93 2.4L Shadow Part 2 : Project Shadicorn

[turboshad]

Amateur stuff. Rookie mistakes. Post back when you actually do something interesting.

I cut 3 round holes and one more ovally. I'm not sure what else I could do to impress you.

[wheming]

Amateur stuff. Rookie mistakes. Post back when you actually do something interesting.





(just kidding....badass!)

I cut 3 round holes and one more ovally. I'm not sure what else I could do to impress you.

Apparently nothing short of 4 round holes...

[turboshad]

Well it's been a busy fall/winter. In October I sold my house and neglected to buy a new one so everything went into storage. I was expecting to get a bunch of machining done but a project I had promised someone else has been taking way longer than expected partly due to not having a garage to work in anymore. So what's left when everything is in storage and you have no garage? Time to make some animations and 3D printed prototypes.


First off is an animation and prototype of the quickspool valve. I didn't like the what was available on the market as seen in the third picture. The butterfly creates a blockage on the second scroll, when closed the exhaust runs into a flat 90deg wall, and you lose all the advantages of a twin scroll header/turbo combo. Instead I designed a collector to house the flapper. This way there is no blockage when opened, when close there is an angled wall to help direct the exhaust and when opened the flapper becomes the division to retain all twin scroll advantages. The prototype turned out good and I'm excited to try out the real thing.


Secondly I thought I'd make an animation of the suspension system........just because it was fun.

[Wastelands Warrior]

Impressive, as always.

[2.216VTurbo]

In your calculations, how much spring rate would you need for each of those? Follow up question, to avoid having to source out 1500lb springs, do you just change the length of the moment arm thingies (not sure what that component is actually called)? Great idea on the DJ valve Might as well put your name on it right?

[Reaper1]

AJ, it depends on the rocker arm ratio (just like the valve train!). I can't tell and I don't remember, but it looks very close to 1:1...maybe 1.5:1, so it won't be that much. If he were to delve into aero, then this gets tricky.

[turboshad]

In your calculations, how much spring rate would you need for each of those? Follow up question, to avoid having to source out 1500lb springs, do you just change the length of the moment arm thingies (not sure what that component is actually called)? Great idea on the DJ valve Might as well put your name on it right?

Like Reaper said the rocker (moment arm thingy)/motion ratio is what drives the spring rate needed to get the desired wheel rate. The motion ratio is how far the wheel travels vertically vs. how much the damper compresses/extends. So if the damper only compresses 1/2" for every 1" of wheel travel then the motion ratio is 0.5. 3/4" to 1" = 0.75, 1" to 1" = 1.....you get the idea. The Wheel Rate = Spring Rate * MR^2 or inversely the Spring Rate = Wheel Rate/MR^2 when using a desired wheel rate. So the lower the motion ratio the larger the spring needed for a given wheel rate. A smaller MR means less damper travel and allows a more compact setup but the spring rate grows exponentially and also puts more load into the chassis.

After much reading I decided to start with a wheel rate of 90% of the corner weight. My corner weights are all guesses at the moment but I will probably start in the range of 550lb/in up front and 450lb/in in the rear with a MR of 1 on all 4 corners. The nice part of the pushrod/rocker system is you can fine tune the wheel rate without being limited by the available spring rates by adjusting the MR through rocker geometry.........if you have the $$$ to make more rockers and the skills to tell the difference. I'm fairly certain that's not me.