transambill

iTrader: (1)

I've already did the boxing of the lower control arms/panhard rod and even made a 3 point strut tower brace for a TPI set up and all that was easy. I'm about to do the torque arm fab but I'm a little worried about screwing up the pinion angle. I don't really need it to be adjustable. I just want -2 degrees of pinion angle and that should be fine for a daily driver that sees the track 3-4 times a year. My question is should I make it attach to the tranny or fab a crossmember and connect it there so it pivits like Spohn's design. I figure I could build it and then with it attached to the rear only i could position the rear where the pinion angle was at the desired -2 and then measure the distance from the tip of the arm down to the new crossmember and get my length for the pivit arm that attaches to the end of the torque arm and attaches to the crossmember. From what I've read here it's best to attach the torque arm to a cross member rather than the tranny and if I was to fab one that connected like the factory one does then I would have to setup the pinion angel where the arm attaches to the rear diff. and this would be more difficult. I'm ready to start this but if I'm way off track here somebody please tell me.

ede

i'd have the front mount to the floor pan not the trans and i think you'll be way ahead to make it adjustable.

MYBLUZ

why attach it to the body,and not the trans?

formula350sd

iTrader: (2)

cause the trans moves under hard acceleration and in turn causes the mount for the torque arm to move

330hp_91RS

Yes, but the more important thing is that you are putting tons of stress on the tailshaft of the trans, especially if you are pushing some power thru the drivetrain.

Once you have a heavy duty torque arm and tires that hook, you risk cracking the tailshaft. Plus if you bolt it up to the body/trans tunnel/ trans crossmember, you can shorten the arm and it will be more effective.

spartyon

dont attach it to the floor pan. it is a weak area. attatch it to the tranny crossmember like spohn and you will be set to go.

MYBLUZ

makes sense I guess, thanks for the input.

330hp_91RS

there are guys using the Jegster unit (the one I have) running TONS of HP and craking 1.6x 60 foots with no problems.

If it is easier for you to fab one that bolts to the trans tunnel (floor pan), go for it. It is not that weak of an area. I have 390 rwhp in my fourth gen using this setup and have had no problems with any weakness in the body.

91banditt2

iTrader: (1)

i'm in the process of making my own adjusable TA.right now i have the peice that mounts to the rear end in our welding shop.i'd post pix but there are way to many bytes to post.

spartyon

no, that is cool. but i am still leary of that because of the fact that i have seen seats tear out of floor pans without proper attactment. unless you really think the mounting point through then try it but i wont. its good to see the jegster piece being proven but i am still leary of the structural integrity of the floor pan. I guess it all depends on the force being applied to the unit...which i dont know.

transambill

iTrader: (1)

The ones I've seen that bolt to the floor pan actually bolt to a big plate that is fastened to the floorpan so the stress to the floor is spred out and not in one central location. I have subframe connecters that run along the factory pinchwelds under the car. I think I'm gonna fab a crossmember that connects them and attach my torque arm to it. Once done if room allows I'm gonna try to fab a driveshaft loop that is also attached to the crossmember.

TheGreatJ

Why not attach the loop to the torque arm? That way you don't have to worry about the driveshaft moving up and down with suspension travel, as the torque arm will be moving as well. You could run a smaller diameter loop that way which will give you more clearance for exhaust and such.

If I were to fab a non-adjustable one, I'd attach it at the front with a pivot-link to the crossmember. It just seems like the best compromise of rigidity and freedom of movement, plus you can always make a couple spare links of different lengths for minor changes in pinion angle.

330hp_91RS

seat = 4 bolts.....

Jegster Torque arm = about 14 bolts....

I think it'll hold.

spartyon

14 holes weakens sheetmetal more that 4. i would rather have 4 solid attachment points that 14!! i am not arguing anything about the jegster torque arm. i am just saying that i am leary of the idea. thats all.

83 Crossfire TA

iTrader: (2)

Sheet metal has little strength at any particular point… drilling a hole in it will not make any big difference, and the more holes you have the stronger the mount. If you want to lessen the number of mounting points then I would suggest adding 1/8” or 3/16” plate reinforcements to the mounting locations to distribute the load, and I would weld around their perimeter as well as drill multiple holes in them that I would fill with a pug weld.

spartyon

i agree with everything but this point. there is no way that 14 holes in the same size location has the same strength as 4. do an experiment with 2 1'x1' piece of sheetmetal. drill 4 holes in one and then 14 in the other and try to bend them or flex them in some way. the one with 14 holes will flex more or easier than the one with 4. now if those holes were spread across the length of the floorboard then i would say that there is little problems to worry about and i am overreacting. but to say that a point for a torque arm with 14 holes in the floor pan in one small area is just as strong as 4 holes in locations like a seat mount (excusing the additional brakets for seat strength) is just obserd.

MYBLUZ

I think that will definatley be the way I do mine. I'm not afraid to engineer my own mounting points/mounts, but I would like to see some of your guys pics on your set ups.

91banditt2

iTrader: (1)

Playing devils advocate here
if said 1x1 were to remain in that state?yes it would be more flexable.But if your adding a peice of steel to that 1x1 that is 1/8''-3/16'' thick plus your addding washers to distribute the metal to metal contact.your making that "flimsy" 1x1 stronger.

small area?i don't know the length of the mount but it appears to be 1 1/2" to 2' long.

One of the guys that belong to GCFBA.net is running in the 500+hp range and he raves about this TA.

my last .02

83 Crossfire TA

iTrader: (2)

The problem is that your example doesn’t work… lets go real world… take some 22ga steel and attach say a roughly 2’x2’ plate to it with 4 bolts and then 14 bolts (that is roughly the area that those attachment points will cover) and start pulling on it. The weak point will be the sheet metal, not the bolts or what you have bolted to it. The sheet metal in our real world example will be the high strength stuff that is pressed to a specific shape, assuming that you’ve got enough attachment points it will be very difficult to distort and even tear out the fasters… with 4 fasteners you’ll rip them out rather easily.

91banditt2

iTrader: (1)

91banditt2

iTrader: (1)

ok lets try this again

spartyon

That is the jegster mount?

91banditt2

iTrader: (1)

s-plane lucy?

spartyon

well if that is how jegs manufactured their piece i think they could have done better. a company like jegs with the machinery they probably have could have done something better than a million and a half washers. it does look beefy ill give ya that but washers? that many?

TheGreatJ

The washers are just to maintain even spacing between the plates. That way you don't have to take the rearend out of the car to fab up the bracket.


I've used washer stacks a few times.....works very well.

91banditt2

iTrader: (1)

allllrighty then,back to the thread at hand

any one else have any exerience with fabbing thier own TA?here is a thread with some usefull info.
i plan on usingthese for my adjustable TA

ME Leigh

Holy washers, i wish i had a supply like that!

eXesiv|83ta

iTrader: (4)

Hey guys,
I'm going to be fabricating a tubular torque arm for a project in one of my classes. I would like to know if anyone has some dimensions that they could give me as far as overall length and such. Its going to go to the tail shaft. The car is an 83 trans am with a 700r4.

Thanks,

91banditt2

iTrader: (1)

i don't have any solid dimensions yet for my rear end bracket since i haven't done a fitment on a rear end yet i hope to some time this week.if that goes allright then i can post some dimensions.

p.s. you could do what i did got ahold of a stock TA and use dimensions off it.

anesthes

iTrader: (12)

And there are guys like me who almost put it through the floor, ebayed it, and went back to a stock torque arm.


If you do make a torque arm, make sure the pinion angle is adjustable, and mount it to the frame somehow.

-- Joe

eXesiv|83ta

iTrader: (4)

ya thats kinda what i'm thinkin but i can't get my damn car in the air cuz i live at an apartment and we can't work on cars. anyways i want to get a stock torque arm, you can get em on fbodymotorsports for 25 dollars but i gotta wait for it to get here. If you get dimensions it would be awesome if you could post em here.

Thanks,

Justin

330hp_91RS

Lemme hear some more details on this...

how exactly did you do that?

91banditt2

iTrader: (1)

Like a glove :rockon: i'll post some dimensions tomorrow

anesthes

iTrader: (12)

Hard launches. Floor in the tunnel area where the seat belts mount, started tearing.. sold the jegster arm. weld and patched the tunnel.

Put a stock arm in with a comp poly mount. works fine.

Prolly get a spohn for next year. But no more tranny tunnel mounting.

-- Joe

eXesiv|83ta

iTrader: (4)

Sweet man thanks. I appreciate it. :hail:

91banditt2

iTrader: (1)

sorry no dimensions yet i need to sit down and get all them on paper.here what i have so fAR
1/2-20 threaded inserts from Coleman Racing they were $3.80 apeice
1/2-20 rod ends
1/2 shoulder bolts to bolt the rod ends to the bracket
threaded rod with left hand and right hand threads 6'' long which i'm going to cut down to 5''.
1/2-20 right hand and left hand jam nuts.

91banditt2

iTrader: (1)

another

transambill

iTrader: (1)

I'm dooing mine exactly like yours 91banditt2. I'm gonna run a crossmember from side to side and attach it to my SFC's and connect my arm to it. Still waiting on my rod ends to show up that I had to order. What are you useing for tubeing? Are you buying that panhard bard tubeing from Coleman Racing or are you getting something locally?

91banditt2

iTrader: (1)

you could say locally :
we have a machine shop in our building and i just happin to be tight with the guys in the machine shop,so anything i can't do myself all i got ta do is ask
i plan on using 1 1/4" O.D. 3/4 I.D. tubing.i also plan on fabbing up something like this :werd:it would be alot easier to just run the TA to the the tail shaft like stock.you can buy replacment bushings through BMR and Spohn for around $15.but where's the fun in doing things the easy way.

91banditt2

iTrader: (1)

here is a simple drawing with dimensions of the torque arm rear end bracket that i made.i test fitted this bracket with another rear end to see if my dimensions were right,and they seemed to be.it fit right over the rear end it didn't look like there would be any interference from the drive shaft.i plan on buying a disk brake rear end sometime this week end.then i'll get some pix of it mounted on the rear end.

if your going to use my design please use some custion as it really hasn't been tested yet.
:rockon:

91banditt2

iTrader: (1)

i did have one problem that i had now that i think of it.
the holes for the rod ends are to close to the top and bottem plates.i would make them 13/16" or 7/8' from the top(or bottem)of course some one may need more room if their using a larger diameter rod end.

transambill

iTrader: (1)

Tony,
Hows the torque arm comming along?
Made any progress?

91banditt2

iTrader: (1)

I bought a 9 bolt rear that i'll be putting in my firebird so i've been spending most of my spare time taking that apart.when i put the TA braket on the 9 bolt i noticed a couple things.the hole weren't lining up.there was too much metal around the top back bolt hole so i needed to fix that.i also had to remove some meterial from the 5 7/8 x 1 1/2 piece. there is a small piece of metal that sticks out from the diff. and it wasn't alowing the TA braket to sit right were it should be.
i'll be checking my work again tonight to see if the bolt holes line up.

Stay Tuned!

transambill

iTrader: (1)

Yea, mine will be going on a 9 bolt as well. I've got my 1/4" steel plate ready for me to lay out the pattern's for the TA bracket.
Let us know when you get it figured out. I've got a stock TA laying around. I'll take some measurements and see what I can come up with.

91banditt2

iTrader: (1)

pic 1

91banditt2

iTrader: (1)

pic 2

91banditt2

iTrader: (1)

pic 3

91banditt2

iTrader: (1)

pic 4

transambill

iTrader: (1)

So how much narrower or shorter did you have to make the 5 7/8 X1 1/2 piece? Can you take some measurements and repost demensions for the bracket?
Sorry to be a PITA but my cars put away for the winter so I cant get under it rite now and your useing the same rear I am.

91banditt2

iTrader: (1)

1 5/16" wide