Jager

iTrader: (10)

What kinda turbos will you run Jim? I think I have a picture of a sema Chicayne that I'll try and post tomarrow with a V8 twin turbo setup, which was amazing to say the least.

What will the cost of the cradle be?

jimlab

Dunno, but I do know that there will only be one of them.

It sure is. I've met Troy, BTW, and Foose. My cousin knows them. Watch your step, don't trip over the pile of names I'm dropping.

Dunno, but I do know that there will only be one of them... oops. Just kidding.

Still don't have word from my stick-metal-together guy if he's interested in making more, but chances are the new welding jig to make it happen is already done.

wptrx7

Can this be used in a fuel injection set up? How tall is this?

I saw it today on Spike TV and got excited.

Edit: should have searched first: http://www.ls1tech.com/forums/showpo...17&postcount=2

Eggie

If you move the engine forward, the CG moves too. Too hard to visualize? Imagine what happens if the engine moves past the front axle line.

Whizbang

looks like you have a gas water heater.

wanklin

iTrader: (2)

It's a bit of a brain bender I must admit since the pressure points on the chassis are still the same. Seems like only PMI and a slight CG shift due to the lever arm trying to lift the DS and the trans shifting forward with the engine. the Please explain using the illustration below.

Narfle

iTrader: (16)

What about moment of inertia?

wanklin

iTrader: (2)

That's PMI. I agree that PMI would change. It's all null and void really as they have no plans of offsetting the engine.

calculon

iTrader: (29)

in the lower diagram, the sphere on the right would be appyling all of it's force (weight) perfectly downward, as with the rest of the spheres. however, this downward force would manifest itself as a moment (torque) tending to turn the sphere/pedestal system clockwise. assuming everything was hard mounted so that nothing could move in terms of its place and orientation on the whole configuration, this moment would be centered on the point where the pedestal is attached to the lever arm, causing the whole system to want to turn clockwise.

While it is not identical to being simply offset, the effect is similar.

To be clear, I tend to agree that at the miniscule difference in weight that has been proven with these swaps, to feel the difference would require quite the seasoned driver. it is CERTAINLY not beyond a very small amount of compensation on the part of any driver who is the caliber to notice such a difference anyway.

Eggie

Man, is this the Futurama thread, or what?

Narfle

iTrader: (16)

I severely disagree with this diagram as well. Its a pretty picture but it lacks any mathematical proof.

In rebuttal lets assume that the chassis is a lever(one of the simple machines). Your contention via diagram is that a weight's force and effect on center of gravity is dependent only on its anchored position on the lever.

Let me paint a mental scenario. Your picture represents the mass as a ball perched on a lever anchored to the primary lever via a traingle with a definite contact point. Imagine the system welded together as it would have to be without the rope, which turns out incosequential because it simply prevents the weight from tipping the secondary platform, or lever.

In this scenario, which more accurately represents an automobile(with the secondary lever as motor mounts and the primary lever as the front subframe). the secondary lever becomes an extension of the primary lever. the combination of the levers creates a greater amount of torque on the front side of the vehicle's frame(or lever) relative to the previous center of gravity.

In conclusion moving the engine farther forward in a vehicle moves the center of mass(center of gravity) farther forward regardless of any engine mount scenario. The defining aspect of center of gravity is the relationship of mass to a volume as opposed to its anchored point on a lever. The necessity of the rope in the diagram in and of itself debunks the entire theory by proving the effectiveness of the secondary lever.

wanklin

iTrader: (2)

Just to clarify, I posted the image simply as a tool for someone to use to explain how the CG had shifted. I did not imply that the diagram was correct.... I still have not made up my mind to be honest.

With that being said I have yet to hear a solid argument. Arguing that the level creates a tendency for the masses to shift horizontally says nothing about the way that the vertical forces behave. Horizontal forces are inconsequential to the CG if nothing can actually move.

The rope and anchor point are simply representative of the diff mount and PPF which hold the diff, trans and engine in more-or-less fixed horizontal positions.

jimlab

Then again, you're also the one who believed that horsepower per liter was the sole measurement of how good an engine's design was...

No offense, but you'll have a hard time convincing me you're qualified to discuss anything.

Narfle

iTrader: (16)

I stand by my previous assertion and fail to find any contradictory argument, though you doubt me so.

Narfle

iTrader: (16)

Nor have I. Just wanted to bounce and idea.

I agree.

But think of the front subframe as a radius. A force(the mass of the ls1 x the acceleration of gravity) will have a greater mechanical advantage the larger Its radius from any giver point(the center of the wheelbase if that was advantageous...im no chassis tuner right jim?).

Even if the powerplant frame connects the the rear of the car. it would tend to lighten the rear of the car, not the front.

Im sorry if i came off blunt I just enjoy a good discussion.

jimlab

Sorry, the rest of the automotive world "doubts" you too.

rajahFD

Nice avatar.

KaoticFdR1

+1

jimlab

Thanks.

trinydex

this is an uninformed question but how is the steering feel affected by the relocation of the steering rack? the hinson kit has apparently gotten some heat for this?

also does anyone have a comparo pic or pics of the jimlab vs hinson subframes? i actually came across this thread searching for pictures of how the hinson subframe locates things in relation to the steering rack but it appears most obviously that the jimlab design is better.

trinydex

as long as the height of the motor remains unchanged (and it isn't because you're using the same subframe right? and it has the same level mounting holes) the cg as defined by what cg is not changed. cg is defined in terms of distance from the ground and distance from the roll center. this doesn't change with transverse movements.

what will change is the polar moment of inertia and the weight distribution which is what i think everyone is trippin' about. the diagram is incorrect in the sense that it looks like a seesaw and people are sayin' that the seesaw would be unbalanced if you shifted one of the weights outward... while this is true it's not anything to do with the real question at hand.

jimlab

It isn't. Compensate for the relocation of the rack and you effectively eliminate bump steer, but there is no change in steering "feel" caused by relocating the rack.

The Hinson kit has gotten some heat for falling apart unexpectedly.

Hinson's LS1 engine cradle (which requires cutting up a stock cradle) looks like this.



My cradle (which is a complete replacement and doesn't require a core) looks like this (LT1 version shown, LSx is similar). Big difference in workmanship and quality.



And just for laughs, here's Granny's cradle. No core required, but you'll have to figure out how to compensate for the engine hitting the hood.

trinydex

those bosses apaprently can be used for fuel injection or nitrous...

so has jim put this on and confirmed it'll back into the firewal nicely?

jimlab

They're inteded for fuel inection. Too large for nitrous nozzles.

Look at the position of the rear intake runners compared to the LS7 and L76 intakes below, and note the position of the rear-most bolt towers in relation to the runners. Plenty of room.

wptrx7

But would it hit the hood