Monday, December 28, 2020

Fixing Home Speaker

 I have a set of Polk Monitor series speakers from the late 1980's.  These are fantastic speakers in my opinion, even now.  However, in one of the speakers (each has 2 drivers) both drivers started crackling very bad.  Upon inspection I found the coils dragging on the magnets.  The drivers in the other speaker were fine.  You can hear the dragging when you press in on the passive bass radiator which pushes the drivers out.  

I looked into these drivers with are part number MW 6503 and have been discontinued.  There are copies available for $35 to $70 range each.

I experimented with pressing on the cone in various places to find a place where it would not drag.  It seemed to be an alignment issue.  Maybe they creped a bit over time? I decided I would try to align them back.  Nothing to lose here right?  Either I fix them or I needed to replace them anyway.  I took a piece of plywood and a vise and began carefully pinching an edge of the magnet where the dragging was gone.  This basically bends the driver frame a bit to realign the coil with the magnet.  To my amazement it actually worked.  Here is the after video.
This is tricky to get right.  The metal has significant spring back and you want to bend in small increments. You have to carefully get it to yield just a bit at a time and retest.  

Saturday, August 29, 2020

Cayman S Water Pump

 I did a dumb thing but it turned out OK.  When I took the Cayman out of winter storage this spring and warmed it up for the first time in a while, I smelled coolant, although none leaked to the ground.  I have seen water pump seals do this before.  On most older cars the water pump has a simple bushing that runs in coolant so a small seep that quits is not necessarily a big deal.  My F250 would do this on severe cold weather but never had a pump failure.  However, the Cayman water pump is not like that.  It has a sealed roller bearing instead, which is far better and should last for life.  However, if you get coolant seeping through the bearing, the bearing will die pretty fast.  The grease will get washed out, the bearing will run dry, and fail.  Well, that is what happened to me.  I had noticed a growling noise from the engine when I started it that morning.  My first thought was far worse than a water pump.  I feared my IMS bearing was going out.  After recalling that I did see dry evidence of coolant from the water pump I sorta convinced myself it could just be some coolant on the belt, which can make all sorts of weird noises.  Honestly I was not that convinced, I was just lazy and in a hurry to meet with some friends.  

On my way back from breakfast where I was meeting with friends I heard a pop and immediately my steering assist was gone and the charging system warning came ON.  Right away I knew I had lost the belt.  I carefully drove the rest of the way home, accelerating moderately up to speed, shutting OFF the engine, and coasting between lights.  By the time I got home the coolant temp was a bit over 200F based on the gauge.  Still safe but I would not want to get it too much hotter.  With no belt, the coolant does not circulate.  You can't go very far like that.  In the video below you can hear the pop right at the beginning.

It is not real loud and I did have the stereo going.  I quickly turned OFF the AC and opened the windows too.  

Once I was home, I removed the panel behind the seats to expose the front of the engine where the belt and water pump are.  I saw the slack belt but upon further inspection I found the water pump shaft had completely sheared off and the pulley was just laying there.

Glad to see it was just a water pump, I quickly ordered parts through the local dealers online website. 


Mid-engine cars have a much trickier cooling system since the engine is in the middle, and the radiators are in the front fenders ahead of the wheels.  This makes it an air pocket nightmare.  A vacuum system is needed to pull a vacuum on the cooling system and suck the coolant in.  I found this one on Amazon for $39.99.

Having the engine behind the driver and not even visible without removing bolt-in panels and carpet sounds like jobs like this would be much harder.  However, it is not too bad really.  It takes about 15 minutes to remove the carpet section and both the top engine panel, and the front engine access panel. Once you have these panels off, access is pretty good for most things.  I will say charging the water pump on this car is far easier than most front-wheel-drive cars.  

I positioned the car on a ramp on the drivers side, and jacked up the passengers side as high as my jack stand would allow.  This positioned the coolant reservoir as high as possible relative to the car. I did this to keep the radiators and heater core full of coolant making it easier to ensure all the air was out when I was done.   

I started by clamping the radiator hose and one of the heater hoses.  

I loosened the hose connected to the water pump at the bottom and stuck an Allen wrench in it to allow the coolant to drain in a more controlled fashion.  In this position, and with the clamps in place, about 2 gallons of coolant drained into the pan I had to catch it.  I then removed the water pump.  It is basically just a set of small bolts.  The nice thing is the gasket is metal and does not stick to the block so it left a clean surface.  Here is a photo with the pump removed.

  When installing the new pump, make sure the longer bolts are in the correct holes, with the alignment dowels.  Here you can see the new and old pumps, both showing the alignment dowels.

Here is a photo with the new pump installed.

Before removing the hose clamps, I drew a vacuum on the cooling system and pulled in the coolant.  

I was able to pull in almost 2 gallons right away.  Remember to open the air bleed valve in the top of the reservoir to allow the air to escape the block while doing this.  I then released the clamps, installed the belt, and ran the engine.  With the engine running I could feel more air purging through the air bleed hose that connects from the oil cooler to the reservoir.  I added about a quart more coolant at this point. I ran the engine some more until I could feel the heater hose warm up, indicating I was getting coolant flow.  I ran the engine until the thermostat opened and I could feel the radiator hose at the radiator warm up, indicating flow to the radiators. I did all of this while the car was still raised.  I took it for a good road test, hitting 7,000rpm at times to create high coolant flow and purge any remaining air.  

The whole job took me about 3 hours.  Not too bad.  

Saturday, May 30, 2020

Mercedes E350 4matic 150k miles

I wrote a review of this car when it hit 100k miles back in December of 2017.  It now has 150k miles and there is not much new to report.  I did upgrade the headlight bulbs to LED.

Here is the things I did to the car in the last 50k miles.

12/27/2017 105k mi drivers seat cover. This is a known issue on these cars. I bought the part and replaced it myself.
1/20/2018 107k mi drivers front tire road hazard warranty replacement
2/25/2018 109109mi blower motor. This had a very minor intermittent squeak. Very simple to replace.
3/13/2018 new windshield
6/17/2019 117,715mi front brake pads. This was the first pair of front pads!
7/8/2018 119,869mi spark plugs.
8/5/2018 121,555mi belt. Although it was still fine. It just seemed like a long time to go on a belt.
11/18/2018 129,401mi Thermostat and PCV cover. Both a simple job.

The car was hit in the back by an inattentive driver in December.

But Banishek and Will fixed it back up again.  Good as new.

This car drives pretty much the same as when we got it.  Runs and drives great, never uses oil, no issues really.

Sunday, May 10, 2020

Kohler Engine Noise

I have a 2001 GT3000 Craftsman mower with a Kohler 23HP 2 cylinder engine.  I bought it used back in May 2009.  It has many hard long hours on it.  I had a 5 acre place I used it on for many years, and my lot now is over half an acre. 

I went to mow the lawn and heard a knocking sound.  I heard it while cranking as well as running.  Engine load made no difference so I figured it was not a main or rod bearing, or a piston issue.  It was an odd sound actually.  I listened with a stethoscope and narrowed it to the crankcase area, not the top end.

I removed the engine and as a drained the oil I could see the metal in it.

Once I took the engine apart, I checked the rotating assembly to find the source of the knock but it all looked good.  Everything was nice and tight still.  Piston skirts looked good too.  This was expected since the knock did not change with engine load.  I had to look deeper.  Finally I found where the crank had worn into the lower case (oil pan) which also serves at the lower thrust bearing.  Strange they have the crank go right against the end case aluminum to serve as the thrust bearing.  I could feel the crank end play was excessive too.  The knock was from the fact that the crank had worn so deeply into the end case that the crank throw was actually grinding into the oil pump gear and bolt.  

I measured the crank end play and found it to be 0.080".  That is ridiculous!  

You can see in the photo below how worn down the oil pan is on the thrust surface. This is supposed to be flat.

Notice the wear on the oil pump gear.

Here is what it should look like.

When I think back to the way it sounded it was not a pure knock.  It also had a grinding sound element to it.  Now it makes sense.  By the way, the photo above is a used part listed on eBay at the time I wrote this.  It had a buy it now for $45.  There were several others around the same price.  Far less than the over $200 for a new one.

Monday, March 9, 2020

Driving Exotics Racing in a Porsche GT3 RS

First person there in the morning

I drove a Ferrari 488 GTB at Speed Vegas last year.  This year I decided to try something totally different and drive the Mustang GT500 at Exotics Racing at the Las Vegas Motorplex.  I booked it the night before but when I got there, the car was in the shop so they asked me what other car I would like to drive instead.  I already had 2 at the top of my want list: The Porsche GT3 RS and the Porsche GT2 RS.  I was able to upgrade to the 991.1 GT3 RS for no additional cost so I went for it.  Exotics Racing does it a bit different than Speed Vegas.  The biggest difference is the 2 laps ride in a Macan to orient you with the track.  That is a nice touch.

The track

Satellite view of the track (Google Maps)

The track is 1.2 miles long with some small elevation changes and banking on turn 2.  The longest straight is still short (1800ft) but it is enough to have a great time and get a good feel of the car.  The mild elevation changes give you a feel of the cars balance under dynamic loading pretty well.  There are 2 turns that are well over 90 degrees.  This track was a bit easier to learn than Speed Vegas since all the corners are very unique.  It is very helpful to have an easy to learn track when you only get a few laps on it.  The drift car leaves a bunch of rubber on the track and much of it is off-line and that can throw you off as your eyes tend to follow it and not the true line.  The section of the track up near the building can get confusing too as the track appears to have been shifted but the old route still shows.  Here again the drift car makes a bit of a mess of it as it takes a different route out of the pits.

Comparing the tracks at Speed Vegas (1.5mi, 12 turns), Exotics Racing (1.2mi, 7 turns), and Dream Racing (1.2mi, 9 turns), Speed Vegas is the longest and you will hit the highest top speeds.  These are all short tracks.

The car

Instructor and I getting ready for the track
Out on the track

This is one of my favorite cars.  I am a big Porsche fan and the GT3 RS is the most engaging drivers car in the lineup.  I suspect the GT2 RS is even better in some ways (power obviously) but the GT3 RS just fits perfectly and does everything you want with no effort.  The sound from the high revving naturally aspirated flat 6 is one of the best engine sounds out there.  The engine response is very crisp too.  Being used to my Cayman S on tracks really helped as this car felt very familiar.  On this track we only shifted up on the main straight and back down in turn 2.  Of course I was plenty sloppy not being at all familiar with this track, or the car.  I never got the car to even squeal a tire.  The grip was fantastic with the Pilot Sport Cup 2 tires.  I looked at my ranking compared to other GT3 RS times at this track and I ranked 1500 out of about 3382, and 6451 out of  43165 for all cars.  I think the GT3 RS times included both 991.1. and 991.2 GT3 RS as they don't show them separately.

Full video of my run on YouTube

My time and rank on the day I ran 

You may recognize some of these folks at the top in the GT3 RS

This car is amazing.  Even with my sloppy 5 laps around this track I got a good feel for what this car may be capable of.  I was never at the limits of grip at any time.  I had plenty of room for more speed everywhere.  The 5 laps were over real fast.  In retrospect, more laps might be worth it.  I think I could easily trim 5 seconds a lap off my least bad time with just a few more laps (and a less nervous copilot).  He had me braking early and corning slow which I suppose makes sense until you get used to the track. I don't envy these instructors sitting in the passengers seat in a very fast car at speed on the track and no idea what kind of nut they have behind the wheel.  I highly recommend this, or Speed Vegas, next time you are in Las Vegas.  Next time I might try out Dream Racing so I can compare these three. 

Sunday, February 23, 2020

The future of aftermarket performance

I have been modifying cars since I was a teenager.  My first was a 1972 Ford Bronco where I rebuilt a 351W engine, upgrading the camshaft, installing a larger carburetor, and headers, to replace the 302.  I installed nitrous oxide on my 1968 Mustang, along with many other mods.  I helped a friend develop a custom turbo system for his Fox mustang.  I installed many superchargers at the Ford Dealer I worked at for 15 years.  I also was a dealer/installer for Allen Engine Development and Explorer Express superchargers.  I developed a low budget custom turbo system for my BMW 318i.  I have also done engine performance tuning on many cars.  I have worked with most types performance enhancements over the years.  I know the pros and cons of the various aftermarket power adders.

I am becoming more and more convinced that the future is in aftermarket hybrid systems.  I am not talking about plug-in hybrid focused at fuel economy here.  I am talking about performance focused hybrid performance enhancements.  Think F1 KERS for the street or track.  This is by no means a new concept.  Think back to the Porsche 918, Ferrari LaFerrari, and McLaren P1.  All three were hybrids.  In the supercar space, more hybrids are coming too.  There is even a company, Vonnen, that has developed the first aftermarket hybrid system for Porsche sports cars now.  While that system has a huge price tag, I expect this approach to eventually go mainstream and the prices to come down quickly.

There are many opportunities once you have a high-voltage electric system in the car.  The Vonnen system eliminates the old heavy starter motor, and replaces the heavy lead-acid 12V battery to reduce the weight penalty down to about 100lbs.  While the Vonnen system puts the motor/generator between the engine and transmission, the motor/generator could instead (or also) be placed at each of the axles which would allow for torque vectoring.  You can also electric drive superchargers to boost the engine performance as well with no back work of traditional supercharging or turbocharging (more net power with less boost).  Unlike superchargers or turbochargers, hybrid drive will not affect the engine durability, tuning, emissions, or sound either.  Performance focused hybrid systems do not require a large heavy battery pack.  Instead, the Vonnen system uses a 1kWh battery pack (versus the 100kWh battery pack of a Tesla Model S 100). Ultra-capacitors can also be used to augment these performance oriented hybrid systems with a low weight penalty and very high power rates in and out.  The battery and/or capacitor weight can be strategically placed in the vehicle too, optimizing balance and handling. Other features can be added such as silent drive for short distances (depending on battery capacity) so you don't wake everyone up in your neighborhood when you start your performance car.  Large capacity electric heaters can augment the HVAC in cold climates to give instant heat before the engine warms up, also making the defrost work better.  Speaking of HVAC, the belt driven AC compressor can be replaced with an electric compressor and be more strategically placed in the vehicle. Hydraulic power steering can be replace with efficient electric power steering, which can include advanced features such as Porsche's advanced electric power steering.

Motors are getting better all the time too.  Equipmake for instance, recently developed a 295HP motor that weights only 22lbs. With all kinds of advanced motor technology, higher voltages, and advanced manufacturing techniques, motors will continue to become lighter, more powerful, and once they show up in volumes, less costly.  Leveraging this development from mainstream manufacturers, the aftermarket can adapt these motors to the aftermarket performance sector to make a cost effective performance enhancement system. Most of these modern motors can also generate electricity to charge the propulsion batteries and/or capacitors.

Motors can be placed in many different areas to provide power where desired and to enable enhanced stability and traction control strategies such as torque vectoring, stop/start, anti-stall, and more.  A motor that drives the engine crank can also be used to stabilize very high performance engines with large aggressive cams to make the car more drive-able.  A great example of that is the Aston Martin Valkyrie.  Hybrid assist is used to make this 1000HP naturally aspirated engine street drive-able.  Motors that are connected to the engine can also assist in changing engine speeds, making the engine rev much quicker.  Motors used in generating mode can be used as retarders for descending hills and decelerating, saving brake heat and wear.

Looking at trucks and off-road vehicles the advantages grow even more.  Drive motors can be placed to drive each wheel independently (or assist) to allow precise torque control for rock climbing and advanced traction control.  High-voltage electric winches will be far more compact, light, and powerful than their 12V counterparts. Trailers can also be equipped with drive motors so an off-road vehicle can tow a trailer and still have all wheels driven to get through very poor traction conditions.

One of the challenges facing aftermarket performance systems and kits is dealing with the implications to emissions and associated regulations.  Hybrid systems would be far easier to deal with here as most would not impact emissions, or would favorably impact emissions, especially in grams/mile impact.  The Vonnen system for instance does not change any engine or powertrain tuning. 

Hybrid and battery electric vehicles have now been around in volumes for over a decade.  More vehicles will go hybrid and full battery electric going forward.  As hybrid and electric drive go mainstream, the cost of this technology will drop substantially.  In some cases, the factory components could be incorporated into aftermarket hybrid systems which will really help reduce cost while also using proven, validated components.  Hybrid drive is not the doom of performance cars but rather the next level.  The future of performance vehicles and aftermarket performance enhancements has never been brighter.

Saturday, January 18, 2020

Engine Sound and Cars for Enthusiasts

We all have different needs and opinions about many things in life.  Even among car enthusiasts we have many different things we like about them.  If you narrow down the car enthusiasts to a specific brand and type of car, you still have significant diversity in what people want from the car.  Owners of the same car model still have this diversity.  Some enjoy detailing their car and showing it.  Some like a fall drive down a twisty road.  Some like driving full out on the track.  Even within one of those more narrow groups we still have many differing opinions about priorities.

One thing that can come from the Porsche 718 Boxster/Cayman flat 4 engine experiment is Porsche found out what a priority engine characteristics are over performance.  This also happened with the PDK only GT3 years ago.  While in both cases Porsche made a car that outperformed it's predecessor, many fans were unhappy.  If you just look at the performance numbers, the cars were better so what was missing?  The term "experience" may get overused these days but that is what this comes down to.  Even for the track crowd (which I am part of) the cars soul really matters.  While lap time is the measure of driving skill there is much more you get from track time that making the quickest laps.  It is the experience from the drivers seat.  The driver and car become one.  If you have never driven full-out on a road course it is hard to understand.  When you are there though, it is the very definition of living.  Your heart rate goes to an aerobic pace.  The adrenaline kicks in.  The feel and response of all the drivers inputs to and feedback from the car are critical to this experience.  The feel of the g-force as you and the car accelerate, brake, and corner give the driver the information needed to make time critical decisions that optimize lap time.  When you get it right it is very rewarding.  You may not think the engine sound should be very important to this experience but it actually is.

Take a listen to the GT3 RS in this video (starting just after the 4 minute mark).  Also notice the comments of the driver and instructor.

Porsche now makes electric cars.  By the way, I am a fan of electric cars.  I love the direct response to throttle command.  I love the fact there is no shifting interrupting the power delivery.  It is by far the best way to make a commuter car.  I would like to have one for my daily commuting.  No more gas stations, oil changes, spark plugs, filters, belts, etc.  Far less, almost no maintenance really.  One pedal driving significantly reduces most brake wear. No cold engine operation.  It can warm up or cool off the interior while its sitting in the garage.  More luggage space.  However, when it comes to a track car I don't want all-electric.  The Porsche 718 is supposed to get an all-electric version in the future.  I may actually want one as a commuter car but it will stay home when I go to the track.  I want the flat 6 engine for that.  The electric 718 would probably put down quicker lap times, but still I want the flat 6.  It may seem odd for a logical engineer such as myself to say these things but even us logical engineers have things we are passionate about that defy pure logic.

Daniel Pink wrote a book called Drive that gives insight into human behavior.
This starts to explain some of this behavior of why we do some irrational things.  He describes three key elements of human satisfaction: purpose; autonomy; and mastery.  This passion that drives High Performance Drivers Education (HPDE or track day) participants is here in these elements.  I think the strongest correlation is with the mastery element.  Mastery is the desire to be good at something.  This is "practice makes perfect" that we have all heard.  It's our desire to achieve perfect and the thrill that comes with it.  So, what does engine sound have to do with this?  That sound, and the non-linear, high RPM power-band of a high performance naturally aspirated engine, give an extra element of feedback and challenge to achieving mastery.  Even more, the same is true for the PDK versus manual with a clutch pedal.  Mastering these extra challenges are part of achieving greater mastery.  If it was easy, the challenge would be gone and mastering it would mean nothing.  I actually like the PDK but I certainly understand those who prefer a clutch pedal.

There is something more to the sound of a great engine though.  It is certainly a much wider crowd than just track people who love the sound of a great engine.  To a real enthusiast it is better than music, or maybe a form of music.  The sound of a great engine is very hard to replicate with audio equipment since you feel it as much as you hear it.  Also, from the drivers perspective it is synchronized with acceleration which is a big part of this experience.  Even the experience between driver and passenger in the same car at the same time is quite different because of this.  I actually was not a huge fan of the sound of a Porsche flat 6 until I drove one.  From inside the car it is quite different.  Driving it is even better.  If you never had that experience, the flat 4 718 would be great.  But those of us that have experienced a Porsche flat 6 at full throttle redline know what I am taking about and that is missing in the flat 4.  I actually love the combination of induction and exhaust sound.  In fact, full throttle induction sound is even sweeter than exhaust sound in my opinion.  Put them together and it is blissful. 

Other manufacturers are understanding the importance of engine sound.  One great example is the Aston Martin Valkyrie.  Check it out on the dyno.

They could have easily turbocharged a V8 to get this performance but instead they went a much harder route of building a naturally aspirated V12 with a very high redline.  Obviously this car is not just about quick lap times but rather driver engagement.  Another is the Shelby GT350 with the Ford Voodoo engine.  The list is starting to grow.

I think the future of performance drivers cars will be more hybrids.  Porsche made the 918, Ferrari made the LaFerrari, and McLaren made the P1 years ago showcasing what street performance hybrids can do.  The Valkyrie is also hybrid, as are many other performance cars.  Now Vonnen has made a hybrid conversion for many Porsche models.  These are very different hybrids than the economy focused ones.  These use hybrid drive that is focused on performance.  The batteries are small so as not to increase the weight.  Just enough battery to add the extra power when you need it, and where you need it.  The hybrid drive augments a high-revving often naturally aspirated performance engine very nicely filling in power down low where these engines lack it.  Yet you still get all the sound and engine characteristics you like, just with more power.  Formula 1 went hybrid (KERS) back in 2009.  Most of the top Le Mans race cars have also been hybrid, such as the Porsche 919.

Wednesday, January 1, 2020

Moto Z4 Review

A few months ago I upgraded my aging Moto Z2 Play with the new Moto Z4 (unlocked).  I chose this device for several reasons:

  • Industry best total battery life (when used with battery mod)
  • Supports Moto Mods
  • Reasonable price and value for the money
  • They also threw in the Moto 360 camera with it and I always wanted one of these
  • Decent cameras with good features
I would consider this an upper mid-range phone.  It's not a true flagship device but it is not priced like one either.  My daughter got one a couple months before I did and she liked it too.  My experience with it so far has been very good.  I have been impressed with the cameras, and overall performance is good.  I like the in-display fingerprint sensor even though it is much slower than the one on the Z2 Play.  It is nice having almost no bezels and the larger display.

I did have to open up the headphone port and charging port on this rim with a file bit other than that it works great and lets you use most mods while this rim is in place.  It also fixes the minor annoyance where the Z4 body is just a bit narrower so the mods slightly hang over the edge. The only mod that does not work with it is the 360 camera.  I just modified the 360 camera (quick job on the table saw) to make it fit.

I would like to discuss battery life as this is one of the most important features for me.  Moto Mod batteries have a mode called "efficiency mode" that optimizes maintaining the phones internal battery to keep it at 80% extending its life.  I have 2 Moto Mod batteries: The Moto Power Pack and the Moto Turbo Power Pack. I always have one of them on the phone.  For normal daily use, I use the smaller Moto Power Pack.  When I go on trips or will be using more battery, or going longer between changes, I will use the larger Moto Turbo Power Pack.  Switching is of course super easy and does not require turning OFF the phone.  You simply pull one off and snap the other one on. These batteries also protect the camera since the battery has a hole leaving the camera recessed.  The batteries also have a great rubbery back surface making it easy to hold the phone securely and they don't show finger prints at all. I never really need to charge during the day.  Even with heavy use I can go all day no problem. I generally have 80% phone, and 50% to 80% of the mod battery at the end of a typical day. When traveling, I will sometimes carry my other battery so it is available just in case I do get low.  The mod batteries are super thin and fit easily into a pocket.

When I went looking for a new smartphone my top considerations were this Z4 and the new Pixel 3a XL.  The deal breaker for the Pixel for me was the small battery.  The Z4 by itself has 100mAh less battery but then you add the mod with 2200mAh to 3500mAh to that and the capacity is much more.  The pixel also lacks expandable memory that the Z4 has. The Z4 has a very slightly better processor too.  The Pixel is only $25 less (comparing full original retail prices).  The Z4 also has a slightly larger screen.  One of the things that interested me in the Pixel over the Z4 was the cameras, which are rated very well on the Pixel.  Here is an article comparing these 2 devices, and another here, and yet another here.. Another family member got the Pixel 3a XL at about the same time. I will be honest both phones get great pictures and I can't see a big difference between them.  Motorola phones have almost completely stock Android too so even that is very similar, mostly identical really. 5G support was not even a passing thought for me.  I live in a smaller town that does not have it anyway and I get crazy fast speeds on 4G already.

I may add some more details later....