Engine Vacuum, and Gearing...
#1
05-22-2011, 11:18 PM
Engine Vacuum, and Gearing...
This may seem like an odd grouping of thoughts, but...
Does anyone have base dyno data for a first Gen 5.9, so I can overlay it with my gearing and speed chart and see where my optimum power would be? I realize that my own dyno data would be more valuable, but I don't even know where to start to find a dyno and run the D, that and the expense.
I have installed a Vacuum gauge and was wondering if there was a chart (I really like charts) that would give me an indication of what the vacuum pressure should be. It'll sit at 16 while at idle, go up to 20 or so when I rev, and while cruising at 2k rpm will ride at 'bout 10, then with any load, (hill or stiff breeze) it will drop to nothing...
I put this chart together right after I bought the D, and can adjust the variables (Transmission gear ratios, Differential gearing and Tire size) pretty easily, If anyone wants it I can put it out there... It's an open source .ods file, but could be saved as a Microsoft .xls
Does anyone have base dyno data for a first Gen 5.9, so I can overlay it with my gearing and speed chart and see where my optimum power would be? I realize that my own dyno data would be more valuable, but I don't even know where to start to find a dyno and run the D, that and the expense.
I have installed a Vacuum gauge and was wondering if there was a chart (I really like charts) that would give me an indication of what the vacuum pressure should be. It'll sit at 16 while at idle, go up to 20 or so when I rev, and while cruising at 2k rpm will ride at 'bout 10, then with any load, (hill or stiff breeze) it will drop to nothing...
I put this chart together right after I bought the D, and can adjust the variables (Transmission gear ratios, Differential gearing and Tire size) pretty easily, If anyone wants it I can put it out there... It's an open source .ods file, but could be saved as a Microsoft .xls
#2
05-23-2011, 09:16 PM
Hall Of Fame
Here: http://dodgeram.org/tech/gas/specs/5_9v8.htm
http://dodgeram.org/tech/gas/specs/f...97-59L_hpx.jpg
I would say it's at 2800 RMP for optimal pulling RPM. Now I am talking about the best of the best, not the best for your engine or trans. What would be a good RPM would be around 2200-2400 RPM.
http://dodgeram.org/tech/gas/specs/f...97-59L_hpx.jpg
I would say it's at 2800 RMP for optimal pulling RPM. Now I am talking about the best of the best, not the best for your engine or trans. What would be a good RPM would be around 2200-2400 RPM.
#3
05-23-2011, 11:47 PM
Hydra,
Thanks I needed that!
BTW, did you happen to have any thoughts on my vacuum pressure question, I think that I am trying to figure out if I have a belly pan gasket leak... I don't know where else my vacuum would go. I don't think I have leaks. Unless the motor really is producing no vacuum under load!
Thank you,
Thanks I needed that!
BTW, did you happen to have any thoughts on my vacuum pressure question, I think that I am trying to figure out if I have a belly pan gasket leak... I don't know where else my vacuum would go. I don't think I have leaks. Unless the motor really is producing no vacuum under load!
Thank you,
#4
05-24-2011, 07:52 AM
THE ULTI-MOD
#5
05-24-2011, 09:56 PM
Hall Of Fame
#6
05-25-2011, 11:20 AM
Hydra,
That is exactly the reason that I got rid of my JGC, the vacuum would run out and I would not have any air moving through the panel...
I was trying to figure out a baseline for where the Vacuum should be. I was thinking that it was low, and maybe my belly pan gasket was at fault... I don't want to open it up if I don't have to!
Thank you
That is exactly the reason that I got rid of my JGC, the vacuum would run out and I would not have any air moving through the panel...
I was trying to figure out a baseline for where the Vacuum should be. I was thinking that it was low, and maybe my belly pan gasket was at fault... I don't want to open it up if I don't have to!
Thank you
#7
05-27-2011, 12:48 PM
Hall Of Fame
Your Plenum gasket sounds fine, the main issue is your under a big load so the throttle plate is open longer and with this the vacuum is lesser resulting in a low vacuum thus creating the issue. This is why they went to electronic actuators in the 2000-2003 design. You could check the check valves.
VACUUM RESERVOIR
The vacuum reservoir is mounted to the underside
of the cowl plenum cover/grille panel in the right
cowl plenum area. The cowl plenum cover/grille panel
must be removed from the vehicle to access the vacuum
reservoir for service.
Engine vacuum is stored in the vacuum reservoir.
The stored vacuum is used to operate the vacuumcontrolled
vehicle accessories during periods of low
engine vacuum such as when the vehicle is climbing
a steep grade, or under other high engine load operating
conditions.
The vacuum reservoir cannot be repaired and, if
faulty or damaged, it must be replaced.of the cowl plenum cover/grille panel in the right
cowl plenum area. The cowl plenum cover/grille panel
must be removed from the vehicle to access the vacuum
reservoir for service.
Engine vacuum is stored in the vacuum reservoir.
The stored vacuum is used to operate the vacuumcontrolled
vehicle accessories during periods of low
engine vacuum such as when the vehicle is climbing
a steep grade, or under other high engine load operating
conditions.
The vacuum reservoir cannot be repaired and, if
VACUUM SYSTEM
Vacuum control is used to operate the mode doors
in the heater-A/C housing. Testing of the heater-A/C
mode control switch operation will determine if the
vacuum, electrical, and mechanical controls are functioning.
However, it is possible that a vacuum control
system that operates perfectly at engine idle (high
engine vacuum) may not function properly at high
engine speeds or loads (low engine vacuum). This can
be caused by leaks in the vacuum system, or by a
faulty or improperly installed vacuum check valve.
A vacuum system test will help to identify the
source of poor vacuum system performance or vacuum
system leaks. Before starting this test, stop the
engine and make certain that the problem is not a
disconnected vacuum supply tube at the engine vacuum
source or at the vacuum reservoir.
Use an adjustable vacuum test set (Special Tool
C-3707) and a suitable vacuum pump to test the
heater-A/C vacuum control system. With a finger
placed over the end of the vacuum test hose probe
(Fig. 6), adjust the bleed valve on the test set gauge
to obtain a vacuum of exactly 27 kPa (8 in. Hg.).
Release and block the end of the probe several times
to verify that the vacuum reading returns to the
exact 27 kPa (8 in. Hg.) setting. Otherwise, a false
reading will be obtained during testing.
VACUUM CHECK VALVE
in the heater-A/C housing. Testing of the heater-A/C
mode control switch operation will determine if the
vacuum, electrical, and mechanical controls are functioning.
However, it is possible that a vacuum control
system that operates perfectly at engine idle (high
engine vacuum) may not function properly at high
engine speeds or loads (low engine vacuum). This can
be caused by leaks in the vacuum system, or by a
faulty or improperly installed vacuum check valve.
A vacuum system test will help to identify the
source of poor vacuum system performance or vacuum
system leaks. Before starting this test, stop the
engine and make certain that the problem is not a
disconnected vacuum supply tube at the engine vacuum
source or at the vacuum reservoir.
Use an adjustable vacuum test set (Special Tool
C-3707) and a suitable vacuum pump to test the
heater-A/C vacuum control system. With a finger
placed over the end of the vacuum test hose probe
(Fig. 6), adjust the bleed valve on the test set gauge
to obtain a vacuum of exactly 27 kPa (8 in. Hg.).
Release and block the end of the probe several times
to verify that the vacuum reading returns to the
exact 27 kPa (8 in. Hg.) setting. Otherwise, a false
reading will be obtained during testing.
VACUUM CHECK VALVE
Two vacuum check valves are installed in the
accessory vacuum supply line in the engine compartment.
One check valve is located near the vacuum
fitting on the power brake booster. The second check
valve is located at the heater and air conditioner
take-out of the accessory vacuum supply line. The
vacuum check valves are designed to allow vacuum
to flow in only one direction through the accessory
vacuum supply circuits.
The use of the vacuum check valves help to maintain
the system vacuum needed to retain the selected
heater-A/C mode settings. The check valves will prevent
the engine from bleeding down system vacuum
through the intake manifold during extended heavy
engine load (low engine vacuum) operation.
The vacuum check valves cannot be repaired and,
if faulty or damaged, they must be individually
replaced.
accessory vacuum supply line in the engine compartment.
One check valve is located near the vacuum
fitting on the power brake booster. The second check
valve is located at the heater and air conditioner
take-out of the accessory vacuum supply line. The
vacuum check valves are designed to allow vacuum
to flow in only one direction through the accessory
vacuum supply circuits.
The use of the vacuum check valves help to maintain
the system vacuum needed to retain the selected
heater-A/C mode settings. The check valves will prevent
the engine from bleeding down system vacuum
through the intake manifold during extended heavy
engine load (low engine vacuum) operation.
The vacuum check valves cannot be repaired and,
if faulty or damaged, they must be individually
replaced.
VACUUM CHECK VALVE
(1) Remove the vacuum check valve that is to be
tested. The valves are located in the vacuum supply
tube (black) at the power brake booster on the left
side of the engine compartment, and in the heater
and air conditioner vacuum take-out of the vacuum
supply tube in the engine compartment. The vacuum
check valve must be removed in order to perform the
following tests. See Vacuum Check Valve in the
Removal and Installation section of this group for the
procedures.
(2) Connect the test set vacuum supply hose to the
heater-A/C control side of the valve. When connected
to this side of the check valve, no vacuum should
pass and the test set gauge should return to the 27
kPa (8 in. Hg.) setting. If OK, go to step Step 4. If
not OK, replace the faulty valve.
(3) Connect the test set vacuum supply hose to the
engine vacuum side of the valve. When connected to
this side of the check valve, vacuum should flow
through the valve without restriction. If not OK,
replace the faulty valve.tested. The valves are located in the vacuum supply
tube (black) at the power brake booster on the left
side of the engine compartment, and in the heater
and air conditioner vacuum take-out of the vacuum
supply tube in the engine compartment. The vacuum
check valve must be removed in order to perform the
following tests. See Vacuum Check Valve in the
Removal and Installation section of this group for the
procedures.
(2) Connect the test set vacuum supply hose to the
heater-A/C control side of the valve. When connected
to this side of the check valve, no vacuum should
pass and the test set gauge should return to the 27
kPa (8 in. Hg.) setting. If OK, go to step Step 4. If
not OK, replace the faulty valve.
(3) Connect the test set vacuum supply hose to the
engine vacuum side of the valve. When connected to
this side of the check valve, vacuum should flow
through the valve without restriction. If not OK,
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#8
05-27-2011, 02:25 PM
Thanks Hydra,
I had checked my check valves when I was having a noise like the reservoir draining back, but then I messed with the vacuum lines to install the led light to indicate when the AC is on and that issue went away. I have not had a problem with the blend doors changing on their own from a lack of vacuum, I was just unfamiliar with the vacuum levels and where the should be under certain situations. I have a trip to Cali in a couple of weeks and want to make sure that the D is in top shape for the trip. And yes all of this has really been about when I am towing. I really appreciate all of the incite.
I had checked my check valves when I was having a noise like the reservoir draining back, but then I messed with the vacuum lines to install the led light to indicate when the AC is on and that issue went away. I have not had a problem with the blend doors changing on their own from a lack of vacuum, I was just unfamiliar with the vacuum levels and where the should be under certain situations. I have a trip to Cali in a couple of weeks and want to make sure that the D is in top shape for the trip. And yes all of this has really been about when I am towing. I really appreciate all of the incite.
#10
05-28-2011, 12:18 PM
Hydra,
Min/Max vacuum numbers would be really hard to nail down. To many variables to take into consideration. I think I have what I need now. Thanks a bunch!
I'm at work now. Brought the car, wife needs to go out and the D won't start. I guess I know what I'm doing this afternoon! :-(
Update: Bought charger, charged battery overnight, Nothing! Dropped battery in from Camper... Started right up. Bad NAPA battery. 8 yrs old!
Min/Max vacuum numbers would be really hard to nail down. To many variables to take into consideration. I think I have what I need now. Thanks a bunch!
I'm at work now. Brought the car, wife needs to go out and the D won't start. I guess I know what I'm doing this afternoon! :-(
Update: Bought charger, charged battery overnight, Nothing! Dropped battery in from Camper... Started right up. Bad NAPA battery. 8 yrs old!
Last edited by Groggy; 05-29-2011 at 10:12 AM.