After getting the car back on the road I discovered a slight vibration that would start around 40-50 mph growing more noticeable as speed increased to 60-70 mph. It was unaffected by varying rpm. I started troubleshooting with a trip to a shop to have the wheel balance checked. That did not eliminate the vibration. I then took the car back to the shop that routinely works on my car, HB Motorwerks, to see if they could diagnose the problem, their assessment was that it was related to the driveshaft. I hate this type of troubleshooting where expensive and time consuming parts need to be swapped out. At the moment I have a re-manufactured OEM two piece driveshaft being delivered from Wholesale Import Parts. While I’m hopeful that this corrects the problem since if it doesn’t it will mean buying additional parts and more work changing them out, if it does turn out to be the Driveshaft Shop single piece driveshaft I’m going to be irate at wasting money trying this driveshaft.
All posts by Jeff
Alignment troubles
I finally got the car transported over to a shop, Racewerks in Virginia Beach, that does alignments. They’d aligned the car before when it was Santorin, had the KW V3’s, and stock upper control arms. I was now having it aligned with Stern adjustable upper control arms and I was interested in seeing how the alignment changed with the new UCA’s. On alignment number one I took the data sheet home and compared it to the previous alignment, huh there was quite a bit more camber this time, an amount that Stasis considered only suited for at the track. My first thought was that maybe the shop had mistakenly felt that I wanted a super aggressive setup, after calling them and raising my concern I learned that there were two people doing the alignment on my car, and the mechanic who was doing the front was a new guy who didn’t realize that the uppers were adjustable.
Back to the shop the car went. This time I got a call informing me that they couldn’t get the adjustable upper control arms to adjust. They said they were going to take the arms off and see what they could do. Long story short, look up galvanic corrosion, that’s what the culprit was. The adjustment nut was seized up. They did their best to get some semblance of an alignment made, but without being able to adjust the UCA’s the alignment was not where it should be. I purchased the UCA’s used, though they looked to be in like new shape the metal and aluminum in contact had frozen together. I figured there was nothing much I could do with these, but when the people at PureMS learned of my problem they offered to rebuild them for the cost of parts. Big thumbs up for PureMS since there was no responsibility for them to service a Stern part that somebody had purchased used.
Now I need to find the time to pull the UCA’s off to send to PureMS, then once they are fixed it will be back to the shop hopefully for the last alignment for a while.
Composite Pressure Loss 2
Based upon some of the latest flow testing I have updated the composite pressure drop chart. The goal of the chart is to show the relative contributions of various components to the overall pressure drop experienced pre and post turbo and help guide purchase decisions.
Adding the flow testing of the intake manifold is problematic due to the way that air flows through the part when operating. Tests on the flow bench consisted of single runner and all runners open, neither of which accurately reflects the operating conditions on the car. As a compromise the average flow through a single runner at 250 CFM was used to establish the pressure loss value used on the chart. Be aware that the magnitude of contribution from the intake manifold could be quite a bit different than shown below.
