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Discussion Starter · #1 ·
If a stock L24 is rated at 151hp gross, and an L28(75-78) is rated as 170hp gross, then why does the Chilton repair guide rate the L28(79-83) n/a as 132-145hp gross? Why then would anyone want the F54 block over an N42 in stock form? I've seen the info on other internet pages state the F54 stronger than the N42 (for turbo reasons) and extra water jackets and compression heads but why bother unless for all out crazy power? Who should we trust, other internet guys or manuals (said with all do respects). Thanks for any input.
 

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Discussion Starter · #2 ·
RE: HP confusion here....

Shouldn't matter until you go into the higher horsepower regions. The F54 is plentiful enough to get cheap, so most feel they want to get the best they can. Torque stresses are lessened with an F54. Street engines under 300 hp shouldn't see any detriment from the other blocks. After all, these engines are really a borrowed Mercedes design and proven to be bullet-proof. Drag-raced cars, high powered, turbocharged and nitrous cars ought to use the F54.
 

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Discussion Starter · #3 ·
<b>RE: net vs gross</b>

This question comes around every few months. 1978 was the last year that Nissan rated their engines at the crank. Thus, one sees the 170 hp figure-- which actually translates to about 135-145 to the rear wheels.

I've read that the later zx's hp is closer to the 145 net range, but I've also seen it reported the other way around, too.

The funny thing about all this HP stuff is most of the manufacturers aren't even consistent today on what constitutes Gross. Many car manufacturers are now switching back to the crank rating because it looks better-- the complete opposite reasons of why Nissan changed to Net in the late 70s.

So stick with 170+. You'll certainly think your car feels faster than if you believe you only have 135.

Cheers,

Matt
 

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RE: net vs gross

net, gross, etc etc. Some manufacturers actually gave ratings with all accessories disconnected (alt, a/c, p/s) and showed a great drop when putting it all back on. It's all numbers, mathamatically manipulated. For the most part they're worthless, UNLESS you have a baseline number, make a modification, and then retest on the same machine. Then you get a RELATIVE indication of what the modification did (good OR bad). Most 240's that are stock run 70-80HP at the rear wheels, and if you get a good one, you might hit 100. That is the exception. But those numbers aren't good for bragging, sooooo.
I respect rear-wheel numbers, but take everything with a grain of salt. Most guys don't have the $$$ to run many dyno checks after EACH mod, or want to spend the bucks to see where they started. My L28, with 400DCOE18 Webers, and a header turned 80HP, at the wheels, but that was with a fuel delivery problem, and after that was straightened out, it went up to around 100. Not quite what Chilton said it would do--EH?
 

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Discussion Starter · #5 ·
<b>RE: how fast?</b>

Tony,

So, with your accurate dyno ticket in hand, about how fast is your car. just curious how that translates into actual speed with your mods.

Thanks,

Matt
 

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144MPH, June 17, 1992

I ran the car on the dyno once and the operator trashed my clutch (boost came on, clutch went POOF). After that, I OBSERVED a lot of other people run their cars. Ran some cars in Japan, but that was on the Bosch Power-Check System, which reads out KW and then is converted to HP. Let's not even GO there...
 

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137 non-turbo

gears were not optimized--I could go faster in 4th than 5th, same as with the turbo. I need 345HP at wheels to do what I want (over 155). Sorry the other post was my Max speed, but that was with Mikuinis, and a blow-through turbo system and 8# boost. It's all bolt-ons: same L-28.
 
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