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Weight 101
By: Ron Lee

          Reducing the weight of your car will make your car quicker, faster, and handle better. When I was a teenager, one day I took maybe 50 pounds out of my 66 Galaxie and I was amazed at the difference it made in the way the car drove. I could feel the difference in the way the car accelerated. I've been hooked on weight reduction ever since (some people think I'm a bit extreme, and they could be right). I do not think you should remove your interior, or any other thing that truly compromises your car for the way you like it to look or function, but that is different things to different people. The point is to not push it to the point where you don't enjoy driving (and showing off) your car, it just isn't worth it.

          Your typical 79-93 5.0 Mustang weighs between 3000 and 3500 pounds, depending on the model and options. Coupes are 60 pounds lighter than hatchbacks, and LX models are lighter than GT models. Convertibles are the heaviest of all. For every 100 pounds you take out of your car, you will gain a tenth second reduction in your quarter mile time. The factory weight distribution is roughly 57 percent front and 43 percent rear. Ideally for handling it would be 50/50 front and rear. Therefore it is better to take weight out of the front end rather than the back end (in a Mustang) to get you closer to the ideal 50/50 weight ratio. There are numerous ways to reduce the weight of your Mustang. Keep in mind as you add braces to your Mustang that you can get them in Chrome Moly steel versus mild steel which will reduce the weight of the brace. Also keep in mind that those huge subwoofers and amplifiers that a lot of people like add a lot of weight to your Mustang. Listed below are a few ideas that I have done.

          You can take 50-55 pounds out of the front end of your Mustang by replacing those cast iron heads with aluminum heads. You will also gain 30 horsepower (or more) in the process. This is the best way to reduce the weight of your Mustang. The heads cost about $1000 and installation cost varies from $100 (doing it yourself) to about $600 (paying a mechanic). This is not a cheap weight reduction idea, but it is the best one because you get both reduced weight and increased power.

          You can take 15 pounds or so out of your Mustang by removing your spare tire and jack. If you have a flat, be prepared to walk and/or call for help, but the weight removal cost is free. I would definitely recommend putting a spare back in the car for any trips out of town.

          You can take another 10-15 pounds out of a hatchback by removing the underlayment under the hatch carpet. This will allow a little bit more noise into the passenger compartment, but most of us performance buffs don't mind that at all. Again, the cost is free.

          You can take another 5 pounds or so out of the car by removing the underlayment under the back seat. Similar to above, it will allow more noise in the car, and is also free.

          I personally always take out the cigarette lighter and ashtray which isn't much, but everything adds up. There are also small black plastic pieces which cover the front seat mounting bolts. I suppose that removing these could allow someone to get hurt on those bolts, but I never have. The hatchback also has a cover that stretches over the hatch area which can be taken out. If you do, you can no longer hide things in your hatch, but again the weight removal cost is free. Another little thing is that I remove one of the two horns. I really don't know if the car still meets whatever the requirement is for volume for horns, but again I get rid of a little bit of weight for free (I'm not a "hornblower").

          If you own an 86 or earlier Mustang, you can take 20 pounds out of the front end by replacing the front steel bumper with a fiberglass bumper from an 87-93 Mustang. You will have to modify the fiberglass bumper to accept your turn signal lights. You will also have to modify the mounting points for the bumper as well. I custom laid a fiberglass bumper instead for my 86 Mustang using the original bumper (covered with duct tape) for a mold. Either way this is a relatively cheap way to eliminate 20 pounds from your front end.

          March sells a slick looking aluminum brace for $45 which allows the removal of the factory air conditioning compressor. I had already removed the condenser, dryer, and hoses, but couldn't remove the compressor because then I couldn't get the right size fan belt. The brace is relatively easy to put on, though I studied it for a little while first, and then the compressor is a thing of the past along with another 10 pounds or so. The brace will also allow the removal of the air pump, but I don't recommend that for a street car. Removal of the air pump can damage your catalytic converters and can confuse your computer.

          Replacing the factory clutch fan with a flex fan will also remove about 3 pounds from your car. Make sure you get a reverse rotation fan if you have the serpentine belt. The fan kit only costs about $55. Flex O Lite is probably the best known brand. The factory fan begins to crack after a while and should be replaced when it does. I personally don't recommend electric fans (except for drag race cars) because they can have trouble keeping up with your car's cooling demands, especially if you drive the car hard and the engine has been modified. If you drive a stock Mustang and drive it reasonably, it may work for you (not for me).

          Steeda sells a tubular front stabilizer (sway) bar that is 8 pounds lighter than the factory sway bar and 30 percent stronger. What a deal. It costs about $175, but is relatively easy to install. The sway bar bushings are a larger size, but fit in your factory bushing mounts.

          Steeda also sells aluminum rear lower control arms which are 30 percent lighter (probably about 5 pounds) than the factory arms and much stronger. Handling and traction will be improved all at the same time. Installation requires the removal of the rear coil springs so it is involved, but can be done in your driveway. Be extremely careful when removing coil springs, they are very dangerous. The arms cost about $250 which isn't bad if you're already planning to buy aftermarket rear lower control arms anyway (steel ones start at about $175).

          If your car is not a street car, Steeda also sells aluminum front bumper mounts that take about 10 pounds out of the front end. They replace the front bumper shocks with a solid aluminum mount which is why they are not intended for a street car. The worst part of installing them is that your front bumper cover has to come off.

          You can take about 6 pounds out of your car by replacing your steel driveshaft with a Ford SVO aluminum driveshaft. The cost is about $165 and they are a snap to install. They come with new u-joints, so I bought mine when I thought my u-joints needed replacing anyway.

          You can also take another 6 pounds out of your car by replacing your standard starter with a light weight mini starter. These starters became factory standard in 91, so this only applies to the earlier years. They cost around $150 and are relatively simple to install. They give you more starting torque, less battery drain, and will also give you more room underneath the car. I wish my starter would die so I'd feel better about buying one.

          You can save another 10-15 pounds by replacing the rear steel bumper with a factory aluminum bumper from an early model turbocharged four cylinder Mustang. The only problem is finding one. I've never seen one, but if I did I would definitely buy it and put it on. Don't know if there are any complications to installation or not.

          You can eliminate another 20 pounds and enhance the appearance of your Mustang by installing a fiberglass hood. Most hoods are available in either bolt on or pin on styles. Get the bolt on unless your car is strictly a race car. The hoods are relatively easy to install, the only problem is that you have to get it painted to match you car. The hood will set you back $300 to $400 plus painting which will put another good dent in your wallet. I'd check on the painting price before I bought a hood. The hood scoop on mine certainly does attract attention.

          If you own a 2 door coupe, you can also get a fiberglass trunk for about $200. This will take about 10 pounds out of your car but will also require painting which can be expensive. Trunks are also a pain to install (or at least mine was). I spent the better part of a day drilling holes, installing the lock, installing the wires, installing the lights, and finally bolting the trunk on the car. They called that a bolt on trunk lid, but I sure wouldn't have called it that. I also had to adjust the spring tension until I added a spoiler on the trunk.

          You can also get fiberglass doors and hatches among other body parts. For a street car, I wouldn't recommend them. They are basically meant for race cars and don't really have (sturdy) provisions for things like windows that go up and down, or locks that work. You can, but expect a lot of work and compromises in the way things work. Always remember the cost to paint, it is very significant.

          Now for some other big weight reductions, but they come at a price and also require a lot of work.

          You can take another 30 pounds (or more) out of your front end by installing a tubular K member. These tubular K members come in many different varieties. Some are extra light weight and are really intended only for drag racing. Others will change your front suspension geometry to improve handling. One question to ask before buying is will the K member move your front tires forward, which (probably) will cause your tires to rub your fenders (unless you modify them and it won't be pretty). Most of the K members are stronger than the factory K member and will therefore improve your handling as well as reduce the weight of your car. Many of the tubular K members will not accept your factory front control arms and also require special adapters to reuse the factory style front springs, so ask questions before you buy. Installing one requires the disassembly of most of your front suspension, so it is not easy. I did mine on a lift and cannot imagine trying to do this in my driveway. In particular, be very cautious with the front springs which can be very dangerous. It will also require a front end alignment when you get done. These K members usually also allow your engine to be moved back 1 inch, but that will require other changes. Expect some custom fitting to put a tubular K member in your car. I had to cut on mine some to allow the steering shaft to turn (somewhat of an inconvenience, okay it was a biggie since you can't drive without steering). Most tubular K members cost about $450 and they are not easy to install. They do make access to everything underneath the front end much easier to work on. The extra space is simply amazing.

          Related to the tubular K members are tubular front control arms which will take another 15 pounds out of your front end. You will have to ask if they will fit your factory K member, assuming you are leaving it in the car. Using tubular control arms does require the use of coil over springs in the front. It also requires the removal of the front springs which can be very dangerous. Use extreme caution if you are doing the work. Replacing the front control arms also requires the disassembly of most of your front suspension and a front end alignment when you get done. Tubular control arms are much stronger than the factory control arms, so handling will also be improved. Tubular control arms cost about $300 and they are not easy to install, but not nearly as difficult as the tubular K member. One final caution, the older lower control arm bolts can be very difficult to get out (they rust to the bushing sleeve) and may require a torch for removal.

          Also related to the tubular K member are coil over springs which go over the front struts. These will take yet another 15 pounds out of your front end because they are smaller and lighter than your factory springs. Coil over springs can be used with your factory front control arms and K member, so that is not a problem. It does require the removal of the front springs and struts, so again use extreme caution if you are doing the work. You will also have to do a front end alignment when you get done. The coil over springs do allow you to set your ride height anywhere you want which is nice. Coil over springs are available in ratings from 200 to 700 pounds per inch. Remember that coil over springs are twice as effective as factory springs which means that a 250 pound rated coil over spring is the rough equivalent of a 500 pound factory spring (approximately stock for 5.0 Mustangs). Coil over spring kits cost about $300 and are not easy to install. I custom fabricated a pair of dust boots for the struts after putting a pair of coil over springs on my Mustang.

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©Copyright 1998 Ron Lee


© 1998 Michael Lee
© 2004 Michael Lee