Torsion bar to Coil Spring Rate conversion

Quantrill · 7/3/11, 8:09 AM

If I am running 26" hollow torsion bars .800 diameter and want to convert the car to coil over front what springs will I need? I am running both the same bars on the front of the car will I want to run both the same springs on the front or heavier on one side vs the other? This is on a 1200 mini sprint car.

Thanks,

TQ29m · 7/3/11, 9:50 AM

Personally, I wouldn't change it, maybe work with the bars some, but if you'll notice, the NEW trend, is BACK to bars again, lot less expensive to maintain, and, again, IMHO, far easier to set up. Bob!

Quantrill · 7/3/11, 10:22 AM

I bent my torsion tube Friday night so one option is to convert to coil overs. I was looking at Hyper racing site and I think I need 233# springs? Anyone know if that is right?

TQ29m · 7/3/11, 10:46 AM

A bent tube ought to be an easy/inexpensive fix, even if you have to remove it, and replace it, but, whatever! Bob!

opnwhlmnd · 7/3/11, 11:21 AM

Here are a couple useful links to help you

Pro Shocks Torsion to Coil Spring Weight Calculator

Schroeder 26" Hollow Torsion Bar Spring Rates

Quantrill · 7/3/11, 11:36 AM

Thanks for the links that help out. I found one for a 1" bar on Schroeders site.

http://www.schroedersteering.com/Trs...7PDFs/1H26.pdf

just in case anyone else is looking for the same info.

Thanks,

darnall · 7/3/11, 12:35 PM

233# sounds AWFUL heavy for a 1200cc car...dirt midgets use 160-200# front springs...and with the extra engine weight I would think they would use heavier springs than a 1200...

You have to use torsion arm length in the equation..center of the bar to center of the pickup point, not length of the entire arm...

I actually have a "torsion bar calculator" thats like a slide rule to give spring rate calculations but it doesn't go down as small as .800

---------- Post added at 11:37 AM ---------- Previous post was at 11:35 AM ----------

also you have to use "effective length" of the torsion bar, not actual length, to figure out a conversion.

Joltin Joe · 7/3/11, 2:07 PM

being the engine is light.....a pair of 165lbs would be a good start......

tqracer53 · 7/3/11, 6:42 PM

on a tq we run 140 lb springs.

Quantrill · 7/4/11, 10:16 AM

It looks like from schroder I need a 165# for the RF and a 130# for the left front. I see they sell 8" and a 10". Which one do I need for 7" shocks? Will a pro shock take the same coil over kit as a afco shock?

Thanks for all your guys help.

7/3/11, 9:50 AM	#2 Re: Torsion bar to Coil Spring Rate conversio
TQ29m Senior Member Join Date: Aug 2008 Posts: 6,558	Personally, I wouldn't change it, maybe work with the bars some, but if you'll notice, the NEW trend, is BACK to bars again, lot less expensive to maintain, and, again, IMHO, far easier to set up. Bob! __________________ "Being old, isn't half as much fun, as getting there"! Ole Robert I!

7/3/11, 10:46 AM	#4 Re: Torsion bar to Coil Spring Rate conversio
TQ29m Senior Member Join Date: Aug 2008 Posts: 6,558	A bent tube ought to be an easy/inexpensive fix, even if you have to remove it, and replace it, but, whatever! Bob! __________________ "Being old, isn't half as much fun, as getting there"! Ole Robert I!

7/3/11, 8:09 AM	#1 Torsion bar to Coil Spring Rate conversion
Quantrill Senior Member Join Date: Nov 2009 Posts: 526	If I am running 26" hollow torsion bars .800 diameter and want to convert the car to coil over front what springs will I need? I am running both the same bars on the front of the car will I want to run both the same springs on the front or heavier on one side vs the other? This is on a 1200 mini sprint car. Thanks,

7/3/11, 10:22 AM	#3 Re: Torsion bar to Coil Spring Rate conversio
Quantrill Senior Member Join Date: Nov 2009 Posts: 526	I bent my torsion tube Friday night so one option is to convert to coil overs. I was looking at Hyper racing site and I think I need 233# springs? Anyone know if that is right?

7/3/11, 11:21 AM	#5 Re: Torsion bar to Coil Spring Rate conversio
opnwhlmnd Senior Member Join Date: Jun 2008 Posts: 2,424	Here are a couple useful links to help you Pro Shocks Torsion to Coil Spring Weight Calculator Schroeder 26" Hollow Torsion Bar Spring Rates

7/3/11, 11:36 AM	#6 Re: Torsion bar to Coil Spring Rate conversio
Quantrill Senior Member Join Date: Nov 2009 Posts: 526	Thanks for the links that help out. I found one for a 1" bar on Schroeders site. http://www.schroedersteering.com/Trs...7PDFs/1H26.pdf just in case anyone else is looking for the same info. Thanks,

7/3/11, 12:35 PM	#7 Re: Torsion bar to Coil Spring Rate conversio
darnall Senior Member Join Date: Aug 2009 Posts: 773	233# sounds AWFUL heavy for a 1200cc car...dirt midgets use 160-200# front springs...and with the extra engine weight I would think they would use heavier springs than a 1200... You have to use torsion arm length in the equation..center of the bar to center of the pickup point, not length of the entire arm... I actually have a "torsion bar calculator" thats like a slide rule to give spring rate calculations but it doesn't go down as small as .800 ---------- Post added at 11:37 AM ---------- Previous post was at 11:35 AM ---------- also you have to use "effective length" of the torsion bar, not actual length, to figure out a conversion.

7/3/11, 2:07 PM	#8 Re: Torsion bar to Coil Spring Rate conversio
Joltin Joe Senior Member Join Date: Dec 2008 Posts: 442	being the engine is light.....a pair of 165lbs would be a good start......

7/3/11, 6:42 PM	#9 Re: Torsion bar to Coil Spring Rate conversio
tqracer53 Member Join Date: Nov 2007 Posts: 156	on a tq we run 140 lb springs.

7/4/11, 10:16 AM	#10 Re: Torsion bar to Coil Spring Rate conversio
Quantrill Senior Member Join Date: Nov 2009 Posts: 526	It looks like from schroder I need a 165# for the RF and a 130# for the left front. I see they sell 8" and a 10". Which one do I need for 7" shocks? Will a pro shock take the same coil over kit as a afco shock? Thanks for all your guys help.