LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently June 15, 2024, 11:46 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 51 posts ]  Go to page 1, 2, 3, 4  Next
Author Message
PostPosted: February 13, 2008, 3:50 pm 
Offline

Joined: March 26, 2006, 6:03 pm
Posts: 216
So I am making my own little death trap and am doing so with a 1k cc bike enigne in a single seater. I hope to make it street legal. I have everything I need except the engine. Kinda hit a dead spot in the progress and money doesn't let me do anything but design for now. Let me know that you think.


You do not have the required permissions to view the files attached to this post.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: February 13, 2008, 3:52 pm 
Offline

Joined: March 26, 2006, 6:03 pm
Posts: 216
last one was too big


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: February 13, 2008, 5:34 pm 
Offline
User avatar

Joined: March 25, 2007, 12:36 pm
Posts: 562
Location: Phoenix, AZ
What are the uprights based on? Are they fully custom or are you using premade ones?

Is there any camber change with wheel motion? It appears that you have equal length, parallel A-arms. This wont give you much traction when the vehicle rolls in turns!

Are those motorcycle shocks? If so, why (save money?)?

Where are the inboard brake/axle parts coming from? All custom (lots of money...)? You might want to look at Jaguar parts, as they came with inboard brakes.

The driver/engine area need more structure. As is, they are going to twist a lot I am guessing (an you wont have anywhere to sit, but that is another issue :roll: ).

It appears that your project has a lot of similarities to Formula SAE cars. I'd take a look at some of them if you havn't already.

_________________
Georgia Tech
Ride and Handling Engineer for a major car company
Locost finished - book frame, IRS, '84 celica GTS donor, '99 tacoma 2rz motor with a turbo, megasquirt DIYPNP. Getting rebuilt with new IRS, F20C
"the all-consuming time-sucking car, which I really enjoy working on" -KB


Top
 Profile  
Reply with quote  
 Post subject: ITs a concept
PostPosted: February 13, 2008, 7:24 pm 
Offline

Joined: March 26, 2006, 6:03 pm
Posts: 216
What are the uprights based on?
They are just a place holder. I will be using the uprights from a miata I have picked apart. This image is more of a conceptual exercise to see how I want things.

Is there any camber change with wheel motion?
It maybe hard to see but the a-arms are unequal even though their geometry is not calculated.

Are those motorcycle shocks?
No those a graphics representing QA1 coilovers.

Where are the inboard brake/axle parts coming from?
The chain dif (which I have already finished) comes from a miata. it has been fitted with a lathed casing to allow it to be open. The axles connect to a rotor plate and that plate mounts to the outputs of the dif. I will most likely end up going with outboard brakes though.


The driver/engine area need more structure.
The origional post stated that the chassis is not finished. I posted this to mostly show my intentions and to get feed back.

It appears that your project has a lot of similarities to Formula SAE cars. I'd take a look at some of them if you havn't already.
I'm very familiar with SAE cars. A friend of mine actually made one and I got the chance to examine it up close. I would say that my project was inspired by the roadrunner sprinter-r more than anything.

Thank you for the input.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: February 13, 2008, 9:57 pm 
Offline
User avatar

Joined: May 8, 2007, 9:50 am
Posts: 602
Location: Minnesota
Very FSAEish indeed. It looks like you have something in mind, but I can't quite see how the chain tension adjustment works. Obvioulsy you have spent the majority of your time working on the front and rear subframes, but clearly you need to add more structure inbetween, as the torsional stiffness is currently minimal (hopefully a fully braced roll hoop?). You may be able to run a single rear brake if you attach it to the diff housing instead of the axles. I like the supports to the the bellcrank pivots, don't underestimate those loads and make sure the brackets are stong enough.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: February 14, 2008, 2:16 am 
Offline
User avatar

Joined: January 24, 2008, 4:47 am
Posts: 58
Location: Daufuskie Island, SC
Great to see your thoughts. Curious about the diff. LSD potential (for any middy)?


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: February 14, 2008, 10:58 am 
Offline

Joined: July 19, 2007, 12:10 pm
Posts: 46
Location: MTL, QC, CA
Wouldn't that chassis twist alot?

-S.

edit : Yes, Chet, I'm talking about those long parallels. Some cross bracing would be required in all 3-4 side of the box...


Last edited by Pollux on February 14, 2008, 1:10 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: February 14, 2008, 12:40 pm 
Offline

Joined: August 15, 2005, 10:13 pm
Posts: 7043
Location: Charleston, WV
Pollux wrote:
Wouldn't that chassis twist alot?

-S.

Yes, just a bit, but like he said earlier it isn't finished. I'd be interested to see it with some stiffenning diagonals.

_________________
He is a wise man who does not grieve for the things which he has not, but rejoices for those which he has.


Top
 Profile  
Reply with quote  
 Post subject: The diff
PostPosted: February 14, 2008, 1:50 pm 
Offline

Joined: March 26, 2006, 6:03 pm
Posts: 216
The differential that I made is a Miata LSD. I lathed up a slave that fits over the dif so that oil doesnt fall out :). Where the bearing for the factory diff housing were I attacked four bot fandge bearings from SKS. These four bolt flang set bearings attach to plates that attach to.... (the hand bones connected to the arm bone, the arm bone is connected to the shoulder bone, the shoulder bones connected too... oops got distracted)

The hard pat with the diff and its sleave was creating a seal that would hold, and milling out the bearing cuff to fit the diff.

And yes there will be more trianglation in the frame, as is it would twist around itself like two peices of string.


Top
 Profile  
Reply with quote  
 Post subject: Frame
PostPosted: February 14, 2008, 1:54 pm 
Offline

Joined: March 26, 2006, 6:03 pm
Posts: 216
This was just a little doodle I did to concept the frame. Its only a concept. I know theres a ton of wasted metel and its over build by a mile. I like to just throw a structure out there then refine what I already have rather than create each peice exactly then try and place them togeter. Its not as clear to start with but hell neither am I, har har har.

This frame doesn't fit the subframes either... just a doodle.


You do not have the required permissions to view the files attached to this post.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: February 15, 2008, 2:00 pm 
Offline
Automotive Encyclopedia
User avatar

Joined: December 22, 2006, 2:05 pm
Posts: 8066
Connect the load points. In the first pic, there are corners where nothing attaches(i.e. above the upper control arm pivot and away from the bellcrank. Connect the dots first. Don't think in boxes, think in polygons.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12


Top
 Profile  
Reply with quote  
 Post subject: little more progress
PostPosted: April 1, 2008, 10:29 pm 
Offline

Joined: March 26, 2006, 6:03 pm
Posts: 216
The sides of the main frame have been triangulated. I need to measure up my seat and get the engine dimensions to start on the top and bottom triangulations.


You do not have the required permissions to view the files attached to this post.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: April 1, 2008, 11:23 pm 
Offline

Joined: February 9, 2008, 1:05 am
Posts: 678
Location: San Antonio
That's a lot of triangle welding!

Are you worried about the inboard brakes getting poor ventilation, and getting brake fade as a result?

_________________
JSullivan


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: April 2, 2008, 4:43 am 
Offline

Joined: March 26, 2006, 6:03 pm
Posts: 216
It is alot of welding but that section needs to be very rigid.

I thought about the inboard breaks and figured I could duct air to the break and dif area fairly easily with an over head scoop and having the rear of the frame covered with an mesh to allow exit flow.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: April 2, 2008, 8:50 am 
Offline

Joined: August 14, 2006, 2:09 am
Posts: 384
Location: Sacramento, CA
Would it be better to have the air flow come up from the bottom? Sort of like the old ground effect cars?


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 51 posts ]  Go to page 1, 2, 3, 4  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 9 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
POWERED_BY