SOHC V6 Supercharger

The purpose of this thread is to discuss the design and possible development and installation of a supercharger for my 2000 Sport SOHC V6 engine. I have no first hand experience with forced induction systems and want to learn from forum members that have them on their vehicles. While I don't plan to implement a turbocharger system, there are many problems common to all types of forced induction systems.

The easiest and least expensive solution would be to modify a Ranger SOHC V6 Banshee kit and purchase a used Thunderbird supercoupe positive displacement blower. However, the kit makes no provisions for an aftercooler which I think is beneficial even with only 5 psi of boost.

The Explorer Express supercharger kit includes a quality looking manifold but one is very difficult to obtain.

Once again, there are no provisions for an aftercooler.

I suspect the best solution for me would be a centrifugal supercharger with a water aftercooler. With my oil coolers and remote filters I have very little room in front of the radiator for an intercooler. I am interested in a boost in the range of 5 to 8 psi - enough for a significant performance increase but not so much to adversely impact reliability and require beefing up of engine internals or the transmission/torque converter.

Procharger sells a kit for the 2005 - 2010 Mustang V6.

But the Mustang configuration is opposit to the Explorer - intake on left and battery on right. Also, there is a lot more room between the engine front and the radiator rear on the Mustang than on the Explorer.


Vortech also makes a kit for the Mustang but there are the same problems.

The logical location for a centrifugal supercharger is the same side as the air filter box and intake manifold inlet port. Unfortunately, that is where the alternator is located. I'm investigating the possibility of replacing the belt driven power steering pump with an electric motor driven pump and then relocating the alternator to the old power steering pump location.

 

[jd4242]

Any updates?

 

[2000StreetRod]

upgrading fuel pump

I'm in the process of upgrading my stock fuel pump to a high flow pump: Fuel pump replacement - 2000 Explorer Sport

 

[2000StreetRod]

high flow fuel pump installed

Today I finished installing the fuel tank after replacing the stock fuel pump with an Aeromotive Stealth 340 high flow pump. My fuel pressure at engine idle was same as before: 62 psi. This was a relief because I was concerned that the stock FPR might not have enough bypass flow capacity to keep up with the Stealth pump output. So far no leaks detected and the fuse didn't blow with the significantly increased current flow.

While I have the rear end raised I'll replace it's broken vent hose. I'll also try to shorten/stiffen the tailpipe hanger by installing a hose clamp around it. In certain body positions the tailpipe contacts the shock absorber and in other body positions it contacts the sway bar vertical link. If I shorten the hanger raising the tailpipe there will be more side to side clearance and if I stiffen the hanger there will be less tailpipe movement.

The only thing I have left on my baseline dyno testing preparation list is to get some vacuum readings for later comparison with the supercharger installed. I'm considering installing the vacuum/boost gauge now so I can get some readings under engine load. I suspect I'll pull the instrument cluster to install the gauge because of the intended location. While I'm doing that I'll replace the burned out Air Bag light (I'm tired of listening to 5 sets of 5 chimes) and fix the broken gear selected indicator (PRNDL). I may also add wiring for an A/C compressor disable switch and a passenger side air bag disable switch.

 

[CDW6212R]

Good progress there Dale. BTW the AC clutch is already disabled at WOT, are you trying to shut it off during the Winter etc? I'm thinking of a switch on the bezel next to the AC controls, for that.

 

[2000StreetRod]

A/C clutch disable reason & location

Good progress there Dale. BTW the AC clutch is already disabled at WOT, are you trying to shut it off during the Winter etc? I'm thinking of a switch on the bezel next to the AC controls, for that.

Yes Don, the reason for the manual A/C clutch switch is to allow disabling the A/C for the panel & floor, floor & defrost, and defrost positions. I plan to mount the switch on the front of the center console next to my Accusump disable switch.

By the way, I have a newer cell phone than the one in the photo. I was forced to upgrade because my provider no longer supported the analog capability which had longer range than the all digital.

The passenger air bag disable switch will be at the same location. I take my parrot (27 years old) to the vet twice a year in his traveling cage that I place on the passenger side front seat. If the air bag ever deployed it would probably crush his cage and kill him.

 

[2000StreetRod]

67 not 62 psi

I did another fuel pressure check this morning and apparently I misread the upside down fuel pressure gauge last time. The pressure is 67 psi with the engine idling instead of 62 psi. I watched it for about 10 minutes with the engine running to make sure that it was stable and not slowly increasing due to the stock fuel pressure regulator. When I shut off the engine the pressure immediately dropped to 62 psi - the normal pressure with the stock fuel pump. My custom tune was with the 62 psi so I suspect my air/fuel ratio is now 8% rich [(67-62)/62] when the PCM is in open loop (WOT). That means my normal 11.6:1 at WOT will be 10.7:1 which is too rich for best performance. I'll do another hill climb datalog to check the A/F ratio. If confirmed I may ask James to adjust my tune for the new fuel pump. I don't want to dyno test without the optimum A/F ratio. There should be no problem in closed loop because the PCM can adjust the fuel trims to compensate.

My fuel check valve is very good. About 5 minutes after engine shut off the fuel pressure had only dropped to 55 psi. About 2.5 hours after engine shut off the fuel pressure was still 33 psi.

It seemed to me that the new pump takes longer than the old one to build up pressure after the ignition is switched on. No pressure registered after the first key on sequence but the pressure came up on the second key on sequence. That may be due to the near empty fuel tank and the incline of the vehicle with the rear end on jacks. I'll check it again next time after adding 2 gallons of fuel and lowering the rear.

 

[CDW6212R]

Those are valuable tests, and they check the limits/capacities of the fuel system. I hope that does work, that is a higher than typical pump performance, and the alternatives are not to be wanted. Crossed fingers here for you,

 

[2000StreetRod]

puzzling richness increase

I reviewed some of the past WOT tests I did for the custom tune. The average air-fuel ratio (AFR) was about 12.1:1. The average AFR for my recent pulls is 11.6:1. The changes between then and now:

1. BP 93 octane with no ethanol vs BP 93 octane with up to 10% ethanol
2. Replacement of camshaft timing related components
3. Installation of engine oil cooler thermostat
4. Replacement of exhaust system

I doubt that replacing the camshaft timing components and installing the engine oil cooler thermostat had any effect on the AFR.

One possible explanation is that my new exhaust system is more restrictive than the stock system. That is unlikely since every component has a higher flow rating. I guess the valve spring in the Dynomax VT muffler could be defective (too strong) but the valve seems to open easily when the engine speed increases above idle. I could measure the exhaust back pressure by disconnecting the EGR pipe from the exhaust manifold and connecting my vacuum/pressure gauge but that seems unwarranted.

The other possible explanation is the change in fuel. The stoichiometric AFR of ethanol is 9:1 and the stoichiometric AFR of gasoline is 14.7:1. For E10 ethanol-blended gasoline the stoichiometric AFR is 14.7*.9 + 9.0*.1 = 14.13:1. My wideband O2 sensor reacts to the amount of oxygen in the exhaust. The corresponding output voltage is converted by the meter into AFR assuming a certain type of fuel which is set for 100% gasoline. The AFR of 12.1:1 is a lambda of .82 (12.1/14.7) for 100% gasoline. The AFR of 11.6:1 is a lambda of .82 (11.6/14.13) for E10 fuel. So the lambdas are essentially the same assuming 10% ethanol.

I'll make another hill climb datalog with the higher fuel rail pressure for comparison purposes. Then I'll try switching my meter to display and record lambda to see if it is more fuel independent. That might make tuning easier for James.

 

[CDW6212R]

That 11.6:1 A/F is very good still, and a fine place to begin with a blower. If the fuel pressure was higher in that 11.6:1 testing, then I'd say that richened it up more than other things.

 

[2000StreetRod]

no pulls yet with new pump

That 11.6:1 A/F is very good still, and a fine place to begin with a blower. If the fuel pressure was higher in that 11.6:1 testing, then I'd say that richened it up more than other things.

My Sport is still on jack stands so I haven't driven it with the new pump yet. Today I spent a lot of time devising a way to route and mount the rear axle vent so it doesn't break again for a few years. The distance between the rear axle and the body is constantly changing due to body roll, braking, accelerating, bumps and pot holes. When the other end of the vent hose is attached to the body the distance changes flex, stretch and compress the hose causing it to fail. I ended up bending a length of hose and just laying the end in a loose loop of two cable ties.

I also spent time trying to stiffen and raise the tailpipe hanger to gain more clearance between the pipe and the sway bar link and shock. I wasn't very successful with installing two hose clamps around the hanger to compress it. I need to puchase a new hanger. Eventually, I should get the curved section of pipe above the axle cut out and replaced with one having less bend to raise the pipe.

 

[CDW6212R]

Please post anything you learn about mounting the vent hose if you find something better. I plan to move mine since it's in the path of where a left pipe would go. Night,

 

[2000StreetRod]

rear axle vent hose

I found a length of 5/16 internal diameter hose with some established bends in my hose box. I cut it to length and installed one end on the rear axle vent and locked it in position with a fuel hose clamp.

I created a loop with two plastic cable ties for the other hose end to hang thru.

I used drdoom's trick of partially inserting a trim panel retainer clip in the open end to keep out dirt and moisture.

There are two grooves in the retainer clip sides that allow ventilation as long as the head is not seated against the hose end.

 

[2000StreetRod]

Stealth fuel pump results

This morning I did a hill climb with the higher pressure (67 psi) Stealth 340 pump installed. Even though the fuel pressure increased 8% (from 62 to 67 psi) the average AFR at WOT below 3700 rpm only changed from 11.5:1 to 11.3:1 or only 1.8%. The acceleration time from 27.5 mph to 59.0 mph increased 8.096 to 8.19 seconds or 1.2% indicating that the mixture is too great for maximum acceleration. However, the performance degradation is not sufficient to justify a retune. I should point out that the fuel used was 93 octane with up to 10% ethanol which means the actual fuel ratio was 11.3/14.13 or a lambda of .8 or an equivalent 100% gas ratio of 11.76:1. According to my Bosch fuel injection manual the best acceleration occurs at a lambda of .86 but the performance curve is fairly flat in that area of richness. Its safer for the engine to be slightly richer than .86 at WOT. Above 3700 rpm (56 mph in 3rd gear) lambda gradually increases to .83 at 5000 rpm and then gradually decreases to .82 at 6250 rpm but I can't test that engine range in the local area.

I must have loaded the reduced knock sensor tune into the PCM because my knock sensor retard dropped at 2900 rpm from +.5 to -1.5 degrees and stayed there until 3000 rpm when it climbed to 0 degrees. That could be the cause of the slight (1.2%) increase in acceleration time. I'll do another hill climb with the dyno lock in 4th gear tune loaded to confirm the knock sensor retard is actually off.

 

[Dono]

Quick question on your intercooler pump wiring...

I know you said you were going to use a relay off your fuel pump.
Have you found what wire to tap off of yet? What color? Location?

Im getting ready to install my relay to get ready for installing my oil scavenge pump and intercooler pump. If you have done this, I'm sure you have used the best location to tap the wire, and I'd prefer not to re-invent what you have already done.

EDIT: found the schematic for fuel pump. Dark Green/Yellow trace wire off the fuel pump relay (In the battery Junction box). It goes all the way to the Inertia Fuel Shut-off Switch.

 

[2000StreetRod]

scavenge & intercooler pump supply

You are correct that the DG/YE wire runs from the output of the fuel pump relay to the input to the inertia fuel shutoff. Fuse 9 in the battery junction box that provides power to the fuel pump relay has a 20 amp rating. Since my Stealth fuel pump can draw up to 16 amps that only left about 2 amps for the intercooler so I planned to add another relay for the intercooler pump. However, I have since learned that the 16 amps max occurs at 340 liters per hour. That amount of fuel would be required for a 600 bhp engine at WOT. If I add a pulse width modulator fuel pump speed controller I suspect the required max current for my engine will be less than 8 amps leaving at least 8 amps for the intercooler pump for a total of 16 amps thru the 20 amp fuse.

What is the max total current for your fuel, intercooler and scavenge pumps? If its less than 16 amps then there should be no problem using the DG/YE wire as a power source for all three pumps. If its 18 amps or more I suggest adding another relay to control one or both of the added pumps.

 

[Dono]

Thanks Dale,

I'll be using the same fuel pump as you are using from James.

Then I'll have approx 5 amp draw from the scavenge pump, and I'm guessing up to another 5 from the intercooler. I'll use a relay to be safe. I'm going to run my boost gauge off the same circuit (Hopefully serial config to the pump, on the negative side) so I know if there is an issue with power to the scavenge pump immediately.

 

[2000StreetRod]

intercooler pump power

According to www.siliconeintakes.com regarding my pump "A Bosch representative has stated that this pump will draw 2.5-3.5 amps depending on other factors in your cooling system."

If you're going to add another relay I suggest using the PCM Power Relay output (RD wire) as the relay control power source and the PCM Fuel Pump Relay Control (LB/OG wire from the fuel pump relay to PCM pin 80) as the ground path. That way the PCM will energize/deenergize the added relay the same time as the fuel pump relay. You'll have to find a hot at all times fused power source for the pumps. In my battery junction box minifuse position 5 is unused. I don't know if it is already wired. If so, it would be a good location to add a 15 amp fuse. Or you could just add an inline fuse to the "bus" connected to the 175 amp megafuse that all the other fuses are connected to. My wiring diagrams don't show any spare relay positions so you'll have to mount it in the most convenient location you can find.

Your pumps and your boost gauge require the full battery voltage. They all need to be wired in parallel (not series) if they have the same power source. In that configuration you'll be able to determine loss of power source with the boost gauge but not individually to each pump.

 

[Dono]

After I posted, I started thinking the boost gauge might not deal so well with the current of a couple of pumps running thru it. I'll take your advice on the relay switching cct. Like you say, I probably don't even need a relay.

 

[2000StreetRod]

current draw

My multimeter has a DC current measuring limit of 10 amps. I guess I should pull the fuel pump relay and connect the meter across the power pins to see what the current draw is. If its more than 10 amps it will probably destroy the meter but I only paid $3 for it when on sale at Harbor Freight. Since we're both using the Stealth pump its worth the risk. If I interpret the provided performance graph correctly the current draw at 67 psi could be 16 amps at max fuel flow. However, the intank fuel pressure regulator is restricting the flow so the current may be less. If I use PWM to decrease the pump speed to provide the original 62 psi the current draw should decrease. Hopefully, significantly. So far the 20 amp fuse has not blown at ignition turn on, normal driving or WOT hill climb.

 

[2000StreetRod]

Resuming work

I haven't accomplished much during the last few weeks due to preparing my deceased mother's house for sale. The home inspection revealed subfloor and chimney chase framing water damage from a leaking chimney chase cover. The cover was made of galvanized steel that had rusted out after twenty-two years. The entire brick hearth (4 layers) and brick trim, fireplace insert, subfloor and framing under the chase had to be removed/replaced along with a new back door and casing. Then I had to spackle, sand and paint the wallboard surrounding the fireplace opening. This morning I closed on the sale of the house so after an extended Labor Day weekend recuperation with my wife at the Greenville downtown Marriott Courtyard I'll resume work on the supercharger preparation/installation.