If you have been using meth for a few years you might have realized that the pumps lose their efficacy as time goes by. I've observed 2 of the areas that are culpable. You will need to disassemble the pump with a torx T20 socket.
1st and foremost, the regulator. If you disassemble the regulator you will notice it has a spring and a small cap that presses down on a rubber area in the pump head. This rubber can also be removed. IF you remove this you will notice 2 small holes. One is actually on the high pressure size of the chamber and the other on the inlet. It works by basically bleeding off from the high pressure to the inlet once it overcomes the spring tension. Over time this seal loses its efficacy and bleeds off much sooner than your desired target pressure no matter how much you adjust the Allen key screw. You may notice the holes have permanently marked/imprinted on the seal. You can flip/rotate the seal giving a the holes a fresh location on the rubber to seal with.
2nd culprit is the clear plastic that houses the EPDM valves. This is prone to cracking and also warping near the oval seal- leading to pressure seeping away from the high pressure side to the inlet area. This can be replaced for a few bucks (Devils own sells it) Also, the black housing that seals with the high pressure oval seal, is also prone to warping. A hot air gun can massage them both into shape but be careful they get mushy real fast, so use low heat even though it may take longer.
Having done the above fixes to your pump you should be back to a dead head pressure somewhere between 160 and 180 psi. By the way, none of the pumps i tested brand new gave me 200 psi for any longer than a few days! In fact, when I contacted Aquatec they themselves told me to ignore re-sellers claim of 300PSI as the regulator isn't designed to hold that much, let alone function at that pressure when spraying! I tested this myself and found it to be true. That is, a dead head pressure of say 200 psi results in about 160 psi while spraying. It won't function at 200 psi for any longer than a few days/weeks as the regulator's seal wears and start bleeding off pressure much sooner.
Ready for some REAL pressure?
I will show you how to get 200-300 psi dead head pressure and 160-200 spraying pressure. You remember the two holes on the regulator?
We won't be needing the inner hole one no more. This hole is on the high pressure side of the assembly and it is through this hole that fluid is bled off to regulate the pressure. I used a soldering iron and a clear tie strap to melt a nice plastic seal for that hole.
The pump deadheaded 220 psi at 12 volts, and while spraying a 520cc nozzle it was at 185 psi. At least there is no more mysterious pressure drops to look out for :)
at 5:38:00 PM No comments:
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SUNDAY, JANUARY 1, 2017
MORE THAN YOU'VE EVER WANTED TO KNOW ABOUT BACKPRESSURE...
Free Flowing Exhaust : Unrestricted flow means unrestricted power.
Cut-outs: Unrestricted flow, but tuned length has changed = power band shifts (depending on length and diameter of pipe). This causes the "loss of low end torque" feeling.
Those examples above are two different tuning methods, and WILL effect torque.
Let's talk about engine mechanics first.
We have a camshaft which is GEARED to the crankshaft. There are VALVE EVENTS which occur at specified degrees in relation to the crank position.
If you look at a cam card, you will see notes like: EVO, EVC, IVO, IVC (etc.)
EVO = Exhaust Valve Open EVC = Exhast Valve Close
You need to understand that these points NEVER change no matter how fast the engine spins. You also need to realize that the exhaust pipes and headers CAN NOT change length as engine RPM changes (obviously).
This means that your INTAKE and EXHAUST pipes are TUNED for ONE specific RPM.
RPM changes which also changes the WAVELENGTH of the PRESSURE PULSE.
Understand that an engine spinning at 1000 RPM creates LESS pressure pulses than an engine spinning at 6000 RPM.
Also understand at higher RPM these pulses must happen FASTER in the same RELATIVE TIME (IE: PER MINUTE)
So...1000 pulses per minute have MORE TIME to happen than 6000 pulses per minute.
This means that higher RPM pulses have a SHORTER wavelength (pulse length).
Anybody here with a basic understanding of audio can relate short wavelength of high frequencies of a tweeter to long wavelength frequencies of bass tones of a sub woofer.
Think about your exhaust system. You are on the DYNO and holding the engine at 2000 RPM.
The exhaust length is 65 inches and let's pretend the pulse length is 65 inches.
In the diagram below you have a RED line which indicates the pressure pulse as it EXITS the exhaust port and travels the length of the exhaust pipe. When the pulse reaches the end of the pipe, it meets the atmosphere. When a moving object HITS another object there is a transfer of energy.
Think of a wave of WATER hitting a wall and bouncing backward - air moves in a similar fashion. When the exhaust pulse hits the atmosphere it will reflect back toward the exhaust port. The dotted blue line represents this reflected wave - notice that the blue dotted line crosses the black line at, or below the axis.
This means the reflected pulse has reached the exhaust port with LOWER PRESSURE.
Will having a low pressure pulse reflect back IMPROVE, or HURT the next exhaust pulse exiting?_
Those who guessed that LOW PRESSURE will IMPROVE the flow of the next pulse are CORRECT.
If you were water, or air exiting this exhaust pipe, would you find it easier to exit if there was a valley, or a hill?
The valley is the top scenario. The hill is the bottom scenario.
Think of low pressure as a WEAK force. `Low` meaning low force, or low resistance. When the exhaust valve is opening and the piston is pushing the waste out of the cylinder, the exiting pulse is HIGH pressure.
The exhaust gas will exit easier if there is little resistance at the exhaust port. You can also think of low pressure as a VACUUM. It actually creates a sucking effect at the exhaust port so that when the valve opens, the low pressure area sucks the gas out of the cylinder.
Remember...fluids and gasses move from high pressure to low pressure - that's a key point here.
So the reflected pulse is tuned to reach the port at LOW pressure.
Now, what happens when you open your cut-out at 2000 RPM?
Have a look at the next diagram. Notice the top drawing has Engine RPM at 2000 RPM. The bottom has Engine RPM at 6000 RPM.
Think about what happens to the `EFFECTIVE LENGTH` of your exhaust.
Things to think about:
Is the pipe tuned for a higher, or lower pulse now? The long RED wavelength is the exhaust pressure pulse @ 2000 RPM.
Question 3: At 6000 RPM with a shorter exhaust pipe, (or cut-out open), will the torque be higher, or lower?
When you're talking about cutouts the distance is CRITICAL and will tune the exhaust to be efficient at ONE RPM, with a tapering curve above and below that RPM. The RED wave in the top example extends beyond the length of the pipe.
The WAVELENGTH/PRESSURE PULSE length at 2000 RPM is LONGER than the TUNED LENGTH of the exhaust pipe.
Now when you open the cut-out at 2000-3500 RPM on the street, you notice a lack of POWER. People say "I lost BACKPRESSURE...That's Why I lost power!"
THAT IS NOT TRUE. By opening the cut out, you have changed the tuning of the exhaust for the RPM range you are using. Think about a pipe organ. Wonder why each note on the pipe organ has a DIFFERENT LENGTH of pipe?
"But why does the frequency of the exhaust decide how much power u make?"
It does not decide how much, but when the power comes in. The _pipe length_ in the exhaust has everything to do with how much power is made.
If you read up a few paragraphs you will see talk of reflected pulses and exhaust pressure.
At 2000 RPM an exhaust pulse is 50 inches _(for example)._ If we cut a pipe to be "resonant" at 2000 RPM, it would need to be 50 inches. This pipe would only be resonant at ONE RPM, and ONE frequency. The reflected pulse at 2000 RPM will reach the exhaust port and create a LOW PRESSURE area.
While the valves are opening and closing, the pulse is reflecting back at 2000 RPM, everything is tuned and resonant...which means it is highly efficient.
Someone driving around in the city would tune their exhaust to this length because it would be more efficient from 1000 to 3000 RPM with a PEAK at around 2000 RPM (or somewhere in the middle).
When this guy goes racing, he opens his cut out. But today, he wants to open the cut out and drive around town. The pipe is now cut _smaller_ in length. The tuned length is somewhere in the 5000 RPM range.
While he drives around at 2000 RPM, the exhaust pressure pulses are still going to have a 50 inch wavelength...but... The cut-out does not allow the reflected pulse to come back 180 degrees out of phase.
The reflected pulse returns at a higher pressure at the port.
Check out this diagram:
Notice the top section on the left and right side.
There is a hump with a green line highlighting the highest point of the hump. Also notice the RPM at where the peak of the hump occurs.
Directly below each is a simulated torque and horsepower graph. Which side represents a tuned exhaust for a SHORT PIPE, or CUT OUT?
Answer: Example two!
Just remember it's not BACKPRESSURE that is causing the torque loss, it's all about the tuning - you need to select a pipe length that provides the best power curve in a window of RPM that the car requires.
Just like above, if you're going to be racing, place the cut-out in a spot that improves the resonant RPM to around 5000 RPM (like the right side). On a Thirdgen Camaro/Firebird this would be right around the catalytic converter area.
Then everything above and below 5000 RPM will taper off within your shift window (4000-6000 RPM).
at 7:19:00 PM No comments:
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SATURDAY, JULY 30, 2016
2016 FORD FOCUS RS - FULL SPECS
Rally-driver wannabes and hot-hatch hooligans, your wait is over: The Focus RS is here. With a turbocharged 2.3-liter four-cylinder that sends 350 hp and 350 lb-ft of torque to all four wheels, the RS comes standard with a six-speed manual and a unique torque-vectoring system. Michelin Pilot Super Sports wrap nineteen-inch wheels; a 0-60 time of 4.6 seconds . Developed with input from Ken Block, we judge the RS to be better than the Subaru WRX, WRX STI, and VW Golf R.
__ 19/25 mpg
EPA __ 4.6 sec
0-60 __ 350 hp
HP __ 165 mph
EPA Classification Mid-Size Cars
Base Curb Weight N/A
Length, Overall 171.7
Width, Max w/o mirrors 71.7
Height, Overall 58.4
Track Width, Front 61.2
Track Width, Rear 60.4
Min Ground Clearance N/A
Liftover Height N/A
Passenger Capacity 5
Passenger Volume 90.7
Front Head Room 39.1
Front Leg Room 41.9
Front Shoulder Room 55.6
Front Hip Room 53.9
Second Head Room 37.9
Second Leg Room 33.4
Second Shoulder Room 52.6
Second Hip Room 52.8
CARGO AREA DIMENSIONS
Cargo Volume with Rear Seat Up 23.8
Cargo Volume with Rear Seat Down 44.8
Trunk Volume N/A
Engine Type Turbocharged and intercooled inline-4
Displacement 2.3 L/138
Fuel Delivery Direct injection
Horsepower @ RPM 350 @ 6000
Torque @ RPM 350 @ 3200
Drivetrain All Wheel Drive
Trans Order Code
Transmission Type 6-speed manual
First Gear Ratio (:1) 3.23
Second Gear Ratio (:1) 1.95
Third Gear Ratio (:1) 1.32
Fourth Gear Ratio (:1) 1.03
Fifth Gear Ratio (:1) 1.13
Sixth Gear Ratio (:1) 0.94
Reverse Ratio (:1) 1.42
Final Drive Axle Ratio (:1) 4.06
Steering Ratio (:1), Overall N/A
Lock to Lock Turns (Steering) N/A
Turning Diameter - Curb to Curb 37.4
Turning Diameter - Wall to Wall N/A
Suspension Type - Front Strut
Suspension Type - Rear Control-arm
Brake Type N/A
Disc - Front (Yes or ) Yes
Disc - Rear (Yes or ) Yes
Drum - Rear (Yes or )
Front Wheel Size 19 X 8
Rear Wheel Size 19 X 8
Spare Wheel Size
Front Wheel Material Aluminum
Rear Wheel Material Aluminum
Front Tire Size P235/35YR19
Rear Tire Size P235/35YR19
Spare Tire Size
Fuel Tank Capacity, Approx N/A
Aux Fuel Tank Capacity, Approx N/A
EPA Fuel Economy Est - Hwy 25 (Est)
Cruising Range - City N/A
EPA Fuel Economy Est - City 19 (Est)
Fuel Economy Est-Combined 22 (Est)
Cruising Range - Hwy N/A
EPA MPG Equivalent - City N/A
EPA MPG Equivalent - Hwy N/A
EPA MPG Equivalent - Combined N/A
Battery Range N/A
Tons/yr of CO2 Emissions @ 15K mi/year 8.0 (Est)
EPA Greenhouse Gas Score N/A
Dead Weight Hitch - Max Trailer Wt. N/A
Dead Weight Hitch - Max Tongue Wt. N/A
Wt Distributing Hitch - Max Trailer Wt. N/A
Wt Distributing Hitch - Max Tongue Wt. N/A
Electronic Stability Control (ESC)
ABS And Driveline Traction Control
Side Impact Beams
Dual Stage Driver And Passenger Seat-Mounted Side Airbags
911 Assist Emergency S.O.S
Low Tire Pressure Warning
Dual Stage Driver And Passenger Front Airbags
Curtain 1st And 2nd Row Airbags
Airbag Occupancy Sensor
Driver Knee Airbag
Mykey System -inc: Top Speed Limiter, Audio Volume Limiter, Early Low Fuel Warning, Programmable Sound Chimes and Beltminder w/Audio Mute
Rear Child Safety Locks
Outboard Front Lap And Shoulder Safety Belts -inc: Rear Center 3 Point, Height Adjusters and Pretensioners
Radio: Sony Audio System w/10 Speakers -inc: HD Radio and SiriusXM radio, SiriusXM includes a 6-month prepaid subscription, Service is not available in Alaska and Hawaii, Subscriptions to all SiriusXM services are sold by SiriusXM after trial period, If you decide to continue service after your trial, the subscription plan you choose will automatically renew thereafter and you will be charged according to your chosen payment method at then-current rates, Fees and taxes apply, To cancel you must call SiriusXM at 1-866-635-2349, See SiriusXM Customer Agreement for complete terms at www.siriusxm.com, All fees and programming subject to change, Sirius, XM and all related marks and logos are trademarks of Sirius XM Radio Inc,
Radio w/Seek-Scan, Clock, Speed Compensated Volume Control and Radio Data System