TonyG

2 things...

1) your spherical rear A arm bushings need to have the mounting holes elongated so that you can get the caster you need.

2) your rear suspension. While the bearing for the spring plate is nice... it doesn't fix much. What you need to do is to create a new spring plate connected to a rod end that is mounted where your bearing is now located. This allows two things: a) it allows you to correct the roll center for lowered cars. b) it allows you to have toe adjustments made quickly and easily without affecting camber.

Take a look at what Vision did (Kokeln) with their rear aluminum torsion carrier.

Even if you don't make the aluminum torsion bar carrier... you should do what they did for the spring plate.

Do that and I'll buy the first one :-)

If those guys were still making them I wouldn't even be writing this... I would own one.


TonyG

333pg333

I'll take a set too.

David Floyd

Antti, I understand you were testing larger bore bolt on master cylinders for the 944, any results ?

333pg333

Ouch!! Bet they weren't giving them away at the gate$...

Antti, what did you think about Tony's point in post #26?

ant771

1) There is no space for doing the modification to a bushing. It's easier to modify the rear axle mounting points.

2) Adjustable spring plate is very hard to design to be used with the stock rear axle and spring plate cover. The only way to design adjustable spring plate is to also build the rear axle or the spring plate cover from scratch. I would say this was the reason why Kokeln didn't produce just the spring plate set.



About the 9P44 project car.. Look's like I need to build a tube frame chassis. Therefore I can't install the cast iron rear axle to it - the custom rear axle will be a solid part of the chassis. It's much easier and better construction to add a mounting points for trailing arm inner heads and spring plate ends straight to the tube frame axle. This design will allow a full adjustment for all the rear mounting points. When I will be working with this I could make a prototype of the rear axle for Porsche chassis too.


OT: Tony, did you get the new brakes installed?

I do have a few drawings and cad pictures but no prototypes have been produced.

TonyG

Nice. Where did you get them?

TonyG

ant771

A former car part dealer had bought these as an Audi transmissions in the 90's. Unfortunately I don't know more about the origin.

TonyG

I'm currently having a Boxter ABS plumbed into the car, which is about finished. Over the next weeks the ABS gets wired up. Once I get the car back, I will install the big brakes.

The big brake conversion is sorta taking on a life of its own as I've had to buy new steering knuckles (non M030) and non M030 Racer's Edge hubs. I could have machined down your adapters to use the current M030 Racer's Edge hubs but I figured that I had 5 years of track use on them and I'd be better off using new hubs given that I run so much front rubber.

Anyway, I have both the front and rear calipers, rotors, and pads, the new steering knuckles, your caliper adapters, new ducted backing plates. I'm just waiting on new front wheel bearings and new front wheel studs.

As far as the rear suspension comments.... couldn't you just cnc new spring plate covers that give you the mounting points for the Kokeln type spring plates? You wouldn't be able to adjust the roll center, but you could at least get the the adjustable spring plate (which would make a huge difference alone).

TonyG

TonyG

disasterman

Remember that the Kokeln also moves the mount axis up one inch which helps significantly with a lower car. I have the Kokeln rear suspension carrier and it works quite well. I can adjust toe to the millimeter in a few minutes.

TonyG

For those who don't know...

The reason the Kokeln rear setup moves the trailing arm mounting points up is to reduce the angle of the trailing arm caused by lowering the car. It's an effort to get the rear trailing arm back to its non-lowered angle.

As the trailing arm moves through it's arc, the toe will change... aka bump steer.

Where the car rests in that arc will determine the bump steer characteristics in the suspension from that point.

Moving the pickup points up, to some degree (I don't know to what degree because I've not measured it) gets the trailing arm back to the stock non-lowered angle, which will result in it having the bump steer characteristics that the factory designed it to have.

Also note that you can't just move up the suspension pickup point at the spring plate cap. You also would have to move it at the inner trailing arm mount point as well (the same amount) (which the Kokeln piece does).

TonyG

333pg333

Antti, it seems a shame to go to all the trouble of a tube frame car and stick to trailing arms? Are you building this project car as a test bed for your 944 parts ?

Dubai944

It mystifies me why no one else has bothered to produce a similar fabricated part to the kokeln carrier. People talk about them like they are made of unobtanium and impossible to reproduce. I't can't be hard to fabricate something similar. I don't see any rocket science in the design.. am I missing something?

Chris White

Some of us have made similar setups….the problem is that when you get to that level of modification everybody wants something slightly different and some people insist that is be completely bolt on. The set up that I like for track only cars involves removing the torsion bar carrier and welding in the new tube steel carrier to the chassis. The set up I use has a 3” height adjustment range for the inner and outer trailing arm mounts (stock to 3” lower). It’s the only way to go if you want to run larger diameter tires in the rear – and that really helps with the widebody high power stuff. I made the jig for that about 4 years ago!

I like the other stuff! Are you planning to use the Audi block in the 944?

95ONE

Tony, while it is painted an aluminum color, it is my understanding that the Kokeln bar that takes place of the torsion bar carrier is actually a square steel tube. Not aluminum. Pretty sure, but not confident. Arms are billet aluminum.

Chris. I'm running out of Custom fab energy here and Planned on doing this myself. But the time and energy are fading. Please PM me a price for one. I may just buy it from you.

Dubai944

Interesting Chris. I figured there must surely have been a few custom solutions tried before! A carrier with adjustable mount points welded in place and tied through into the cage sounds like the most sensible solution short of going to a space frame and custom supension. Will look at doing that.