Weight Reductions Guide & Tips - Features - Import Tuner

It's not uncommon to see a car on the streets decked out with a custom body kit, full audio system and a set of Volk rims, to name the least. As the list goes on and expands so does the overall weight of the vehicle. So what does that mean to the average import enthusiast looking to improve the performance of their prized possession vehicle? Probably jack crap, but what many automotive enthusiasts fail to realize is lightening the vehicle and altering the vehicles curb weight does have its advantages. With every ounce or pound of weight removed from a vehicle, the car will possess a better horsepower/weight ratio enabling the vehicle to accelerate faster, improve handling characteristics, reduce braking time, while also reducing fuel consumption and emissions (due to the engine having to work less to move the vehicle). A general rule of thumb is for every 10 percent reduction in weight has a comparable 10 percent reduction in the force required to accelerate or decelerate an object. The same applies for an automobile.

To break it down in quarter-mile drag racing, every 100 lb removed from a vehicle equals [approx.] 1/10th of a second improvement. That might sound unimpressive when written on paper but those tenths of a second can mean the difference between winning a race by a mere bumper's length and staring at your competitors taillights in defeat.

For road racing vehicles and even drift cars the goal is to obtain an idealistic 50/50 weight balance from front to rear and improve in the vehicles overall handling characteristics. To be able to enter and exit an apex without loosing the vehicles momentum initiate a more stable turn, and induce accelerated pickup speeds can lower the lap times at the track.

Having to do the dirty work is never easy but 2NR took the job of getting down to the nitty-gritty for our readers just so you don't have to sit there in the blazing sun with your mom's weight scale, disassembling and weighing every item in your vehicle. For this article we have enlisted the help of the Skunk2 and documented the weight on various components on their custom carbon-fiber road race Civic, scaling every component from the seatbelts all the way down to the ECU brackets. We've done it all! Also in the mix are some lightweight aftermarket components that have replaced the OEM Honda parts. Keep in mind although we dissected and documented many of the parts from the Skunk2 Civic, there are still many more components that can be replaced or removed from the car--the sky's the limit. This isn't the final word in weight removal but rather a comprehensive article on how much weight can be removed.

Calculating power to weight ratio In order to approximate the horsepower to weight ratio theory and determine how much power you can expect, we used this simple formula to calculate how much horsepower and torque is increased with every pound removed from the vehicle. Used within the formula is a stock Civic Si. Note: Curb weight is the total weight of the vehicle without a driver. Gross weight is the total of the car with the driver included.

With calculations complete, final numbers show a horsepower to weight ratio of 18.18. For every 18.18 lb removed, the car will gain approximately one horsepower. The same properties apply for the torque figures as 1 lb-ft of torque is gained for every 22.04 lb removed from the vehicle. Keep in mind the calculations were made with a 165 lb driver on a bone-stock Civic. If your weight is on the heavier side, plug in your own numbers before dividing, Porky!

LEVEL 1 * WEIGHT REDUCTION * BEGINNER LEVEL

Level one details simple methods to reduce the overall weight of the vehicle by removing material that can easily be re-installed by the owner without a fuss. In less than an hour, almost 380 pounds were removed from the vehicles weight without sacrificing the overall appearance of the vehicle or structural integrity of the chassis.

OEM Passenger Seat w/Brackets
32.64 lb each
If you're tired of having friends mooching rides off of you every weekend, removing the passenger seat might just do the trick and deter them from crawling into your car.

Rear Seat and Cushion
21 lb
Decisions, decisions. Will you remove the rear seats and forego your opportunity to have a hot and steamy make out session with a girl named Shelly (self-proclaimed import model)? Isn't life a bitch? Removing the upper and lower half of your rear seats will lop off that excess weight you've been itching to rid yourself.

Rear Seatbelt Brackets
11.08 lb
No back seats equals no make-out sessions with Shelly the import model. Depressing, but lets get back to reality. With the rear seats discarded, the next step would be to remove the rear seatbelts, as now they serve no purpose.

Head Unit/Speakers
20.08 lb
Enjoy listening to the monotonous buzz of your exhaust and busting the occasional karaoke in the car? Removing the radio is quite a sacrifice, especially in California traffic, but can serve as additional weight conservation.

Floor Mats
5 lb
Screw the dirty feet! If you're that anal about getting your carpet dirty... well, drive barefoot.

Spare Tire Trunk Liner
3.4 lb
I, for one, never liked those flimsy cardboard or plastic covers that lie underneath the carpeting to access the spare tires. If you're like me, you won't loose any sleep over discarding this item.

Spare Tire and Jack
33.5 lb
Keep your AAA Automobile Card handy as you remove the only insurance that will ultimately determine if you're driving home safely after experiencing a flat tire or sitting dumbfounded on the side of the road.

Skinny Import Model vs. Fat Import Model
100 lb vs. 180 lb
Let's assume you've actually got game and managed to hook up with that import model that's been dogging you the whole year. When you met her for the first time she looked hot as hell and only weighted 100 lb. After a year or so she let herself loose (literally) and tacked on an additional 80. So what do you do? 2NR has solutions for you so you can kill two birds with one stone. Dumping Chunky Ass will stop the constant teasing from your peers, but the most important thing is to break up with her and remove that 180-lb Gordita sitting next to you. Being single sucks, but in the long run going solo will remedy a large portion of added weight to your vehicle. Plus, you're probably no cream puff either. Get yourself to the gym!

OEM Fuel Tank
Full at 13.2 Gallons = 81.84 lb
If you are looking for the simplest, most economical, way of loosing weight, look no further than the fuel you are pumping in to your car. Fuel, you ask? Yes, fuel! Remember that Physics class you took in school but always seemed to fail? Well if you were fast asleep in the back of class like me, there is a thing called F@#$-if-I-Remember-Because-I-was-Asleep-Theory. Seriously... I don't remember what it's really called but the theory basically explains the relation of weight to liquid mass. Every one gallon of fuel is equivalent to 6.2 lb of mass weight. Of course, depending on the type of fuel--for example, Methanol displays a different buoyancy and will weigh less than pump gas--you use, the weight will be different. But we will concentrate on pump gas for this article. With the standard 13.2-gallon fuel tank top off in a Civic, the total weight of fuel will come out to a whopping 81.84 lb. Hey! Just as much weight as your model chick tacked on over the past year! A general rule for racers is to fill up with only a quarter tank of gas (3.3 gallons = 20.46 lb) and you save a total of 61.38 lb.

TOTAL WEIGHT REMOVED
Total weight w/driver + Girlfriend + Full tank of gas = 3170.84 lb
3170.84 lb - 180lb (throwing your girlfriend out the door) = 2990.84 lb
2990.84 lb -127.42 lb (interior removed) = 2863.42 lb
2863.42 lb - 61.38 lb (running on a quarter tank of gas) = 2802.04 lb

Total
3170.84 lb - 2802.04 lb = 368.80 lb SAVED!

LEVEL 2 * WEIGHT REDUCTIONS * INTERMEDIATE LEVEL

Level 2 is for the more experienced mechanics in the automotive world. In order to lighten the load these steps require simple removal of various amenities that you might consider expendable. An example would be the air conditioning. Sure, this creature comfort was one reason why you paid a premium over the sticker price at the dealership, but are you really concerned with having a nice, ice-cold breeze showering your face when temperatures skyrocket in the upper 100 degrees? Of course not! Scrolling through the list, you will come across various aftermarket products that have replaced the OEM components, and dramatically reduced the overall weight of the car.

Power Steering
12 lb
Callused palms? Perhaps it's a good idea to either stay away from the lotion and Rosie and her five-fingered friend, or better yet, try relaxing that kung-fu grip on the steering wheel--whichever method floats your boat. Power steering is another luxury you can decide you want to eliminate or keep for the future.

Headliner
7.5 lb
Who needs headliners? They only make your car look presentable, not to mention the only time you'll be staring at it is when you're in the back seat making out with Miss Import model, but since those rear seats are a thing of the past, get rid of the headliner, right?

Air Conditioning
32.5 lb
Are you willing to endure the hot summer days with no air conditioning? Consider driving in just a pair of chonies (underwear, people!) or better yet, remove the air conditioning unit, including the AC condenser, lines, pump and misc. brackets. Driving with the windows down will ultimately net you a reduction of 32.5 lb.

Door Panels
12.9 lb each
Ugly as it may appear, removing your side door panels will enable you to scrounge around for those precious weight saving numbers you aim to acquire. Not to mention how cool it will look with all your power window controls dangling by the wires!

SEATS
OEM Front Seat w/Brackets vs. Recaro/Braille Carbon/Kevlar Stage 3 Bucket w/ Brackets
32.64 lb vs. 13 lb
An often overlooked item when building a race car that will keep your body from tumbling around in the seat when taking high-speed turns is an aftermarket bucket seat. Skunk2 decided to replace the driver side seat in favor of a Carbon/Kevlar Stage 3 bucket from Recaro/Braille Racing which netted a saving of 19.64 lb from stock. Take into consideration the two factory seats that weigh in at a stunning 65.28 lb, compared to two Recaro seats which weight in at a scant 26 lb [w/ brackets]. Not to mention it's a better fitting seat for your body.

Factory Battery vs. Braille Performance Battery
28 lb vs. 8 lb
Replacing the factory battery with an aftermarket battery, such as this Braille unit, requires only 10 minutes of your time and a simple 10mm socket. Talking to the techs at Braille, they assured 2NR that this lightweight battery has dual purpose and can be used in either a daily-driven vehicle or full race car, providing enough cold cranking amps to power any vehicle under the harshest conditions. A savings of 20 lb over stock.

OEM Rear Exhaust vs. Skunk2 Megapower Exhaust
15 lb vs. 8 lb
Considering the exhaust picks up considerable horsepower, we were surprised to see how much weight it shed in the process. Weighing the OEM back half exhaust against the Skunk2 Megapower Exhaust shows a weight difference of 7 lb over stock.

OEM Civic Header and Catalytic Converter vs. Skunk2 Prototype Mild Steel
23 lb vs. 15.28 lb
Of course we can't condone you running your vehicle without a catalytic, due to smog regulations (COUGHbullshitCOUGH), and of course who wouldn't want to increase the overall horsepower right? Riiight! Dumping the factory press bent headers in favor of a Skunk2 prototype was a no brainer. A savings of 7.72 lb over stock.

OEM Crank Pulley vs. Unorthodox 6061-T6 Aluminum Crank Pulley
5.10 lb vs. 0.75 lb
Reducing parasitic drag on the crank while reducing overall weight from the OEM crank pulley is a sure bet that horsepower is sure to be found. Unorthodox Racing reps state their soon-to-be-released crank pulley for the Civic Si will weight in at an amazing 12 ounces. A savings of 4.35 lb.

OEM Hood vs. Braille Carbon-Fiber hood
47.8 lb vs. 14 lb
Still not satisfied with all the weight you've removed from the vehicle? Greedy bastards! Consider replacing your factory hood with either a quality fiberglass or carbon-fiber unit. With many manufacturers offering decent hoods at competitive prices, it's not hard to find the hood of your choice. Skunk2 opted to replace their Civic skin with a Braille carbon-fiber unit, weighting in at only 14 lb, a savings of 33.8 lb over stock.

WHEELS
OEM 15x 6 alloy wheels w/ 195/60 R15 88v All-Season Tires vs.
Forged Monoblock Volk TE37 18x 8.5 w/ 215/40 ZR18 BF Goodrich G-Force
41 lb vs. 40 lb
Weither you're into road racing, drag racing or drifting, driving on the proper set of rims and tires will determine if you're some half-ass wannabe or a performance minded enthusiast. Although the weigh in came out to only 1 lb, differentiating between the stock rims and tires versus Volk TE37s, keep in mind the stocks are 15 inches while the Volk's are 18 inches. With a larger rim and tire combination, the improved handling is attributed to applying more surface area to the tarmac with a decrease in tire slippage.

TOTAL WEIGHT REMOVED
Total
171.31 SAVED!

Stage 1 (2802.04 lb) - Stage 2 (171.31lb) = 2630.73 lb

ADDITIONAL COMPONENTS TO REMOVE OR REPLACE

* replace all glass windows and windshield with Plexiglas
* remove sunroof if applies to vehicle
* replace trunk lid with fiberglass or carbon fiber
* replace both door shells with a carbon or fiberglass unit
* replace lower control arms/suspension components with aluminum or chromoly components
* Add a chromoly cage (for strength and weight) to add rigidity to the frame as well as for safety purposes
* Acid dipping the frame/shell (There are two types of acid dipping which involve either removing the paint, or the more performance orientated, which eats at the metal surface to further lighten the shell.)

LEVEL 3 * WEIGHT REDUCTION * ADVANCED LEVEL

Level 3 is the advanced level in weight removal and should be considered for individuals who plan to campaign their vehicles as race-only. Although the items listed below can be done by most novice tuners in the world, we strongly advise anyone who plans on altering their chassis support and frame structure to ask for a professionals help. Hell... it's only your life were talking about here right? Remember to always add additional support to any chassis section that has been altered or removed.

OEM Steel Flywheel vs. Fidanza 6061 -T6 Aluminum Flywheel
14.18 lb vs. 8.04 lb
Replacing the factory flywheel with an aftermarket Fidanza flywheel will enable the vehicle to reduce the amount of horsepower needed to turn the flywheel so that potential horsepower can be used to turn the wheels instead. A savings of 6.14 lb over stock.

Sound Deadening Material
19.02 lb
Next to the dimmer switch, the sound deadening material is probably the most useless component in a Honda. Not only is this sticky, tar-like material sparingly positioned within various areas of the floorboards and trunk space, it serves minimal purpose in filtering out road noise. Taking a chisel and some WD40, Skunk2 managed to extract 19.02 pounds of muck from the floor, trunk and firewalls, while grimacing as they shoveled the delightfully appetizing crap into a box.

Dash Support
17.44 lb
Hacking and chopping is the name of the game. Removing various brackets and support beams enabled Skunk2 to shave 17.44 lb of dead weight off the dash.

Roof Support Webbing
5.68 lb
Enjoy listening to the paper thin sheet metal on your car roof flutter when speeding down the road? We sure don't! But if push comes to shove and its weight conservation you're looking for, consider dissecting the webbing from the roof and pray nothing comes crashing down on you from up above.

Door Beams/Side Impact
19.38 lb
There are two types of people who would knowingly remove the door side impact beams. Type one is an autocross or drag race enthusiast looking to shell out the 80-plus pound doors to save weight, with plans to eventually install a roll cage. Then there's type two, who is a self-proclaimed bad ass, removing the beams on his daily driven car thinking he/she will never be t-boned by another car. Which one are you?

Rear Speaker/Side Panel Metal support
2.26 lb
Removing the speakers and radio was just one step to lightening up. The second is to begin removing the sheet metal that supports and holds the speakers in place. Understand once you cut that support, there's no looking back. It's Karaoke for life baby!

Misc. Brackets
(ECU bracket, fuse box bracket, etc.)
12.2lb
Damn, don't be so anal! Being nitpicky is necessary when looking to remove every ounce of unnecessary weight. Removing various brackets from the ECU and fuse box can contribute to as much as 12.2 lb.

Firewall Layers (3 layer OEM equipped) Two removed
15.14 lb
Honda seems to have gone overkill with their firewall diameter thickness for your safety. Scanning through the NHRA rulebooks we were giddy to reveal that obtaining just one layer of factory equipped, three-layer firewall is sufficient enough to pass tech-n-spec. NHRA 2004 rulebook regulations state a minimum .024-inch steel firewall (per class requirements) extending from side to side of the body and from the top of the engine compartment's upper seal, cowl, hood or deck. In certain instances fiberglass, carbon fiber, or other composites may be used. Skunk2 removed the top two layers, leaving he final layer intact.

Race motor mounts brackets
4.32 lb
The OEM motor mounts are designed to accommodate a factory-spec engine. In high-performance situations, the OEM motor mount will flex and bend the engine in an awkward motion. To remedy the problem Skunk2 devised a set of custom solid mount brackets that weigh in at a scant 4.32 lb. Saving weight is one issue but having a set of reliable motor mounts is just as important.

TOTAL WEIGHT REMOVED
Total
101.58 SAVED!

Stage 2 (2630.73 lb) - Stage 3 (101.58 lb) =
2529.15 lb

Final numbers=
2909 lb - 2529.15 lb = 379.85 lb removed

CALCULATIONS * POWER TO WEIGHT RATIO

Step 1: Determine Vehicles Weight: 2003 Civic SI
Curb weight/MT w/o driver: 2744 lb
Gross weight w/165 lb driver: 2909 lb
Step 2: Determine Vehicles Horsepower: 2003 Civic SI = 160 hp to the flywheel
Step 3: Determine Vehicles Torque: 2003 Civic SI = 132 lb-ft to the flywheel
Step 4: Divide the weight of your car (w/driver) by the horsepower: 2909 lb/160 hp = 18.18
Step 5: Divide the weight of your car by the torque: 2909 lb/132 lb = 22.04

FINAL COMMENTS
Remember, just lopping off weight from any section of the car does have its consequences. Removing 200 lb off the back end of a RWD vehicle will reduce traction and handling capabilities because the front of the vehicle is now accommodating for most of the weight. The same applies to a FWD vehicle, as the main emphasis is to have as much weight to the front wheels to aid in traction. The most crucial situation comes when you are planning to drag race the vehicle. What are you waiting for? Now go out there and start dissecting your car!

ADDITIONAL WEIGHT REDUCTIONS MISCELLANEOUS ENGINE COMPONENTS WEIGHT

Braille Battery 11.5 lb Stock battery 28 lb OEM Civic Header + Catalytic converter 23 lb Skunk2 Prototype Mild Steel 15.28lb OEM stock header w/o catalytic 8 lb OEM rear exhaust 15 lb Skunk2 Megapower exhaust 8lb OEM intake manifold + throttle body 14.25 lb Axles + midshaft 37.06 lb Starter 7.34 lb OEM flywheel 14.18 lb Fidanza aluminum flywheel 8.04 lb OEM clutch disk 2.72 lb OEM Pressure plate 8.66 lb OEM flywheel bolts 8.64 oz OEM clutch bolts 2.56 oz Fidanza clutch bolts 2.56 oz OEM crank pulley 5.10 lb Unorthodox Crank Pulley 12 oz Valve cover 6.84 lb Timing chain cover 3.22 lb K24 Timing chain guides 11.2 oz L20 Timing chain guides 10.56 oz OEM coil packs (4) 1.72 lb OEM fuel rail + OEM injectors (4) 1.75 lb RC Engineering injectors (4) 14.4 oz Aluminum Oil Pan 7.66 lb Steel Oil pan 4.60 lb Wire harness 6.30 lb Race motor mounts brackets 4.32 lb OEM rods, cast pistons, rings, bearings 2.06 lb Custom K24 Castillo Crank 96.5mm stroke   (micro polished, balanced) 36.44 lb Oil Pump (K24/TSX) w/balance shaft assembly 11.3 lb Oil baffle plates (K24/TSX) 0.38 lb OEM head studs 2.64 lb VTEC Solenoid 1.24 lb OEM fuel pump 5.58 lb OEM fuel pressure regulator 1.50 lb OEM Battery Tray 1 lb