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Anti roll bars
http://gemellocattivo.com/forum/viewtopic.php?f=7&t=321		 Page 1 of 3
Author:  mk e [ Thu Jan 24, 2019 12:16 pm ]
Post subject:  Anti roll bars
Does anyone know how to make anti roll bars?

I currently do not have a rear anti-sway bar as it doesn't fit with the wide wheels...it might...I have some rod ends I thought might help..... I honestly didn't really miss it as I replaced the stock koni coil-over things with adjustable ohlins dampers and eibach springs. The stock springs were....my memory is failing but like 180/200 lb/in f/r, the new are 450.400 iirc and a huge improvement. Even with the rear bar remove the rear roll stiffness was a bit high and rear grip was not all I'd like it to be so I planned to drop the rear spring rate....or maybe increase the front but was leaning to softening the rear to try to improve grip. Anyway I put all that on hold when the engine swap started to wait to see where I was with the new engine. ...I'm not sure the weight is much different than the V8+blower but I figured best to wait.


All that said I learned the hard way in my FSAE days that it just plain bad design to try to use the springs to both hold the car up and control roll. I can't find a pic that really show it, you can kind of see on the rear in the pic with the body....I had a progressive linkage that you could adjust progression rate....pain in the butt because changing anything changes everything.

So...who know how to make anti-roll bars? is there a thread or good web site I haven't found?

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Author:  mk e [ Fri Jan 25, 2019 8:44 am ]
Post subject:  Re: Anti roll bars
Last night I set the car down and had a bit of a look.....I think it needs wider tires. It currently has 285s on 10.5" wheels which are a little wide for those tires I think.... but man it sure looks like a 315 on an 11" wheel is doable

......which means I think the order needs to be pick a tire size, pick a wheel, fit the antiroll bar.

Over on the grassroots site I got pointed to Coleman and speedway racing as sources of off the shelf antirollbars that seems cheaper that I could make one...and I don't have to make it.

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Author:  mk e [ Mon Jan 28, 2019 4:04 pm ]
Post subject:  Re: Anti roll bars
So a sent a link to the GRM thread to a buddy I worked with WAY back when I first got this car and the response was basically WTF are you using for wheel Studs?  (a couple of the brake upgrade pics show home made wheel studs)

Me - remember, these are the studs Al made for me when I didn't have a proper shop, to fit the aftermarket wheels I put on back then"

Buddy - Dude....that's not safe!  Get me the specs and I'll get you proper bolts!

me- What?

Buddy - I have a Ti bolt company now, Ti64. We make stuff like proper wheel bolts for all kinds of race teams that aren't just waiting to break like the ones I see in the pic....you can't use those you dumb a$$ (my translation) 

me - Sweet!  ....now I need to figure out what I'm doing for wheels and somehow magically get my wife to approve the spending of money I probably don't have so I can tell Greg what bolts I need.  :)

Before I pull the engine I need to remove the rear springs so I can cycle the rear suspension and see exactly what will fit width wise, where it would put the antiroll bar, maybe even actually right some of it down so I only need to do this once.  I guess that's the next step.
Author:  mk e [ Mon Jan 28, 2019 4:50 pm ]
Post subject:  Re: Anti roll bars
And I wonder...should I be thinking about changing the front spindles? hmmmm......
Author:  mk e [ Sat Feb 02, 2019 1:45 pm ]
Post subject:  Re: Anti roll bars
On the rear I measure 34" to the outside of the frame. I read add 3" for arms and collars....so the super common 37" seems right.

Up front it like 30" outside frame....but space is tight. Maybe like 32 and collars on the inside of the mounts...maybe

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Author:  TheDarkSideOfWill [ Tue May 28, 2019 10:46 am ]
Post subject:  Re: Anti roll bars
If you're looking at a large bar, then your roll rate and jounce rate are going to be significantly different. Dampers can only match one.
Author:  mk e [ Tue May 28, 2019 1:42 pm ]
Post subject:  Re: Anti roll bars
Stupid everything has to match to work right :(

I'm really not sure where optimal is exactly. I know the balance was not everything it could be and there seems to be more roll than seems optimal so my thought was to do something with the bars then move to the springs, then damping rates and see what I have.

.....maybe....but I need the engine running to test anything
Author:  mk e [ Thu Jan 28, 2021 9:54 am ]
Post subject:  Re: Anti roll bars
I kind of have myself talked into piecing together something from here or similar
http://1speedway.com/index.php?route=pr ... ry&path=76

like a 1"x.095 wall in the rear:
http://1speedway.com/index.php?route=pr ... duct_id=90

then there is a good selection of gun-drilled 1 1/4" for the front but only in 1 length of 37 1/2"...but I remember thinking it would work
http://1speedway.com/index.php?route=pr ... duct_id=89

so very light compared to solid bars.....I just need a running engine more at the moment.
Author:  TheDarkSideOfWill [ Thu Jan 28, 2021 2:17 pm ]
Post subject:  Re: Anti roll bars
Oh yeah, I forgot you know the Ti64 dude. I re-discovered them and have been thinking about snagging a few bolts from them.
A pair of Ti 5/8" bolts in each rear strut should save me about 1 lb of unsprung weight per rear corner. I'm thinking of titanium clutch cover bolts to reduce engine speed rotating mass and using Ti in the Northstar external case half locations just for S&Gs.
Author:  mk e [ Thu Jan 28, 2021 4:10 pm ]
Post subject:  Re: Anti roll bars
TheDarkSideOfWill wrote:
Oh yeah, I forgot you know the Ti64 dude. I re-discovered them and have been thinking about snagging a few bolts from them.
A pair of Ti 5/8" bolts in each rear strut should save me about 1 lb of unsprung weight per rear corner. I'm thinking of titanium clutch cover bolts to reduce engine speed rotating mass and using Ti in the Northstar external case half locations just for S&Gs.


I'm starting to think you like the fiero more than you like your ferrari....... :lol:
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