Corse I CV joints

**ProtoTipo** · 08-05-2018, 07:37

Steve,
Why are the spring seats at different heights, left to right?

**Strat Fan** · 08-05-2018, 08:20

Originally Posted by hollytree

Are there any known problems with Corse I rear geometry.
Are the CV alignment angles OK with 17" wheels

The other thing you need to look at is the length of the dampers and their position relative to the ride height of the car?
Have you got too much travel which is leading to too much droop.
How high is the drive flange above the bottom of the chassis
How much rear camber are you running etc etc
The right hand shaft is longer so is subjected to less angle change,
As Chris says why is one spring pan higher up the damper than the other?
The shaft looks to be almost parallel to the lower wishbone so the length change through motion should not be excessive.
More information is needed to determine why it has failed

**hollytree** · 08-05-2018, 08:23

Originally Posted by ProtoTipo

Steve,
Why is are the spring seats at different heights, left to right?

More weight on left (gearbox?).
Thats what i needed to set them at for the same clearances in the arches.

**hollytree** · 08-05-2018, 08:27

Originally Posted by Strat Fan

The other thing you need to look at is the length of the dampers and their position relative to the ride height of the car?
Have you got too much travel which is leading to too much droop.
How high is the drive flange above the bottom of the chassis
How much rear camber are you running etc etc
The right hand shaft is longer so is subjected to less angle change,
As Chris says why is one spring pan higher up the damper than the other?
The shaft looks to be almost parallel to the lower wishbone so the length change through motion should not be excessive.
More information is needed to determine why it has failed

Got the suspension all correctly set up a couple of times, and a checked again on Saturday before driving up on Sunday.
Did the springs before I broke my leg. They are 600lb ones. Possibly too soft?
I have that much clearance to stop the tyres hitting the bodywork at the 10 oclock position when cornering hard.

EDIT
Looks like the outer CVs 86mm PCD are ref VKJA 8688 or PJ11N
Inners PJ89N

**Paul** · 08-05-2018, 21:00

I wouldn't have thought 600lb springs too soft - my Corse I has 450lb in the rear which I'm happy with from a ride/stiffness trade-off standpoint (this in on a way without anti-roll bars). I solved the issue of wheels hitting the bodywork in bump by removing (quite a bit of) material from both the arch lip on the clam and the inner arch area on the main tub until I got enough clearance. Now it's the damper bump stops that limit travel. This gave me roughly equal bump and droop distances. Otherwise either my ride height would have been off and/or very little bump and too much droop.

**hollytree** · 11-05-2018, 17:27

Talking to the ever helpful Craig, it is apparent that whilst the double wishbone rear is a great idea, nobody ever actually completed the design in that, the top mounts of the dampers are too high to stop the wheels hitting the bodywork, and I don't think droop was thought about to limit damper extension to stop drive shafts pulling on the CV joints.
AVO can add more bump stops to the top of the damper rods, though really the triangular top damper mounts need to be revised to lower the top damper fixing hole.
AVO are also going to put stops on my damper rods to reduce droop a bit.
I will see where that all ends up.

**strat24v** · 11-05-2018, 18:39

Rally cars used a cable to limit droop.

**gtmpaul** · 12-05-2018, 08:35

Originally Posted by strat24v

Rally cars used a cable to limit droop.

My brothers Astra rally car has them on the rear to stop the beam dropping to much and the springs coming off their seats.

**john** · 12-05-2018, 11:59

Yes, the Corse I design seems always to have been in a state of flux. You can see differences in virtually all photographs of the early cars and not just between the Honda and Alfa engined cars. Damper and spring lengths were never sorted properly and those triangular top mounting plates front and rear just added to the confusion. Lionel just ordered part numbers supplied by Hugh Carson with out much thought as to if they were right or not. IIRC we tried different lengths of damper on Micks first car but he resolved matters with extra bump stops in the end. Steve Ellis fabricated new damper mounts front and rear.
I guess the lesson is for anyone building to check suspension movements very thoroughly with the springs off to make sure nothing binds up or reaches the limit of its travel throughout its range.
Looks like you have the part numbers for new joints now Steve? Shaft length is another matter.

**hollytree** · 12-05-2018, 15:40

The original inner and outer joints both had single circlips on the drive shaft with 2 holes in the end for circlip pliers.
The new inner - Alfa - came with the same style circlip.
The new outer - Ford - came with something that looks like a concave thrust washer and a circlip without any holes.

Does anybody know what I do with these 2 parts, or do I just replace the original circlip?

EDIT
It is for certain applications, but not how I will be using it. So original circlip back on.