Horsepower Calculation from Injector Duty?

sethron71

Authorized Vendor
Jul 19, 2005
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Curious if it is possible to do a rough HP estimate from your injector duty?

For example(very rough numbers):
550cc injectors have a max of roughly 550rwhp at 100% duty cyle
So can I say my duty cycle is at 62% at 12psi does that = 550x.62 or 341hp?
Also I am at 62% at 12psi and 74% at 14.5psi both with an AFR or 11.5
So does that mean that:
550x.62=341hp
550x.74=407hp
407p-341hp= 66hp/2.5lbs boost gain = 26.4hp/lb of boost?

Is this a correct way of looking at it? Just more out of curiousity for me the car will be on the dyno soon and I can do a direct comparison but just wanted your inputs!

Thanks,
Seth
 

figgie

Supramania Contributor
Mar 30, 2005
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sethron

only issue with this is that no injector is linear. So an inector that has 550cc/min @ 100% duty cycle will more than likely have 550@ cc/min @ 85% duty cycle because most injectors are not linear....

how would you know the response curve for the injectors? Paul Yaw over at injector dynamics can characterize the injectors based on voltage, fuel pressure and how they respond.
 

sethron71

Authorized Vendor
Jul 19, 2005
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www.SethIngham.com
Hey Fig,
Thanks for the response. Yea I was just looking for a rough idea, not really worried too much about diggining into it. It was just an idea I had! lol I will see soon enough on the dyno if it is remotely close and I can actually build a little table for my car based off the dyno numbers.

Thanks,
Seth
 

Cz.

CAR > FAMILY
Mar 31, 2005
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Seattle, WA
If you go to the injector dynamics website, they have an excel spreadsheet that you can calculate HP off of based on injectors. You need to know some specifics about the engine though.