Steel Vs Aluminum in the FT86

[blur]

Originally Posted by OldSkoolToys

From my short experience in an auto plant working mainly with the body shop (not for car's coming off the line, but for the part's division), I'd say Aluminum hood and trunk lid are the best bets. Doors,...maybe, at the suggested price range at least.

I'd love all that to be aluminum. It shouldn't be difficult at the current price point, and it could be very beneficial to the weight savings.

[iDriveFast]

I just want the car to start production

[OldSkoolToys]

Originally Posted by blur

I'd love all that to be aluminum. It shouldn't be difficult at the current price point, and it could be very beneficial to the weight savings.

For reasons Dimman pointed out (light-weight doors w/ safety already there) and my reasoning (heavy ass coupe doors = destroyed hinges after years of service, VERY typical in Toyota cars), if the doors themselves were aluminum and nothing else, I'd be perfectly happy.

[chulooz]

Agreed, heavy coupe doors FTL.

[Aki]

Originally Posted by Dimman

Time to clear up some metallurgy here people.

There is NO way any form of steel is going to weigh only 15% more than aluminum.

Steel's density is approximately 490 lbs/cu ft.
Aluminum's density is approx. 170 lbs/cu ft.

Except it's not simply about density, but rather the amount of aluminum needed to have the strength and rigidity to fit the application. Size for size, obviously aluminum is a lot lighter than steel, much more than 15%. But this is why cars use a lot of high-tensile steel typically in the A, B and C pillars (like I previously mentioned)--it's able to do more in a compact space than aluminum. It's why there's a distinction in weight between higher tensile-strength steel and regular steel. With the stronger alloy, you can have more strength with less--it's not that the alloy itself is dramatically lighter. To that end you can't simply compare their densities. Even though Aluminum is 2x+ lighter than steel, the body in white (BIW) won't be 2x+ lighter than a steel BIW. It doesn't work that way. Take a look at aluminum-bodied Jags--they're not exactly featherweight.

[PAImportTuner]

Originally Posted by iDriveFast

I just want the car to start production

This.

[arsenaljohn]

Could someone please explain to me how they made the last gen celica under 2500 pounds without the need for aluminium?

[PAImportTuner]

Originally Posted by arsenaljohn

Could someone please explain to me how they made the last gen celica under 2500 pounds without the need for aluminium?

It was 2500-2600lbs for the GTS depending on transmission..

No RWD.

Small 15 and optional 16" wheels

Single exhaust.

A 6speed RWD transmission is longer in length and heavier. Than a fwd 6 spd trans. Then you have the crossmember and mount located in the tunnel area.

no driveshafts and all associated hardware

no rear differential, and being double wish or multilink that adds more weight.

[iff2mastamatt]

Originally Posted by PAImportTuner

It was 2500-2600lbs for the GTS depending on transmission..

No RWD.

Small 15 and optional 16" wheels

Single exhaust.

A 6speed RWD transmission is longer in length and heavier. Than a fwd 6 spd trans. Then you have the crossmember and mount located in the tunnel area.

no driveshafts and all associated hardware

no rear differential, and being double wish or multilink that adds more weight.

At least Toyota claimed that they are focused on cutting the weight on this car.

[Allch Chcar]

Originally Posted by PAImportTuner

...A 6speed RWD transmission is longer in length and heavier. Than a fwd 6 spd trans. Then you have the crossmember and mount located in the tunnel area.

Actually I watch out for this kind of information and the difference is in the chassis layout not the transmission. A FWD 5spd Honda gearbox weighs as much as a RWD 5psd Mazda gearbox, 75lbs(dry). While the heavier duty T-56 weighs as much as the Aisin AZ6 at about 125lbs (dry) both are RWD gearboxes though. I've never bothered to check the difference in weight for any transverse 6spd gearboxes .

One things for sure, a 6spd gearbox is larger in dimensions than a 5spd or 4spd gearbox. And when the engine is 240lbs for just the longblock like for the S2000, the transmission weighs half as much as the engine alone .

[Aki]

Not an apples to apples comparison, but isn't the Hyundai Veloster something like 2584 lbs? So even with stringent crash regulations, it is possible to have lightweight cars--and not necessarily decking it out in aluminum. That makes me hopeful that the FR-S will be 2800ish pounds or under.

[Allch Chcar]

Originally Posted by Aki

Not an apples to apples comparison, but isn't the Hyundai Veloster something like 2584 lbs? So even with stringent crash regulations, it is possible to have lightweight cars--and not necessarily decking it out in aluminum. That makes me hopeful that the FR-S will be 2800ish pounds or under.

Yeah. That's been mentioned in the dimensions thread already. And probably a couple other threads too.

[blur]

Yea, that Celica is a close second if I can't have the FT86. High revving, lightweight, liftback. Just the wrong wheel drive but I suppose I could live with that. The only downside is the exhaust note, at which the Celica really doesnt impress. A nice v6 rumble would be seducing.

[Dimman]

Originally Posted by Aki

Except it's not simply about density, but rather the amount of aluminum needed to have the strength and rigidity to fit the application. Size for size, obviously aluminum is a lot lighter than steel, much more than 15%. But this is why cars use a lot of high-tensile steel typically in the A, B and C pillars (like I previously mentioned)--it's able to do more in a compact space than aluminum. It's why there's a distinction in weight between higher tensile-strength steel and regular steel. With the stronger alloy, you can have more strength with less--it's not that the alloy itself is dramatically lighter. To that end you can't simply compare their densities. Even though Aluminum is 2x+ lighter than steel, the body in white (BIW) won't be 2x+ lighter than a steel BIW. It doesn't work that way. Take a look at aluminum-bodied Jags--they're not exactly featherweight.

That was addressed in the post you are quoting.

Originally Posted by Dimman

Comparing 6061-T6 to mild steel for component weight, compare the aluminum's tensile strength of approx. 45000 psi to mild steel's approx. 60000 psi. So the aluminum would need about 50% more cross-sectional area for the same strength. Then compare the density of aluminum at 170 lbs/cu ft to steel's 490 lbs/cu ft. Now you can get an idea of where the aluminum gains in the strength to weight area.

Added the emphasis to 'component weight'.

I was addressing this:

Originally Posted by Aki

Advanced High-tensile strength steel (AHSS) keeps evolving, but it's something like 10-15% heavier than aluminum I think?

As written this is not correct.