How Much HP Needed to Reach 300 MPH in a Nissan 350z?

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Discussion Overview

The discussion revolves around the horsepower required to propel a Nissan 350Z to 300 MPH from a standstill, particularly in the context of high-performance racing and speed competitions. Participants explore various factors influencing speed, including engine modifications, aerodynamic drag, rolling resistance, and the physics of acceleration.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant suggests that achieving 300 MPH will require around 2000 horsepower, while others provide calculations indicating that maintaining such a speed against aerodynamic drag alone would require approximately 893 HP.
  • Another participant estimates that considering both drag and rolling resistance, a total of around 1600 HP would be necessary to reach and maintain 300 MPH.
  • Some participants emphasize the importance of specifying the time taken to reach the target speed, noting that this significantly affects the horsepower requirement.
  • Concerns are raised about the feasibility of achieving the necessary power output from the engine, particularly in a street-legal vehicle with space constraints for modifications.
  • Safety issues at high speeds are discussed, including the need for modified aerodynamics to maintain stability and the challenges of reaching high speeds from a standing start.
  • There is a discussion about the differences between power needed for acceleration versus maintaining speed, with some participants clarifying these distinctions.

Areas of Agreement / Disagreement

Participants express varying estimates for the horsepower needed, with no consensus on a specific figure. There is agreement on the need to consider both aerodynamic drag and rolling resistance, but differing opinions on the implications of these factors for the vehicle's performance and safety.

Contextual Notes

Participants mention various assumptions, such as the vehicle's weight, drag coefficient, and rolling resistance, which influence their calculations. The discussion also highlights the complexity of achieving high speeds and the interplay between power output, vehicle design, and external conditions.

Who May Find This Useful

Individuals interested in automotive engineering, high-performance racing, and the physics of speed may find this discussion relevant, particularly those looking to understand the challenges of achieving extreme speeds in modified vehicles.

  • #31
The battery ( and/or capacitor bank) would be purchased. I don't know of a commercial high power density 2000 HP e motor source.

Sure, the power density is doable, but with non trivial engineering and manufacturing chops. Tesla's motors for instance are 2.5 HP/lb (4kW/kg), and even higher power density is reportedly available, though these are built in the hundreds of HP range. Challenges include mechanical loads on the windings, with 200 lb-ft race car typical torque, and heat rejection when packing a lot of power into a small space, especially for the rotor. Guys like the OP have been machining high performance IC engines from scratch for a century. E-motors at 2000 HP and 3 HP/lb? Not that I know of. Dividing the load among multiple motors at 300 mph would present other challenges, like multiple gear boxes, and stable vehicle control.Example GE 1.5 MW generator and gearbox, when high power density is not a design constraint:

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  • #32
Why mess with internal combustion? Because that's what I know. Why not electric power? Because I don't know anything about it. Lol
 
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  • #33
Nissan Jon said:
Because that's what I know.

That's actually a very good reason.
 
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  • #34
I'm worried the amount of boost pressure necessary to generate said level of power would be too much for the stock motor. (assuming your engine, or the one you plan on purchasing is stock) From my knowledge of speed-machines, most cars running in the range you hope to achieve are running on 12+ psi, which few engines (apart from something to the likes of rb26s or 2jzs) can handle. At least for very long. Forged internals however, are always an option. Are you hard set on the vk56?
 
  • #35
automotiveadam7 said:
I'm worried the amount of boost pressure necessary to generate said level of power would be too much for the stock motor. (assuming your engine, or the one you plan on purchasing is stock) From my knowledge of speed-machines, most cars running in the range you hope to achieve are running on 12+ psi, which few engines (apart from something to the likes of rb26s or 2jzs) can handle. At least for very long. Forged internals however, are always an option. Are you hard set on the vk56?

Well, my shop represents Nissan motorsports, and I intended to stay with in the Nissan family. The only V8 option in the Nissan line up is the VK, however, as a testament to Nissan innovation, Nissan Supercar AU built a 714bhp Naturally Aspirated VK50, on almost entirely stock upper components and completely stock lower parts.

Now, I'll be far from stock. We'll be running primarily titanium parts, like: block sleeves, rods, pistons, ect., 320,000 psi head bolts, the works.

2,500 bhp is really easy to achieve, making it reliable is tricky, but cramming it all in a Z33 body will be the real challenge.
 
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  • #36
Another Ford GT, this time 279.9 mph. (280.1 at Arkansas). Despite the claim of no body mods, there's a 1 1/2" or so spoiler added to the rear, perhaps to direct air flow over the braking chute. The Ford GT body is based on a Lemans race car (Ford GT40), and is less prone to speed related issues (lifting of rear end or lifting of front end and blowover). My impression is that the 350Z body style is going to produce lift at high speed without some modifications. If there's enough excess power such as the drag cars, the entire body can be pitched nose down to produce downforce.

 
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  • #37
Nissan Jon said:
Now, I'll be far from stock. We'll be running primarily titanium parts, like: block sleeves, rods, pistons, ect., 320,000 psi head bolts, the works.
Oh, well you're set then.
 
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