Not sure if anyone is interested in this sort of stuff, but here's some pics of the fabrication that went into putting new boing sticks under the Evo.
What started this whole mess:
The old Malaysia's Best™ had more problems than just the fact I mushroomed that rear top mount, the front struts were limited to 6" of travel and were overall just too short for gravel suspension. Plus no matter how you adjusted them, the damping curves sucked.
We started out with 8" 50mm inverted Bilstein universal motorsports struts up front and 8" travel Bilstein ASN shocks out back:
Here's the dyno plots from the rear shocks, although we've revalved them since so that was just our starting point. The reason there's 3 traces on the dyno plot is I bought 3 rear shocks to have a spare and that's how repeatable the valving is on Bilsteins.
The fronts come w/o any sort of mounting on the strut body and the top pins need to be machined to fit the top mount. Here's the machining done on the top pin, what you can't see is the top pin is gun drilled and tapped to fit a Schraeder valve so we can de/pressurize the shock. Never mind the borked bushing, it was damaged in shipping and we got a fresh replacement.
The ears were notched where they meet the shock body and were TIG welded in multiple passes so the entire width of the ear is welded to the body with a fillet on the outside. This give us much more weld length and precludes the need for reinforcements to the ears.
The rears needed a clevis adapter made to mount to the lower control arm.
Jump forward a bit, and here's the dampers test fitted, look at that glorious droop travel up front!
Here's the car on the ground after the springs had been fitted. The car basically settles at ride height and very little spring preload was needed to get the car corner balanced.
I took the car over some 2-foot wide/~8-inch tall speed bumps at 40 MPH and it was glaringly obvious that we needed more rear rebound damping, the rear rebounded too quickly and oscillated about 2.5 cycles before returning to ride height. So the rear shocks got pulled apart and re-shimmed and I tested it out the next day.
The car is completely composed now taking those speed bumps at 50 MPH and the rear settles down in around 1.1 - 1.2 oscillations. Part of that same road is really rough with choppy/broken concrete and from inside the car it feels freshly paved. A big part of that is the zero-preload in the suspension. For how much more compliant the suspension is, it doesn't wallow around and doesn't heel over discernibly more than it did before under hard cornering. Oddly enough, the nicest riding car we own is now the rally car.
So now, more testing. Need to get the car out on some gravel roads and see how it does.
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Basic
Cassandra
Originally Posted by Basic
