SSpeed

No offense taken, enjoying the conversation. Did you have a roots or centrifugal supercharger? The reason your pressure went down was because your engine was consuming more air volume. All power adders can produce a certain pressure at a given volume. When volume increases beyond what they can give, pressure goes down. That's why you see smaller turbos choking at higher RPMs. If you had a Procharger, this is what they say: https://www.procharger.com/centrifugal-supercharger The centrifugal supercharger contains an impeller which spins at high speed to draw air into a small compressor housing (volute). When air leaves the impeller, it is traveling at high speed while having a low pressure. This low-pressure, high-speed air is sent through a diffuser which converts the airflow so that it is high-pressure, and low-speed. The air is then fed into the engine, where the additional airflow (caused by increased pressure) gives the engine the ability to burn more fuel and have a higher level of combustion. DIFFUSER Located between the impeller and the volute is the diffuser. Downstream of the impeller in the flow path, it is the diffuser's responsibility to convert the kinetic energy (high velocity) of the gas into pressure by gradually slowing (diffusing) the gas velocity. So I guess I had it partially wrong too. The impeller speeds up the air into high velocity/low pressure, while the housing itself converts it to low velocity/high pressure, but it's still happening inside the power adder housing. Without that, you aren't getting any appreciable boost. The intercooler is in place to act as a heatsink to extract heat from the air, heat that is a result of the air being compressed. If air were compressed simply by backing up in the engine, the location of the intercooler would be useless.

If this were true, a 3-port EBCS would not work. The way a 3-port EBCS works is that the boost signal from the compressor housing port goes to the EBCS port, which then modulates the signal to the wastegate allowing it to open at the desired level. If it were true that the air is not compressed in the compressor housing, then you would never see compressed air at the wastegate either because the only signal the wastegate is getting is coming directly from the compressor housing line. Is what Western Turbo says wrong? https://www.westernturbo.com/blog/how-does-a-turbocharger-work-anyway/ "Compressors are the opposite of turbines. They consist of two sections; the impeller or compressor wheel and the compressor housing. The compressor wheel is connected to the turbine by a forged steel shaft. As the compressor wheel spins, air is drawn in and is compressed as the blades spin at a high velocity. The housing is designed to convert the high velocity, low pressure air stream, into a high pressure low velocity air stream, through a process called diffusion. In order to achieve this boost, the turbocharger uses the exhaust flow from the engine to spin a turbine, which in turn spins an air pump. The turbine in the turbocharger spins at speeds of up to 150,000 rotations per minute (rpm) that is about 30 times faster than most car engines can go." Cummins seems to say the same thing as well. https://www.cummins.com/components/turbo-technologies/turbochargers/how-a-turbocharger-works The compressor also consists of two parts: the compressor wheel (5) and the compressor housing (6). The compressor’s mode of action is opposite that of the turbine. The compressor wheel is attached to the turbine by a forged steel shaft (7), and as the turbine turns the compressor wheel, the high-velocity spinning draws in air and compresses it. The compressor housing then converts the high-velocity, low-pressure air stream into a high-pressure, low-velocity air stream through a process called diffusion. The compressed air (8) is pushed into the engine, allowing the engine to burn more fuel to produce more power.

No it isn't. Air leaves a turbo compressor housing already compressed, it doesn't get compressed as it backs up in the engine. That's one reason why just blowing lots of air is completely different than compressing the air.

The HP and airflow on that Mustang is not much different than a 2.5i. Even though it's a 4.6, it's only making <200hp and the airflow would be a direct correlation. The method of compression for a turbo isn't moving enough air that it creates a backup. The actual method of compression is specially designed fins that compress the air, very high RPMs and a specially designed compressor housing that aids in taking air from atmospheric pressure and compressing it down. The backup only comes into play when the volume of the turbo outpaces what the engine can consume. Volume and pressure are different, from what I can see the eSCs only produce volume, and even that is questionable.

I guess that goes back to questioning how they make gains on an engine. Most of the electric superchargers I see are just blowing lots of air and not really compressing it. We all know there is a difference. If people are seeing a gain by blowing lots of air vs compressing it, then essentially they are seeing a gain by alleviating an intake restriction. Without compression of the intake charge, no additional air is getting packed into the cylinders at static atmospheric pressure. I've seen several posts where people say they get 1psi at certain points of the RPM range. We all know how many HP gains 1psi is from turbo tuning. And in this case, it's maybe in a select range of the RPM. Something doesn't add up.

I agree on all that, they did show that the supercharger run was a lot richer, but didn't give exact numbers. Is 10-20hp under the factory spec really that unreasonable for a 23 year old car? In what ways would they set up the test differently? It seemed like a fairly real world scenario for the type of situation where people would be installing them. On the flip side I feel it was a fairly reasonable analysis of what happens when you install an electric supercharger. You're not compressing air, you're not packing more into the cylinders. I don't see how people expect gains.

Cleetus McFarland did dyno testing of an electric supercharger on a 5.0 Mustang. 15:00 Baseline pull of the 5.0, holy cow that is weak! 18:24 their predictions for what it does and the actual dyno run with electric supercharger.

Installing a used Blouch Dom 1.5 XTR (the silver looking one, 2.4 in inlet, 8cm2) in an '05 Legacy GT over the weekend and running into some fitment issues. Wondering if I have an old version, just unlucky or if everyone runs into this? 1) Wastegate touches the factory oil line. I bent the line slightly, was nervous doing that since I just removed the intake manifold and crossover water pipe to replace it. 2) Compressor outlet is basically against the PCV drain tube 3) Compressor inlet is behind the TGV housing (I've removed the TGVs). I had to remove the intake manifold and power steering and squish the snorkel to get it on. Even now it seems to slowly slide itself off even when tight. 4) One uppipe bolt is under the water line, so I had to remove the water line to put it on. I dropped half a dozen copper washers into the engine bay. 5) Wastegate line is pointed down towards the uppipe, not a huge deal, but crappy to put the line on.

One article I read said this:

If you care about optimal athletic performance, you shouldn't be afraid of salt unless you are one of the relatively few who has blood pressure affected by sodium.

No, my MAF connector was fine. I tested that to no end with a multimeter and logging in Romraider, that was one of my first guesses. It wasn't affecting my MAF, the MAF was reading as it should, voltage-wise and airflow wise. My guess is bad grounding was either affecting the injectors or the ECU, but I have no idea. Basically the ECU was telling the injectors to send x amount of fuel and that signal was getting reduced by the time it got to the injectors, dead consistent on idle, cruise and WOT. Don't know on the grounding, my car has 153k. No rust anywhere as it's Colorado. I cleaned the lower engine grounds, but never checked continuity to ground. Sometime in the next few weeks I'll check all 8 factory grounds that I know of. I did check the passenger frame rail ground and continuity wasn't great. I just ordered new factory grounds for all the ones that can be replaced.

So I thought I would update this. My running lean appears to have been completely a ground issue. Haven't found a broken ground, but adding a ground solved the issue. Never would have guessed that running lean was a ground issue when everything else looked ok (fuel pressure, voltage, intake leaks, etc).

Thank you for the link, my running lean appears to have been completely a ground issue. Haven't found a broken ground, but adding a ground and putting my original tune back on solved the issue. Never would have guessed that running lean was a ground issue when everything else looked ok (fuel pressure, voltage, intake leaks, etc).

Overthinking again... All of the factory grounds are on painted surfaces. I see when people clean them they often wirewheel down to bare metal? Isn't that a recipe for rust? And why didn't the factory grounds have to be on bare metal? Are they grounding through the bolt threads vs the head surface?

Hey Max, Dave is a good friend, I helped him install his dyno. He's heard more about my car's oddball issues than anyone else. Thanks Mike, normally I'm not a fan of them either if everything is working right. There is definitely some sort of oddball issue going on that is caused by grounding, or insufficient grounding. I'm going to recheck and clean all of the factory grounds and see if one broke or something. Dumb question because I've never considered it, the Big 3 kit is that the Paranoid Fabrications kit or a general term people use? The PF kit says sold out on their site.

Thanks Mike, I always overthink things. I think the sludge was just contaminants from old coolant since the oil and new coolant look fine. It was clumped in the bottom, completely separate from the coolant. You make a good point about the factory radiator being aluminum. This is long, bear with me. After a run at the drag strip last year, the car went lean, I have another post on that. It went 12% lean everywhere, idle, cruise, WOT, on boost, off boost, very consistent. I went through checking fuel pressure, voltage, MAF voltage, pressurizing the intake with smoke for leaks, I had the injectors cleaned and flow tested, I took the intake manifold off and replaced every gasket and vacuum hose, cleaned the bottom engine grounds. Finallly, I gave up, with 153k miles on the car, original motor, abusing it daily, I just decided to drop injector size 12% to bring it all to zero everywhere. I know that's the wrong way to go about it, but I was done and I'm not sure how much life was left in the car. I threw it on the dyno and it made the same power and AFR curve with the correction as it did before the issue occurred, Learning View zeroed out. I was satisfied. Then this "issue" popped up. Before you posted it wasn't necessary, I thought what could it hurt to ground the radiator, so I did. I went for a ride and all of a sudden I'm hitting 10.8 at WOT vs my 11.6 target. I went home and pulled a Learning View, the ECU is pulling 12% fuel out everywhere, basically back to my original injector size. I'm having a hard time believing running 12% lean across the board was a ground issue and a crappy ground at the radiator fixed it. The car has at least 8 factory grounds that I know of and I've cleaned most of them and checked continuity. Two on TGV One on passenger side frame rail Two on bottom of motor One on pitch stop One on trans One on driver side strut tower Am I missing any? I guess if nothing else putting that ground there gave me insight to that original issue I had awhile back and can help me get to the bottom of it.

Have you tried parking on a significant hill? I can tell you from experience that the parking brake won't disengage on its own. You have to use the switch. The OPs experience sounds more like issues with the electronic throttle. The electronic throttle is dumbed down to circumvent unintended acceleration issues, making it really bland for those of us who might use the throttle more aggressively.

So I just checked. With the key on, but the car not running, I have 0.06V running through everything, intercooler, radiator, alternator, etc. I do not have voltage on the chassis from what I can tell. That isn't much. With the motor on, it drops to about 0.027V on everything. Everything I read says electrolysis minimum voltage is around 0.4V. Just for fun, I checked my 2017 Legacy. Key on ignition but not running, it has 0.022V through everything. With the car running it has -0.035V like the polarity is reversed, not sure what that means? Maybe I need to rev the car and check it around 2000+rpm?

Oh, as far as the water goes. For the 153k miles I have on this engine if I do mix I use soft water. Right or wrong it was never a problem with the stock radiator. I never know what is right as far as water goes. Some sites, like this one https://www.hyperlube.com/blog/blog/why-you-should-never-use-distilled-water-in-your-cooling-system/ say distilled water is ionically hungry?

It wasn't a complete flush, just let it drain the engine from the water pump outlet. It had green Subaru coolant in it before. The last time it was the Subaru pre-mix green that doesn't need water. I haven't added the conditioner for years. The latest info I see from Subaru is they no longer recommend it? I'll drop a multimeter into the coolant and see if there is any microvoltage, just guessing that's the issue. My grounds are clean though and show continuity to ground. What are your thoughts on a complete flush and the Subaru blue coolant?

Last year I installed a new Koyo aluminum radiator after my factory radiator neck cracked. I installed with new Subaru green coolant. At the same time I cleaned my engine grounds. Last week I pulled the radiator and water pump. As I was cleaning the gasket surface I noticed pitting in the aluminum that couldn't be removed. Looking inside the radiator it had a white film like you see with aluminum corrosion. Inside my overflow tank was about 1-2 tablespoons of an unknown sludge. A couple of questions come to mind: 1) Does an aluminum radiator have to be grounded? Could this be electrolysis? 2) Is Subaru coolant sufficient for a Koyo radiator? (ie the non-amine phsophate formula eating possible brass) I put in an email to both RallySportDirect and Koyo and haven't heard anything back yet. On the electrolysis question, I did find a Ford TSB that seems to link electrolysis to heater core failure. ISSUE: Some vehicles may exhibit (repeat) heater core leaks. This may be caused by a chemical reaction called electrolysis. Electrolysis involves an ion exchange between the heater core and engine coolant which can result in a breakdown of the heater core material. This is similar to the operation of a battery. ACTION: Check for electrolysis on any vehicle with a heater core failure. If electrolysis is verified, flush the coolant and follow additional steps as required. Refer to the following Service Procedure for details. SERVICE PROCEDURE: Electrolysis Inspection: If there is a condition of a heater core leaking or repeal heater core leak, check for electrolysis using the following procedure: 1. To check for electrolysis use a DVOM set on DC volts. Place the positive probe of the meter in the engine coolant and the negative probe on the negative battery post. 2. Adjust engine throttle to 2000 RPM to properly get coolant flow and true electrolysis voltages. 3. If more than .4V is recorded, flush the coolant and recheck (follow guidelines in TSB 98-23-16 for Cougar). See Coolant Fill Procedure below to remove trapped air on 4.6/5.4/6.8L modular engines. NOTE: Export markets, be sure the water is desalinated. 4. If there is still excessive voltage present in the coolant, check the engine to body/battery grounds. Also, verify proper grounding of any aftermarket electrical/electronic equipment which has been installed into the vehicle. Improperly grounded electrical devices can cause electrolysis to occur. 5. If the condition is still present after the grounds have been checked, it may be necessary to add extra grounds to the heater core and engine. A hose clamp can be used to secure a 16 AWG stranded copper wire to the heater core inlet tube. The other end should be secured to an EXISTING FASTENER on the body sheet metal. Extra grounds to the engine should be attached between EXISTING FASTENERS on the engine and body sheet metal. Verify continuity of any added grounds to the negative battery terminal. 6. If the condition is still present, add a restrictor (part F1UZ-18D406-A) on the inlet hose with the arrow facing the direction of coolant flow (toward heater core). Cut the line and install with 2 hose clamps. It is important that the restrictor be installed in the right direction of flow and as close to the engine block as possible (not near the heater core itself).

Having a hard time figuring out what oil line I need. Currently I have the BNR oil line that runs up to the front of the head vs the stock location. I don't even remember what was at the front of the head where I did the BNR line so I can put it back to stock there? Does anyone remember? Looking at the Blouch lines, they both seem to be at the stock back of the head location, just the fitting is a bit different. Seems like I need the WRX line? WRX http://www.bptstore.com/BPT-Subaru-WRX-Oil-Feed-Line-Ball-Bearing_p_90.html STI http://www.bptstore.com/BPT-Subaru-STi-Oil-Feed-Line-Ball-Bearing_p_91.html

Surely done by now?

It's a good question, but I'm positive. I've been running this exact tune for 3 years with under 3% on Learning View Fuel trims and WOT AFRs at 11.6-11.7, verified on multiple dynos. Just one day everything went lean. I've gone through the fuel system and have good pressure, I cleaned the injectors, I took the intake down to the cylinder head and also smoke pressure tested it, I had the motor health verified. The fact that it's 12.5% lean everywhere (idle, cruise, WOT) seems way too uniform to not be an ECU problem. At this point I have to assume the ECU isn't giving the injectors the fuel it thinks it is. I suspect I could change out the ECU and the problem will go away. Not sure I want to mess with the immobilizer and such when I can just bump fuel 12.5% globally.

So, been awhile since I posted an update. Still haven't figured it out. But... I bumped fuel 12.5% globally and now my Learning View Fuel trims, cruise AFRs and WOT AFRs are spot on. Very weird. Since I've been through the fuel system, tune and intake, it's almost as if it's an ECU problem. I may just leave it bumped 12.5% and call it good. I also did a compression and leakdown test, I'm at 15x,000 miles. I'm high altitude, new STIs compression test about 130psi here. #1 125 psi, 2% leakdown #2 130 psi, 2% leakdown #3 125 psi, 3% leakdown #4 119 psi, 2% leakdown The very strange this is, when I tested at 50k, I was 116-119 psi on all cylinders, and one cylinder had 10% leakdown. I don't know how numbers can get better over time, I use different oil now. {shrug}