GT Dash Pix, When Underway

[JoeHall]

We took a 392 mile jaunt in the GT today, and I captured some pix while the wife was driving, and while I was driving. One is of the new AC unit temperature which, when set on low fan speed, would pull down to 29F degrees. Outside temps were 84-87 for most of the drive. The other is of the dash, with wife tooling along at an indicated 70 MPH. Then is a pic of the speedo and GPS, at an indicated 76 MPH, at an actual 72, per the GPS. This is a lot closer than most OEM Hawk speedos I've seen, but I like to get them closer. Since the odometer is only 2-3 percent off, I will leave the pinion gearing alone, and simply calibrate the speedo head. Just one more thing in the round-2-it file.

[brngarage]

Joe, you better take a jacket with you when you turn on the A/C. Brrrrrrrrrrrr.

[StudeNewby]

Now that's what I call air conditioning!

[alaipairod]

Joe.........What freon are you running in your a/c..........??

[JoeHall]

Joe.........What freon are you running in your a/c..........??

I use WalMart 134A, left over from a couple of years ago. I heard it was going up, so bought about 24 cans of it, and still have several cans left over.

I use the OEM condenser, and have always preferred them over the more modern, smaller ones. It held 39-40 degrees, with the fan on high speed. On high, the air reaches all the way to the back seat, with the two center vents blowing straight back and between the GT's bucket seats. Yep, pretty pleased with the current set up.

[TWChamp]

Hope your cans of spare Freon hold up better than my cans of R-12 did.
A couple of my cans rusted and lost the Freon after about 8 years.

[wdills]

Joe, I love the style of the under dash unit you installed. I wish I had seen that before I installed the Vintage Air Mark IV unit in my Hawk. The styling of your looks much more period correct.

[JoeHall]

Joe, I love the style of the under dash unit you installed. I wish I had seen that before I installed the Vintage Air Mark IV unit in my Hawk. The styling of your looks much more period correct.

Thanks. Funny you mention a Vintage Air Mark IV. I recently bought one for the 56J, but have not yet had time to install it. The 56J, with front bench seat, has always been more difficult to get cool air to the passengers in the rear seat. The GTs have a wide gap between the bucket seats, and the air will blow rearward to the back seat, if the evaporator has a strong fan (as this one does). I am just hoping the Mark IV will do a good enough job, but not expecting rear seat passengers to ever be comfortable, especially if outside temps go above 90.

The 56J has had an auxiliary heater under the driver's seat, and it works great. So no need for a heater in the AC unit. Since the late 1990s, I have had a 1966 Mopar evaporator in the 56J. It looks identical to 66 Stude, but different script on bottom. However, the fan has became way too weak, over the decades. How well does the Mark IV cool? I could not find any specs on it, so went ahead and took a chance.

[RadioRoy]

70 MPH at only 2200 RPM? That's great! What transmission and rear axle ratio is fitted?

[JoeHall]

70 MPH at only 2200 RPM? That's great! What transmission and rear axle ratio is fitted?

Despite the indicated 70 MPH, its actually about 66 MPH at 2200 RPM (speedo error). But as for your question, if you look closely at the one pic, you will see a clue in the shift quadrant (P-R-N-D-L), which is from a mid-60s Impala. This Stude has a 700R transmission, with 3.54 rear gears. I have tried many rear end ratios with overdrive transmissions, and have found 3.54 to be the best match nowadays, for V8 Studes.

[wdills]

My Mark IV does a decent job, but it never gets the interior cold on a hot day. It makes it bearable on a 95 degree day but that is about all I can say. It will freeze your arm or leg or whatever the vent is pointing at, but your other side is still too warm. This may just be a limitation of any under dash unit. Everything else I have ever owned either had no AC or AC with vents both in the center and the outside edges of the dash.

[56GH]

Despite the indicated 70 MPH, its actually about 66 MPH at 2200 RPM (speedo error). But as for your question, if you look closely at the one pic, you will see a clue in the shift quadrant (P-R-N-D-L), which is from a mid-60s Impala. This Stude has a 700R transmission, with 3.54 rear gears. I have tried many rear end ratios with overdrive transmissions, and have found 3.54 to be the best match nowadays, for V8 Studes.

Which brings up a question for me. Ideally, what should the rpm be for a 1962 GT with a 289, Flightomatic and 3.31 rear end be at, say, 70 mph? It seems to me like my engine is "screaming" at 70 mph and I don't know the accuracy of the replacement electronic tach sender from S-I.

[JoeHall]

Which brings up a question for me. Ideally, what should the rpm be for a 1962 GT with a 289, Flightomatic and 3.31 rear end be at, say, 70 mph? It seems to me like my engine is "screaming" at 70 mph and I don't know the accuracy of the replacement electronic tach sender from S-I.

With TC slip as a variable, and 205/75 tires, I am gonna guess around 2900-3200 RPM at 70 MPH on level ground.

[56GH]

Thanks, Joe. I'm running 215 radials and my speedometer reads a 2-3 mph error anyway. The various radar traffic devices that I go by once in a while indicate I'm going 30 mph when I'm showing about 28 mph on my speedo.