solder_guy Posted September 9, 2008 Share Posted September 9, 2008 One way that I have taken weight away from my car is replacing the heavy steel fuel tank with a custom aluminum one. About half the weight. Now I have purchased an aluminum scissors jack and handle. Much lighter than the steel Toyota jack that I had in the car. This one is for the 86-91 RX-7s. Of course my wife would suggest another way to lighten my car would be that I lose 30 pounds .... Other ideas to lighten the car? Rob http://www.usa7s.com/aspnetforum/upload/572185039_jack.jpg http://www.usa7s.com/aspnetforum/upload/137286503_tank.jpg Link to comment Share on other sites More sharing options...
BusaLoco Posted September 9, 2008 Share Posted September 9, 2008 Our Jaz Cell is pretty light too! http://www.usa7s.com/aspnetforum/upload/197990013_Jaz sponge fuel cell.jpg Link to comment Share on other sites More sharing options...
slngsht Posted September 9, 2008 Share Posted September 9, 2008 busa, rotus uses a tank that mounts above -and in front of the axle. so it has to be a custom tank. Link to comment Share on other sites More sharing options...
Dave W Posted September 9, 2008 Share Posted September 9, 2008 Leave the jack and spare tire home, carry a can of Tire - Fix. 217 wt reductions implemented 1 Oz at a time. Dave W Link to comment Share on other sites More sharing options...
MHKflyer52 Posted September 10, 2008 Share Posted September 10, 2008 Leave the jack and spare tire home, carry a can of Tire - Fix. 217 wt reductions implemented 1 Oz at a time. Dave W Carry a AAA Plus card...... :d :d Link to comment Share on other sites More sharing options...
Davemk1 Posted September 10, 2008 Share Posted September 10, 2008 Hey, I pulled a good bit of weight of my Birkin this year in the places where you get the double bang for the buck if you will. .......... rotating weight. I installed an aluminum flywheel (10 pounds lighter than stock) and an aluminum undersize crank pulley (2 pounds lighter than the stock Ford part). So between these two thing I pulled of 12 pounds of engine speed rotating weight. So not only did it remove 12 pounds from the car but 12 pounds that needs to go from 1000 rpm's to 7000 rpms as quickly as possible. It made a huge difference in throttle response and acceleration. I also moved from the stock Birkin wheels to a set of Team Dynamics wheels which are 3 pounds lighter each for a total savings of 12 pounds of wheel speed rotating weight. Not as good as engine speed stuff but good nonetheless. Lastly I also ditched the stock full length 2" Birkin exhaust system and replaced it with a side exit 2.5" system. It removed another 8 pounds and freed up 10hp do to it's better breathing. It no longer runs out of steam at 500 rpms but pulls hard until it hits the limiter at 7200. So what I've learned is take the weight off the stuff that performs a double duty of you can and get as much benefit as you can from your time and money. The responsiveness and feel of the car are greatly improved and it's a joy to drive hard and just wants to rev. Sure it will help if you put in a light battery or something like that but not as much as a light flywheel........ unless of course you spin your battery at 6000 rpms. my 2 cents. dave Link to comment Share on other sites More sharing options...
Alaskossie Posted September 10, 2008 Share Posted September 10, 2008 Solder_guy, I've substituted an aluminium jack that looks like your Mazda jack, but from a Porsche 944. I am presently skeletonizing it. The Porsche jack was built to lift 900 kg (so the label says) with a presumed safety margin, so I figure that adding lightness by removing about 25 percent of its mass will still leave a sufficient margin for lifting one corner of a Caterham. Besides, when it's done it will look cool.... A Triple-A card doesn't help much when you are 300 miles and half a day (or more) from the nearest AAA-authorized tow truck, I'm afraid. Link to comment Share on other sites More sharing options...
Kitcat Posted September 10, 2008 Share Posted September 10, 2008 Nor does a AAA card help when you break down where there is no cell phone coverage, as I found out. Link to comment Share on other sites More sharing options...
gjslutz Posted September 10, 2008 Share Posted September 10, 2008 Dave, That is the way to go. What flywheel & crank pulley did you use, and is the engine staying cool with the undersize crank pulley? If you don't mind, where did you purchase? Gary Link to comment Share on other sites More sharing options...
sparecr Posted September 10, 2008 Share Posted September 10, 2008 I also moved from the stock Birkin wheels to a set of Team Dynamics wheels which are 3 pounds lighter each for a total savings of 12 pounds of wheel speed rotating weight. Not as good as engine speed stuff but good nonetheless. Actually this is unsprung weight. The ratio I have heard is that every 1 lb of unsprung is equal to 10 lbs sprung. So this really is a 120 LBS weight savings. Easiest way to save money without affecting drivability. Link to comment Share on other sites More sharing options...
Davemk1 Posted September 10, 2008 Share Posted September 10, 2008 Dave, That is the way to go. What flywheel & crank pulley did you use, and is the engine staying cool with the undersize crank pulley? If you don't mind, where did you purchase? Gary My car runs an early Zetec and I found both the alloy flywheel and undersize pulley on eBay. The flywheel is a Fidanza and fits perfectly. The undersize pulley was also found on eBay and I honestly forget the brand but it was some company that made them for lots of different applications. It was not expensive and the quality looks very good. I have had no overheating issues with the smaller pulley. The car tends to run cold (by the gauge at least) so I thought it would be OK. In the end I notice no difference at all. I suspect that if anything the thermostat opens a bit sooner or further but the engine runs at the same temperature. If I were doing this over again I would have also used an alloy pressure plate. I'm using a stock Ford stamped steel thing and could have saved another 5 pounds or so with a Spec brand alloy pressure plate. But like usual I was (and still am) on a budget and the extra $500 was out of reach at the time I was doing the work. But next time the engine comes out an alloy pressure plate will go in. I hope that helps. dave Link to comment Share on other sites More sharing options...
Kitcat Posted September 10, 2008 Share Posted September 10, 2008 I think the weight savings between rotating and non-rotating mass is the square of the amount saved. For instance-save 4 lbs by going to a lighter battery = 4 lbs. But save 4 lbs by going to a lighter wheel = 16 lbs. If the new wheel is 10 lbs lighter = 100 lbs. Multiply that by 4 wheels and you have done something. Link to comment Share on other sites More sharing options...
solder_guy Posted September 10, 2008 Author Share Posted September 10, 2008 I've substituted an aluminium jack that looks like your Mazda jack, but from a Porsche 944. I am presently skeletonizing it. The Porsche jack was built to lift 900 kg (so the label says) with a presumed safety margin, so I figure that adding lightness by removing about 25 percent of its mass will still leave a sufficient margin for lifting one corner of a Caterham. Besides, when it's done it will look cool.... Yeah I had noticed that the Porsche jack and the Mazda jack look alike ... Post a pic of it when you are done. I also have the lightweight Odyssey MJ680 battery in my car. And relatively light aluminum rims x 5. Rob Link to comment Share on other sites More sharing options...
southwind25 Posted September 10, 2008 Share Posted September 10, 2008 I think lightening the car, is porportional to lightening the wallet..:ack: :ack: would love to put some pretty carbon fiber bits on, and all those aluminum thingies.. we are heavy and poor...but always fun! Link to comment Share on other sites More sharing options...
DeanG Posted September 10, 2008 Share Posted September 10, 2008 Check the dip stick weight, some are massive. Put it in the tool box at home and use a plastic plug. Link to comment Share on other sites More sharing options...
gjslutz Posted September 12, 2008 Share Posted September 12, 2008 Dave, where did you find the light "Spec brand alloy pressure plate" listed? I have not been able to find any. I have plans on pulling my engine this winter due to a rear main seal leak and adding the billet oil pump gears. I would like to do all at once. I need to miss a few meals to fund the project. My bug converted deflector / aeroshield reduced weight as well a major drag reduction. It makes faster RPM that you notice starting in the top side of 3rd and all of 4th as well as 5th. It was a 5 hour & $50 project. Gary Link to comment Share on other sites More sharing options...
Davemk1 Posted September 12, 2008 Share Posted September 12, 2008 Dave, where did you find the light "Spec brand alloy pressure plate" listed? I have not been able to find any. I have plans on pulling my engine this winter due to a rear main seal leak and adding the billet oil pump gears. I would like to do all at once. I need to miss a few meals to fund the project. My bug converted deflector / aeroshield reduced weight as well a major drag reduction. It makes faster RPM that you notice starting in the top side of 3rd and all of 4th as well as 5th. It was a 5 hour & $50 project. Gary I don't have the link any longer but I'm pretty sure if you Google "Spec clutch" you'll find it. Dave Link to comment Share on other sites More sharing options...
oilteq Posted September 12, 2008 Share Posted September 12, 2008 Try here http://jdmultimate.com/Store/Product/drivetrain/p-10026.aspx Link to comment Share on other sites More sharing options...
locostv8 Posted September 13, 2008 Share Posted September 13, 2008 Rob Did you strip the paint on the fenders and other fiberglass? When stripping Mazda's fenders I found the rears had a HEAVY coat of what almost appeard to be clay, when it was all off the fenders semed to be about a third lighter there was no jell coat on rears. I will fix with light coat of jell coat then sand. Link to comment Share on other sites More sharing options...
solder_guy Posted September 13, 2008 Author Share Posted September 13, 2008 Did you strip the paint on the fenders and other fiberglass? No clay .. We sanded them down .. applied bondo to patch the original light housing holes .. and primed for painting .. Rob Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now