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FEA is not magic, it's math. It's only as good as the parameters you put into it, and I would argue the contrary: The fact that you're using an FEA program to get these results throws up a big red...

Hi Jim, Did you apply the appropriate end releases on the beam elements? You're looking to create a mechanism (your suspension) that is only constrained in compression by the pushrod. You should not...

Indeed, I was mostly referring to the 1/4" rod ends. The others seem about right.

Looking good Jim. You should revisit your suspension arm loading, though, as your constraints are not corfrect in the analysis. You really need to add in a push-rod (or pull-rod) to react the...

It's been a while since I knew for sure as we always just had a class D around, but my quick google seach finds this:

"Dry cast iron chips graphite powder combined with heavy hydrocarbons, and...

Looking good, very nice renderings too!

Sharp tooling is a must to minimize the chance of chip ignition. Also, heavy cuts (large chips) help as well. And definately don't use any coolant! A class D fire extinguisher is best to have...

You could add steel and titanium to the above numerical comparison and draw the same conclusions. It really depends on the application, but in bending magnesium will win in a stiffness competition...

Uh-oh, now you're going to get me started on proper constraints for a finite element torsion test... ;)

And don't worry about stress plots on your overall chassis, if you hit your stiffness...

Jim,

Looks like you're making progress, here's some more info to chew on:

You will want to use a shell mesh for that entire structure. With the smaller elements you show there, you could get...

Jim,

First off, you've done a lot of good looking work here. Most people don't realize the number of hard hours this takes until they actually try it for themselves! I do have one cautionary...

I was running an analysis and had nothing to do until it finished so I created a spreadsheet that calculates aero drag forces on various suspension arms with inputs for length, velocity, etc. It...

I completely agree. I think the benefit of reduced frontal area and clean air to the wings far outweigh any benefit of slightly cooler and slightly higher air pressure to the engine. It wouldn't...

You can make the camber curve (camber angle vs suspension travel) change based on your particular suspension geometry (it's a simple 4 bar linkage in 2D, more complicated in 3D when you throw in the...

MiniFormulaIndy-

Richard Pare's post above is pretty spot on. The criticism (well most of it anyway) toward your car given in this post and the last was constructive. Proof of this can be seen...

DMac,

Like the chassis, the upright is just a fancy bracket that connects the dots. I suggest designing the suspension kinematics first, that will determine where your outboard pickup points as...

Just a coupe quick suggestions:

1) Finite element analysis can be tricky. Without a good amount of experience and understanding of the underlying theory, it is easy to get a incorrect results. ...

Have a look at the spec linked above from the Army Research Laboratory. The material is rather anisotropic (see differences in longitudinal vs. transverse tensile tests), particularly in elongation...

Wierd, I replied earlier, but somehow my post dissapeared??? Maybe the attachment was too big?

Anyways, our engine didn't suffer much from the restrictor - it redlined fairly low (11,500) and...

The idea would be to find the engine that makes it's power down low in the RPM range. (typically smaller bore, longer stroke, i.e. an older model). A restrictor (any type) limits airflow, and...

Rennie-

I was originally arguing for the SIR to be put in place for this class to even out the HP numbers and deter the "engine of the year" phenomenon, but later changed my mind because of the...

Perhaps "instability" was the wrong word, rather I should have written "uncertainty".

Sure, but the point I was trying to make is that it's not a huge difference. I understand the concerns in trying to control costs, but this is racing - it's not possible! People will always be...

I was under the impression they just changed the injection system. Anyways, I don't think the 11 sec all came from the motor...

First off, IIR vs. SIR - is there really a difference as far as how the computer will react? I have no experience with an IIR setup, but I highly doubt it would make a difference since it is...

Thanks Gary for the plug and Mike for putting up my contact info. Chuck, have a look at the website (www.luxonengineering.com) and feel free to give me a call or email with any questions. As far as...

Chromic Acid is Type I (as described in your post) and is generally clear.

Type II is sulfuric acid anodize, which is typically colored, a bit thicker, and tougher than Type I, though it raduces...

Looks good Jose. Hope to see you and Hector again at the ARRC.

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Most likely the assymetry is from an assymetrical distribution of pathline initiation points. I had the same issues on some internal flow problems using Cosmos - the initiation points auto...

Looks pretty good Gary. Don't forget the tie-rods! When's the first test?

Lee-

The revised design looks much better. How much adjustment are you planning on using the rod-ends for? Or they just in place as bearings? If just bearings, you might want to consider...

Just looking at this quickly, I wouldn't imagine you would have a problem with either method. I would suggest going with bent tubing rather over welding as it will be a slightly stronger design...

Jerry-

Optimum caliper position depends on a few factors, primarily packaging, CG height, Polar moment, and bearing loads:

Packaging: You've got to put it where it fits!

CG Height: The...

Those do look to be mounted upside-down, the brake caliper is on the wrong side (from a polar moment standpoint at least). Maybe they are upside-down for packaging reasons?

Matt-

Sounds good, do you guys have an expected completion date for the first prototype?

The renderings look nice, but I think there's too much Armor-All on those tyres, they're kinda shiny... What's in there for side impact protection? The low sidepods certainly reduce the frontal...

It will actually act beter than the Quaife until you get wheelspin (no preload), but then again, wheelspin is the problem! Hence a limited slip diff...

An excel spreadsheet is posted on the FSAE forums for power commander map help. I haven't looked at it, but it might be of some use:

http://fsae.com/eve/forums/a/tpc/f/125607348/m/82910595341
...

I was just pointing out that since it wasn't explicitly stated that the wing dimension included endplates, it was reasonable to make the wing the full width and bolt on the endplates. Now that there...

It shouldn't matter what the rules have been for other classes, it should only matter what the rules are for the FB class. Isn't the racecar engineer's job to exploit the rules as much as possible...

George-

Did you test with a SIR and a Power Commander setup? Just curious if this might solve the problem or not. What diameters of SIR were you using? Flate plate or nozzle?

It seems to...

It would be very difficult to cheat the actual SIR. A simple diameter check can be preformed with a go/no-go type gauge to ensure compliance. Flexible membranes would be rather easy to catch. ...

I'm not exactly sure, but I would assume that the mixture would go very rich. I'm really not farmiliar with the power commander, but I think the lack of available air would be out of its tuning...

Ok, I'll chime in here... During my FSAE time I did a project optimizing our inlet restrictor and spent a LOT of time in front of the computer, NC lathe, flowbench, and dyno. Throughout the project...

These guys make some of the best stuff available, though you will have to pay for it:

http://www.burnsstainless.com/

There are some other companies selling similar stuff cheaper, just not...

Limiting fuel flow and limiting air flow will accomplish exactly the same thing, though I would much rather have excess fuel than excess air. It's a lot harder to ruin your engine running rich than...

There are ways to cheat a SIR as well... If someone really wants to cheat, they can always find a way. It just might be a little more difficult with the SIR.

I personally like the idea of a...

Jerry-

Things look to be coming along pretty well. I will be at the ARRC, hope to see you and your car there. Good luck with the tuning and development!

Is that an actual camera on the top of the scoop, or are they just trying to look like F1? I've noticed this on the Speeds cars as well.

WD-40 is way too light to use in this application or any chain for that matter, it's really only good as a penetrating lubticant. I always liked PJ1 Blue Label. It stays on the chain reasonably well...