Write-up: How to determine approx. HP gains from removing weight! - Page 5 - Focus Fanatics
Ford Focus Forum
HomeContact UsAbout UsGalleryDiscussion ForumsMarketplace


Go Back   Focus Fanatics > Ford Focus Discussions > Ford Focus & General Car Chat

Ford Focus & General Car Chat Discussion Forum relating to nonspecific Ford Focus models, car purchasing, auto industry news and any car talk.

Search This Forum | Image Search | Advanced Search    
Ford Focus Tire & Wheels FocusFanatics Merchandise

Reply
 
Thread Tools Display Modes
Old 10-14-2005, 04:24 PM   #41
remyx
Focus Rookie
 
Join Date: May 2005
Fan#: 23447
Location: Michigan
What I Drive: 2002 White Focus ZTS

Posts: 5
FF Reputation: 1 remyx Good Standing Member
Buy-Sell-Trade Rating: (0)
I only read two pages in the thread so far, but your (original poster) equation is just wrong, yet alone doesn't make any sense.

Think of it this way, if you take a 350 HP Hemi (just an example) and put it into a Focus, it's still going to be a 350 HP Hemi. Of course your performance will increase but your calculations are just ridiculous. Nice try though.
remyx is offline  
    Reply With Quote
Sponsored Links
Advertisement
 
Old 10-15-2005, 11:23 AM   #42
Taiden
Focus Enthusiast
 
Join Date: Aug 2005
Fan#: 26198
Location: Portland, Maine
What I Drive: 94 Grand Cherokee 55k mi, standard

Posts: 65
FF Reputation: 1 Taiden Good Standing Member
Buy-Sell-Trade Rating: (0)
Quote:
Originally posted by remyx
I only read two pages in the thread so far, but your (original poster) equation is just wrong, yet alone doesn't make any sense.

Think of it this way, if you take a 350 HP Hemi (just an example) and put it into a Focus, it's still going to be a 350 HP Hemi. Of course your performance will increase but your calculations are just ridiculous. Nice try though.
To those who say I am wrong, please read the original article fully before making yourself look stupid. This is HORSEPOWER EQUIVALENTS. There is no way in hell that removing weight would increase horsepower at the crank or the wheels. What I am doing is converting "weight loss" into a more palpable form like "horsepower." Of course, this weight "horsepower" only effects acceleration. It has a greater effect on handling, but not one that can be measured in theoretical "horsepower."

There are two ways to make your car accelerate faster.

1) Increase horsepower.
2) Decrease weight.

At some point, removing a certain amount of weight will be just as effective as increasing your housepower by a given amount. This allows you to find out just when that is.

Once again, before flaming, read and UNDERSTAND what I have written. This is not meant to be 100% accurate, but to give a ballpark estimate.
__________________
I doubt anyone on a Focus board would be interested, but I'm selling a '94 Jeep Grand Cherokee with 55k miles, all power options and a manual tranny. PM for details. :)
Taiden is offline  
    Reply With Quote
Old 10-17-2005, 09:42 AM   #43
Carrera26
Focus Fanatic
 
Carrera26's Avatar
 
Join Date: Aug 2004
Fan#: 12237
Location: Gainesville, FL
What I Drive: 2005 Mazda3 2.3/2003 VW Passat GLX

Posts: 2,957
FF Reputation: 2 Carrera26 Good Standing Member
Buy-Sell-Trade Rating: (0)
Maybe just going for power/weight ratio from the beginning would have been easier...
__________________
Don't waste another minute waiting on parts, or anything else. Just get out there and start racing! You will suck at first, and you will be slower than many other cars, but the only thing you will regret is not starting earlier...
Carrera26 is offline  
    Reply With Quote
Old 10-17-2005, 01:39 PM   #44
Taiden
Focus Enthusiast
 
Join Date: Aug 2005
Fan#: 26198
Location: Portland, Maine
What I Drive: 94 Grand Cherokee 55k mi, standard

Posts: 65
FF Reputation: 1 Taiden Good Standing Member
Buy-Sell-Trade Rating: (0)
Quote:
Originally posted by Carrera26
Maybe just going for power/weight ratio from the beginning would have been easier...
Maybe not making this post in the beginning would have been easier. ;P


To everyone else:

Know that the concepts discussed in this thread are not false in any way, and are reasonably accurate. This is not the end all be all mathematics for determining HP/LB equivalents, if we wanted that, it would involve calculus.

These are meant to be used to give someone an idea, or an estimate of how much weight they could lose to get the same performance out of a given upgrade.

Example:

Since my car wieghs W pounds, and I want the performance of Y hp, I could either spend money on upgrade X to get Y hp, or I could remove Z lbs from my car.
__________________
I doubt anyone on a Focus board would be interested, but I'm selling a '94 Jeep Grand Cherokee with 55k miles, all power options and a manual tranny. PM for details. :)
Taiden is offline  
    Reply With Quote
Old 10-17-2005, 04:21 PM   #45
Carrera26
Focus Fanatic
 
Carrera26's Avatar
 
Join Date: Aug 2004
Fan#: 12237
Location: Gainesville, FL
What I Drive: 2005 Mazda3 2.3/2003 VW Passat GLX

Posts: 2,957
FF Reputation: 2 Carrera26 Good Standing Member
Buy-Sell-Trade Rating: (0)
If anybody wants to use power to weight, here are some decent baselines.

Weight / BHP = Power to weight ratio = Pounds each BHP has to push around.

Remember to apply the ratio for type of weight loss as well

Sprung 1:1
Unsprung Rotational 1:3 (Wheels, tires)
Driveline 1:15 (Flywheel, clutch, pistons, Rotating driveline mass)

There is also the element of torque to weight, which will make a real difference, especially with FI cars. But as this also involves the area under the torque curve, it is much more complex, so let's keep it simple. That is, unless somebody really feels like diving into it.

(Rounded to the hundreth)

ZX3 Zetec - 20.53
ZX3 ST - 18.13
SVTF - 16.18
RS - 13.08

2005 Mustang V6 - 15.71
2005 Mustang GT - 11.5

Cobalt (LS Coupe) - 20.62
Cobalt SS Supercharged - 14.59 <@ 205 BHP, this has been argued as low, 13.29 @ 225BHP>

Corvette C6 (coupe) - 8.1

WRX STI (2005) - 11.02

Ferrari Enzo - 4.41
Ariel Atom - 3.38
TVR Speed 12 - 2.358

Suzuki GSXR 1000 - 2.33


Here is a good site to look cars up.
__________________
Don't waste another minute waiting on parts, or anything else. Just get out there and start racing! You will suck at first, and you will be slower than many other cars, but the only thing you will regret is not starting earlier...

Last edited by Carrera26; 10-17-2005 at 04:29 PM.
Carrera26 is offline  
    Reply With Quote
Old 12-07-2005, 07:34 AM   #46
Blurry
Focus Enthusiast
 
Blurry's Avatar
 
Join Date: Feb 2005
Fan#: 18821
Location: Freeport, ME
What I Drive: 02 SVTF, 83 GTi 16v

Posts: 55
FF Reputation: 1 Blurry Good Standing Member
Buy-Sell-Trade Rating: (0)
Can't wait till spring...bought a set of SSR GT1s that weigh 15lbs. so that's about 7 lbs. a wheel lighter then the stock SVTF rims...new tires that weigh 1.5 lbs. less each then the stock Contis and so far I've lost 35lbs. with some more to loose...My SVTF should really feel much quicker by spring.
Blurry is offline  
    Reply With Quote
Old 12-07-2005, 07:50 AM   #47
b16sir1991
Focused Focus
 
b16sir1991's Avatar
 
Join Date: Dec 2004
Fan#: 16612
Location: Kannapolis, NC
What I Drive: 2004 SVT Focus, Sonic Blue

Posts: 6,403
FF Reputation: 175 b16sir1991 Excellent Standing Memberb16sir1991 Excellent Standing Member
Buy-Sell-Trade Rating: (116)
I just figured mine (keep in mind this is a approximation because im going off of what Wayne dynoed one at already) and it should be appx. 8.57hp/lb. Not bad, never thought about it till i saw this thread.
__________________
"The right driver can work magic"

Oct 2005 Ride of the month.
SVT Squad #25
Call me Mike......

Give rep points and feedback when you appreciate someone on here!
b16sir1991 is offline  
    Reply With Quote
Old 12-07-2005, 08:33 AM   #48
Carrera26
Focus Fanatic
 
Carrera26's Avatar
 
Join Date: Aug 2004
Fan#: 12237
Location: Gainesville, FL
What I Drive: 2005 Mazda3 2.3/2003 VW Passat GLX

Posts: 2,957
FF Reputation: 2 Carrera26 Good Standing Member
Buy-Sell-Trade Rating: (0)
^^^Just a tick off of a C6. Good Job! There's always the question of gearing, traction, and how you're accesing the power curve, but I have always thought that this is the best "from the hip" estimate.

I think it's pretty fun to look up too, so here's 3 race cars

2005 Dodge Magnum NASCAR - (3400lbs / 850bhp) = 4.00 lb/bhp
1973 Porsche 917/30 - (1872lbs / 1100bhp) = 1.70 lb/bhp
2005 Ferrari F2005 F1 car - (1333lbs / 1000bhp) = 1.33bhp

It just cracks me up that a street-legal, $40K, 4-cylinder, Honda engined car (Atom) has a noticeably better power to wieght ratio than a full-on Nextel Cup car...
__________________
Don't waste another minute waiting on parts, or anything else. Just get out there and start racing! You will suck at first, and you will be slower than many other cars, but the only thing you will regret is not starting earlier...
Carrera26 is offline  
    Reply With Quote
Reply

Bookmarks & Social Networks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:58 AM.


Copyright 2002-2014 FocusFanatics.com. All Rights Reserved : Terms of Use : Privacy Policy : Advertise Information : Site Map

Focus Fanatics Ford Focus Forum offers many fun ways for you to engage with other Ford Focus Owners from across the world. Whether it be about the aftermarket performance modifications, technical how-to's, European tuned suspension or awesome fuel economy similar to the Acura TLX or Fiesta ST. You can find all Ford Focus and Focus ST related information here. Join our Ford Focus discussion forums and chat with local Focus enthusiasts in your area.