Trans/drive angle ls7 dry sump?

[67ragtp]

Im working with an LS7 in a 69 camaro, my drive angle measured at the crank pulley shows the trans down 4 degrees. Does this seem excessive? If I lift the trans Im smashing the tunnel and this is with a tko 600 install. Just curious if 4 degrees is ok for fluid levels and possible vibration issues?

I believe I will have to lift the rear yoke up 3 degrees(dse 4 link)?

Thanks Rich

[Silver69Camaro]

Im working with an LS7 in a 69 camaro, my drive angle measured at the crank pulley shows the trans down 4 degrees. Does this seem excessive? If I lift the trans Im smashing the tunnel and this is with a tko 600 install. Just curious if 4 degrees is ok for fluid levels and possible vibration issues?

I believe I will have to lift the rear yoke up 3 degrees(dse 4 link)?

Thanks Rich

That's just fine for the engine, but I can't comment on driveline angles and such. I don't know how the DSE setup is adjusted.

[67ragtp]

Thanks Matt- I just called dse they to said the trans down 4 degrees is fine, they want me to drop the pinion yoke 2 degrees(downward). I almost fell out of my chair, seems like a lot of angle to me. I figured moving it up would make it more parallel. I wish I understood why?

Rich

[Vegas69]

Because 4 degrees is not Optimal. With 4 degrees of drivline angle and a good stance like you'll see on my car or bad penny, etc. You will have an UPWARD driveshaft angle with equal and opposite drivline/pinion angles. That means your working angles are getting severe for high speed run out. All you're doing by pointing the pinion down is making the working angles as small as possible. I was able to achieve under 3 degrees of working angle where with equal and opposite you would have 7-8. The driveshaft will actually slope down towards the rear a little which is optimal. Personally, if you are in the fabrication phase? I'd cut that tunnel in a heart beat and set that thing up with equal and opposite numbers. You're going to need 2-3(approx) degree driveline angle to do so. That would allow you to get your working angles between 1-2 degrees which will make your car run out super smooth until you run out of horsepower. I'm not saying it's not possible with 4 degrees of driveline angle, I'm simply saying it's the second best way to skin the cat. Take a look at a modern corvette/camaro etc and take note of the driveline slope.

[GregWeld]

Thanks Matt- I just called dse they to said the trans down 4 degrees is fine, they want me to drop the pinion yoke 2 degrees(downward). I almost fell out of my chair, seems like a lot of angle to me. I figured moving it up would make it more parallel. I wish I understood why?

Rich

Rich --

There's a ton of info to be found on all of this via the 'net....

The pinion "down" is kind of a counter action to it wanting to climb under acceleration. The pinion wants to climb the ring gear - so with urethane bushings etc - you'd probably be running 1* down maybe even 0* with bushing deflection. Although this varies with length of the control arms etc... and leaf springs used to really allow the pinion to rise..

Todd wrote about working angles - and these are important and often overlooked. There has to be some working angle in the driveline or the bearings in the U joints won't tumble (probably the wrong use of the word but you'll get the picture) and that leads to premature wear.

Most of the engine installs I've seen are typically "down" 3*'s at the tail shaft. So one more degree isn't really that big of a deal.... If I was building a chassis and installing the engine etc -- I'd be trying to get the carb mounting (as measured on the intake) in that 3* mark.

In the end - and someone jump in here if I'm explaining this incorrectly -- is that you want the driveline angle to be equal to or within around 1* of each other (canceling each other out). So it's more a matter of what that "takes" to get it there. There's only one way to get there - and that is to set it up and measure it. Measure it loaded and unloaded. And you for sure want these angles to be less than 3*'s or you'll just chew up your u-joints.

[67ragtp]

Todd - Im a thick itralian, If I lift the trans to zero level at my ride height and drop the pinion down 1-2 degrees, would that be optimal? Im thinking it would be nice to drop the pinion a bit to gain clearance in the very back of the tunnel above the yoke/ pinion.

Thanks Rich

[GregWeld]

Rich --


You're working too much on the angles of the tail shaft vs the pinion angle -- and missing the important steps that are critical.

So --- lets see if I can write this so you can understand.

Engine DOWN 4* -- Driveline DOWN 2*'s -- that "angle" is 4 - 2 = 2* angle

Pinion down 2* - driveline DOWN 1* - that angle is 2 - 1 =1* angle

The one angle is 2* -- minus the other angle of 1* equals the DIFFERENCE is 1*
which would be fine. And this difference can be MAX of 3* (really depends on drive line speeds less for high speed and more for low speed).

So it really doesn't matter what the down angle of the engine is -- or the pinion angle is -- but they MUST relate to each other measuring the angles to get the driveline angle...

Does this make sense?

[GregWeld]

Rich --

Took me a couple minutes to upload a photo to Photobucket -- but this will help you with this set up process.


http://i919.photobucket.com/albums/ad33/gregweld/BuWicked/DrivelineAngle.gif

[Vegas69]

Greg, that diagram is great for a 4x4 but it simply won't work in this application with 4 degrees of driveline angle. The drivshaft slopes up in that scenario which means you add the working angles, NOT subtract. I tried the 4 degree driveline angle with a pinion angle of 2 degrees and it vibrated like hell.

Rich,
I'm saying to have a 2-3 degree driveline angle and say 1-2 degrees up or pinion anlge. (Within 1 degree for smooth runout) It's whatever get's your working angles in compliance at RIDE HEIGHT.

[GregWeld]

The diagram shows HOW TO MEASURE -- not the actual angles to use... It's posted to help him understand what's important to be within 'tolerance' and what needs to be measured. From there - he can make the necessary adjustments for his situation.

I was getting the sense that he's 'hung up' on the up down angles of the two components -- without measuring or taking into consideration - the working angles relationship to the driveline.

I totally get the issues with tunnel clearance etc.

[GregWeld]

Todd ---


I had to chuckle to myself -- thinking -- no wonder I got rid of all my 69 Camaros -- the driveline tunnel is just too damn small!

[67ragtp]

Thankyou Greg and Todd- Appreciate your time explaining it. I think its clear now. My drive shaft should be delivered next week so I will mock it all up and start measuring angles to get it right. If I have to cut the tunnel then it will get cut.

Thanks again Rich

[GregWeld]

There ya go Rich.... And Todd is totally correct and I completely understand the issue with the low stance trying to be achieved etc.

In most cases -- you'd have a down tailshaft angle and a nearly equal UP pinion angle - but if YOU did that your driveshaft would be going UP towards the rear and interfere with the tunnel.

I was attempting to get you to understand that the angles are more than just one goes this way and the other goes that way... so that when you're setting this up you have a firm understanding of the possible issues of vibration and u-Joint problems you'd be creating. I also try to write so that others can read the posts and "get it" as well.

The more we all do this stuff -- the more respect I have for the engineers that design factory cars -- ala the Vette and Camaro etc.... they're getting huge horsepower in these cars and they have fantastic road manors and they're built in mass... Then we come along and try to do all this engineering in our garages. :thumbsup:

[67ragtp]

Think I need a bit more help. Ive got the driveshaft in. It measures .7 degrees going down towards the rear pinion.
The trans is at 4 degrees down
The rear is at 2 degrees down

Front working angle = 3.3
The rear angle is where Im confused do I add or subtract them : 2 +.7= 2.7 deg or 2 - .7 = 1.3 deg

It doesn't seem to bad if the rear angles are added only 1/2 a degree apart. If it goes the other way theres 2 degrees between the two.
Thought?

Thanks Rich

[Vegas69]

Rich, you subtract the angles if they are on the same plane and add them it they are not.

Your scenario:
Add:Your rear pinion is pointing down from level 2 degrees and your drivshaft is sloping up towards the front of the car .7 degrees. They are on different planes so you add them to get - 2.7.

Subtract: Your drivline is pointing down from level 4 degrees and your driveshaft is sloping down towards the rear of the car on the same plane .7 degrees. Your working angle is -3.3.

Now you see why I mentioned raising the tail shaft of the trans. The RIGHT way to do it is to have equal and opposite numbers. You have two negative numbers but that's all you can achieve without slicing and dicing the tunnel. I'd at the very least take it out for a high speed run before you put in the carpet and dynamat if you decide to run it this way. I'd cut the tunnel.

[67ragtp]

Thanks again Todd, Im convinced now. My trans is always going to be down even if its 1 degree, the only way to get them close to equal and opposite will be to bring the rear pinion up slightly over level. Even cutting the tunnel the bell is close to the floor/firewall. Thanks again - Rich

[Vegas69]

I'm a little confused by your post. If you are able to raise the tail shaft of your transmission to achieve a driveline angle of 2-3 degrees, you will then be able to put your pinion on the same plane as the driveline and have equal and opposite numbers. This crap can be very confusing at first.

[67ragtp]

Sorry for the confusion, the transmission is currently extremely close to touching the tunnel, I can not raise it any further. The tail is at 4 degrees down. My last post was simply a speculation of where these angles will end up if I cut the tunnel and raise it.

Rich

[GregWeld]

Rich -- Todd is right - cut and raise the tunnel while you have the chance.

[Vegas69]

Gotcha Rich..

[67ragtp]

Ok the saga continues, I opened the tunnel yes I cried through every cut :(
I was able to lift the tail of the trans almost a full inch from the trans member mount. The best I could get is 3 degrees down, any higher and the trans will be in the dash board. I played with the upper bars in the rear and the yoke is at zero and the driveshaft is at zero. I dont think I can point the yoke up would 1/2 or 1 degree pointing down be ok?

Thanks Rich

[Vegas69]

Rich, I was hoping you could do better than that. Is it a low rider?:unibrow: You need to play with it until you find the sweet spot. Bottom line is if you go 1 degree down, you'll end up with a working angle in the front of about 2.5 and a rear angle of a about 1.5. Those are some really small working angles and the car should run out really nice.

[67ragtp]

Thanks Todd- really appreciate the help, Time to fire up the torch and put bandaids on my tunnel.

The more I look at it, it almost seems like dse built the frame mounts for the motor mounts very high so the engine sits high and needs to slope down more than a typical stock sb or bb. The collectors on there pipes are almost completely above the frame rail. I imagine there were some kind of comprimise's during the design phase. They even sneak the steering shaft between two of the header tubes.

Thanks again- Rich

[Vegas69]

Now you have the room to play. If you need to lower it a little for your steering shaft, etc you have the option.

I've got the DSE sub and I ended up using 302 small block mounts since they put the engine the lowest in the chassis. I realize you have an LS7 but my oil pan is pretty close to the crossmembers. I bet they are at stock height.

[GregWeld]

This thread is funny.... Rich -- Welcome to hot rodding 101.... move one thing half an inch --- and something else is either in the way, or requires modification.