Re: Ultramatic normal behaviors
|
||||
---|---|---|---|---|
Home away from home
|
There is only the torque convertor's 2.5:1 multiplication to assist takeoff, so you are never going to leap off the line in high range. Because of the limited torque multiplication, two factors loom large in how an Ultramatic feels: first is rear axle ratio. Your car has a 3.23, the 52 a 3.54 or possibly even a 3.9. That makes a big difference in feel. Second I have found that when these cars are in any way off tune the decreased low speed torque is very noticeable and you have to give a lot of gas. That may come from low compression, late timing, or even how the throttle linkage is adjusted.
Of which, direct engagement speed is a function of throttle opening played against road speed. If the linkage down to the trans is adjusted "high" the trans will upshift later. Of course this is also true if you are giving more gas. 35 is rather high for a normal upshift so you might want to shorten the pull rod to the carb a bit. According to contemporary roadtests, the cars were of course quicker if you started in low and shifted to high, but not as much quicker as one might think: somewhere between 1.5 and 3 seconds on the 0-60. But the feel is very different especially at takeoff. Over in Studebaker world many people are incensed that the V8 cars start in second gear in normal driving and complain about takeoff. In actual point of fact none of my cars has the slightest trouble keeping up with the stoplight derby, but neither will you get the burst of acceleration at the outset that makes you feel the car is powerful. Even a Henry J will snap your neck if you play it right but the sensation is very short lived.
Posted on: 2023/10/18 6:48
|
|||
|
Re: Ultramatic normal behaviors
|
||||
---|---|---|---|---|
Home away from home
|
I had no idea that the rear axle ratios were different between the two years. I just assumed they were all the same. That would definitely explain some of the difference I felt.
Regarding the tune on the Panama, compression is good across all (145-155), timing should be on but I might need to double check, and I've never adjusted the throttle linkage. The car does seem to run rich (based on plugs) though the mixture screws have been adjusted using a vacuum gauge. I'll look into adjusting the pull rod to the carb to lower the speed for direct drive. It seems to "hang" a bit as it stands now before it drops into direct. I've tried the starting in low and switching to high, and was rewarded with a loud and violent clunk. Haven't done it again since.
Posted on: 2023/10/18 11:54
|
|||
|
Re: Ultramatic normal behaviors
|
||||
---|---|---|---|---|
Forum Ambassador
|
Quote:
I've tried the starting in low and switching to high, and was rewarded with a loud and violent clunk. Haven't done it again since. The original Ultramatic was never designed for this manual shift that many were trying to do at the time. The completely unsynchronized actions between low band releasing and high range clutches engaging was one of the issues Packard faced in having one of the first automatics yet still trying to be competitive with other brand transmissions that were newer and coming into use. They actually issued a service kit to try and tame some of the unPackard like problems with the shift but stopgaps were never really successful. You can read about the kit in the Sept, 1953 issue of the Service Counselor. A later article revised the size of the restriction pin to address an issue the kit introduced. If you do try the manual shift again let off on the gas until the high range clutches are fully engaged. Kind of defeats the purpose of the shift but does save wear and tear on the trans. The GearStart was the end result of all the work to get a real shifting transmission but many feel it was sort of rushed into production and suffered from a lack of testing. Work continued in 55 units renamed the Twin Ultramatic but the high HP and high torque engine didn't help the situation since they added other things to try and tame. Many of those added issues didn't get addressed until the 56 models and by then, while the trans was becoming fairly decent, the time was over.
Posted on: 2023/10/18 12:33
|
|||
Howard
|
||||
|
Re: Ultramatic normal behaviors
|
||||
---|---|---|---|---|
Home away from home
|
Quote:
Maybe the problem is you didn't drop a 374 in it.
Posted on: 2023/10/18 13:21
|
|||
1955 400 | Registry | Project Blog
1955 Clipper Deluxe | Registry | Project Blog 1955 Clipper Super Panama | Registry |
||||
|
Re: Ultramatic normal behaviors
|
||||
---|---|---|---|---|
Home away from home
|
Quote:
Lol. I'm not expecting a speed demon here, but was just surprised at the difference between two cars with the same engine and transmission.
Posted on: 2023/10/18 13:42
|
|||
|