Wow suddenly a month’s gone by!
We left off with heading out for the first test day of the year at Streets of Willow CCW. This was a Roadster Cup event so the plan was to have equal parts fun hanging out with friends in that series and doing demo laps in their run group and also to work on initial setup and testing of the changes made during the winter.
On the testing side, I did one shake-down session Saturday afternoon. The car felt stronger than ever on the E85. However, it was showing some issues in the chassis and handling; brakes were touchy and quick to lock up, the car wouldn’t rotate the way I wanted, and it was skipping over bumps (particularly problematic on such a bumpy track). This resulted in quickly flat spotting the set of tires I was on, and here is where my first BIG “thank you” comes along because Saturday night I left the racetrack and drove to Northridge where Moti met me and generously loaned me the wheels and tires right off Creampuff so I could have something to run the car on on Sunday.
Sunday was more of the same struggles. I had to drive very patiently, give myself extra braking distance, reduce corner entry speed until the car would be willing to turn, etc. Tip-toeing around these issues resulted in a best time of 1:19.488, an exact match to the thousandth with the existing Miata lap record.
Hard to be unhappy with matching the Miata record, but I left the event feeling like I have some unfinished business with this track knowing the car wasn’t right. I didn’t even post an update here because I put the car on the rack and immediately started crawling around on it to figure out what was wrong. My second big “thank you” goes to 949Racing/Supermiata who provided a ton of input to help pinpoint the issues and then work through them.
We uncovered several surprises. The largest one was that the new V8R tubular front lower control arms interfered significantly with the downpipes during suspension compression. Easy to see why the car was skipping over bumps and the shocks couldn’t do their job – the suspension was going effectively solid. Not the fault of the arms, obviously I’m the one who put downpipes in the wheel wells, and I had factory arms when I made them. One item or the other had to be altered, and for several reasons I decided it was the arms that had to be reworked. The arms were cut, reshaped, reinforced with extra gusseting, and then capped. With the revisions, the suspension could finally do its thing:
Along with the major interference of the front lower arms, once that item was sorted I launched into a week of examining the suspension and wheel/tire travel. Even though my previous shocks had the same total stroke as these, the XIDAs use more of that stoke for bump travel. As a result, I found several other areas that had more minor interference issues at close to full compression, and we dealt with each item as I found it until suspension range of motion was maximized.
Finally, I’ve been chasing a pad knockback issue caused by significant flexing in the front uprights. Stoptech has been superb in their ongoing support, and to establish whether a floating rotor can solve this issue I’ve switched to Stoptech’s 11″ floating rotors in front.
With things sorted out much better at this point, I went to West End to get re-aligned and properly corner balanced. They got the cross weights exact to the pound.
The Streets of Willow test was invaluable in that it uncovered some big issues to address, but because the suspension wasn’t working right there was zero progress on learning and setting up the new pieces in the system. The next test day at Chuckwalla Valley Raceway will be the first opportunity for this.