Getting the angle of the dangle

[The WidowMaker]

RELATIVE TO THE CHASSIS BEING LEVEL - Suspension loaded. These settings we're talking about are pinion angle relative to the Engine. So if you start with a level chassis - set the motor down relative to that - and the pinion angle relative to the setting of the motor.

all im saying is where do you measure? i could pick 10 different spots on the frame, and each would come up different. obviously i pick the same spot every time for my own sanity, but when numbers are thrown around on the internet its never given what the heck is being measured and compared

I also agree with Frank -- motor down 4* and pinion down 1/2* in these 4 link rear ends... they don't crawl much. My Jim Meyer chassis - and the Art Morrison Chassis I'm working on right now - set the motor down 3*

which way is the pinion when you say 1/2* down? 1/2* to the chassis or the 4* of the motor? if youre talking about a 4* tailshaft and a 3.5* pinion, it usually works. in my situation, the pinion is sitting higher than the tailshaft, therefore the common \ _ \ setup yielded working angles that were approaching 4*. will it cause an isssue? probably not. but, when starting with a clean slate its best to get them right at 1* but not under. the less common \ _ / is what i ended up going with. i still have working angles that cancel each other in order to minimize harmonics, and i still left .5* for pinion wrap.

How critical is the centerline?

you want your working angles as close to 1* as possible (without going under since they will stop rotating as greg stated), and you want both angles to be within .5* of each other.

if you set up your tailshaft and pinion in a straight line and have 0* working angles in plan view, youre needles will still rotate since you have enough of an angle in side view. but if your wa's are huge in plan view, it doesnt matter how much work youve done to keep them minimized in side view, you might end up with a high speed vibration.

i know im over thinking the crap out of this, but i didnt want to end up being one of those "high speed vibration, need help" threads once this thing is finally on the road. what frank and greg said will usually work, but i know youve got yourself a pretty low ride and its worth really checking into the working angles.

Tim

[Vegas69]

I'd start with 2-3 degrees if your tunnel clearance will allow it.

[dtedler]

Hey Ned - The cross member that I am sending you will have the pinion angle set a 2 1/2 degrees down using the stock mounting location. With your suspension being channeled up another 1 1/2" in the chassis this will increase the angle by.......let me play with the CAD and I'll tell you exactly. More to come.

Tony Edler
Hurst Drive Line Conversions

[dtedler]

Ned - By raising the front suspension into the chassis by the 1.50 inches will change the pinion angle by 4.75 degrees. This is taking into effect the location of the motor mounts on the 3G Hemi, the bell housing depth and the distance to the isolation mount to the transmission.

After our conversation last evening I think the individual parts is the best course of action for your application.

Tony

[DRJDVM's '69]

This page was helpful..

http://jniolon.clubfte.com/driveline...nephasing.html

[The WidowMaker]

This page was helpful..

http://jniolon.clubfte.com/driveline...nephasing.html

he briefly mentioned it towards the end, but his setup technique didnt take into account the actual working angles. and again, the trans and pinion yokes do NOT need to be parallel. parallel sets up most cars perfectly, unless you are far from stock.

download the free trial, and it will make it almost too simple

http://www.vibratesoftware.com/html_...ction_tool.htm

[DRJDVM's '69]

So basically I've set the rear pinion yoke at 90* to the ground at ride height.... that should get me close enough to adjust the upper control arms to pivot it up and down a couple of degrees...everything is tacked in for now...

Then I stuffed my T56 magnum in.... that was a PITA.....waiting for the crossmemeber to arrive so I dont want to trim more of the stock frame crossmember yet, but as of right now, the remaining ears sticking into the tunnel make it impossible to raise the tranny level and then move it forward... the T56 is too wide and hits the ears....so I had to angle it a ton to get the input shaft into the bell and then pivot it up.....dont have a clutch etc yet, so this way will work for now, but no way in hell once the clutch is in there.

Had to trim the tunnel quite abit to get the trans tail up enough to get the engine at 4 degrees down..... I'm gonna trim some more.... I'm shooting for an engine angle of about 3-3.5*. I'l post some pix soon.....

More tunnel trimming than I had hoped but oh well..... thats what happens when you make a tunnel and then drop the car another 2 inches ...its only sheetmetal.......

[GregWeld]

Every time I do stuff like this - I become more and more impressed with the engineers at the big auto makers... imagine that they get so much stuff right - and then they make millions of 'em.

Don't ya just love "custom" stuff!? LOL

Of course - in many cases - they're working with "known" parts and dimensions... but it's still impressive.

I fit the tranny in the 55 - by installing it all in the chassis (AME) and then slicing the tunnel fore and aft - and side to side in a couple places... dropped the body (using my lift) and lifted back my "pieces" of tunnel until I liked the look and the clearance - tacked a couple of holders in place - and then made fill pieces... LOL

You may find it easier to install your tranny already connected to the motor and put motor and trans combo all in at one time.

[GregWeld]

One other 'thought' -- cut the ears off that won't be used... or are just in the way of a nice install... USE A FEW DROPS OF TRANNY FLUID on the blade if using a saw with teeth of some kind... it keeps the aluminum from filling up the saw teeth...

[DRJDVM's '69]

The "ears" I was referring to are on the remenants of the factor crossbrace.....there was a crossbrace that contoured the floor and went up into the tunnel. With the first tunnel, that section was cut out but still had some pieces left that impinge on the tunnel area "space"....so the trans is just too wide to pass by them as it sits right now....I'm waiting on the trans crossmember before I cut any of those pieces off.....

There are 1-2 "projections" off the actual trans that may come off too

I want to have it all set up so I can pull the trans without pulling the motor if in the future I need to do that.....just less work.