spare tire? - Page 2

bryanf89 · 12-04-2009, 05:18 AM

That jawsgear website really came in handy. Much apperciated. I will definatly invest in the lighter drive shaft. As far as modifying the engine, what should i consider and of course any good websites will help.

cre · 12-04-2009, 08:32 PM

Add a DS loop or cage or whatever you want to call it... if it grenades you don't want it hitting the ground and tossing the ass of the car 3' in the air or, worse yet, have the broken DS cone up through the rear floorboard. I recommend steel over aluminum. The saving from either is HUGE over the stocker but between those two it's only a couple pounds and the steel is more resilient to the type of stresses a drive shaft goes through.

bryanf89 · 12-04-2009, 10:05 PM

If steel is better with durablity then why is aluminum more expensive and why even put aluminum as an option for the track?

cre · 12-04-2009, 10:42 PM

Expense is because aluminum is more expensive to produce (Did you know it takes 10 tons of boxite to produce 1 ton of aluminum? Also, aluminum doesn't naturally form in our atmospheric pressure, so giant pressurized smelter are required for production.) and it is harder to work (This is due to the metal not having much of a liquid range in our atmosphere... It's not much harder to work with, but it's enough to raise the price.).

The reason it is so popular is that it is strong and light. It's popularity in race vehicles is because it's a sport where every single ounce must be cut in order to move the car faster... less inertia to over come. Very high end cars may even have a thinner walled drive shaft which can't be used more a a hundred times or so before.

Steel has a much higher elasticity. As such it is far better suited to the centrifugal stresses which a drive shaft sees. There is a mathematical equation for how much stress a drive shaft can take, at what speeds it is most likely to fail and serves as a guide as to how long you can expect to run it before needing to replace it (PRIOR to failure)... it has to do with the type of metal, the length of the actual shaft, the offset angle of the differential and transmission, the diameter of the shaft and the wall thickness.

If you look around, you'll find more people who've had aluminum drive shafts fail at the track than steel. There's also the unending string of complaints about all the vibration which in inherant in aluminum and even CF drive shafts.

For a daily driver, steel is the most comfortable and longer lasting bet... for a track only car, aluminum is a great choice... I just assumed your car is a daily driver, so if that's incorrect then I apologize for the false assumption.

EDIT: Ever wonder why everyone isn't making aluminum crank shafts?

bryanf89 · 12-04-2009, 11:38 PM

Im more of a weekend driver but ill go with the steel DS and yes you made me realized why they only make cracnkshafts in steel. How big of a gain will i feelwith lightweight rims with low profile tires and a 1 piece steel DS from jawsgear?

cre · 12-05-2009, 12:00 AM

It's been so long that I really can't remember how big the difference was... I know I was rather surprised by it. Reducing rotating mass has a bigger effect, pound for pound, than other weight reduction.

There is a lot you can do to lighten the MKIII:
Remove the power seats.
Replace the stock baffled muffler and resonator with free flowing resonance based muffler and resonator.
Tubular intake manifold.
Replace the heavy stock noise matting with modern noise liner.
Delete the A/C system.
Convert to a manual steering rack.
Delete the rear seats (and do NOT replace them with a wooden or reinforced fiberglass box).
Do NOT add a subwoofer.
Remove the spare tire.
Run a rebuilt W58 transmission as opposed to the R154 (if your car has a R154); This one isn't as recommended on a high power build, the W58 is not as durable... I prefer the W58 though as it is lighter and smoother.
Lightweight flywheel.
Lightweight driveshaft.
Lightweight wheels (weigh the rims and the tires.... sometimes a smaller rim with a bigger tire is lighter and sometimes it is the opposite, it depends on how they are built).
Drive with less fuel in the tank... :P
Replace the charcoal canister with a smaller unit off of a newer Toyota or other import; One from a Toyota is recommended as the plumbing will more than likely be the same and require no modification. The CC from the Tercel is about 1/2 the size and weight of that in the USDM 7M MKIII.

et cetera, et cetera.....

bryanf89 · 12-05-2009, 01:05 AM

i dont want to modify the interior or exterior look of the supra i want to keep that classic untouched look. im spoiled i need ac in the summer and the ladies love it. the ac in total weighs about 30 pounds i rather get light weight pulleys than sweat my ass off in a heat wave..the noise matting i can do because im lookin to get a new carpeting to restore the interior, rear seats are staying merly for looks or just in case sum1 is small enough to fit bak there...manual steering rack is too much of a pain in the ass(what is the weight difference?)....i got two 12in subwoofers with a 350w amp screw the weight of that i like blasting music

...im going to get a complete exhaust system eliminate manifold cover or any other cover nd go cat less...

you know where i can buy a CC from a tercel?

cre · 12-06-2009, 04:26 AM

Let's move this to another thread specifically about weight loss.. it'll make it easier to keep track of and easier for future users to locate.

12-04-2009, 10:42 PM	#14
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Expense is because aluminum is more expensive to produce (Did you know it takes 10 tons of boxite to produce 1 ton of aluminum? Also, aluminum doesn't naturally form in our atmospheric pressure, so giant pressurized smelter are required for production.) and it is harder to work (This is due to the metal not having much of a liquid range in our atmosphere... It's not much harder to work with, but it's enough to raise the price.). The reason it is so popular is that it is strong and light. It's popularity in race vehicles is because it's a sport where every single ounce must be cut in order to move the car faster... less inertia to over come. Very high end cars may even have a thinner walled drive shaft which can't be used more a a hundred times or so before. Steel has a much higher elasticity. As such it is far better suited to the centrifugal stresses which a drive shaft sees. There is a mathematical equation for how much stress a drive shaft can take, at what speeds it is most likely to fail and serves as a guide as to how long you can expect to run it before needing to replace it (PRIOR to failure)... it has to do with the type of metal, the length of the actual shaft, the offset angle of the differential and transmission, the diameter of the shaft and the wall thickness. If you look around, you'll find more people who've had aluminum drive shafts fail at the track than steel. There's also the unending string of complaints about all the vibration which in inherant in aluminum and even CF drive shafts. For a daily driver, steel is the most comfortable and longer lasting bet... for a track only car, aluminum is a great choice... I just assumed your car is a daily driver, so if that's incorrect then I apologize for the false assumption. EDIT: Ever wonder why everyone isn't making aluminum crank shafts? Last edited by cre; 12-04-2009 at 10:45 PM.

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12-04-2009, 05:18 AM	#11
bryanf89 3" Exhaust Join Date: Nov 2009 Location: NYC Posts: 231	That jawsgear website really came in handy. Much apperciated. I will definatly invest in the lighter drive shaft. As far as modifying the engine, what should i consider and of course any good websites will help.

12-04-2009, 08:32 PM	#12
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Add a DS loop or cage or whatever you want to call it... if it grenades you don't want it hitting the ground and tossing the ass of the car 3' in the air or, worse yet, have the broken DS cone up through the rear floorboard. I recommend steel over aluminum. The saving from either is HUGE over the stocker but between those two it's only a couple pounds and the steel is more resilient to the type of stresses a drive shaft goes through.

12-04-2009, 10:05 PM	#13
bryanf89 3" Exhaust Join Date: Nov 2009 Location: NYC Posts: 231	If steel is better with durablity then why is aluminum more expensive and why even put aluminum as an option for the track?

12-04-2009, 11:38 PM	#15
bryanf89 3" Exhaust Join Date: Nov 2009 Location: NYC Posts: 231	Im more of a weekend driver but ill go with the steel DS and yes you made me realized why they only make cracnkshafts in steel. How big of a gain will i feelwith lightweight rims with low profile tires and a 1 piece steel DS from jawsgear?

12-05-2009, 12:00 AM	#16
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	It's been so long that I really can't remember how big the difference was... I know I was rather surprised by it. Reducing rotating mass has a bigger effect, pound for pound, than other weight reduction. There is a lot you can do to lighten the MKIII: Remove the power seats. Replace the stock baffled muffler and resonator with free flowing resonance based muffler and resonator. Tubular intake manifold. Replace the heavy stock noise matting with modern noise liner. Delete the A/C system. Convert to a manual steering rack. Delete the rear seats (and do NOT replace them with a wooden or reinforced fiberglass box). Do NOT add a subwoofer. Remove the spare tire. Run a rebuilt W58 transmission as opposed to the R154 (if your car has a R154); This one isn't as recommended on a high power build, the W58 is not as durable... I prefer the W58 though as it is lighter and smoother. Lightweight flywheel. Lightweight driveshaft. Lightweight wheels (weigh the rims and the tires.... sometimes a smaller rim with a bigger tire is lighter and sometimes it is the opposite, it depends on how they are built). Drive with less fuel in the tank... :P Replace the charcoal canister with a smaller unit off of a newer Toyota or other import; One from a Toyota is recommended as the plumbing will more than likely be the same and require no modification. The CC from the Tercel is about 1/2 the size and weight of that in the USDM 7M MKIII. et cetera, et cetera.....

12-05-2009, 01:05 AM	#17
bryanf89 3" Exhaust Join Date: Nov 2009 Location: NYC Posts: 231	i dont want to modify the interior or exterior look of the supra i want to keep that classic untouched look. im spoiled i need ac in the summer and the ladies love it. the ac in total weighs about 30 pounds i rather get light weight pulleys than sweat my ass off in a heat wave..the noise matting i can do because im lookin to get a new carpeting to restore the interior, rear seats are staying merly for looks or just in case sum1 is small enough to fit bak there...manual steering rack is too much of a pain in the ass(what is the weight difference?)....i got two 12in subwoofers with a 350w amp screw the weight of that i like blasting music ...im going to get a complete exhaust system eliminate manifold cover or any other cover nd go cat less... you know where i can buy a CC from a tercel?

12-06-2009, 04:26 AM	#18
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Let's move this to another thread specifically about weight loss.. it'll make it easier to keep track of and easier for future users to locate.