Weight Reduction Thread.
#46
Man of many SIGs
Rennlist Member
Rennlist Member
Snipe, I wasn't trying to be derrogatory when I said " a little bit" of performance. I was only saying that I am not ready to throw away a large part of my car in order to save weight. I would do it in certain cases but not all. For instance, I was recently contemplating the replacement of my power seats with some light weight manual seats. This was not purely weight driven. I was having trouble w/ my head scrubbing the ceiling of my car. So I was gonna mount some manual seats, which can be mounted lower, and save some weight at the same time. Then I realized that I had never tried the middle button on my power seat to see what it did. Vioala! It lowered my seat to a height where I can fit. ( By the way, I feel really dumb for not realizing that earlier) Now I don't need to replace my seats so I wont be saving weight.
My car is a driver not a racer. ANd here in Florida, air conditioning is a necessity more than a luxury. I think it great that you guys are stripping the weight from your cars. I'd love to take a ride to see what the difference is. Hopefully I will see you at SITM this year.
My car is a driver not a racer. ANd here in Florida, air conditioning is a necessity more than a luxury. I think it great that you guys are stripping the weight from your cars. I'd love to take a ride to see what the difference is. Hopefully I will see you at SITM this year.
Originally Posted by m21sniper
Just for the record, it's not a 'little bit' of performance bro. Shaving 300lbs from a 3300lb car is the same as adding about 40 horsepower.*
Shaving 500lb from the same car would be akin to adding about 70 horsepower*.
IOW, if you shave 500lbs from your shark- you basically just added the effect of a supercharger, but without the cost.
Currently i am about 300lbs under stock, and i have a 95% intact interior, with all creature comforts installed but the A/C system. I can easily shave another 100lbs without doing anything that will make the interior or exterior look any different to the casual eye.
* = how much power will be 'added' is a matter of the adjusted power to weight ratio, and is a floating(ie non-fixed) figure based on power/weight.
Shaving 500lb from the same car would be akin to adding about 70 horsepower*.
IOW, if you shave 500lbs from your shark- you basically just added the effect of a supercharger, but without the cost.
Currently i am about 300lbs under stock, and i have a 95% intact interior, with all creature comforts installed but the A/C system. I can easily shave another 100lbs without doing anything that will make the interior or exterior look any different to the casual eye.
* = how much power will be 'added' is a matter of the adjusted power to weight ratio, and is a floating(ie non-fixed) figure based on power/weight.
#47
Inventor
Rennlist Member
Rennlist Member
My poor old OB - which barely scratches 200hp/225tq* to the pavement - doesn't have any 'bog' anymore at 2900ish lbs**. I put the hammer down, she takes a big gulp, and goes like mad.
I am still surprised when I put the pedal to the floor, because I drive around all day with the throttle just cracked open.
__________________
* When it's below 40f degrees outside.
** 3100 with the nut behind the wheel.
I am still surprised when I put the pedal to the floor, because I drive around all day with the throttle just cracked open.
__________________
* When it's below 40f degrees outside.
** 3100 with the nut behind the wheel.
#48
RL Community Team
Rennlist Member
Rennlist Member
What about something goofy like filling the tires with a lighter gas, like Helium? That might be overkill, but it might give the hardcore weight-trimmer something to add to his/her list.
#50
m21sniper,
I'm curious as to how you calculated your weight-HP relationship. I got more like 7 HP/100 pounds of weight reduction
"Just for the record, it's not a 'little bit' of performance bro. Shaving 300lbs from a 3300lb car is the same as adding about 40 horsepower.*"
.
I'm curious as to how you calculated your weight-HP relationship. I got more like 7 HP/100 pounds of weight reduction
"Just for the record, it's not a 'little bit' of performance bro. Shaving 300lbs from a 3300lb car is the same as adding about 40 horsepower.*"
.
#51
Lance J nitrous can fill a tire also
#52
Originally Posted by AJK
m21sniper,
I'm curious as to how you calculated your weight-HP relationship. I got more like 7 HP/100 pounds of weight reduction
"Just for the record, it's not a 'little bit' of performance bro. Shaving 300lbs from a 3300lb car is the same as adding about 40 horsepower.*"
.
I'm curious as to how you calculated your weight-HP relationship. I got more like 7 HP/100 pounds of weight reduction
"Just for the record, it's not a 'little bit' of performance bro. Shaving 300lbs from a 3300lb car is the same as adding about 40 horsepower.*"
.
http://www.network54.com/Forum/42613...hp-+It+Depends
#53
That link was very enlightening, thanks very much, as to this quote
Don't forget apart from acceleration, you must consider the handling, why do you think those Lotus Elises are so fast around a track? Can't be because of their 1.8 liter engines can it. Weight is a killer, in an F1 car they shave off weight up high just so they can reposition it lower in the car, that is the ballast, minimum weights to be maintained.
It is also less strain on the car's componants.
Cheers Greg
AJK m21sniper,
I'm curious as to how you calculated your weight-HP relationship. I got more like 7 HP/100 pounds of weight reduction
"Just for the record, it's not a 'little bit' of performance bro. Shaving 300lbs from a 3300lb car is the same as adding about 40 horsepower.*"
.
I'm curious as to how you calculated your weight-HP relationship. I got more like 7 HP/100 pounds of weight reduction
"Just for the record, it's not a 'little bit' of performance bro. Shaving 300lbs from a 3300lb car is the same as adding about 40 horsepower.*"
.
It is also less strain on the car's componants.
Cheers Greg
#54
I agree about the other advantages of less weight, especially in the wheels. My thought was in how much can be gained in acceleration with respect to weight reduction. For instance, could I detect the difference by removing the AC? How about the AC and the stock exhaust system together? My use is on the street only, no track time.
#56
It really depends on the model.
For my Shark, at it's current weight and power level, one HP = approx 9.9lbs.
So for me a loss of 100lbs would be the equivelant to 10hp.
If my car was 1000lbs lighter, it would only require approx 6.5lbs to = 1 HP.
7lb/HP is probably about right for a bone stock S4.
For my Shark, at it's current weight and power level, one HP = approx 9.9lbs.
So for me a loss of 100lbs would be the equivelant to 10hp.
If my car was 1000lbs lighter, it would only require approx 6.5lbs to = 1 HP.
7lb/HP is probably about right for a bone stock S4.
#57
Originally Posted by AJK
I agree about the other advantages of less weight, especially in the wheels. My thought was in how much can be gained in acceleration with respect to weight reduction. For instance, could I detect the difference by removing the AC? How about the AC and the stock exhaust system together? My use is on the street only, no track time.
Another one of those general rules of thumb is that an increase of 10hp OR an equivelant decerase in weight(for my car that would be 99.4lbs), will decrease 0-60 and 1/4 mile time by approx. .1 second.
A .1 sec margin of victory for a car running a trap speed of 100mph in a 1/4 mile run equates to 14 feet of distance.
So if you did JUST THE EXHAUST(assume a 30hp gain and loss of 50lbs in weight), and you raced an otherwise identical shark, you would beat it by approx .4 seconds, and would have a margin of victory of approx. 56 feet(or about 3 lengths)
Remember, these are just general rules, and will vary depending on the exact example cited.
#58
Man of many SIGs
Rennlist Member
Rennlist Member
There is also a difference in performance gains depending on whether you are removing sprung or unsprung weight. Removal of unsprung weight will result in a higher net performance gain than the same lbs removed from the sprung weight. I'm not sure about the formula's involved. I'm sure with a little time and google you could find out.
By the way. I recommend clicking the link that sniper provided. It is a very educational post.
By the way. I recommend clicking the link that sniper provided. It is a very educational post.
#59
hey snipe my car weights a little less than your car now. my 79 not my s4 which i had to sell.. man i miss that car. but yeah with weight reduction and bolt on his 83 auto us beat my 83 euro auto. by that much. about 3 cars. from a dig. but when it came to topend my euro has longer legs and better cams for highway pulls. with a turbo @ 7 psi you'll spank that ferrari. lol
Last edited by Lance J; 02-21-2006 at 06:23 PM. Reason: errors
#60
Originally Posted by Fabio421
There is also a difference in performance gains depending on whether you are removing sprung or unsprung weight. Removal of unsprung weight will result in a higher net performance gain than the same lbs removed from the sprung weight. I'm not sure about the formula's involved. I'm sure with a little time and google you could find out.
By the way. I recommend clicking the link that sniper provided. It is a very educational post.
By the way. I recommend clicking the link that sniper provided. It is a very educational post.
PS: thanx for the compliment, you are very kind.