Magnus

iTrader: (4)

2 weeks ago I went racing with a non adjustable torque arm. I was under the car hundereds of times but never actually measured pinion angle.. I could have sworn it was near or at 0.. At least no visible angle..

I cut 1.40 60's stock internals NA.. pulling big air.. shocks 1 all around

2 weekends ago I cut many 1.3 60's all dead hooking.. Even cut a 1.31 60.. All getting mad air.. front shocks at 1 rears at 4. I dead hooked every pass.

So I blew up the torque arm that day.. and with a very VERY big + pinion angle I was still able to hook a low 1.4..

So I put in a new adjustable torque arm.. adjusted it to -2.. Now I cannot hook for crap.. Went last weekend and didn't hook the car once. I spun off the t-brake every single time.

My rear end does not move at all on launch.. Everything is so light and stiff I find it hard to believe the pinion angle really moves so I am thinking about putting it back to 0.

It is real frustrating to have no traction problems with the car ever.. and then put a new torque arm in, adjust it to -2 and all of a sudden not be able to hook the car.

I race on a 28x10.5x15 ET Drag at 13psi hot. I should be hooking!!!

so how does pinion angle affect traction and launch?

SMOKIN01TA

iTrader: (10)

kinda wondering myself, im just typing so that if you get a response from brian on this one i can find it quicker

FANTAZ28

iTrader: (2)

my car has a spoohn tq arm i think at about -2 or so the car dead hooks with stock shocks and springs and stuff, but from what ive been told is to keep going negative till the car hooks than go bakc just a bit till it hooks with the least amount of negative pinion angle

MADMAN

iTrader: (4)

Whose arm did you put on the car MAGNUS.??? Does this one mount different than your old one??

Pinion angle on a t/a car is usually set at 2.5 to 3 degrees down. I think the problem on Magnus's car is instant center.

10.5 Dave

iTrader: (5)

I set the pinion angle with my old combo at -3.5 degrees per Steve Spohn.I hooked really well,mid 1.40's in a heavy stick car.

Loudmouth LS1

iTrader: (10)

Hmmm, I have mine set at -1.5, hooked amazing on stock shocks, but then I got hals, and ever since, i've been having issues gettin her to hook up, would the shocks make a diff in where the pinion angle needs to be set? Cuz I did testing when I was on the stock one's, set it at -1, then went to -1.5, then went to -2, from -1 to -1.5, the 60' got better by .04, and from -1.5 to -2, it got worse by .02, so I put her back to -1.5 and have left it there ever since. I heard between negative 1 and negative 2 is where you want it on an auto car, but now i'm not sure, should I try goin more negative when I get the car running again?

kcsoz20

I have heard -2 is basically the standard for autos.

I actually need to adjust my pinion angle after TH400 install. anyone have the formula for doing this or the link to that one guys pictorial/instructional?

Ken

MADMAN

iTrader: (4)

If all you changed is the trans then you dont need to reset pinion angle.

Anytime you change a suspension part you have to test until you find the setting the car wants. The best thing to do is go to the track make a pass, then make ONE change. See if it helped or hindered. Then try something else. You might have to make 20 passes to find your combo.

Loudmouth LS1

iTrader: (10)

Yeah, that's what I figured, guess i'm gonna have to get out to bradenton one of these days after I get her back up and running to test everything out, cuz moroso never hooks consistently for me to feel confident that it was the setting that caused the worse 60' and not the track!

gator's 99TA

iTrader: (2)

come up to bradenton devon, no doubt 1.4s will be yours there.

Loudmouth LS1

iTrader: (10)

****, i'm lookin for 1.3's!!!! I've actually already pulled 1.4's, cut a 1.47 at moroso, was my best 60' ever there!!! And she was initially hooking and then unloading the rear and blowin the tires off, so hopefully that'll be taken care of with the new rear swaybar and lca relocate brackets I got, and maybe i'll even be able to hook some 1.3's at moroso, that would be badass!!! I just gotta get my new motor together, still waitin on parts to come in! And i'm sure i'll make my way up to bradenton after she's together so I can get the suspension all tuned in!

Magnus

iTrader: (4)

I went from the MAC/Jegs torque arm which is non adjustable to the Alston torque arm that is adjustable.

I used the same center style tunnel mount. It has a yoke that sticks out that the torque arm slips over.. I didn't have to change that at all.

I just put on the new torque arm and adjusted it.. The torque arms look identical but the Alston has an extra brace and is adjustable..

I go from dead hooking my car EVERY PASS to not dead hooking the car at ALL.

It feels like with the torque arm set at -2, the front just doesn't want to lift up.. Before, the front end of the car would lift up easily and the car always hooked.

I need the front to lift more.

redline2k

iTrader: (9)

I had the same problem after changing to an adj. torque arm. After It was installed it seemed like my rearend was pushed farther back in the car. I didn't have adjustable lca's at the time so I couldn't verify that was the problem.

sikws6

How does pinion angle affect how a car hooks at all? it doesn't affect instant center does it? I thought it was set negative so that when the car launches the u joints are more in a straight line to keep them from self destructing?

Maggie

Adding pinion angle in excess from O degrees (neg. pinion angle) causes pinion bind and slows the rate of movement of the housing as power hits the tire. Idealy the pinion angle should be set to acheive 0 degree when the car is moving. So, ideal pinion angle would be the angle at rest being the amount of angel needed to bring the angular distance between the drive shaft center line and the center line for the axle pinion to netural angle under power with the car in motion.
A lot of us racers have used pinion bind as a tool to add or remove hook but like any other "bind" it is damaging to parts... a little bind= little damage, big bind = big damage... just part of racing!!

RyanJ

Have you set it back to 0 yet? From what I understand, adjusting it negative is only to counteract the pinion moving during launch? I may be wrong there...but what Maggie wrote makes me think I'm right. Still...simple answer is move it back and see what happens.

Magnus

iTrader: (4)

I plan on moving it back to 0 and probably just leaving it there.

When my car launches, the rear end does not move at all.. Everything is so siff back there and the car is so light.. Even when I wheelie huge the wheel gap is the same..

I find it hard to believe the pinion angle is changing.

Seems like I lost a couple MPH as well with a -2 pinion angle vs 0..

Shon Herron

iTrader: (25)

You said you reused the front mount from the Jegster set up, could that have gotten tweaked when the other TA bent/broke?
Would it be worth putting the Alston front mount on the car and check?

RyanJ

That's what I'm saying. The neg. angle is to counter-act counterproductive suspension/weight movement, but your car is stiff and REALLY light. Go back to zero...or buy a Madman TA like you should have in the first place

Magnus

iTrader: (4)

The jegster mount didn't get tweaked.. I must have spent 10+ hours under the car with the torque arm debackle.. The whole mount looked fine.

Not sure how a madman torque arm would differ than the alston... The alston style is exactly what I want, it bolts to the inside of the upper trans tunnel allowing full clearance for duals and anything else..

oh well..