400 pound weight loss??

[mitchell]

You think saying it will be lighter will make Chevy and Dodge do what exactly?

The weight should be known around April unless they expect people to place orders blindly. I'm not seeing how those few months of silence gives Ford any advantage.

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[thePill]

Yes 150 or close to it. If it adds 150 and adds even more with safety equipment and they get it to almost break even isn't that aggressive weight savings for a car that is the same dimensions? BMW system is not identical. Different strengthening requirements for the weight delta of each car and also the halo models, among other things.

Ask yourself this, Dave P has had every opportunity to talk about saving weight. Ford said repeatedlly it'll have more power without giving exact HP. Why not say "it's lighter but we're not releasing that now"
? Anyone?

I consider that aggressive regardless on the final number. I had also heard that several hundred pounds were removed from the safety structure. While this number could be inflated, I could also see almost 100-200lbs removed from the shell. The Fiesta lost 88lbs just by switching to Boron with a more efficient design, the Corvette lost 100lbs in the shell all while getting larger as well. Tech and safety ate that 100lbs back up and also took an additional 100lbs if I remember correctly. They lost 100lbs from the 3350 curb weight but ended up 100lbs heavier at the end...

Anyway, this means the EB4 will be at 3450lbs. Far from the 3200lbs people wanted..\\


Edit: I still cannot account for any additional weight the ILIRS has over the CBIRS or traditional SLA IRS. The CBIRS was within 30-40lbs of the Solid Axle Mitch, and it used an upper cradle spring cup. The 1/2 shafts are said to be engineered on the GT, base cars use them. brakes were the same in the rear (I thought), rear-ends were identical... Sways, springs and struts are the only place weight gain could occur. The lower cradle in the S550 is tiny compared to any other IRS...

I cannot see where the weight is coming from, I'll have to wait and see one.

Here is the issue I have with the weight, all of the weight on the ILIRS is UNSPRUNG, if the ILIRS gains 150lbs Mitchell, that would mean the ILIRS has more unsprung weight that the Solid Rear Axle. This is what that math is equaling out to...

Wasn't the solid axle's weight about 188lbs?

Even the sloppy Short-Long Arm IRS is 350lbs, that has an upper and lower cradle and a front and rear cross member, coil-overs, and HUGE disc. I can't see the 150lbs gain...

 

[thePill]

Yeah, Control Blade IRS was typically within 50lbs of the Solid Rear Axle Mitchell. Granted, the systems that use a full size shock are among the heaviest (40-50lbs), the compact shocks would get very close to the Solid Axle but, was not preferred for performance applications. Smaller systems on Compacts were about the same weight all while reducing unsprung weigh dramatically. Although, CBIRS used an upper cradle which is completely absent on the ILIRS, a rather large rear sub-cross member and a front sub-cross member that was pretty much the same size as the ILIRS. The Control Blades (trailing arms) were large and replaced by the Integral Link. The Integral Link's function is similar to the Control Blades of the past however, the I Links are 1/64th the size.

The ILIRS system was designed to be lighter than the out going CBIRS and have less unspung weight than the Solid Axle by far. It should also have less unsprung weight than the CBIRS.

The upper cradle is now integrated into the shell like BMW and Merc does. This provides more resistance against chassis flex between the rear wheels. This, along with the use of what Ford calls the "Lions Foot" stiffens the chassis in that vulnerable area.

Edit: The 2005 S197's proposed IRS was said to be just as light as the S197's solid axle. M6G member S550Boss did a nice write up on it a long time ago. It had a HUGE aluminum sub-frame, upper/lower cradle and huge fore and aft sub-cross members. It also used coil-overs, another heavy option.

 

[Diver Down]

Look for the mustang to drop about 200 lbs. The numbers aren't finalized yet because they're still weighing parts as they come in. I think they're still working hard to hit this goal.

 

[thePill]

Look for the mustang to drop about 200 lbs. The numbers aren't finalized yet because they're still weighing parts as they come in. I think they're still working hard to hit this goal.

Is cold weather testing finished DD?

 

[Diver Down]

Is cold weather testing finished DD?

Lo siento. No hablo ingles.

 

[S550guy]

Know why everyone is still keeping quiet? Because the car is still half a year away from actually being built. Auto show cars are just that: show cars meant to give customers an idea of what the car will look like. Everything else? preproduction. Not finished yet.

Patience is a virtue.

 

[thePill]

Lo siento. No hablo ingles.

Of course...

 

[jjw]

Know why everyone is still keeping quiet? Because the car is still half a year away from actually being built. Auto show cars are just that: show cars meant to give customers an idea of what the car will look like. Everything else? preproduction. Not finished yet.

Patience is a virtue.

+1
We went from nothing to a pretty huge reveal and I think people forget how far off the car still is. They still have lots of work to do before production. It's not a matter of withholding info as much as it is waiting for solid info to announce publicly.
They also also need to stretch out the strip tease until April.

 

[S550guy]

Frankly, I'm waiting for the same thing to happen with the new Z06... Everyone now knows what it looks like, plus basic specs, but there's still a lot of development to be done.

 

[thePill]

Not only do I have trouble accepting the ILIRS has gained 150lbs over the Solid Rear Axle, I have trouble believing this...

...even weighs 150lbs overall. Even with the addition of the rear-end, half-shafts and sub-frame, it's pretty far fetched...

Edit: Mitch, I need some clarification on this now. If the 150lbs you are talking about in the ILIRS isn't possible, neither would any per-production weights. The ILIRS and Solid Rear Axle seem to be about the same weight...

Here is the proposed 2005 IRS. Notice the huge cradle... The blogger claimed this IRS system was close to the solid axle's weight, I don't think that is accurate. This, I could see being 150lbs heavier than the solid axle.

Here is a Control Blade diagram, notice how much smaller the sub-frame has gotten in the CB. Control Blade was said to be within range of the solid axles weight.

the 5th Gen Camaro's IRS, weighs like 350-370lbs...

Terminator IRS, another heavy system, 300-325lbs....

The solid axle was weighed at 188lbs (looking for a link), an additional 150lbs puts the ILIRS up in the 350lb range. I don't see it in the diagram, even with the parts that are missing. Maybe 200lbs at most, I see 150lbs, not much more...

 

[Grimace427]

Not only do I have trouble accepting the ILIRS has gained 150lbs over the Solid Rear Axle, I have trouble believing this...

...even weighs 150lbs overall. Even with the addition of the rear-end, half-shafts and sub-frame, it's pretty far fetched...

A Mercedes W211 E-Class rear IRS with airstruts minus the brakes and knuckles is right at 150lbs, figure 225lbs complete. Adding 150lbs on top of the SRA is unlikely to say the least, especially for a small car like the Mustang.

 

[crysalis_01]

Yeah, a 340lb (190current weight + 150lbs) would be nothing less than ludicrous.

 

[Stuntman]

Here is the issue I have with the weight, all of the weight on the ILIRS is UNSPRUNG, if the ILIRS gains 150lbs Mitchell, that would mean the ILIRS has more unsprung weight that the Solid Rear Axle. This is what that math is equaling out to...

Not true. The entire subframe and rear-end (differential) are bolted to the chassis and is SPRUNG weight. About half of the weight of the CV axle shafts and half of the weight of all the control arms (including the aluminum lower arm) is unsprung. I could be wrong but i think the unsprung hubs/uprights are also aluminum.

Either way the ILIRS will have A LOT LESS UNSRUNG weight than a solid axle which the entire thing is unsprung (except half of the weight of the 4 arms -which includes the phb).

 

[Grimace427]

Not true. The entire subframe and rear-end (differential) are bolted to the chassis and is SPRUNG weight. About half of the weight of the CV axle shafts and half of the weight of all the control arms (including the aluminum lower arm) is unsprung. I could be wrong but i think the unsprung hubs/uprights are also aluminum.

Either way the ILIRS will have A LOT LESS UNSRUNG weight than a solid axle which the entire thing is unsprung (except half of the weight of the 4 arms -which includes the phb).

Yeah I wasn't sure where he was going with that. I would guess around 60% of the weight of an IRS is in the diff and subframe, with about 30% in the knuckles/brakes and the rest being the control arms and springs/shocks. However, the LCA with the ILIRS looks pretty big but being aluminum hopefully means it's stiff without being too massive.

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