LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently March 28, 2024, 8:47 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 13 posts ] 
Author Message
PostPosted: August 9, 2013, 1:53 am 
Offline
User avatar

Joined: March 20, 2011, 9:49 pm
Posts: 116
Hi, i am finally at the point that i can start building my suspension. I am not very familiar on "race oriented" suspension and am a little stuck on what parts i need.

What i have to work with are mustang ii spindles and a speedway motors catalog. I would like radius arms and the 5/8 rod ends from kinetic for every thing exept i would prefer ball joints for the spindles. I also have .120 wall dom round tubing if i cant use radius arms for the lower control arms.

Can someone help me put a parts list together of what i need, or at least walk me through the process? Im sure im missing a few things. (I wont order radius arms until i know the correct lenths. Until then, i will be using pvc pipe to mock it together the way kinetic does on there website)

I like the way these two cars are setup but i am not sure about any of the pros and cons of these designs.


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


Top
 Profile  
Reply with quote  
PostPosted: August 9, 2013, 8:09 am 
Offline
User avatar

Joined: December 7, 2012, 8:28 am
Posts: 1410
Location: Sarasota
The inboard shocks in the top photo are a better design as you can get approximately 1:1 movement ration between shock and wheel. The outboard shock is more like 2:1.

The way I an building mine is with the frame on the floor I positioned the wheel hub in the right place on the floor to get eh same width as the rear then just start to put everything together. Jack's kits have everything you need either buy his kit, or buy the parts and substitute other parts that you need such as sourcing the ball joins from ebay, amazon or google shopping. Then start assembling everything and keep checking that the upright is the correct distance and has approximately the right amount of camber.

_________________
2015 & 2016 EMod Florida State Autocross Champion
2013 & 2014 DSP Florida State Autocross Champion

Scrap Metal Build Log viewtopic.php?f=35&t=14558


Top
 Profile  
Reply with quote  
PostPosted: August 9, 2013, 9:13 am 
Offline
We are Slotus!
User avatar

Joined: October 6, 2009, 9:29 am
Posts: 7651
Location: Tallahassee, FL (The Center of the Known Universe)
Good mornin' Mr. Smith-
You didn't mention what size that .120 wall tubing is... I bought and modified some lower A-arms from Speedway which were made from 1" X .120 tubing. I cut off the bushing rings and converted them to heim joints. In the rear (IRS) I made lower and upper A-arms from the same size DOM tubing.

You'll need something like this: http://www.speedwaymotors.com/Steel-Weld-Bung-for-1-Inch-ID-Tube-5-8-18-RH,39128.html to attach the heim joints to the tubing. Just match up the sizes and weld them into your tubing (with its carefully cut, squared-off ends). I don't think Speedway has much variety of these bungs to pick from. Personally, I like Lefthander Chassis and Day Motorsports for this kind of stuff, but YMMV.

You'll want RH and LH bungs as well as RH and LH heims so that you can twist the tube between them and lengthen/shorten the length to adjust the settings.

Clear as mud? Totally confusing? Good, my work is done here... Good luck!
:cheers:
JDK

_________________
JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom


Top
 Profile  
Reply with quote  
PostPosted: August 9, 2013, 2:16 pm 
Offline
User avatar

Joined: March 20, 2011, 9:49 pm
Posts: 116
O yea, I forgot, its 1in tubing.

Its still fuzzy but Im a little more awake now.

Tell me if this is an acceptable order to part together my suspension.

Because I have my spindles and know my kpi, I can determine what off set I need for my wheels to get the correct scrub radius.
Next, build my LCAs to get my desired track width.
Then build my uppers after I know the correct geometry.

Is there any good bolt on ball joints that I can use for my LCA?I can probably use the moog 772(?) screw in type for the UCA.
Is there any problems when using radius arms for the LCA?


Top
 Profile  
Reply with quote  
PostPosted: August 9, 2013, 2:17 pm 
Offline
User avatar

Joined: July 27, 2013, 3:16 pm
Posts: 336
Location: Cedar City UT
i personally prefer direct A-arm mounted shocks (but keep in mind that my background is mainly offroad...)
the inboard shocks do have the advantage that you can play with the shock & spring ratio and locate the less then aerodynamic C/O`s out of the slipstream (if that is important to you)
however, the cooling airflow to the shock is greatly reduced (again, that is maybe not so critical in an on-road car)
and by adding a pushrod and rocker you increase the moving/oscillating (or un-suspended) mass of your suspension,
as well as add many heims & bearings that could develop wear/ endplay/ noise over time
(i guess i`m a KISS guy :P )

imho the A-arms in the second pic look a little sketchy to me (too many adjustable points)
unless you really need all that ability for fine tuning i would stick to a solid welded lower A-arm.
the lower A-arm takes the majority of the forces so i prefer less parts = less points of failure

many of the Cycle track vendors sell the balljoint ring/sleeves individually ... so it is fairly simple to build your own A-arms

on my little project i plan to design my frame points around pre-fabricated upper arms like this Afco ones ....
Image
....simply for the fact that they are fairly inexpensive and save me the time and hassle to build them (and a jig for repeat-ability) myself

plenty of adjust-ability for me ... at least for a "non racing" application

again, just my 2 cents ;)

_________________
- Stephan - Image


Top
 Profile  
Reply with quote  
PostPosted: August 9, 2013, 2:30 pm 
Offline
User avatar

Joined: July 27, 2013, 3:16 pm
Posts: 336
Location: Cedar City UT
smith wrote:
... Is there any good bolt on ball joints that I can use for my LCA?I can probably use the moog 772(?) screw in type for the UCA.
...



imho i prefer the screw in type (IIRC 772 ?!?)
for replacement parts simplicity i used the same BJ for the lower & upper Arms ,
except on on some heavier cars i reamed/enlarged the lower spindle tapper for the significant larger (722?!?) balljoint
stay away from cheap (= china) knockoffs ... i had good experience with Moog and especially the low friction Howe (however, the price of the Howe`s is not locost friendly :ack: )

_________________
- Stephan - Image


Top
 Profile  
Reply with quote  
PostPosted: August 9, 2013, 6:17 pm 
Offline
User avatar

Joined: March 20, 2011, 9:49 pm
Posts: 116
Thanks for the advice. I think i have enough info to get it started. Now if i knew what offset i need for my wheels.


Top
 Profile  
Reply with quote  
PostPosted: August 9, 2013, 8:06 pm 
Offline
User avatar

Joined: July 27, 2013, 3:16 pm
Posts: 336
Location: Cedar City UT
the Pinto (Mustang II) spindle can take some radical offset/large backspace wheels (aka "FWD" wheels)
like this deep 16" late model explorer wheel i used as a mockup on this little mid-engine offroadgolfcartkindathing :P :
Image

so wheel offset basically depends on how much scrub radius you like/prefer

btw if the stock spindle is to "tall" for your application you may want to look at this 2" dropped one from SWS:

Image
http://www.southwestspeed.com/index.php?sec=view_menu&cat=Steering&sub=Spindles&ssub=Pinto,%202%5C%22%20Drop

price is not bad :) ... and according to SWS it is also forged steel like the stock one
.... i`m actually looking into switching to that spindle for my R-T project myself
i guess it would lower the mass of the A-arms/shock in relation to the frame (lower CofG) ...


definitely better then just flipping the spindle :shock: :ack: :
Image
(just stumbled over this pic :? ... wonder how that will affect handling ??? )

_________________
- Stephan - Image


Top
 Profile  
Reply with quote  
PostPosted: August 9, 2013, 10:39 pm 
Offline
User avatar

Joined: March 20, 2011, 9:49 pm
Posts: 116
I have the wilwood 2" drop spindles (i believe i would have been happy with a cheaper alternative now that i think about it).
I plan on using the american racing torq thrust wheels. I would like them to be around 8 or maybe even 10in wide. Im guessing that is a little on the over kill side. So i guess i need something with a little mor scrub radius. I think 3-5 cm is what i hear people say.


Top
 Profile  
Reply with quote  
PostPosted: August 10, 2013, 10:28 pm 
Offline
User avatar

Joined: July 27, 2013, 3:16 pm
Posts: 336
Location: Cedar City UT
yeah ... imho Wilwood is overpriced ... and i had some not so pleasant experiences with some products.

btw
what hubs/rotors are you going to run on the Pinto spindles ?

i`m seriously considering one piece "metric hybrid" rotors (a pinto hub mixed with the lightweight GM metric vented disc)
i used some different aluminum hubs over the years (pinto and grandnational pins),
but found that if you add up everything the weight saving of modular aluminum hubs is actually very small (especially considering the $$$)
all the (steel) bolts to bolt up the brake disc (and adapter plate) add up quickly

in fact today i weighted a leftover aluminum wilwood pinto hub with the light solid 1/4"x 10.5" disc
(that warps badly if you use the brakes hard :roll: ):
it is exactly 10 lbs (withraces, 5/8 studs and all bolts safety wired)... so i guess with a vented disc it would be at least 12 lbs
a one piece afco metric hybrid rotor (with a heavier vented disc) is 14.8 lbs (also complete with races and 5/8 studs)
... but only a fraction of the wilwood hub price
... and no worry about bolts getting loose (or spending a lot of time to safety wire everything)

just a idea :wink:

_________________
- Stephan - Image


Top
 Profile  
Reply with quote  
PostPosted: August 11, 2013, 2:07 am 
Offline
User avatar

Joined: March 20, 2011, 9:49 pm
Posts: 116
I am using the wilwood dynapro hubs with the 11in vented rotors and 4 piston brakes. To be honest, the brakes, hubs and rotors cost more than my donor car :shock: .

As far as length goes, is my desired track width the only thing I need to consider when building my lower control arms?


Top
 Profile  
Reply with quote  
PostPosted: August 11, 2013, 11:16 am 
Offline
The voice of reason
User avatar

Joined: January 10, 2008, 4:47 pm
Posts: 7652
Location: Massachusetts
RoosterBooster, thanks for the good information and pictures you are providing on this site.
:cheers:

_________________
Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.


Top
 Profile  
Reply with quote  
PostPosted: August 15, 2013, 6:46 pm 
Offline
User avatar

Joined: March 20, 2011, 9:49 pm
Posts: 116
Thanks for the info guys. A local tire shop loaned me an american eagle torq thrust look alike and a tire to mock up on the car so now im going to start building my suspension! What size rod ends do you prefer for your pickup pionts? If you used 1/2in do you wish you used 3/8in or are happy with them?


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 13 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 15 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