 in it, and when he got on the gas, the car wanted to lurch right out of its lane (TOO much engine as he said). I hate people who do burnouts and donuts in their Z. Doesn't impress me. I like to see cars vault ahead with smooth efficient power without losing any of their handling characteristics also. And original engines = greater worth, in theory.

Here's that youtube video I was referring to:

Supercharged V8 as it turns out. It looks like he's about to veer into oncoming traffic at one point. I also suspect those wheels, beautiful as they are, might be doing some rubbing there. Anyway...different strokes for different folks I suppose. If I had a 240Z I'd definitely want the original 2.4L in it.

Edited October 6, 2008 by skunkbud280Z

[doradox]

http://en.wikipedia.org/wiki/Horsepower scroll down to SAE horsepower. See net and gross. Probably why the 260 was rated with less HP than the 240 and why the 75 280 had about the same rating as the 240. Where the extra 20 HP that the 76 has came from I don't know. I'll bet someone here does though.

Steve

[skunkbud280Z]

Didn't think to use Wiki for some reason.

So all these fabled cars I always gawked over like the '69 Hurst/Olds with their ~400HP ratings were pared back a great deal due to how they measured horsepower differently.

Still doesn't explain the extra 21 HP like you said. Could Nissan have reverted back to Gross Horsepower in 1976, where they hadn't done so in prior years? Or were they always using GrossHP in those prior years?

[mikewags]

Mine says this as well...Something like 170hp @ 5300 RPM or something.

[sblake01]

"And he replied back "That engine does NOT have 170 HP!"

He could have meant rear wheel hp as opposed to flywheel hp which is how they were rated regardless of which method was used.

[five&dime]

You lose about 20% or so from the fly to the wheels so.... My stock s14 silvia engine rated by Nissan as 220hp was dynoed at 186 to the wheels.

I saw them dyno a mid 90's mustang GT on one of those spike tv shows and it put down 160 at the wheels. Don't you know mustang GT owners all over were severely let down by that. No wonder my 510 can walk all over the mustang GT's from the 80's-90's

[m4xwellmurd3r]

Mine says this as well...Something like 170hp @ 5300 RPM or something.

my 78 says 170HP @ 5600rpm

[doradox]

You lose about 20% or so from the fly to the wheels so.... My stock s14 silvia engine rated by Nissan as 220hp was dynoed at 186 to the wheels.

I saw them dyno a mid 90's mustang GT on one of those spike tv shows and it put down 160 at the wheels. Don't you know mustang GT owners all over were severely let down by that. No wonder my 510 can walk all over the mustang GT's from the 80's-90's

It's funny that people can be happy with the performance of their cars then get all sad when it doesn't dyno out at what they thought. Dynos are for tuning not for "racing".

Steve

[WingZr0]

It's funny that people can be happy with the performance of their cars then get all sad when it doesn't dyno out at what they thought. Dynos are for tuning not for "racing".

Steve

Thats true, but theres a simple recipe to that solution, add more Gas

and add more Air.

I also like the sound of the L24, nothing beats a tri carb.

~Z~

Edited October 6, 2008 by WingZr0

[skunkbud280Z]

suggests that the only change made between 1975 and 1976 was that the ammeter was changed to a voltmeter. And it lists the 1975 engine at 149 HP. It doesn't explicitly state that the power was increased in 1977 but it strongly implies it if you take the wording as it sounds.

http://auto.howstuffworks.com/nissan-z-history3.htm

What I'm curious about, if anyone has a 1975 280Z, is what does your plaque under your hood say regarding your engine's HP?

If Nissan didn't raise power to 170 till 1977, why does it say that on our cars? If they raised it in 1976 then Howstuffworks is wrong, as is another website I visited (don't remember which one).

And if there is a 21HP difference between any of these 280s, WHAT made the difference?

[mgood]

My car is a 1976, 11/75 mfg. date. Here is a picture of the info plate under the hood.

[skunkbud280Z]

11/75 and the same plate.

Oh I like your car! Thanks for linking.

Not that I'm partial or anything...

wait, yes I am!

We chose virtually the same air dam and spoiler it looks like.

Edited October 8, 2008 by skunkbud280Z