suspension physics majors???? step up - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**crossy** · 07-03-2009, 05:04 PM

somone with waaay more knowledge than me please explain why i have been told that traction bars(slappers) are a waste of time on my 81. the rear is still mounted UNDER the leafs as it cam althought the truck is lowered about 5" in the back. I did come up with a way to make traction bars that will mount under the diff and drive up on the front leaf eye.

I just added 4* of negative pinion wedge because i came up with exactly 0* offset while at rest.
I had 4* positive on the pinion and 4* negative on the tranny. My pinion is now 0*. I understand that even the 4*I installed may not be enough. i can't afford any more trial and error. I lost(split) a $1000 trans from this truck on pass #13. thanx , crossy

djracer · 07-03-2009, 05:38 PM

buy Cal tracs!

rookierodbuilder · 07-03-2009, 10:18 PM

Quote:

Originally Posted by djracer

buy Cal tracs!

yup, i'm an engineering major, and the caltracs by my knowledge are the best way to go in order to have traction bars that will not bind the suspension

**crossy** · 07-04-2009, 12:07 PM

The truck planted fine at the track last night . it's only a 13 sec. truck.

so i havea few more questions for those who chimed in.

What is the safe LOW air pressure that can be run in a BFG drag radial?? i have 275-60-15 on 8" wide wheels.

Super73 · 07-05-2009, 08:10 PM

You can run them pretty low (12psi).. But you should be reading th tire and setting PSI based on that.

gchemist · 07-05-2009, 08:30 PM

Make your own!

My write up.
http://www.geocities.com/abetterchem...ustombars.html

djracer · 07-06-2009, 04:30 PM

The M/T drag radials hook hard with 18 to 20 psi.

Outlaw72 · 07-06-2009, 04:56 PM

Agree with everyone here....traction bars ARE a waste of time...

Your tires.....I had the MT radial 315x60 and ran them at about 15. That was in cold weather tho.

Wild83C10 · 07-06-2009, 09:43 PM

Traction bars aren't a waste of time, but they aren't as efficient or adjustable as the caltracs. Traction bards will work, but for the money caltracs win. They have a longer arm which helps weight transfer and if you preload them the springs wont move at all.
Look Super73 said, read the tires. You may need to do some experiementing on a back road (I mean track), to see at which PSI you get the biggest tire patch.

Wild83C10 · 07-06-2009, 09:49 PM

Quote:

Originally Posted by gchemist

Make your own!

My write up.
http://www.geocities.com/abetterchem...ustombars.html

Interesting writeup. How does it ride. It seems that you have basically locked the leaves from "compressing" or flexing downward. I guess if it's a track only truck then it wouldn't be so bad.

AlienYouth · 07-07-2009, 12:27 AM

i think ive got my bfg's (325/50/15 on 10") at 10 PSI, they wrinkle up n hook good

**crossy** · 07-07-2009, 08:22 AM

G, I thought you moved to Chevytalk only. didn't know you were still here. I remember your thread a few years back on t-bars and thats when people were saying they were not functional because of our spring placcement. I also remember people there was a clearance issue and my truck is LOW. I would still like to see a pic of the caltracs installed. how far in inches are they below the shock mounts or axle tube. thanx , crossy.

franks72 · 07-07-2009, 02:28 PM

Hey Dave, havent run into you in a while. I run 17 psi in my 275s. When are you going to the track again. Im going friday night.

**crossy** · 07-07-2009, 04:58 PM

wazzup big man:-) , now there are actually 4 whole people on this forum that are a rocks throw from me. Dude you know the deal with me. 18 projects going on. None worth mentioning. I'm a part timer at the track and now i don't want to break anything. I'm scared for the first time to hurt something. I'm prolly going to have a FOR SALE sign in it at the 'BIG SHOW' in Pennsville and i don't want any more shrapnel holes in the floor. I have to work this Thurs/ Friday and going to the shore on saturday for the BBQ competition. THOUGHT about this Wednesday night though. This past Friday was madhouse there. crossy

Wild83C10 · 07-08-2009, 08:20 PM

Quote:

Originally Posted by crossy

I would still like to see a pic of the caltracs installed. how far in inches are they below the shock mounts or axle tube. thanx , crossy.

I will take some measuremets and dig up my pictures. My truck is lowered 6" in the rear. Flip kit, overload leaf removed and a 1-1.5" drop shackle. No clearance issues with the caltracs.

**crossy** · 07-08-2009, 11:07 PM

wild, where in Jersey are you located? thanx, for that info. If your truck is low with no clearance issues. they should be good.

Wild83C10 · 07-09-2009, 07:27 AM

I'm in Millstone Township (western Monmouth County) by Great Adventure. If you want to get a better look we could meet up sometime.
Here are some older pictures. I'll get the measurements soon.

Wild83C10 · 07-09-2009, 08:53 PM

Dimensions were taken with a 25.5" tall tire. The front bracket sits 5" off the ground and the bracket at the axle sits 4.25" from the ground. That is with the overload leaf removed and only 4 springs, if you have extra leaves in there then it might sit lower.
My suspension is slightly different then what you see in the photo above.

AirMale · 07-11-2009, 05:53 PM

looks like a good concept: run a soft leaf spring and use the cal-trac to control warp. should've tried that myself.

85sqbdy · 07-13-2009, 09:37 PM

t-bars do work, but only to a certain extent. mine worked fine until i put alot of power to them. the axle twisted anyway and pretty much destroyed the driveshaft and the transmission.

07-03-2009, 05:38 PM	#2
djracer Registered User Join Date: Feb 2001 Location: Wetumpka, Al, U.S. Posts: 8,892	Re: suspension physics majors???? step up buy Cal tracs! __________________ Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole!

07-04-2009, 12:07 PM	#4
crossy Oh,you can't buy that new Join Date: Apr 2000 Location: Pennsville,N.J. 08070, USA Posts: 2,039	Re: suspension physics majors???? step up The truck planted fine at the track last night . it's only a 13 sec. truck. so i havea few more questions for those who chimed in. What is the safe LOW air pressure that can be run in a BFG drag radial?? i have 275-60-15 on 8" wide wheels. __________________ "been there, done that, ruined the T-shirt". 2007 LBZ GMC Sierra, ECSB 2006 LM7 RCSB Silverado 98 Vortec project. 94,3500,6.5L 4L80 81 SWB GMC POS finally gone 73 Pinto, stock, w/CragarSS's-eww LOTS of Cummins trucks.

07-05-2009, 08:10 PM	#5
Super73 Registered User Join Date: Nov 2007 Location: Bay Area, Ca Posts: 2,841	Re: suspension physics majors???? step up You can run them pretty low (12psi).. But you should be reading th tire and setting PSI based on that. __________________ ------Motor---------------Bottle 60'---1.53---------------1.41 1/8---6.58 @ 105.92----5.87 @ 118.41 1/4---10.38 @ 126.97----9.24 @ 142.49

07-05-2009, 08:30 PM	#6
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Re: suspension physics majors???? step up Make your own! My write up. http://www.geocities.com/abetterchem...ustombars.html __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos

07-06-2009, 04:30 PM	#7
djracer Registered User Join Date: Feb 2001 Location: Wetumpka, Al, U.S. Posts: 8,892	Re: suspension physics majors???? step up The M/T drag radials hook hard with 18 to 20 psi. __________________ Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole!

07-03-2009, 05:04 PM	#1
crossy Oh,you can't buy that new Join Date: Apr 2000 Location: Pennsville,N.J. 08070, USA Posts: 2,039	suspension physics majors???? step up somone with waaay more knowledge than me please explain why i have been told that traction bars(slappers) are a waste of time on my 81. the rear is still mounted UNDER the leafs as it cam althought the truck is lowered about 5" in the back. I did come up with a way to make traction bars that will mount under the diff and drive up on the front leaf eye. I just added 4* of negative pinion wedge because i came up with exactly 0* offset while at rest. I had 4* positive on the pinion and 4* negative on the tranny. My pinion is now 0. I understand that even the 4I installed may not be enough. i can't afford any more trial and error. I lost(split) a $1000 trans from this truck on pass #13. thanx , crossy __________________ "been there, done that, ruined the T-shirt". 2007 LBZ GMC Sierra, ECSB 2006 LM7 RCSB Silverado 98 Vortec project. 94,3500,6.5L 4L80 81 SWB GMC POS finally gone 73 Pinto, stock, w/CragarSS's-eww LOTS of Cummins trucks.

07-06-2009, 04:56 PM	#8
Outlaw72 Hay Team!! Join Date: Jun 2003 Location: Ft. Worth, TX, USA Posts: 366	Re: suspension physics majors???? step up Agree with everyone here....traction bars ARE a waste of time... Your tires.....I had the MT radial 315x60 and ran them at about 15. That was in cold weather tho. __________________ 1972 Chevrolet Cheyenne LWB "Orange and White" 8)

07-06-2009, 09:43 PM	#9
Wild83C10 Registered User Join Date: May 2002 Location: NJ Posts: 910	Re: suspension physics majors???? step up Traction bars aren't a waste of time, but they aren't as efficient or adjustable as the caltracs. Traction bards will work, but for the money caltracs win. They have a longer arm which helps weight transfer and if you preload them the springs wont move at all. Look Super73 said, read the tires. You may need to do some experiementing on a back road (I mean track), to see at which PSI you get the biggest tire patch. __________________ 83 C10 Stepside (SOLD, it was a blast!) 383 MASS-FLO EFI/TKO II 600/3.90 Posi 10 bolt S475 and C4 DM running, fine tuning turbo= Douchebag Racing: Runs Fine all the Time

07-07-2009, 12:27 AM	#11
AlienYouth Registered User Join Date: Apr 2007 Location: Westminster, Maryland Posts: 411	Re: suspension physics majors???? step up i think ive got my bfg's (325/50/15 on 10") at 10 PSI, they wrinkle up n hook good __________________ Picturesss 71 C10 383/TH400 13.65 @ 99... 2.06 60' spinnin :/

07-07-2009, 08:22 AM	#12
crossy Oh,you can't buy that new Join Date: Apr 2000 Location: Pennsville,N.J. 08070, USA Posts: 2,039	Re: suspension physics majors???? step up G, I thought you moved to Chevytalk only. didn't know you were still here. I remember your thread a few years back on t-bars and thats when people were saying they were not functional because of our spring placcement. I also remember people there was a clearance issue and my truck is LOW. I would still like to see a pic of the caltracs installed. how far in inches are they below the shock mounts or axle tube. thanx , crossy. __________________ "been there, done that, ruined the T-shirt". 2007 LBZ GMC Sierra, ECSB 2006 LM7 RCSB Silverado 98 Vortec project. 94,3500,6.5L 4L80 81 SWB GMC POS finally gone 73 Pinto, stock, w/CragarSS's-eww LOTS of Cummins trucks.

07-07-2009, 02:28 PM	#13
franks72 Junior Member Join Date: Mar 2005 Location: Wilmington DE Posts: 218	Re: suspension physics majors???? step up Hey Dave, havent run into you in a while. I run 17 psi in my 275s. When are you going to the track again. Im going friday night. __________________ 72 cheyenne super BB402 TH400 Air Tack Tilt Posi P/S P/B AM/FM 12.96 @ 101.82 mph 60ft 1.82 12.39 @111.33 With a 180 shot nos 69 Camaro RS http://s94.photobucket.com/albums/l117/fdelcoglin/ email fdelcoglin@hotmail.com

07-07-2009, 04:58 PM	#14
crossy Oh,you can't buy that new Join Date: Apr 2000 Location: Pennsville,N.J. 08070, USA Posts: 2,039	Re: suspension physics majors???? step up wazzup big man:-) , now there are actually 4 whole people on this forum that are a rocks throw from me. Dude you know the deal with me. 18 projects going on. None worth mentioning. I'm a part timer at the track and now i don't want to break anything. I'm scared for the first time to hurt something. I'm prolly going to have a FOR SALE sign in it at the 'BIG SHOW' in Pennsville and i don't want any more shrapnel holes in the floor. I have to work this Thurs/ Friday and going to the shore on saturday for the BBQ competition. THOUGHT about this Wednesday night though. This past Friday was madhouse there. crossy __________________ "been there, done that, ruined the T-shirt". 2007 LBZ GMC Sierra, ECSB 2006 LM7 RCSB Silverado 98 Vortec project. 94,3500,6.5L 4L80 81 SWB GMC POS finally gone 73 Pinto, stock, w/CragarSS's-eww LOTS of Cummins trucks.

07-08-2009, 11:07 PM	#16
crossy Oh,you can't buy that new Join Date: Apr 2000 Location: Pennsville,N.J. 08070, USA Posts: 2,039	Re: suspension physics majors???? step up wild, where in Jersey are you located? thanx, for that info. If your truck is low with no clearance issues. they should be good. __________________ "been there, done that, ruined the T-shirt". 2007 LBZ GMC Sierra, ECSB 2006 LM7 RCSB Silverado 98 Vortec project. 94,3500,6.5L 4L80 81 SWB GMC POS finally gone 73 Pinto, stock, w/CragarSS's-eww LOTS of Cummins trucks.

07-09-2009, 07:27 AM	#17
Wild83C10 Registered User Join Date: May 2002 Location: NJ Posts: 910	Re: suspension physics majors???? step up I'm in Millstone Township (western Monmouth County) by Great Adventure. If you want to get a better look we could meet up sometime. Here are some older pictures. I'll get the measurements soon.

07-09-2009, 08:53 PM	#18
Wild83C10 Registered User Join Date: May 2002 Location: NJ Posts: 910	Re: suspension physics majors???? step up Dimensions were taken with a 25.5" tall tire. The front bracket sits 5" off the ground and the bracket at the axle sits 4.25" from the ground. That is with the overload leaf removed and only 4 springs, if you have extra leaves in there then it might sit lower. My suspension is slightly different then what you see in the photo above. __________________ 83 C10 Stepside (SOLD, it was a blast!) 383 MASS-FLO EFI/TKO II 600/3.90 Posi 10 bolt S475 and C4 DM running, fine tuning turbo= Douchebag Racing: Runs Fine all the Time Last edited by Wild83C10; 07-09-2009 at 08:54 PM.



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07-11-2009, 05:53 PM	#19
AirMale Senior Member Join Date: Jan 2003 Location: Atlantic City, NJ Posts: 1,073	Re: suspension physics majors???? step up looks like a good concept: run a soft leaf spring and use the cal-trac to control warp. should've tried that myself. __________________ 86 SWB 9.0 LITER T-400-OD 4.11 eaton-4/5 drop Best 1/4 12.51 @112mph no traction

07-13-2009, 09:37 PM	#20
85sqbdy Registered User Join Date: Jul 2008 Location: Orange,Texas Posts: 99	Re: suspension physics majors???? step up t-bars do work, but only to a certain extent. mine worked fine until i put alot of power to them. the axle twisted anyway and pretty much destroyed the driveshaft and the transmission. __________________ if it ain't broke, fix it until it is.

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