torque arm rear and anti-squat

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torque arm rear and anti-squat

Postby Vega Guy » Wed Jul 03, 2013 3:25 pm

My 77 wagon has been getting loose in corners in the rear and i was curious if anyone has had any luck increasing anti-squat with the torque arm suspension. It appears lowering the car will change trailing arm geometry in the wrong direction so i was planning on raising the front trailing arm mounts enough to still lower the car and gain more anti-squat as well as lower the CG.

Thoughts? Insight? Thx!
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Re: torque arm rear and anti-squat

Postby cjbiagi » Wed Jul 03, 2013 4:50 pm

Lowering the car does hurt the anti squat characteristics. The rear lower control arms should be at a slight upward angle ( chassis point higher than the axle end). There are kits available for Camaro's to help adjust the control arm angle, I was hoping someone could make these for H bodies as well. I am not sure if the Camaro ones would work or not.
http://www.youtube.com/watch?v=nBWTBcUXoWo
Clyde.........75 Monza 2+2
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Re: torque arm rear and anti-squat

Postby Vega Guy » Wed Jul 03, 2013 5:46 pm

I'm planning to fab 2 or 3 adjustments (higher) into the front trailing arm (TA) mount and a few at the rearend mounting point as well. My main goal is to gain a bit of anti-squat for better tire loading on acceleration but also be able to drop the car for a lower CG. The rear coils need a little hack to stiffen things up a tad. I'd like to do a little autocross action and be able to throw the hammer without losing ground so much.

Does anyone autocross? Do tell!
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Re: torque arm rear and anti-squat

Postby cjbiagi » Wed Jul 03, 2013 6:53 pm

I don't think there is much room to move the front of the control arm up, unless you are planning to cut the floor. I recall the top of the control arm is already pretty close to the floorpan. It seems a lot easier to move the back of the control arm down, it's just a matter of making these relocation brackets. I seem to recall a angle of about 7 degrees is about right but of course every car is different.
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Re: torque arm rear and anti-squat

Postby Vega Guy » Wed Jul 03, 2013 9:17 pm

True. Kinda tight and a little notch would have to be done. This point would tie into the frame box and frame connectors to join up also. The seat is just above this as well but easy enough to carve that too. Want a little play on each end so I can really fine tune it and drop the car down without sacrificing too much... if there is such a thing : )

I think you're dead on with the 7 degrees on that trailing arm. Do you recall if that figure was in reference to a set-up for auto cross or drag?
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Re: torque arm rear and anti-squat

Postby cjbiagi » Wed Jul 03, 2013 9:25 pm

I really don't remember where I heard that spec but it's really just a starting point of reference. Everyone knows how drag cars have all sorts of adjustments on their links so even they have to be fine tuned for the track. I know my arms right now are pretty much level which I know is not great. I did lower the back of my car somewhat as it always sat high in the rear even when it was new so this of course took away whatever angle was originally there.
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Re: torque arm rear and anti-squat

Postby rpoz-29 » Thu Jul 04, 2013 8:08 am

I autocross in an '02 Z-28. Ran a Vega from 1975 until 2003. If the issue is oversteer, a larger front/smaller rear bar will help. How modified is your car?
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Re: torque arm rear and anti-squat

Postby Vega Guy » Fri Jul 05, 2013 10:04 am

How modified? Not very. V8, Urethane bushings, stiffer front springs, 1" front sway bar, and just removed the rear bar last night as the rear was skipping in turns. I'd love to hear any insight our suggestions you might offer.
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Re: torque arm rear and anti-squat

Postby rpoz-29 » Fri Jul 05, 2013 10:48 am

Try it without the rear bar and see how it goes, or find a larger bar for the front. On the Vega, I had a 1/16" front bar and a 3/4" rear, stock springs, and a set of PST bushings. I was running a cheap set of hydraulic front shocks, and a set of KYB HP gas on the rear. Before anyone rolls their eyes, I had also run Mulholland, Konis, Gabriel Striders, and the KYB's on all 4 corners. For what ever reason, the cheapies/KYB's worked great with the stock springs. If anything, I had a touch of understeer with that setup, but not enough to "grind" the tires in a tight corner. What type and size tires are you running?
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Re: torque arm rear and anti-squat

Postby Vega Guy » Fri Jul 05, 2013 10:59 am

205/60/13 now. Going to a five bolt down the road and have a set of 15x8 wheels. Kinda large for the front but i love these wheels. Old westerns.... Mini lite look.
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Re: torque arm rear and anti-squat

Postby rpoz-29 » Fri Jul 05, 2013 8:06 pm

I wouldn't go too crazy until I had the wheel/tires I intended to run on and how serious I want to be. Once you're there, start making changes. Just my .02
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Re: torque arm rear and anti-squat

Postby Vega Guy » Wed Oct 16, 2013 9:48 am

On a side note I am at a loss here in trying to figure out the rear end in my car (77 Vega Wagon-non GT).

Diff cover is labed "Limited Slip Lube Only" on metal tag. However with car in the air one wheel is turned and the other rotates the opposite direction... shouldn't both wheels rotate the same way with limited slip?

The numbers on the tube of this rear end are HMC 7007 1 ... would that make this a 6-1/2 ring rearend with a 2.92 ratio?

Any suggestions would be awesome! I checked out item #3 at--> http://h-body.org/library/hbodyfaq/index.html

thanks!!!!
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Re: torque arm rear and anti-squat

Postby cjbiagi » Wed Oct 16, 2013 3:32 pm

Turning the tires in the air is not the best way to check for a posi. There is not enough drag. It's easier to just do a burn out and see if you get one patch or two :lol: . Otherwise pull the cover off and see what you have in there.
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Re: torque arm rear and anti-squat

Postby hammerdown7 » Fri Jul 17, 2015 10:06 pm

Funny, I just came across this old thread. When I was autocrossing my Monza, I had switched to running slicks and I was having trouble with wheel hop. A good friend of mine was a chassis engineer at Chrysler's and said he would help me cure the problem. What he did was shorten the torque arm about 15 inches and connected the front of it to a 2 inch square piece of tubing that was bolted to the bottom of the car. The torque arm was attached with rod ends to the tubing so it was free to pivot. I no longer had any wheel hop.

Wonder if Vega Guy is still around?

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