Been researching on the net about driveline angles and come accross this article.

I've noticed that a few members have had the problem of flywheel bolts coming loose, maybe this might have something to do with it.

Gary

http://www.roddingroundtable.com/tech/articles/driveline.html

Yeah,
A good article. The velocity change in a uni is not commonly known, but as they say in the article, it is very important to get the phasing correct so both joints are increasing and decreasing speed at the same rate, at the same time. I have never thought of it in terms of flywheel blts but you could be onto something here .


To remove a lot of the angular change, some luxury saloons (300C ) and 4WD'S use a double Cardan joint (double cojoined iniversals) at each end of the shaft. This halves the joint angle experenced by each joint. These are a smoother tougher drive shaft but are very expensive to make.

I have a double jointed tailsharft in my dirt car, It's out of a 180B ( wagon I think ) It's the same length as all the other a series tailsharfts and I had to use it cause the car is an auto and a 180b man spline fits an a series auto. Hi-tech and I didn't even know it.
So there

At the moment I am modifying the sump to lower the engine so as to have the motor sitting at 1deg neg.(gearbox output lower) and the pinion angle at 1 deg neg. (with no passengers in the car) so when the pinion angle is in its working degrees (1 deg neg- 0 deg) I will be in the optimum set up to achieve a good "phase".

Feral,
Can you see any problem with having the engine sitting near horizontal, I've looked at oil drainage/return. I"ll be putting a "wing" on the side of the sump to compensate for any volume I have trimmed off the original profile.
Gary

or what about changing the pinnion angle by re-positioning the diff by its mounts, platforms etc ? surely that would be work bit easier than cutting up the sump make new mounts to lower the engine?
anyways the only A series ive seen come loose was tightened and the bolts worked loose as they had no form of theard sealant on them if i were building a powie A series I would look into dowling the flywheel aswell

Hello monkeywrench and welcome to the site. Where are you from? Fill out your profile so we know abit about yourself.

Your question about changing the pinion angle is a good one, my answer is I have been adjusting the pinion angle (via the adjustable top and bottom four links I have made up) over the last couple of rallies I have been in. The changes I have made to this area have been by far the most significant changes I have made to the rally car with respect to getting power to the ground.

Prior to the changes the pinion angle was at 4 deg positve, I thought the car handled pretty good with that. After fitting the adjustable link arms and setting the pinion angle to 1 1/2 deg neg. I was completly amazed at the difference to the whole car it has made, it really is truly amazing.
No axle tramping off the line, the hook up is instant, before I would have to wait till after the apex of the corner before I booted it now I can literally attack corners before entering them knowing full well the arse end is going to stick to the road. This modification alone has given me nearly two seconds per Km and best of all it has given me more confidence in the cars handling.

So as far as I'm concerned if making the gearbox and the pinion angles is a lot of work but if it give me a chance of getting more power to the ground its very well worth the effort.

so this 4 link set up is in what sort of car as im trying to picture in my head how your setup would look. also with vechiles that run a standard setup say a 1200 coupe with just a panhard rod added and no major changes( slick's fitted) you get massive spring wind and alot of nastie thing's start to happen at the rear of the car.

Matty, Sorry I should have mentioned before its in a Sunny (a few photos of it in my photo album)

I'm not the best person to discuss leaf spring set ups with on this site.

I do know though from what I have read that is on leaf spring set ups people usually set the pinion angle somewhere between 4-7 deg. neg. to allow for spring wind up.

Gary
Edit: I have just put a photo in my album of the T & B adjustable link arms.

I would be inclined to think the noticed difference in grip, is actually a result of the changed 4 link arm lengths and the way they make the vehicles body supply load to the wheels. And the changed pinion angle is just an unwanted result of adjusting the arms.
I believe you could correct the pinion angle by cutting the link arm mounts off the diff and rewelding them with the pinion set on the correct angle. And still have good grip with good pinion angle.