Nissan 370Z Forum - View Single Post

TBatt · 08-15-2016, 11:46 AM

Here are the latest updates on my Z.

Saturday I spent most of the day trying to fix the toilet by working on the sink.......what I thought was a boost leak has turned out to be a belt slip issue. After working on the SC to IC plumbing for several hours trying to get the 45 degree coupler to work I gave up and went back to my 90 degree way and then did a leak test. I found that I had to really crank down on one of the clamps to get it to stop leaking. It wasn't a big leak and it didn't show up until I got to 7 psi.

What I did to perform the leak test was to disconnect the 90 degree coupler from the SC and rotate the coupler 180 degrees so I could put my homemade leak tester on. The leak tester is made from PVC pipe and electrical tape. The electrical tape was used to build up the end of the pipe so that it would stay clamped to the coupler. It worked like a charm. To introduce the air I used a spare air hose coupler I had and simply drilled a slightly undersized hole for it and then screwed it into the end cap. Next I used some 15 minute epoxy to lock the fitting to the cap by putting epoxy on the threads that were protruding on the inside of the cap.

Next I closed the regulator on my air compressor and put the hose on to the leak tester. I then turned on the car (did not start the engine) so that I could monitor the boost gauge. Then I slowly turned up the air pressure until I found the leak which took about 7 psi for it to show up.

After I had determined that I no longer had any leaks I put the new Fast Intentions tow bar on. It fit perfect.

By this time the sky was not looking very friendly so I knew that if I wanted to get a data log run in I had better do it quick. Drove the car to get it up to temp and then did a quick 3rd gear run. Got back home and dumped the log data and saw that the boost was STILL not where it should be. I started studying the log data and saw that the boost had built up pretty linear up to about 6K rpm and then started flatting out at 7 psi and then as the rpm increased the boost actually started to go down. By the time the engine was at 7K the boost had DROPPED to 5 psi. This looks like a belt slip issue.

I was going to spray the serpentine belt with some CRC belt dressing to try again but the rain had started. Looked at the radar and saw that it was going to be staying for awhile. I'll try again sometime this week and see if the belt dressing helps.

My next battle plan is to use Pauly Z's idea of using an additional idler to get more wrap of the drive belt on the SC jackshaft pulley. As soon as I get the items needed I'll be doing that mod.