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2003 Toyota Matrix baseModifications:Eibach Sportline springsHella Angel eyes fog lampsE-manage blueZeitronix Zt-217" Konig Absolute rimsYokohama ES100 tiresProgress rear sway barScangauge IIFuture plans for the car are to increase fuel economy. Current goal is 50 mpg. Currently getting approx 35 mpg. The modifications for fuel economy won't compromise comfort, utility, or driveability.The first step for mileage enhancment is a custom built water injection system. I'm just finishing selecting all the components for this system. So, it'll be a while before I actually get around to installing it. I'm not really planning on this modification improving mileage a ton. However, I'm told that I may be surprised. We shall see.The reason for the water injection system is this. As you may or may not know, much of the fuel injected into the engine does not actually produce power. I've heard a few different numbers, but it generally goes between 10 - 20% of the fuel injected is actually used to create mechanical power. BTW, do the math real quick, 20% means you could get 5X more power out of your gas. What mileage are you getting? 30 mpg * 5 = 150 mpg. This how much power is chemically in gasoline, but getting it is the tricky part. So, what is the other 80% of the fuel for? Why, its for cooling the explosion. Remember, if we lean our mixtures out too much what happens? Our EGTs go through the roof and start melting things. So, what we do is inject more fuel into the engine to absorb some of that heat and carry it out the exhaust where it now burns in the good ol catalytic converter. Sounds like a sucky waste of what is quickly becomming liquid gold going through my engine. One more thing to mention is that the 10 - 20% of fuel that actually produces power is not actually liquid fuel, its fuel vapor. As you can imagine, vapor burns much faster than liquid. Liquid fuel simply can not fully burn by the time the piston is already comming back up to shoot it out the exhaust. The liquid droplets are what carry our heat out.So, we have two problems. Problem one is that we can not use liquid fuel for generating power. Problem two is that we need something to help carry the excess heat out of the combustion chamber so we don't melt stuff.Lets start out with problem two as its a bit easier to take care of. The simple answer here is to inject water in place of the droplets of liquid fuel that absorb the heat. Not a bad idea, eh? I think so, but implimenting it is a bit more of a problem. Finding injection components that won't corrode with the constant existance of water in them is proving troublesome. There is also the problem of metering the amount of water to inject. It has to increase in flow directly proportionally to how much fuel is injected. As I mentioned this system is almost all done. Here is a model of of the components. Its not to scale as the tank must be custom fit somewhere on the car, won't be that square, and the injector nozzles will obviously be in the intake manifold, not just spraying into the air. Anyway, take a look. Its basically a seperate fuel system for water.So, now that we have the heat issue taken care of we can taper back on how much fuel is injected, right? Well, we can do that, but we'll loose power which is obviously not desired. Remember that 10 - 20% fuel vapor that creates power? Well, when we trim fuel injection back that 10 - 20% is obviously going to be less. So, we need a way to increase the amount of fuel vapor created per amount of fuel injected. For this step I am currently looking at a few solutions. I don't have much more information on it at this point. More to come soon, hopefully.

Nice picture Daox...I have a few questions on this...You claim that 20% of the fuel injected is actually used to create mechanical power - can you substantiate that claim? I'm kinda curious where this number comes from.Quote, originally posted by Daox »BTW, do the math real quick, 20% means you could get 5X more power out of your gas. What mileage are you getting? 30 mpg * 5 = 150 mpg. This how much power is chemically in gasoline, but getting it is the tricky part.What do you feel is the limit for this car, in terms of fuel economy? In your write-up above, you indicate that 150 mpg is attainable, but what do you feel is really likely? Recall the equation for maximum theoretical efficiency in the ideal Otto cycle (the thermodynamic cycle a car uses) is:eff = 1 - (1/comp. ratio) ^(gamma - 1)where gamma = (C_p/C_v) or the heat capacity of the car. Gamma is typically calculated at about 0.60, but in practical manners, ends up being between 0.25 and 0.30 thanks to irreversibilities (the conversion from chemical to heat was not 100%) alone.So lets use 0.27 (very typical)...this gives us an efficiency = 0.46 (46%). But, this is ideal chemical efficiency to push the cylinders. But not all of this chemical energy (transformed into heat) is kept in the cylinder...typically only about 75% of this energy is actually used to push the cylinders, as the rest is heat expelled to the cooling system, the fact that combustion takes time and isn't instantaneous, and valves open before TDC and close afterwards. This gives us a total chemical efficiency of around 35%.Now the engine efficiency needs to be taken into account. The engine has to overcome friction (energy lost as heat), and pumping work that has to be done (drag). Engine efficiency varies greatly with RPM - the higher the RPM the greater the friction, the lower the RPM the greater the pump losses. I have never really seen engine efficiencies greater than 80%, but lets use 80% to be generous. This means system efficiency is now 0.35*0.80 = 0.28 or 28%. Lets now assume that drivetrain efficiency (for an automatic - manuals are closer to 99%) is 95%. So system efficiency is 0.28*0.95 = 0.245. Furthermore, you have miscellaneous system loads (alternator, radio, a/c) that account for about 5% of total energy usage. This gives an overall system efficiency of 0.245*0.95 = 0.221 = 22.1%.So the maximum fuel-to-wheel efficiency is about 22.1%. If you are at 20% now, that indicates that the greatest fuel economy improvement you could see would be a little over 10%.Quote, originally posted by Daox »One more thing to mention is that the 10 - 20% of fuel that actually produces power is not actually liquid fuel, its fuel vapor. As you can imagine, vapor burns much faster than liquid.If you don't have fouled fuel injectors, I would be surprised if you actually had any liquid fuel droplets present in the combustion process. With atomizing spray nozzles, droplets should be just a few microns each. The latent heat of vaporization would be reached almost instantaneously inside an engine that was at operating temperatures. Remember the temperature inside the cylinder is significantly higher than the melt point of the metal, but residence times are small, preventing large amount of heat transfer into the cylinder wall and reducing heat build up to the point that the material is compromised....When you look at water injection, most theories on water injection improving fuel economy are because of the hydrogen that is present in water. You are correct that if you can reduce the EGT, you can have a more efficient engine. The problem is, you have to extract that heat during combustion - not just provide another source to transfer the heat to. So short of increasing the stroke (and thus increasing compression ratio), you aren't going to be able to get that increase in fuel economy for a reduced EGT....As for the excess fuel for cooling EGT, it is a very minute amount and reduced EGT is a byproduct if the primary purpose of a low stoichiometry. It is true that lean fuel mixtures burn hotter - this is because of the burn temperature of O2 being higher than the burn temperature of C8H18 (tri-methylpentane - the octane additive for fuel).Older muscle cars typically operate with stoichiometry ratios ranging from 1.0 to about 1.3. This creates a hotter burn, and thus more power. However, NOx formation occurs at higher temperatures, so automotive companies have been forced to reduce the stoichiometry and restrict it to the values between 0.98 and 1.10. Surprisingly enough, it was discovered that when the stoichiometry ratios were lower than 1.0, NOx virtually went away thanks to avoiding the NOx formation temperatures altogether.An added bonus was that excess fuel (when stoichiometry was So, while your primary incentive to improve fuel economy is to ease the pain and suffering on your wallet, preventing excess fuel flow to the catalytic converters will result in higher emissions, more build-up of greenhouse gases and ultimately, the equivalent emissions of a vehicle with lower fuel economy. Maybe you don't care about the emissions though.I wrote all of this out, not as any direct shot at you (please don't take it that way), but as an engineering approach to explain what goes on during combustion and some of the reasons it may not be possible to reach 50 mpg, sustained, without detriment to vehicle performance, and without reducing significant amounts of weight. A lot of people have debated the added benefits of $5 wunderkind products that increase HP and fuel economy by 50%, but it is important for them to get to see exactly what the science and truth behind it is.

Welcome to the site! My comments.... I work in the auto industry and if this water injection were so great one of the major auto companies would have already perfected it and used it. The EPA wants to up the fuel economy ratings but the auto companies are not looking into something like this. Water sprayed into the engine usually cleans the tops of the pistons and breaks the carbon off. An old trick with carburated engines would be to kick up the idle and then dump water right into the carb. Loads of smoke would follow and the top end of the engine is cleaned. If I were you, I would get a free flowing air filter if you do not already have one and by Lucas Fuel Additive. The Lucas alone will boost your MPG. Oh and make sure you do not have a heavy right foot! Not trying to bash you or the idea but it is just my comments...

Thanks for the input fellas. I'll answer what questions I can. As I stated in another thread, I'm just a guy trying things out.Quote, originally posted by engineertwin2 »You claim that 20% of the fuel injected is actually used to create mechanical power - can you substantiate that claim? I'm kinda curious where this number comes from.Nope, I can not. I've read it several places (books, internet). If I'm wrong we'll find out eventually. Quote »What do you feel is the limit for this car, in terms of fuel economy? In your write-up above, you indicate that 150 mpg is attainable, but what do you feel is really likely?I have no idea what the absolute cap may be for this vehicle. As I said above, the goal is 50 mpg. If that is 'easy' to attain I'll increase the goal. I do see 50 as being likely.Quote »When you look at water injection, most theories on water injection improving fuel economy are because of the hydrogen that is present in water. You are correct that if you can reduce the EGT, you can have a more efficient engine. The problem is, you have to extract that heat during combustion - not just provide another source to transfer the heat to. So short of increasing the stroke (and thus increasing compression ratio), you aren't going to be able to get that increase in fuel economy for a reduced EGT.I've been thinking about this lately and how the tuning with water injection will effect EGT and the effeciency of the engine. Any findings I have will be shared. I currently have a spare exhaust manifold I'll be fitting with a K-type thermocouple to hook up to the Zeitronix for logging.Quote »As for the excess fuel for cooling EGT, it is a very minute amount and reduced EGT is a byproduct if the primary purpose of a low stoichiometry. It is true that lean fuel mixtures burn hotter - this is because of the burn temperature of O2 being higher than the burn temperature of C8H18 (tri-methylpentane - the octane additive for fuel).Older muscle cars typically operate with stoichiometry ratios ranging from 1.0 to about 1.3. This creates a hotter burn, and thus more power. However, NOx formation occurs at higher temperatures, so automotive companies have been forced to reduce the stoichiometry and restrict it to the values between 0.98 and 1.10. Surprisingly enough, it was discovered that when the stoichiometry ratios were lower than 1.0, NOx virtually went away thanks to avoiding the NOx formation temperatures altogether.So, doesn't this mean I should be able to inject 0-30% water, 100-70% fuel. That'll lower my combustion chamber temps, not create NOx, and keep horsepower ratings nearly the same?Quote »An added bonus was that excess fuel (when stoichiometry was So, while your primary incentive to improve fuel economy is to ease the pain and suffering on your wallet, preventing excess fuel flow to the catalytic converters will result in higher emissions, more build-up of greenhouse gases and ultimately, the equivalent emissions of a vehicle with lower fuel economy. Maybe you don't care about the emissions though.Very good point, and this may be a huge hang up with my setup. However, I am planning on getting gas analysis done before and after modifications to keep track of this.Quote »I wrote all of this out, not as any direct shot at you (please don't take it that way), but as an engineering approach to explain what goes on during combustion and some of the reasons it may not be possible to reach 50 mpg, sustained, without detriment to vehicle performance, and without reducing significant amounts of weight. A lot of people have debated the added benefits of $5 wunderkind products that increase HP and fuel economy by 50%, but it is important for them to get to see exactly what the science and truth behind it is.Glad to hear our your ideas. Keep em comming. Quote, originally posted by MiVibe-ToolGuy »Welcome to the site! My comments.... I work in the auto industry and if this water injection were so great one of the major auto companies would have already perfected it and used it. The EPA wants to up the fuel economy ratings but the auto companies are not looking into something like this.I don't think water injection alone is the answer to the problem. It has to be combined with other things to be real useful.Quote »Water sprayed into the engine usually cleans the tops of the pistons and breaks the carbon off. An old trick with carburated engines would be to kick up the idle and then dump water right into the carb. Loads of smoke would follow and the top end of the engine is cleaned. If nothing else I'll come out with a nice clean engine, lol.Quote »If I were you, I would get a free flowing air filter if you do not already have one and by Lucas Fuel Additive. The Lucas alone will boost your MPG. Oh and make sure you do not have a heavy right foot!Thanks. The normal air filters on cars usually aren't very restrictive, especially at low engine loads which is where 90%+ of my driving is spent. I'm currently having a friend test out a fuel additive I've heard works (and has been tested by a university). We'll see where that goes and I'll check up on that Lucas additive too.

You may want to look into Aquamist water injection systems... http://www.ndimports.com/01_vo...x.aspNot a new concept, it's been done for YEARS, espically back in the early 80'z when rally cars were basicly unregulated... Imagine 800hp 4 bangers running 40psi of boost... with only water keeping them from detonating into the atmosphere... Another system, VERY MUCH like the one you drew up... http://www.aquastealth.com/ind...ID=88I'll be very interested if you pull this off... And as far as water Di/RO water is the way to go, ultrapure.

engineertwin2 and Doax, this is a fantastic discussion. Great postings!I'll be following this project with great interest!

wow, some serious thinking going on in this thread. I don't know what the average efficiency of an automobile engine is, and I had terrible luck googling, ten gazillion hits, did find some page at http://ffden-2.phys.uaf.edu/21....html that says "the typical internal combustion engine remains only about 20-25% efficient." What that really means in this context is unclear. There was also a thread here http://forums.genvibe.com/zerothread?id=28117 where it was claimed that one reason for poor mileage was increased fuel usage just to cool the engine and exhaust, especially at higher RPMs In that case, use of water to cool could save wasting gas, but then again, only if the ECU is remapped to take advantage of the water. By itself, water will probably just confuse the standard ECU routines. The engine may run cooler, but if the software doesn't care, it will still throw in the preprogrammed amount of fuel. Somewhere else here, someone mentioned a modified engine that had a water cycle between gasoline cycles, using the resulting steam from water hitting the hot cylinder walls to assist pushing the crank, but to do that in these engines would require potentially modifying the cams, valve assemblies, and again, the ECU code. Turing water into steam can generate power, but only if the machine is designed to take advantage of it. Just venting the steam out though the exhaust is still losing energy as heat.I am not sure why a custom water injection system built from scratch would be preferable to buying somebody else's water injection kit. Is that to allow easier customization, tuning and control, or is there a design element in yours that others do not have? My overall concern is that as you try these things out, be prepared for some bad side effects. My car is something I depend on daily, so I won't do significant engine experiments on it. It would really suck if something goes wrong and you blow the engine, or waste the catalytic converter. I am not trying to talk you out of your admirable quest, just want you to not be surprised if there's an expensive repair as a result. Maybe you can figure out a way to install some sort of regenerative braking like the hybrids have, but instead of using the recaptured electricity to run an electric drive motor, incorporate an electrolysis device into your water injection system, to increase the hydrogen content. That might give you some reuse of the energy without having to add in a drive motor and a computer to control switching between gas and electric drive.and use distilled, not tap water, but you already knew that

First of all, this is probably the first time that a Garage thread will have hijacked itself into another discussion! Still, I think it will be an excellent arena of scientific and engineering discourse. Regardless of how Daox's experiments work out, this is the true spirit of GenVibe.That said, I'll focus first on the efficiency of internal combustion engines.Quote, originally posted by Daox »The reason for the water injection system is this. As you may or may not know, much of the fuel injected into the engine does not actually produce power. I've heard a few different numbers, but it generally goes between 10 - 20% of the fuel injected is actually used to create mechanical power. BTW, do the math real quick, 20% means you could get 5X more power out of your gas.Quote, originally posted by engineertwin2 »You claim that 20% of the fuel injected is actually used to create mechanical power - can you substantiate that claim? I'm kinda curious where this number comes from.When it is stated that internal combusion engines are only about 20% efficient, it means that only 20% of the energy released from the explosion of fuel vapor actually contributes to mechanical operation. The remainder is converted to heat. (see HowStuffWorks see also: Wikipedia)Nearly 100% of the vaporized fuel is burned. The original statement seems to imply that only 20% is converted to mechanical work and that the remainder is used to disperse heat. That is not correct, otherwise, gasoline would recondense in the exhaust system upon cooling and collect in the catalytic converter or muffler.

Nice Wheels! Needs some tint though.

Quote, originally posted by Sublimewind »You may want to look into Aquamist water injection systems... http://www.ndimports.com/01_vo...x.aspNot a new concept, it's been done for YEARS, espically back in the early 80'z when rally cars were basicly unregulated... Another system, VERY MUCH like the one you drew up... http://www.aquastealth.com/ind...ID=88I'll be very interested if you pull this off... And as far as water Di/RO water is the way to go, ultrapure. I have looked at the aquamist systems. They are quite expensive. My system is quite a bit cheaper. They also aren't intended for the use I am going to use them for, and I'm not sure if the components will hold up.Quote, originally posted by joatmon »I am not sure why a custom water injection system built from scratch would be preferable to buying somebody else's water injection kit. Is that to allow easier customization, tuning and control, or is there a design element in yours that others do not have?Most all water injection systems are made for being used intermittently. My system has to hold up to constant use. The main difference here is the pump and pressure regulation system. I'm also using different nozzles.Quote »My overall concern is that as you try these things out, be prepared for some bad side effects. My car is something I depend on daily, so I won't do significant engine experiments on it. It would really suck if something goes wrong and you blow the engine, or waste the catalytic converter. I am not trying to talk you out of your admirable quest, just want you to not be surprised if there's an expensive repair as a result.Well, with the e-manage I can control the water injection. I should be able to start from virtually no water injection to full blast.Quote »Maybe you can figure out a way to install some sort of regenerative braking like the hybrids have, but instead of using the recaptured electricity to run an electric drive motor, incorporate an electrolysis device into your water injection system, to increase the hydrogen content. That might give you some reuse of the energy without having to add in a drive motor and a computer to control switching between gas and electric drive.lol woah there. Lets take this one step at a time. Your talking major fabrication not to mention major electronics work.Quote »and use distilled, not tap water, but you already knew that You betcha. Got that covered.

Man, i'm sorry, i forgot to say HI and Welcome..!!I'm new here as well, and i don't yet own my Vibe... Just as soon as i can make the trip to Buffalo, NY i'll have it... but till then, it's all reaserch to me... i'm kinda "pre-gaming" it... I do frequent other auto forums and have been for years, so i see a LOT of interesting auto technoligy. I also, like you, try to be as much of a benifit to the forums i'm on as i can... It's good for everyone... So again, welcome..

Haha, thanks for the welcome. I know I was here a few months before I actually picked up my Matrix too. BTW, love the Ohm's law sig.

Quote, originally posted by ZubenElGenubi »... I think it will be an excellent arena of scientific and engineering discourse. Regardless of how Daox's experiments work out, this is the true spirit of GenVibe.i totally agree. i've learned tons about my vibe from this forum, and this is a great example of the depth of knowledge our members have and are willing to sharei'll be following this thread and a belated welcome to doax

In all my ranting above, I never even mentioned how much I love those rims, Daox...you got yourself an amazing ride there!

Well, my wife was driving home from work yesterday with the Matrix and got rear ended by some woman not paying attention. I'm still in the anger stage, so I'm really pissed off that people think they can just jump behind the wheel and not look where the heck they're going. I just glad my wife is alright. Hopefully there won't be any aches tomorrow or anything. Here are the pics. It doesn't look too bad, but it always sucks to get crunched. Only had her for 2 months too. Hopefully it'll be fixed in no time.

Well, I just got the first quote back from one body shop. $2500. He said he would replace the bumper, hatch, repair the rear quarter pannel, pull out some damage that may be under the quarter panel and replace some trim pieces. $1000 in parts, $1500 for about 15 hrs of labor.

Its been a while since posting in this thread. But, I finally got around to doing something with the car.I took this weekend to work on a grill block for my Matrix this weekend. The reason? My wife uses the car for work. She makes many trips from company to company throughout the day, many of them are short trips. So, anything I can do to reduce warm-up time should be of benefit not only to fuel economy and emissions, but also to her comfort (yes, bonus points for the husband.) Anyway, its fairly straight forward I think. Here are some before and after pictures. It doesn't fit perfect, but its not bad. I also used toolless fasteners so they can be removed anytime.BeforeAfter. Upper grill block.After. Upper and lower grill block. I ran out of fasteners so I used the upper ones on the bottom until I ran to get more.

Stage two in keeping the engine warm is here. I just got finished installing a block heater. It wasn't too bad. There was just a hole in the block on the driver's side above the transmission. The heater slides in with some grease over it and clips into the hole. Unfortunately, the hole is very burried and I wasn't able to take any real good pictures. Here are the ones I do have though.I still have to see what of timer/remote I can find exactly for it though. But, that can wait a little bit at least.Kit contents.Heater installed.Heater wiring. I routed the wire around the batter following the main wire harness to make it look clean. It then goes through the front of the car through the headlight hole along with a few other wires.The plug. It is held in place roughly by the grill block. You can kind of tuck it up under it while it is not in use.

Those block heaters come standard up here...kinda a neccesity. Good job though on the install.

Well, its summer again and that means its time to work on the cars. After monitoring the operation of the Matrix and getting to know it better I have canned the water injection. The car simply doesn't operate out of closed loop enough to see any tangible benefits from it. This is a very good thing.So, I have turned my focus to aerodynamic modifications. More specifically, the underside of the car.The front of the vehicle will probably get attention first. I don't have any good pictures of it, but as with most cars, it only has a front skirt that extends back a little ways. I'd like to do a full belly pan under the engine bay.Here is a shot from another one of our Matrix owners on the board (sorry, forgot your name). As you can see, there are two support members on either side of the exhaust. There is a fairly large step there. I'm thinking of using some aluminum flashing to cover the whole middle section between the support members.That leads us to the back. I'll have to see what can be done with it. The muffler sits sideways in the very back of the car. Definitly going to need some aluminum there.Other than the underside aero mods, I'll be looking at a WAI (warm air intake) to increase load while cruising. The wife doesn't P&G (pulse and glide), so this is probably one of the cheapest ways to increase mileage. I'll just have to experiment with different temps. I have a feeling the engine may be sensitive to warmer intake temps as it already has a 10.5:1 compression ratio and still runs on 87 octane.

Alright, here is the rest of what I have to work with. I hiked up the Matrix this weekend to snap some pics of the bottom.Even with the two front grill blocks, there was still the area between the bumper cover and main support that was open. This will need to be closed up.This is the area I'd like to go over with aluminum flashing between the two support members. The only thing I don't like about it is the aluminum flashing may rub the exhaust as it hangs down a bit below the support member's lowest level.This is the large drop off between the engine bay and passenger compartment. Definitly not good for keeping airflow attached.Moving backwards you can see that the floor of the car actually tapers down towards the back of the car.In these next three pictures you can see Toyota did seem to try to use some underbody panels for one reason or another.However, once you get beyond the rear axle, all bets are off. There is nothing here to help airflow. Thankfully, the bumper cover doesn't hang down real low. So, there isn't much parachute effect going on.

Ill be very interested to see how you put the under panels on, I have seen many types of under panels for the celica, matrix and corolla from Japan. only problem is they are expensive!

As of right now I just plan on using existing holes in the chassis and tapping holes where needed. The panels will be made of corrugated plastic and sheet aluminum so they will be very light. It shouldn't take much to hold them on.

How did you make the grill blocks? I need to put some covers on my lower grill since taking them off

The original blocks were made of foamboard. It really didn't fare too well in the winter months, but it is still intact. I'd recommend using coroplast or something more weather resistant.

Alright, I finally had a free weeknight! So, I decided it should be Matrix bellypan time. Last week I picked up a 4'x8' sheet of black coroplast for this project. The front piece here took half the sheet. Not much to it really, just cut, fit, cut, fit, etc. I really am liking the results even though I didn't have enough time to fasten the back side of it yet. Darn sunlight, theres never enough of it.Here is what we are starting with.Here is the coroplast sheet. I used half of it for the piece you'll see below.I took off one of the wheels and traced out where it needed to be cut for clearance. You can kind of see my pencil marks here.This is the near final form.And here is it fitted on the car using the jack to hold the back side in place.

The belly pan looks good! I might've tried to tuck it under that front lip, but I'm not sure how easy that would've been...looks great anyways!Let me know if you notice any difference. Didn't want to go the Lexus "dimpled" route? j/k

Thanks. I'll be doing some coast down testing once I get it finished up.

The bellypan is finished up. The back is held to the chassis with those plastic expanding body fasteners with the pin in the middle. They work great. Unfortunately, the pictures turned out really dark though so I'm not even going to bother posting. They look like the last picture but without the jack. I took it for a spin on the highway and everything is nice and smooth and quiet (no flapping noises). When I get some time I'll do the coast down testing and get some final pictures.Edit: Here is my best picture... I had to provide something. Told ya its dark though.

that stuff actually hold up to that kind of heat???

The only thing that would get hot enough to melt it is the exhaust. The exhaust really isn't that close to the exhaust. If its a problem I'll replace sections of the coroplast with aluminum flashing.The next step will be to cover up the area between the two support members under the car. This will be done in aluminum flashing. Its slightly more of a pita too cause I'm going to have to drill a bunch of holes in the support member for mounting.

In preperation for my vacation trip to Wyoming this comming week I'm going over the Matrix to make sure she's ready to go. However, winter took its toll on my good 'ol foam board grill block. The nice satin black finish was totally worn off to a paper like material under it. Needless to say it looked kind of silly on an all black car. So, I took the night to remake the block in coroplast.The old grill block. Still worked fine. I guess I'm just picky about looks.The new grill block. Looks strikingly like the original. It has a few minor tweaks and fits slightly better.

After 3400 miles of pleasant cruising I'm back from vacation. The mileage was surprisingly good. I'm really glad I had the belly pan on for this trip. We drove from Milwaukee, Wisconsin out to Yellowstone area and worked our way back. The sights were simply amazing. I drove a good part of the trip and 3 others also participated. We averaged 37.1 mpg over the 3400 miles traveled, and thats even with the high 75 mph speed limits out there. The worst of it was the initial trip out there. 1000 miles and a good third of it was straight into 30+ mph winds. That gave me a wonderful 30.5 mpg tank. However, the rest of the trip redeemed the mileage with a few tanks over 40 and a few in the high 30s.Heres a pic of the Matrix in Yellowstone.

Just got a new high in the Matrix at 47.6 mpg. Most of this tank was a highway trip at higher than ideal speeds. I'm absolutely sure I could hit 50 if I would have went a different route that takes me through country roads vs interstate.

Very cool. A couple of questions, though. Where do you get the coroplast sheets? And, did you make a provision in the belly pan for oil change time?

I got the coroplast at a local sign shop. No other place had any, but I've heard you can get it from plastic suppliers.I was going to make provisions for oil changing, but later found that removing 5 screws and two plastic fasteners takes all of a few minutes. Doing this a few times a year is acceptable to me. I also don't change my oil every 3k miles though.

Thanks. It's a really interesting idea and I'll try it. Did you allow a space to let the air dump out as it builds up under the hood when you are up at speed. It has to flow out somewhere, right? There should be enough space behind the belly pan, around the back end of the subframe for it to move through I would guess. What did you fasten the back side of the pan to. Any mid support?

There is tons of room for the air to escape between the wheel wells, and where the exhaust pipe goes through. No problems there.I used two of those expanding plastic fasteners with the pin in the middle to fasten the back side of the pan to the subframe. I used an existing hole for these. I also fastened it on the sides close to where the little air dams are in front of the tires.

Got it, Daox. Thanks again. edited... how big a sheet of coroplast did you use?

I think I mentioned a while back, the plug of my block heater had been drug on the ground and the prongs were pretty shot. So, after seeing Ben Nelson's nice Marineco plug in for his Metro I had to get me one of those. I ebayed one and took some time tonight to install it.Here we have the patient for tonight.Here is the damage done.I wanted to put the plug in an easily accessible location. The hardest part here was finding a relatively flat surface. This place worked out perfectly. A 1-7/8" hole saw and a few seconds and we had this nice hole punched in the bumper cover.Next, I cut and stripped the heater's wire. Thankfully the ground was marked and was easily identified on the Marineco plug. I also added dielectric (conductive) grease to everything to prevent help prevent corrosion on the plug and leads.Last but not least was to tuck it in and tighten things down. It just fits in there, but it fits nice.

nice job!

wow thats neat.. more pics when the snow clears!

Quote, originally posted by lunarcrusader »wow thats neat.. more pics when the snow clears!+1 --- your trix is super salty...mmmm

Well, the snow definitely isn't gone. But, the wife did run the Matrix through the car wash today. Here are some zoomed out shots of it.All tucked in ready for warmth in the morning. I keep the block heater on a timer that turns on roughly 3 hours before we leave for work.

Nice Work! That looks pretty slick!

Time for new summer tires for the Matrix. The previous tires I had were General Exclaim UHP, a summer performance tire. They were a great grippy tire, and oddly enough rated as a LRR (low rolling resistance), but they only lasted one summer. So, I picked up a different set of LRRs, Michelin HX MXM4's. I got them mounted on my summer wheels and put them on the car last night. I also went from 215s to 205s so its a skinnier tire too. I'll got to test out their usefulness this weekend as I went out to LaCrosse area. Its about 200 miles one way, so I went through about 3/4 tank of gas. Just gotta wait for the wife to fill it up today likely.The MXM4s on air blender wheels!Nice tread pattern. I can see why its LRR, those grooves are HUGE, I'd say almost 1/4".Also, again (I do it yearly), these are my winter tires that say 35 psi max sidewall. I use them all winter at 50 psi. After two years and probably ~15k miles they still look like this.

Bad news for the Matrix. According to the past few oil analysis test I've had done, I have too much silicon in my oil. I called up the testing facility and talked with them trying to find out what it could be. It sounds like it is from coolant leaking into my oil. This means a bad head gasket. It also means increased wear on all engine components that require oil. I'll be changing the oil one last time very soon to see if switching oils makes any difference. If there is no improvement, its time for a new head gasket at the least.This does make sense. My average mileage has been slowly slipping down (versus last year) for no apparent reason. The last long trip I made was last weekend and I didn't even break 40 mpg! I took the same trip last November and averaged over 44. Time to test compression and/or do a leak down test to see if thats a problem. Any other tests you might suggest?

Good idea to keep the oil changes up if you've got coolant mixing, hopefully it's no too bad and doesn't cost you an arm & leg.

Thankfully, it won't cost too much. I'll do the work myself, so just parts and machine time if the head needs to be resurfaced.