Little Blue Project Log

[Tygen1]

I haven’t really considered making a project worklog before, but recently I’ve been thinking about writing up one. Maybe it’s because I finally have some direction in improving this car. Anyway, this is a good forum to do this and I hope you guys enjoy the silliness!

Background: Some may remember from my entry into last years COTM contest and the lengthy story about this car, so I will spare the details and just hit the high points. My wife bought this car new in Aug. of 1998. It’s a Denim Blue with Blue interior ZX2 Cool with ATX. After we were married in Aug. of 1999, I began driving it and when the 3yr/36,000 mile warranty ran out, I began doing the service. The only trouble we had with it before 100,000 miles was the alternator going out. Other than that it was a rock solid car and the even the original tires lasted nearly 90K. After the 100,000 mile tune up things started to go wrong and I really loathed the car until I found this site and was able to tame the vibrations, get it running well and driving well. After joining this site around Oct. ’03 I started to mod the car for a little better performance. Installing a K&N filter and the Keman intake were the very first mods, but it was the Knock sensor that really got me excited about doing more mods. Next came a cat back from Trubendz after the stock exhaust rusted out after 200K. Started to get some crank walk and the ATX was acting up so sometime around 215K I put in a motor from Yellow2000SR and a junkyard ATX. Then the mods really started to speed up with a Powder UDP/ODP, POTS, EV6 Injectors, SVTF Header and high flow cat. It was MechTech’s 40+ MPG thread and $4 a gallon gas that really served to inspire some mods to get better MPG. I joined another Forum, Ecomodder.com, and it has been instrumental in educating me in what works and what doesn’t to get better mpg. Since then I’ve added: a 400w engine block heater, 150w oil and transmission pan heaters, lowered the car by 1.5” by cutting the stock springs, completely blocked the lower grill, removed the mud flaps, made rear fender skirts, put on a 5” Home Depot Garden Edging front lip, did the Coil On Plug conversion, made a manual shifting box for the ATX, created a vacuum leak, made a mild Hot Air Intake, got an Iceman intake to replace the Keman intake, put resistors on the EPC transmission solenoid to up the trans pressure, and put in the 5.6K ohm resistor on the IAT to advance the timing a little. These are not listed in any particular order.

So this brings us to today. What is the purpose of this project worklog? To get the best mpg possible within my limited means. Why? I just can’t afford to make another hot rod and I drive this car 80+ miles each day for my commute and saving money with my growing family is primary. Right now the car has just under 265,000 miles, has turned a best

[Tygen1]

Now to quantify these changes:
First: Torque converter lock will not be a difficult task and is not likely to yield much improvement because I’ve been able to reduce the number of stops and starts in my commute quite a bit and the shifting of the ATX is pretty efficient to start with. However I have found that by needing to speed up to 40 mph to achieve torque converter lock sometimes means I am going faster than traffic and need to slow down to 30-35mph which is quite inefficient because of torque converter slip. If I can lock the converter in 3rd gear, then I will loose less during those situations. If I didn’t find myself in those situations everyday, I probably wouldn’t be doing this. I believe I can do this very cleanly by using a small momentary push button to activate a latching relay to switch between lock and allowing the PCM to control the TCC. The key will be choosing a properly sized resistor to fool the PCM into thinking it still has control so it won’t go into limp mode when I take control of the TCC. In the reading I’ve done, I’ve seen improvements as much as 26% http://ecomodder.com/forum/showthrea...-10028-13.html on a Toyota Previa driving in mostly stop and go traffic and hilly terrain which would maximize the improvement from this type of mod. I don’t expect this much improvement, but I believe it justifies the time and expense involved.
Second: Lightweight wheels and Low Rolling Resistance Tires. I’ve been eyeing the Original Honda Insight wheels and tires. Combined they weigh around 24 lbs and are much more aero friendly than most rims. The tires are Bridgestone Potenza RE92’s and are not only LRR but are also some of the lightest tires available at 13 lb’s http://www.tirerack.com/tires/tires....t&autoModClar= I’ve read about as much as a 10% improvement from using this combination. Additionally they use the same bolt pattern and offset we use J
Third: Lean Burn. Right now I’ve just made a controlled vacuum leak that has maxed out the Long Term Fuel Trims and caused the motor run slightly lean, http://ecomodder.com/forum/showthrea...g-10237-4.html I have no idea how much though. So next would be to purchase a Wideband 02 Sensor http://www.innovatemotorsports.com/products/db.php to see where I am now. Next step would be to force the PCM into Open loop and alter the AFR via MAF signal modification http://autospeed.com/cms/A_110767/article.html I’ve read about improvements as high as 29% by going from 14.7:1 to 18:1, so this modification should be very effective if the motor can tolerate burning that lean. In its current lean state, I see improvements around 4-5mpg instantaneous readings during light load cruise, this is a very significant improvement and the motor is tolerating this amount of lean very well.
Fourth: Aero Improvements. I believe the LRR tires and Aero Improvements will be key to making 18:1 lean burn possible. Otherwise the engine load would be too high to allow that lean of operation. The ZX2 starts out with a 0.33 CdA, which for 1998 was good, today that is not that great and really a Prius at 0.28 is not that good either. The goal would be to drop the CdA by 30% from 0.33 to 0.23, which has a theoretical yield of 9.8% improvement in fuel economy. This is also very ambitious, but I believe it to be necessary. First of all I need to get some baseline numbers to see what my CdA is now, http://ecomodder.com/forum/showthrea...-car-1610.html There are two areas of the ZX2 that will need to be addressed: Trailing wake behind vehicle and the wake at the side of the vehicle. These appear to be the two highest contributing drags now that I have blocked the grill. A majority of the wake at the side of the car is due to turbulence created by the front wheels. I’m not exactly sure how I will deal with this, however I have read about two methods. First is to bring the front air dam down to the ground with virtually no ground clearance to block all air from running into the front wheels then put on front wheel skirts to keep all air from interacting with the front wheel wells. The next option would be to have a more mild front air dam that is designed to deflect the air under the car and around the outside of the tires without using front wheel skirts. This method would be considered a compromise to a full-blown aero treatment and is best engineered with CFD programs and wind tunnels, however it would look nicer than front wheel skirts. Both options would include a belly pan and side skirts. The rear of the vehicle is probably the highest contributor drag and this is true of all vehicles. The angle of the rear glass of the ZX2 is approximately 24 degrees and optimal is around 15 degrees so this presents a problem. The method I have been exploring is to raise a spoiler up to make a “virtual” angle of 15 degrees if you measured the angle between the top of the spoiler and the top of the rear window. So far this experiment has been a failure, however it has given some direction. The next step will be to tuft test the rear of the vehicle to see how the air is acting now, then I will attempt to build a more flat spoiler that extends off the rear deck, think Bonneville salt flats racer. Two examples of this are the Hot Rod Camaro that achieved a 0.21 CdA with a raised spoiler http://www.hotrod.com/techarticles/b.../photo_07.html and the Ford Fusion that was taken from 0.34 to 0.21 http://ecomodder.com/forum/showthrea...34-0-a-85.html Additionally, the underside of the rear is important, so it is necessary to build some sort of diffuser that would combine with the rear and sides of the deck lid extension making a sort of car carrier attachment tail cone which would connect via the hitch.

By now you are either “all in” or you have “checked out”. I realize that 99.7% of people just won’t understand or care what I’m doing and I really don’t care J It’s much like taking an Escort and putting a turbo on it. What are we really doing here? We’re just having fun with what we got. If I am able to average 50 mpg during this coming summer that will be a 100% improvement over what this car was rated at by the EPA and that places the ZX2 within the top percent of vehicles listing their mpg improvements. I think that would be pretty sweet. The added benefit of these mods is they also help other performance pursuits. Light wheels can help

[Tygen1]

Ok, now a more conventional post with pictures.
Here is the oldest picture we have of the car, probably late '98

and here is a one from today...


and now for some mostly random pic's with some explanation:

The three different intakes I've tried. Stock, Keman & Iceman.


The three different alterntor pullies I've tried. Stock, Focus & Powder.


SVTF Header:

SVTF Header Installed:

Highflow Cat installed into midpipe:

Highflow Cat on car:

Reference this thread for the full details of the header install. It also has links to the cat.
http://teamzx2.com/showthread.php/89...ht=svtf+header

Circuit Diagram for Manual Shifting Box for ATX:

Finished Box (minus TCC control):


BSFC chart for 2.0 Zetec:


Best Time Slip Eva!: Car# 7422


Fairly recent engine bay shot with Hot Air Intake hooked up:


ZX2's are great mini bike haulers:


Detail shot of rear wheel skirt:


Some say that cutting the stock springs to drop the car is not good. No problems so far:
Front strut before and after

Rear Strut before and after

Front gap before

Front gap after

Rear gap before

Rear gap after

Result of struts:


Vacuum leak:


Best T-shirt Eva!


Yes, my wife and I were married in the ZX2


Trubendz Boooorla!


Yep, I've tried a ram air...


All work is done on the patio.


Trans and Oil Pan heaters installed.



One time a ground hog took up residence under the hood...that didn't last long


250,000 miles till your rack bushings will wear out

[Tygen1]

Ok, here's a little update. Couldn't really do much work to the car this winter, just too much snow. So I've been thinking about, researching, and doing calculations to try and determine the true potential benefits from the modifications I listed.

I started out with the Lean Burn theory. I found a formula that uses the MAF reading to output MPG, then by altering the AFR I am able to see how the MPG changes. Formula is (AFR*6.17 pounds per gallon of gas*454 grams in a pound*VSS in mph)/(3600 seconds in a hour*MAF) MAF is measured in Grams Per Second and MPG is related to fuel use which is seen as Gallons Per Hour. The graph I am attaching was made using the normal MAF range I see at 50mph. The formula seems to be predicting the real mpg numbers I see, therefore I believe the predicted improvement is probably real. Potentialy a 12% improvement from going from 14.7:1 to 18:1.
This formula also seems to predict that I am running around 15.3:1 with the vacuum leak that I have now, which seems reasonable.
If the formula is correct I would be going from the 52-57mpg of instant readings that I see now to 64+mpg instant readings at 50mph.
Because the potential improvment is so high and the cost is fairly low, it is mostly likely to be the first modificaiton done.

I have also been working on sourcing those rare orginal Honda Insight wheels. I have been able to find them for $50 each plus shipping. When I add in the cost of new RE92's, the cost bollons to almost $600. I really need to find a better deal or a better way to make this happen. Additionaly the wieght of the wheel may be higher than I thought. I found a person saying the wieght of the tire and wheel combo is 31 pounds, so a 13lb tire on there means the actual wheel wieght may be higher than I first thought. The Mazda Miata BBS wheels are around 10 lb's each, so they may be a better option....need to spend some time on this.

[zetec00]

Nice job, I like what you're doing here. Would an AC/PS delete gain some MPGs? Just a thought.

[ZeroF0rce]

This is intense, but very good stuff. I like what you're doing and applaud you on it, cuz i sure as hell don't have the brain for it.

[Tygen1]

Nice job, I like what you're doing here. Would an AC/PS delete gain some MPGs? Just a thought.

Yes they would, next time I have the motor out those will happen. There is not a huge benefit, but it is a worth while mod. I just fixed the Powersteering about a year and half ago so I don't want to trash all that hard work

This stuff really isn't complicated, it just takes some time to process and understand things correctly.

Thanks for the comments!

[Tygen1]

Ok, back in the groove....kinda.

Wide Band is on it's way and I am scheduled to do some undercar work this coming weekend. I doubt the wideband will be here in time, but I will weld in the bung and get things ready to go.

Now that summer gas is here my mpg's have risen nicely. My last tank was my best ever commute tank at 46.59 The three before that were all 45's. This is very encouraging, mods are starting to pay off. I even got my best to work individual commute today at 52.8mpg, although traffic coming home was crazy so I ended the day at 45.4 average, that's the breaks This tells me the car is capable of quite good mpg, given the proper circumstances. I am very excited to try Lean Burn and here is why:

Driving technique is the most important thing for mpg and then modding your car to compliment that is next. I've refinded my commute pretty well to eliminate many stoplights and have learned to time lights better and this helps, however stops lights and such are such a big killer that those techniques and routes only help to minimize the losses. The big gains, for me, come on the highway. I make my gains on the down hills by feathering the throttle to just maintain my speed at 50mph. Doing this I see instant mpgs around 70-100mpg for maybe a mile or so. This really racks up the mpg number, however as soon as I get the the up hill, the real challenge starts because the instant mpg will drop into the 25-45 range, depending on how steep it is and if it is a long hill, then it can take away all of the gains. This is where I'm hoping the lean burn will help, if I can keep the load light enough, I might be able to continue gaining on the up hills vs. trying to minimize the losses. I believe the potential gains here are pretty big and this is why I believe the Lean Burn will complement my driving style and commute.

Enjoy!

[99fordzx2]

Subscribed. Reps


-D

[Tygen1]

Wideband is here.....hopefully get it installed this weekend and see how lean I am running.

[zetec00]

That is the same one I have installed. I think you'll like it!

[The_underclassman]

What have you noticed with the COP setup as far as acceleration and throttle response?

[Tygen1]

The only difference I noticed with the COP setup is that I no longer have to buy plug wires. They seemed to make no difference at all. The benefit may be so small that I could not detect it. It cost me the price of a good set of plug wires, so I'd say it was worth it.

[Tygen1]

Well, the wideband is in and calibrated. It was actually a pain to install, I thought it would be much easier...the hardest part was the guage. I went to the junk yard and got a dark charcoal trim piece, because I don't want to cut up my nice (hard to find) blue ones. The place I picked was not deep enough so the gauge sticks out quite a bit. I'll just have to go back and make a mount for it another time, also need a mount for the scangauge, so I guess I'll take another weekend to do that. The other part that bugged me was trying to get power and ground. I finally gave up and just spliced it into the PCM's power and ground, they ought to be stable enough....No USB cable...what's up with the RS232??? Either way, it's in an functioning.

Only took one drive with it, to the grocery store and back and in just that short time, I learned a whole bunch. If you've read thru most of this Log, then you'll know I have a "vacuum leak" going that has helped my mpg. Doesn't seem that is the case. Wideband says I'm ocilating between 13.5 and 14.5, which I presume is normal running or worse yet, so even though the Fuel Trims are maxed out, it is still compensating. The only exception is that on start up the the mixture is lean 16-17:1. During regular idling it is 13:1 and WOT is 13:1. Interesting stuff, so I'll first reconect the "vacuum leak" and see how that changes things. So even though I'm getting crazy good mpg at 50mph, there is still a lot to be gained by going to 18:1. After I get a good feel and with the "vacuum leak" reconected, I will install a potientiometer on the MAF and disconect the O2 sensor to force the PCM into Open Loop.

[Tygen1]

Finally got the MAF fooled tonight. Just using a simple Voltage Divider on the MAF. Doesn't take long for the PCM to figure out the sillyness going on and correct it. However, for the couple miles it takes for it to figure this out, it is sweetness. Cruising along at 50mph at a 21tps (this means a nice light load) I was getting around 55mpg with an approximate 14.7:1 AFR. Flip the switch and the AFR goes to 18.5:1, TPS needs increasing to 23 to maintain 50mph and the MPG shoots up to 75-80 No decernable ping, just a big time loss in power, but not really an issue till you get to a large hill, then just turn off the Voltage Divider and back to 14.7:1.

The O2 sensor cut out was a giant failure. The PCM goes into "Oh Snap, what just happened mode" or "Limp Mode" and it forces it into 2nd gear and for some reason the TPS goes to 99. Looks like that ain't happenin. So I'm wondering if the MIL Eliminator Circuit wil work to fool the front O2 sensor while I'm fooling the MAF? What made me think the O2 sensor cut out would work was a time last year when I bottomed out and smashed up my O2 sensor and the PCM when into Open Loop. Car opperated normally, just real rich. I was expecting this to happen again. Maybe by putting in the MIL Eliminator, it might still compensate because the MAF reading will be way lower than what it expects....

Just some thoughts...but I'm real excited to get this working right. 75-80mpg at a steady state cruise will get some great improvements in my commute.