Whp vs. Engine hp?

onzedge

Must be that "New Math".

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Econ

your right,

i just based the formula off stock Z's 332 bhp vs 275 whp, which is a 17% decrease.

The formula would have to be weighted, so if you were doing individual mods you would have to increase the .17 (17%) to maybe .25 or .3


300whp would be around 351bhp using the 17% formula which sounds about right

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Pelican170

Gotta be higher percentage than that since the nismo at 350 bhp isnt going to dyno at 300whp...

Econ

you're right it won't

350 * (1-.17) = 290whp

which sounds right (although i have no idea what a stock nismo whp is)

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Pelican170

Actually, thats right around the mark. Ive seen around 284-286 average on dynojets from what ive read...

Pelican170

But its gotta be different for when bolt ons are being added because if you use that formula, the whp to bhp between the nismo and sport dont add up, unless im doing my math wrong again.

Econ

well if you take a stock sport Z and add intake/exhaust netting you 25whp

you end up with around 351 BHP (300*(1+.17))

if you did the same to a stock nismo Z

you end up with around 364 BHP (311*(1+.17))

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2014 Triumph Thruxton 900
2013 Fiat 500 Abarth
2009 Nissan 370z

Pelican170

Wait im confused. Where did you get the "300" and "311" numbers from?

eksigned

I'm not entirely sure if I understand your post, but I just skimmed through it. Edit: I don't understand your post. Despite as some mentioned, drivetrain loss is mainly to blame for the difference you seen in crank versus wheel horsepower. Typically it's around 15% loss for RWD (has to send it all the way to the back), and a bit lower for FWD cars (less distance to travel).

I think someone mentioned whp from mods. Individual mods add a good amount, ie intakes, tps/hfc, exhaust. Put them together though, and they unfortunately don't yield the given whp added together. Understand? Stillen Gen3's add...what? 20 whp...supposedly? Pipes and exhaust add 27 whp (let's just say). The total gained doesn't equal 47 whp.

No idea if that even answered your question...

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Dizon248

You can't do that. When you use the 17% drive train lost, you can't convert back up 17%, you are using a different baseline and it will give you a different value.

So Whp = bhp*(1-.17) is right, but when you do Bhp = whp*(1+.17) you are multiplying by a different baseline. Try it. Say I have 300bhp and I multiply that by (1-0.17), I get 249. Now use 249 to multiply by 1.17, you get 291.33. You just lost 9HP from converting like that.

The right way is this, Whp = bhp*(1-0.17), solve for bhp now. bhp = whp/(1-0.17).

Summary

Whp = bhp*(1-0.17)

bhp = whp / (1-0.17)

Pelican170

Nope lol but thats ok. I agree with what your saying. To put it simply, if you add hfc's and exhaust that show dynos of 24 whp, what bhp does it convert to?

Dizon248

24whp converts to this, bhp = whp / (1-0.17). bhp = 24 (1-0.17) = 28.91bhp

Pelican170

Sorry but no way. As mentioned, if the nismo exhaust and small tune adds 5whp and 19bhp, a 24 whp gain isnt going to add only 4 more bhp. Its going to be way higher than that....

Dizon248

Ever figure that the 19bhp figure is wrong? Did you even think about how the hell can 5whp give you 19bhp? Yeah, that's right.

We already pointed out that your figure of 3.8x is totally whack. Why are you still assuming that the 19bhp is right?

Or the 5whp figure is wrong, something is wrong. There is no way there can be more than 300% differences between whp and bhp.

And what do you mean 24whp is only going to add 4bhp?. It is 28bhp. Your logic is confusing the crap out of me.

m4a1mustang

When you guys finish sorting this out I'd like to know how many whp and bhp my NISMO plate frame buys me. It's stainless steel powdercoated black if that makes any difference... super durable.

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