LocostUSA.com

Hello all,
I am new to this forum, but currently i am in a dilemma on whether or not I need to reinforce the chassis anymore. So the purpose of this build is to place the largest engine possible with a 6 foot 5 tall person into the smallest car. I have just finished building the engine and it's a 468ci big block chevy with 11:1 compression pulling 642 hp and 607 foot pounds of torque. I do have the F.A.S.T. XFI 2.0 installed and all is ready to run. I am planning to mate a T56 transmission to this block. So what had to be done to the chassis to fit the block was adding the McSorely 442 seating area width, Chris Gibss' rear independent suspension widened by 50.4mm and also elongating the passenger area and the engine bay by around 200mm. Thankfully, for simplicity, I will be incorporating Chris Gibbs' book front and rear suspension mounting points. So far I have been running torsion tests and kept on adding in beams to reinforce it. With the current design, I have managed to achieve 4688.3 lb*ft/deg without the R- tube. There simply is no space for it. You can find my designs of the chassis on https://grabcad.com/library/locost-1 and I was wanting to get some input on some unnecessary beams or some that i could add in. The suspension mounting points and engine dimensions are marked with the long construction lines. Here are the attachments. Thank you all for your help in advance.

Here is the link again.
https://grabcad.com/library/locost-1

What is your goal?

From where I sit, that package will not be competitive in any racing class due to weight and size constraints.

Perhaps you would consider an EcoTech or EcoBoost motor in the passenger footwell?
This solves the weight and wheel base limitations of your concept.

Otherwise don't fixate on design numbers for the chassis, just build it safe and cage the cockpit.

On a side note there are a few guys hill climbing retired circle track modified chassis that seem to work very well.
You can just leave the roof off for an open cockpit and be on the road in weeks instead of a year or two.

_________________
Honey anyone?

I can see some torsional soft spots in your chassis. I couldn't get on grabcad without joining so I can't see all that you are doing. How are you measuring torsional rigidity? Why is 4688 ft lb per degree not enough? (See my post on roll stiffness vs. chassis stiffness).
Also see my post on strengthening a "generic" locost chassis. Let me know if I can run some numbers for you, too.

Finally, ignore everyone's opinion here and build it like you want to, dammit!

Hi Bobber,
Thanks for your reply, attached I have done some chassis improvements last night. Let me know if you could take a look at them. I am applying a force of 10000N per joint in opposite directions along the front plane. I have a formula calculated in the excel spreadsheet, and the final torsional numbers that i got were near the 6500s Lb*Ft/deg. The distance between the two joints where the forces are applied are 1600mm, and the length of each arm to the center is 800mm. Then i substitute the sum of the modules of displacement. I end up with a formula of the ((overall force)x(1600mm+2x800mm))/ angle. The angle is found with the arc tangent. Could you let me know if these calculations seem correct and any other improvements that you could see that could be made to the chassis. Thanks!

I'm still unable to download any files. Can you resubmit in a different format?
Your rigidity calculation sounds correct in principle. I have to re think to metrix. Kilonewtons are a'killin me! Are you analyzing your entire space frame in Excel?

ps: If you measure torsion rigidity on an actual frame, the frame should be supported in the appropriate locations, and the loads should be suspended in the appropriate locations, all by chains. That eliminates any possibility of any lateral forces and thus excludes any frame lateral deflection that may affect the torsional deflection of the frame.

Hello,
So I uploaded to megafileupload. Here are the links. Lets hope they work. I believe they stay up for 7 days so hopefully you'll have a chance to take a look at them.

http://www.megafileupload.com/760w/Book1.xlsx
http://www.megafileupload.com/760x/Fina ... n_1.SLDPRT

I am analyzing my frame in Solidworks. So I am inputting a force of 10000 Newtons downward and another 10000 upwards along the front plane and the suspension arms, so just along the Y Axis. I just input the data and keep the modification history in Excel for simplicity.

I still can't download the Solidworks file. Can you dxf the file? I can also read Staad and Risa files.

I am having troubles with converting to a Dxf file. I have uploaded tis to google drive, so anyone should be able to download it without a problem. Here is the new link. Let me know how it goes.

https://drive.google.com/open?id=0B9LNS ... mNHSTBjZ1U