dead perch

[GPster]

Things have been on hold for the last couple of days. My son and daughter-in-law, 5 months into a pregnancy with twins, lost them both Sunday morning.  Sometimes it's hard to understand the trials of this life, aint it.  trackster

A lot of times people seem to label their discussions with O/T and apoliguize for using the space to vent. These O/Ts keep me in line with the important things in somebody's life that fall ahead of cars. At the moment my list of things between me and cars is certainly not as devistating as that. I thought maybe I could help with the other problem but all I can do is offer condolences for this one. GPster

[trackster]

Thanks for the concerns. Yeah, something like this sure helps to get the priorities in line.  Son and wife are doing well.  He just bought a 1967 Camaro Z lookalike  two weeks ago and called this evening to see if I wanted to go cruisin' Saturday.  Probably a good idea, to get their minds off of everything, and I never turn down a chance to get the abone out.
trackster

[Dingus]

I have run a dead perch on my car for 15 years or so. It works great for me. I have built some for friends and they like them too. I have built them from old perch bolts and also from new bar stock. The one shown in an earlier post is too long from bolt to spring mount and moves the car off center with the axle. I can e-mail drawings of my design for those interested. My drawing was published in Rod Action some years ago.

[trackster]

Dingus, Thanks for the input. Good to hear from someone who has a lot of experience with the dead perch setup. I would very much like to see the drawing you made.  You wouldn't by any chance remember which issue of Rod Action that is in would you?  I have a complete set and can look in there if you don't want to do the email thing. Thanks.

trackster

[DrJ]

...
The dead perch should go on the same side as your steering box from what I understand.
Makes sense, panhard chassis mounts - front and rear - go on the steering box side.

The second sentence makes sense and therfore makes the first seem wrong.
If half of the spring is now taking the place of the Panhard bar, the other end of the Panhard connects to the side of the axle away from the steering box and the counterpart dead perch would be on that away side too, wouldn't it?

I was thinking about this on the way home from the LA Roadster Show after discussing with the owner, the "dead perches" on both sides of that Candy Brown Model A modified that is on the cover and in R & C this (sept) issue.
He's currently running a very flat spring and hopeing some flex in the hairpins it's mounted in the middle of can take the flex without breaking anything. He said they did that because the front end was all over the place with shackles. I suggested using one dead perch and one shackle and he seemed to think that was a good idea. I suggested the dead perch on the drivers side becasue he has the rear Panhard frame mount on the drivers side like C9 said, but my "road thoughts" tell me the dead perch should go on the same side as the axle end of a Panhard.
Watcha think?

[enjenjo]

That is a neat looking car, but there are many engineering compromises made for the sake of looks.  I saw several things that gave me pause when contemplating driving it any distance.

[Dingus]

Dingus, Thanks for the input. Good to hear from someone who has a lot of experience with the dead perch setup. I would very much like to see the drawing you made.  You wouldn't by any chance remember which issue of Rod Action that is in would you?  I have a complete set and can look in there if you don't want to do the email thing. Thanks.

trackster[/quote
I don't remember the issue. It has been quite a while. I had the drawing so I could print it on a standard piece of paper. I can e-mail it ,I think, if I had your address. I will try to attach it and a pic of it installed and post it tomorrow.

[tomslik]

I have no experience with a dead perch.


The dead perch should go on the same side as your steering box from what I understand.
Makes sense, panhard chassis mounts - front and rear - go on the steering box side.

i've seen 'em both ways on oem stuff, late model 2wd 'burb rear axles  for example

[C9]

...
The dead perch should go on the same side as your steering box from what I understand.
Makes sense, panhard chassis mounts - front and rear - go on the steering box side.

The second sentence makes sense and therfore makes the first seem wrong.
If half of the spring is now taking the place of the Panhard bar, the other end of the Panhard connects to the side of the axle away from the steering box and the counterpart dead perch would be on that away side too, wouldn't it?

I suggested using one dead perch and one shackle and he seemed to think that was a good idea. I suggested the dead perch on the drivers side becasue he has the rear Panhard frame mount on the drivers side like C9 said, but my "road thoughts" tell me the dead perch should go on the same side as the axle end of a Panhard.
Watcha think?

No exactly sure what to think.
Ineresting question and I'm beginning to think it doesn't matter on a street car.

All the dead perches I've seen have been on the drivers side.

A perusal of an old Deuce Factory catalog shows the dead perch on the drivers side of the cover illustration 32 roadster.  (not a photo)

A photo inside the catalog makes it appear that the dead perch is on the drivers side.

I've found the Deuce Factory's information and recommendations to be right on in their catalogs and on the phone.
(Good place to deal with by the way.)

If you look at the dead perch setup as a very short panhard then it does look like it should be on the passenger side.

If you think about having the axle precisely located similar to a panhard so the steering input from the draglink isn't affected then it seems the dead perch should be on the drivers side.

Things could get interesting with a very curved front spring.
Seems that hard bumps there could create a bit of bumpsteer with a dead perch regardless of which side it's mounted on.

Since the dead perch is a circle track racing device and USA circle burners run CCW (or, all left turns) perhaps they ended up on the left side of the car due to requirements for the left turn and keeping the loaded right tire on the ground over the bumpy dirt as an aid to steering traction.
Since that's the way it's traditionally done on the tracks, street dead perch runners probably copied the circle track choice of sides.

My end guess - ambivalent it is - is that it probably doesn't make any difference.

It would be an interesting experiment to try both sides and see what happens.

(When ya do, lemme know.)

[SimonSez]

If you have cross steer, then the dead perch should be on the side as the drag link attaches to the spindle. i.e. the passenger side.

This is exactly the same as you should mount a panhard bar if using cross steer.

If you have a rear panhard bar, it should mount to the passenger side of the rear axle as well, or else the car will be twitchy over bumps.


The guy who built my '32 chassis had previously done some work on a '32 roadster where the dead-perch was on the drivers side. He swapped it to the passenger side where it should be and said that the difference was very noticable and the car was a lot nicer to drive.  This was a cross-steer car.

Based on his recommendation, I am using a Deuce factory dead perch but I am still a few months away from driving it.

[trackster]

Simon, Thanks for the info. I am a long way from the driving stage and would appreciate a report when you get yours on the road.  I have decided to go with the dead perch setup, when I get to the purchasing point for the front end.  I will be using a cross steer (Vega) box and will be running a triangulated 4-bar in the rear, so that should not be a factor.

Thanks to all who have added to my knowledge base.   the learning never ends, but it doesn't seem to keep up with the forgetting!

trackster

[Dingus]

I am not a fan of the Deuce Factory dead perch. It is too long and moves the whole car off center. The shackle ends up being almost straight down and binding. I would suggest you make your own. A friend made his by measuring the angle of the shackle as installed in his car and welded the links to his perch bolt. Looks stock and works great.

[SimonSez]

I had noticed that, but assumed it was a problem with the length of the main leaf in my front spring.

I am going to get a shorter main leaf made which will fix the shackle angle and the off-center problem at the same time.  Making my own dead-perch would be another option, but I spent too much for the one I've got to not use it  

I am not a fan of the Deuce Factory dead perch. It is too long and moves the whole car off center. The shackle ends up being almost straight down and binding. I would suggest you make your own. A friend made his by measuring the angle of the shackle as installed in his car and welded the links to his perch bolt. Looks stock and works great.