LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently December 10, 2018, 4:23 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 9 posts ] 
Author Message
PostPosted: August 13, 2018, 1:08 pm 
Offline
User avatar

Joined: January 18, 2015, 4:48 am
Posts: 69
Location: Carlsbad, CA
Thinking out loud if anyone would like to partake.

So I found some inspiration for a different type of chassis design. Ideally I'd like to throw an LS3 in a tube frame chassis of my own design for street/track fun. I have posted earlier of a strictly load path driven chassis design (image at bottom) but it just seems like it will be too ugly going down the street. I don't really want to bother with making a body.

Then I came across these rock bouncers (google them if you haven't seen how ridiculous the are). Obviously they are designed for offroad, 4wd, solid axles, etc. But I was thinking I could take some of their design cues: shock mount hoops, similarly angled A pillar and B pillar, etc, and include them into a chassis design. Then I could add aluminum panels between many of the rails to create a body-like structure and keep some of the wind out of the car (the middle photo includes some of these type panels). The car would have double A-arm suspension front and rear.

Any thoughts? Immediate concerns would be added weight from some non-ideal load paths, limited sight lines with the shock hoops, and ingress/egress.

Rock bouncers for inspiration:
Image


Boring engineering driven chassis design I did a few years back:
Image

Thanks.


Top
 Profile  
Reply with quote  
PostPosted: August 13, 2018, 3:03 pm 
Offline
User avatar

Joined: October 24, 2008, 2:13 pm
Posts: 3721
Location: Carlsbad, California, USA
If you want it to be a performer on the track, you might want to start with the suspension first. The chassis layout will flow in large part from those considerations plus the packaging for the driver, passenger(s), engine, transmission, rear axle and other large items like the fuel tank.

The problem with big engines is getting the power they produce effectively onto the ground in a controllable way.

Cheers,

_________________
Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886


Top
 Profile  
Reply with quote  
PostPosted: August 13, 2018, 4:35 pm 
Offline
User avatar

Joined: January 18, 2015, 4:48 am
Posts: 69
Location: Carlsbad, CA
Lonnie-S wrote:
If you want it to be a performer on the track, you might want to start with the suspension first. The chassis layout will flow in large part from those considerations plus the packaging for the driver, passenger(s), engine, transmission, rear axle and other large items like the fuel tank.

The problem with big engines is getting the power they produce effectively onto the ground in a controllable way.

Cheers,


I agree. I've designed a few suspension setups. The initial chassis design I included at the bottom was designed around control arm pickup points. This post was more to feel out the chassis arrangement.


Top
 Profile  
Reply with quote  
PostPosted: August 14, 2018, 5:39 am 
Offline

Joined: June 5, 2016, 7:03 am
Posts: 219
Location: ontario
SkiRideDrive wrote:
Thinking out loud if anyone


Boring engineering driven chassis design I did a few years back:
Image

Thanks.


There is always something to learn from different envelops,
with rock crawlers however you are looking at a rather remote set of engineering factors that do not fit into a seven design. Rock crawlers are not designed for speed and overbuilt for punishment, suspensions have long legs to hug the terrain...etc. However you have a valid question, the tube structure of integrated roofs is worth looking at :)


Top
 Profile  
Reply with quote  
PostPosted: August 14, 2018, 9:08 am 
Offline
User avatar

Joined: July 17, 2008, 9:11 am
Posts: 4797
Location: West Chicago,IL
Lonnie-S wrote:
If you want it to be a performer on the track, you might want to start with the suspension first. The chassis layout will flow in large part from those considerations plus the packaging for the driver, passenger(s), engine, transmission, rear axle and other large items like the fuel tank.

The problem with big engines is getting the power they produce effectively onto the ground in a controllable way.

Cheers,


And here I thought that proper suspension design started with the tires and wheels chosen.

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my active Cushman Truckster resurrection log: over HERE
or my archival Locost build log: over HERE


Top
 Profile  
Reply with quote  
PostPosted: August 14, 2018, 11:46 am 
Offline
User avatar

Joined: January 18, 2015, 4:48 am
Posts: 69
Location: Carlsbad, CA
rx7locost wrote:
Lonnie-S wrote:
If you want it to be a performer on the track, you might want to start with the suspension first. The chassis layout will flow in large part from those considerations plus the packaging for the driver, passenger(s), engine, transmission, rear axle and other large items like the fuel tank.

The problem with big engines is getting the power they produce effectively onto the ground in a controllable way.

Cheers,


And here I thought that proper suspension design started with the tires and wheels chosen.


You have a point, but honestly in a world where we aren't fabbing our own wheel assemblies, I think it really revolves around the uprights we utilize.


Top
 Profile  
Reply with quote  
PostPosted: August 14, 2018, 12:09 pm 
Offline
User avatar

Joined: October 24, 2008, 2:13 pm
Posts: 3721
Location: Carlsbad, California, USA
@SkiRideDrive

Reinforcing your point, tires used to come in a limited number of sizes in terms of diameter, aspect ratio, rubber compounds, etc., etc. With today's huge variety of vehicle types and large number of tire and wheel manufacturer's, your choices in all those dimensions are enormous.

You can use a resource like Tirerack.com to go from your desired tire specifications (rolling diameter, aspect ratio, general compound type, tread type, etc.) to a particular tire vendor and tire model/size. Also, as I did with my build, wheel makers have a huge variety of wheel sizes available. I ordered my two rear wheels with different characteristics of offset and rim width to accommodate the particular tires I selected for front and rear, and so that my rear track was smaller than the donor setup. The wheel side that shows to the world looks identical on all 4. Extra cost? Zero$$$. They manufacture on demand.

Cheers,

_________________
Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886


Top
 Profile  
Reply with quote  
PostPosted: August 23, 2018, 11:56 am 
Offline

Joined: August 23, 2018, 11:44 am
Posts: 2
As a middle ground between the rock bouncers and the pure triangulated design, check out the Ultra4 race cars. There are more engineering driven, but some of them have a decent aesthetic appeal to them. https://bomberfab.com/ is one of the more popular Ultra4 chassis, the other is https://goatbuilt.com/

Simple changes to your current chassis design can make a big aesthetic difference. For your door bars, instead of doing a the X like you have it, you can do a single tube for the top V and another single tube for the bottom V, then use a formed sheetmetal filler with dimple dies to create a gusset. Similar to what is below. This will help add the soft radius that lends to the "flowy" chassy design.

Image


Top
 Profile  
Reply with quote  
PostPosted: December 7, 2018, 12:40 am 
Offline

Joined: April 19, 2018, 2:02 am
Posts: 21
Somehow I ran across "rock bouncers" on Youtube one night, very cool and cool looking.

But for a street car how about something similar for the Ar-i-el At-om? Minimal body and lots of exposed frame with some style.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 9 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 3 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

Search for:
Jump to:  
POWERED_BY