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      10-15-2014, 10:30 PM   #1
p66
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HP per lb

Is there a rule of thumb for how much weight reduction is equivalent to 1 hp?
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      10-15-2014, 10:51 PM   #2
EldRick
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Well, the 1M weighs about 3300lbs, and has approximately 330HP, i.e. around 10lb/hp, thus...

The answer is left for the student...
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      10-16-2014, 07:40 AM   #3
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Quote:
Originally Posted by EldRick
Well, the 1M weighs about 3300lbs, and has approximately 330HP, i.e. around 10lb/hp, thus...

The answer is left for the student...
I've always heard 10lb per 1HP was the perfect amount for a sports car.....long before I ever had a 1M or it was even introduced. Hence another attribute which is nearly perfect about the 1M!
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      10-16-2014, 09:20 AM   #4
MDORPHN
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Although I don't have the answer, I believe that the OP is asking a different question than has been answered.

Since lighter is faster, how many pounds of weight reduction is comparable to a hp of increased power?

Probably could google it...

Neil
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      10-16-2014, 09:50 AM   #5
Kgolf31
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Best way to look at it is to just take your rated Rate/HP.

For example, a 128i with full fluids weighs in at 3200 lbs at rated 230 HP.

That'll give me a 13.91 lb/hp ratio.

I'm currently weighed in at 2981 lbs in race trim at 250.7 bhp (assuming 15% drivetrain loss from my dyno)

That'll put me at now 11.89 lb/hp

So I effectively increased my lb/hp by 14.5%

I know this doesn't answer the question, but it is the easiest way to look at things
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      10-16-2014, 10:18 AM   #6
MDORPHN
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OK, I googled it. This article is pretty good.

http://www.tuneruniversity.com/blog/...-weight-ratio/

Neil
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      10-16-2014, 11:26 AM   #7
l888apex
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Quote:
Originally Posted by MDORPHN
OK, I googled it. This article is pretty good.

http://www.tuneruniversity.com/blog/...-weight-ratio/

Neil
Quick summary:

Initial Starting Weight (lbs) / Improved Weight to Power Ratio from mods (lbs/Hp) = New HP equivalent.

3300 lbs / 335 hp = 9.85 lbs per HP.

Car is lightened to 3100 lbs with 335 hp, ratio improves to 9.25 lbs per hp.

So 3300 / 9.25 = 356.75 hp equivalent at 3100 lbs.
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      10-17-2014, 12:39 AM   #8
p66
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Quote:
Originally Posted by MDORPHN
Although I don't have the answer, I believe that the OP is asking a different question than has been answered.

Since lighter is faster, how many pounds of weight reduction is comparable to a hp of increased power?

Probably could google it...

Neil
Precisely what I'm asking.
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      10-17-2014, 12:40 AM   #9
p66
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Quote:
Originally Posted by MDORPHN
OK, I googled it. This article is pretty good.

http://www.tuneruniversity.com/blog/...-weight-ratio/

Neil
Thanks for finding the answer.
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