Speedo, etc.

[JJRJR]

Hi guys, quick update. Car has been at a Mopar speed shop this week to help me get it running right and clean up some things that weren't done. Spoke to him yesterday and he ordered a 1" carb spacer. He said in his experience the 383's love more plenum volume and he thought the carb was just too close to the manifold (heat issues, etc.) So, we'll see. Mopar Magazine had a nice dyno test article on the carb spacers and the 1" on a 383 picked up about 5 HP and 5 TQ, so seems like money well spent. He'll also get the Pro Systems carb dialed in right. He has one on his 68 Super Bee. He has over 200 track runs this year and best time is mid 9 seconds. 500 stroker motor, so I assume he knows what he's doing.

Anyway, a couple questions:

1) What is the right speedo gear with 3.91 gears, 4 speed, and P235/79SR15 in front and P275/60R15 in the back? We bought a 37 tooth gear and the speedo seems about 20 MPH too high. Also, the speedo needle bounces up and down pretty good and sometimes gets stuck at 20 MPH or so. I was told it needed grease and it would work itself out. Any thoughts? Should I try a new cable?

2) I realize I'll never get the fuel guage exact, but I'd love to get it closer. Right now it reads way low. With a full tank, it reads a bit above 1/2 tank. Is there something we can do to the float to make this better?

Anyway, the saga never ends. A/C guy told me the new evaporator was bad so I paid him to pull it and send back to Classic Air. They say it's fine and that it must be leaking at some fitting. Paid $1,500 for the Perfect Fit System and probably another $1,500 for installation and I still don't have A/C. Bullshit. I'm feeling bummed about the project recently. I paid a King's Ransome to have this car done and I can't even drive it. Hopefully this will all get worked out. I realize these cars require plenty of maintenance, which I'm fine with, but I can't even get to the point where I can enjoy it and I've had it for like 2 months.

Ok done venting. Thanks for your thoughts and help guys.

John

 

[mac]

if i did the math right should be a white gear according to this chart.

http://www.mymopar.com/index.php?pid=112

 

[JJRJR]

if i did the math right should be a white gear according to this chart.

http://www.mymopar.com/index.php?pid=112

Thanks. I think I'm using the 37 gear. I don't know, maybe the speedo itself isn't right, but I had it all recalibrated.

Thanks,
John

 

[zupanj]

I think the white is a 37 tooth gear unless I miscalculated.

 

[CompSyn]

Try to grease the speedo cable first before buying a new one. After greasing the cable, compare and contrast your actual speedometer/tach reading to this visual calculator, e.g., 1650rpms @ 35mph with 275/60/15 rear tires and 3.91:1 gears: http://vexer.com/automotive-tools/speed-rpm-calculator

Good luck! :cheers:

 

[droptop]

I sure am glad this thread is about your car, and not your choice in swim wear..... :lmao:

 

[69hemibeep]

I sure am glad this thread is about your car, and not your choice in swim wear..... :lmao:

Harold where are you going this :jester:

 

[Basketcase]

I don't want to know.... :leave:

 

[dobie]

Ive tried 3 separate sending units, and bending all of them certain ways after installing them un-bent, in an attempt to get a halfways correct fuel reading. Ive come to the conclusion that I'll never have a correct reading. Unless I find a NOS 3/8" sending unit that is. Mine reads the same way...at a full tank it reads 1/2, and then drops from there rapidly. I just text myself the miles at a fill up, and try to fill up about every 100 miles or so. That way Im sure to never run out.

 

[69hemibeep]

I used an ohm meter and bent mine before I put it in and its pretty close. Empty is empty and each quarter tank is about 5 gallons but it goes past full. If I ever pull it out again Ill adjust a stop for full.

 

[JJRJR]

Ive tried 3 separate sending units, and bending all of them certain ways after installing them un-bent, in an attempt to get a halfways correct fuel reading. Ive come to the conclusion that I'll never have a correct reading. Unless I find a NOS 3/8" sending unit that is. Mine reads the same way...at a full tank it reads 1/2, and then drops from there rapidly. I just text myself the miles at a fill up, and try to fill up about every 100 miles or so. That way Im sure to never run out.

Thanks Dobie, that's kinda what I'm thinking is that it will never be right. Oh well. Seems odd, assuming that they worked out of the factory. Good idea on the texting. Thanks,

John

 

[Roadcuda]

Ive tried 3 separate sending units, and bending all of them certain ways after installing them un-bent, in an attempt to get a halfways correct fuel reading. Ive come to the conclusion that I'll never have a correct reading. Unless I find a NOS 3/8" sending unit that is. Mine reads the same way...at a full tank it reads 1/2, and then drops from there rapidly. I just text myself the miles at a fill up, and try to fill up about every 100 miles or so. That way Im sure to never run out.

I'm not so sure that an original unit will work either Steve. There is one in my car now that appeared to test ok before it was installed in the tank and it STILL, don't work! :brickwall: While the guy who's doing the work has said that we WILL, figure out the problem we haven't done so yet. It may wait until spring now. He really wants to check the gauge itself next to make sure that it's working ok. So we shall see!

 

[Basketcase]

why don't you guys do what I've always done? just buy a car with a working gas guage :huh:
:acme: :acme: :acme: :acme: :acme: :acme: :acme: :acme: :acme: :acme: :acme:

 

[dobie]

That dang gas gauge has irritated me since I started driving her back in 2008. Maybe some day someone will create a fix for it.

 

[mac]

this is the direction i was going to take in the spring. i will fill the tank, and take an ohm reading at the sending unit. then remove the sending unit and place the float at the point of the ohm reading. i would then reference the float location and adjust the arm until the proper full ohm reading is matched (73 ohms empty, 10 ohms full) . then reinstall. that is the plan anyway. i hear that the replacement sending units have a straight linear range as opposed to the stock units that change the windings along the path to compensate for the shape of the fuel tank.