Monday, April 13, 2015

Sometimes you just have to do the work. I've been doing a lot of mechanical work on my car during the last couple of months. I installed a battery hold down clamp. The battery had been just sitting there unsecured an accident just waiting to happen. Though it didn't seem like it had much room to go anywhere. I found that the battery tray was rusted through. I used a plastic tray from one of my old Zs under the battery . I ordered a replacement battery tray from National Parts Depot, one of the advantages of having a popular car- plenty of repop parts. I pulled the front springs to replace the spring perches and isolators. That took care of the irritating screeching sounds. I also replaced the rt.side tie rod end which removed a lot of slop in the steering. I bought a tach and installed it on the steering column. This wasn't done to aid performance driving but to provide me with info on the relationship between the power curve and gearing. The next week I installed poly urethane bushings on the front sway bar mounts. I found that the front bar had been replaced with a 3/4 in. unit that I learned was standard on Mach Ones. I have ordered a new set of KYB gas charged shocks which will be especially useful on the rear end, the existing shocks are some worn air shocks. Even without the new shocks I am pleased with the handling of the car. The lowered suspension and  larger sway bar, combined with the wider and lower profile tires contribute to a good riding, responsive and steady handling. My goal has been to improve the handling without ruining the ride. So far mission accomplished.

 I installed a tachometer on the steering column which has given a much better understanding of how the power curve and gearing interact. I have driven my car on several longer trips, once to my brother's house over a hundred and twenty miles. I drove at an indicated 65-70 mph. and of course most other traffic went screaming past me. Still there was no real problem. I've been using my odometer to keep track of my fuel use. What I discovered is that the motor spins a lot higher than my newer cars. First I calibrated my speedometer using a smart phone app. I discovered that the speedo reads three mph faster at speeds up 45 mph. From 50 mph. on it reads five mph. faster. Cruising at an actual 65mph. I'm turning 2,800 rpm. At 70 mph. I'm spinning at 3,100 rpm. well below the 4,000 power peak. But it does sound kind of busy, though I'm getting used to it. My 96 Mustang GT auto turns 2,200 rpm at an indicated 70 mph. Cruising at what sounds like a comfortable rpm level is an actual 60 mph, at 2,500 rpm. I've noticed that most old six cylinder Mustangs on the freeway are cruising at this speed which feels the most comfortable to the ear. Even V8 cars have trouble cruising in modern traffic flow because they also turn some pretty high rpms, especially if they are running lower performance gearing of 3.50-4.11 in the rear end with a 4 speed manual or three speed auto. Average speeds on the freeways around here are at least 70-80 mph. and that's just the old ladies in Camrys!
Actually my car is geared perfectly to maximize performance from the 155 bhp. six motor. Torque peak of 1,600 rpms is achieved at approx. 45 mph. Max hp will probably be achieved near maximum speed of 95-100mph. as 70 mph. is at 3,100 rpm. and their is still a thousand rpms. left to go. So I'm always in the middle of the powerband and acceleration is always pretty positive ( not really fast, but adequate). I've run it up to 85 mph. and that's at about 3,700-3,800 rpm. This gearing is not the best for fuel economy but it does keep the car from feeling underpowered. Realistic cruising speed is 65-70 mph. but there is still power left for passing and pulling hills.
I took a mini road trip of a little over a hundred miles, up into the Santa Cruz mountains on SR17 to Summit Rd. than took Summit Rd to San Jose Soquel Rd. Then I took SR-1 south to Watsonville then across SR152 e/b over Mt. Madonna to Gilroy then up US101 to San Jose. This trip gave me a chance to experience how the car runs so great up hills.  The torque of the six  feels different from a V8 and the handling on the twisting mountain roads was very positive. The key to safe back road driving with drum brakes is to find a speed that allows you to enjoy the rhythm of the curves without braking hard all the time. Sure you drive slower than all out, but this is safer and much more relaxing. In a modern car the tendency is to rush up on situations then brake hard to slow down abruptly. Do that in an old car and you will experience brake fade. Something I'm sure most younger driver's have never experienced.