Archive for the 'Uncategorized' Category

Mar 31 2009

Tips to Improve Your Gas Mileage on the Highway

Published by Benjamin Jones under Uncategorized

One response so far

Jul 11 2008

Mini How-To: CRX Timing Belt and Water Pump

Published by Benjamin Jones under Uncategorized

So it’s that time again. It may seem intimidating, but changing your own timing belt and water pump isn’t really that hard. You’ll also save a bundle by doing it yourself. I’ve done this on an engine sitting in my driveway for two reasons. The first is that I was going to use that engine anyway. The second is that it is easier to see what’s going on from a DIY perspective when all the pictures are not of random hands crammed into an engine bay. Hope this helps!

Tools:
3/8″ Rachet
1/2″ Breaker Bar
Torque Wrench
Manual for Torque Specifications and General Goodness
10mm, 12mm, 14mm 3/8″ Sockets
17mm 1/2″ Socket

Parts:
New/Remanufactured Water Pump: $28
New Timing Belt: $28
RTV: $2

Process:

1. Take everything off so that it looks like this. I didn’t show this but it’s the reverse of installation and pretty self explanatory. I stuffed my water pump hole to the block with a paper towel so junk wouldn’t get in there, by the way.

2. Look at all your parts and make sure they’re all there. They are for me.

3. Here’s your new water pump; shove some rtv into the slot where the gasket sits, and then push the gasket in. Don’t over rtv, just enough to help seal the gasket. Mine is a little sloppy cuz I just used my finger.

4. Position the water pump on the block, fit it on, and finger tighten all the screws. I had to whack at it with a hammer a little bit to get it to fit, but that’s life. Then torque everything down like you should, mine only torqued to 9 ft/lbs, so that was pretty easy to do.

5. Position your cam so that the up on the cam gear is up and the lines are aligned with the head.

6. Now position the crank so that the cutout for the key (little metal rectangle, don’t lose it, I almost did) is up and the mark on the gear matches the oil pump arrow on the block. If I need to label this picture, lemme know.

7. With the tensioner not tensed, slip the timing belt on trying to keep out slack everywhere but around the tensioner. Then tighten up the tensioner to torque, which was 33ft/lbs for mine. Now slip the crankshaft pulley back on and use it to spin the engine (counterclickwise you want to spin it) through two rotations of the crank. After this check to make sure the timing marks you set up before putting the belt on are correct. If not you need to take the belt off and redo it until they are so that the timing will be correct.

8. I got it on the first try, so yay! Start putting things back on and try to keep them clean as you do:

9. Bottom cover on (I didn’t put the crank pulley on yet because I don’t have a torque wrench powerful enough to give it the 137ft/lbs it deserves:

10. Top cover on with valve cover over top of that:

11. Me trying to get flywheel bolts of my blown block in the basement, I’ll just pull the crank and bring it in to work.

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Jul 10 2008

SuperMID: Fuel Economy Display

Published by Benjamin Jones under Uncategorized

UPDATE: Because of the cost and relative hard-to-getness of the SuperMID (though it is awesome), I’ve been pointing people to a DIY open source project called the MPGuino, currently being worked on over at ecomodder.

The mecca of fuel economy is instantaneous feeback. With this you can tailor your driving to absolute perfection in terms of gas mileage. There is no way, none whatsoever, to realize what’s actually happening with some sort of instantaneous, accurate feedback. It also helps to have something that can log tanks, laps, and trips so that you can watch yourself improve or test various techniques and modifications.

The thing that makes the superMID special is that it works for cars that are obdII and pre-obdII alike. The other tool, the Scangauge, only works for cars running obdII electronics (most 1996 and newer models). So, when I learned that a Japanese man named Yoshi had created a device to monitor his Prius’s mileage, and that this device could be used on my 1991 Honda CRX, I was justifiably happy. With this little device I have done more than I ever could have imagined, and I will go into some function in a later argument.

In the mean time, if your car is fuel injected you may be able to use this little baby!!! Send me an email if you’re interested with your information and your car’s information and I’ll see what I can do in terms of hooking you up with one of these things. So far there are only three of us in North America that use them (how exciting)!

Purpose: To better monitor your fuel economy. A week with instantaneous feeback is like a year with tank to tank results.

Time: 1 hour

Tools:
- Wire Strippers
- Soldering Equipment (including heat shrink)
- Anything you might need to access ECU/under dash wiring

Supplies:
- MID and all install contents
- Some stranded wire
- Female/male end connectors

First thing’s first (a little homage to those who helped me get this thing going):

Thanks to Dan and Yoshi. To Dan for his dedication and the ability to hit over 99.9 mpg with the prius making this little device necessary. Thanks for all your help and for giving us the inspiration to know that we can get crazy numbers through driving technique and patience. To Yoshi-dono for building this awesome piece of equipment and for providing great support. I still can’t believe it came from Japan to the east coast of the US in only three days!

Now, before I start in earnest, just let me say, this thing is incredibly well designed. All the wiring is consolidated into a thin, pluggable lan cable that is very easy to work with and will make mounting a breeze! Yoshi kicks butt!

Procedure:

Here’s all the stuff you get. LAN cable, MID, black box.

Expose your ecu. Prolly the most difficult step, but mine is always exposed, so I win.

Figure out which spot on the fuse box will give constant power. You’ll want to power the MID from this spot so you don’t lose data when you engine off coast.

More glorious shots of the device. Notice the red wire coming off for power, will plug up to that wire you saw coming from the fuse box.

Spliced the MID ground into the other ground I use for junk.

All wired up. Yellow to an injector from the ECU and purple to the VSS (vehicle speed sensor).

Temporary mount point until I fab something up to sit in the center of the dash.

Here’s the final mounting, kinda ugly, but it works:

Thanks again to Yoshi and Dan!

NOTES: The speed part isn’t working because I have a mechanical VSS. I am unsure if this is completely because of the VSS or some other issue, but I have upgraded to an electronic VSS and it works like a charm. Get in touch with me if you want to hear more about this and possible solution for your personal vehicle.

3 responses so far

Jul 10 2008

Choosing a Fuel Economy Transmission

Published by Benjamin Jones under Uncategorized

This article will be technically geared towards the CRX and other Civic models from 1988-2000. However, the general implications of these changes are applicable to almost any make and model of car or truck. I will detail my own changes as well as cite a few cases of fellow members from my primary forum: ecomodder.com as well as give resources that will allow you to make your own decision on the matter. While I will be primarily discussing the transmission that will give you the best mileage, there are many forms your gearing can take to meet all of your goals.

First things first, what I did with my CRX. I began with an automatic and could barely squeeze 40 MPG out of it. Needless to say I was very frustrated with its performance. Not only did I hate the gas mileage, I hated the way it drove. So, I embarked on the mission to begin my auto to manual swap. That’s a whole other ordeal, which I will discuss in a dedicated article, but suffice it to say that when I weighed my options I chose the most fuel efficient transmission I could. I wanted the most bang for my buck, and I got it; I picked the transmission up for free from a www.honda-tech.com member. In the end I’ve averaged ~51 MPG over my last two tanks with the stick shift, and I’ve loved every minute of it.

On the technical side of things there are 5 basics transmissions found in 88-91 Honda Civics: the auto, the DX/LX, the Si, the HF, and the STD.

  • The automatic is just that, automatic. It gets terrible mileage and doesn’t have much potential. If this is what you have a swap is highly suggested for greater gas mileage. Even with the most fuel economy-minded transmission the car will seem to have more power. If you can’t drive stick, learn; Hondas are very easy cars for new stick drivers.
  • The DX/LX manual transmission is basically the middle of the road; it is basically the same as the Si transmission with a lower final drive ratio.
  • The Si transmission has the shortest gearing of an US civic transmission from this era. As far as fuel economy is concerned this transmission should be avoided, it will give you ~3,000 RPM at 65 MPH.

  • I have the HF transmission in my car. It was built for fuel economy and it certainly delivers. The gearing is longer than any other car you’re ever likely to drive and delivers a healthy 1700 RPM at 55 MPH on the highway. Without this transmission I doubt I could so easily hit 50 MPG.
  • The STD was the super economy Civic, and as such received a 4 speed manual transmission. This thing is just a step above an automatic and should be eliminated at all costs!

To compare on the technical side of things, here are the gear ratios from the four most used options you will have:

Civic STD
CRX HF
Civic/CRX DX/LX
Civic/CRX Si
Clutch Type
Cable
Cable
Cable
Cable
Trans. Code
L3
L3
L3
L3
First
3.250
3.250
3.250
3.250
Second
1.650
1.650
1.894
1.894
Third
1.033
1.033
1.259
1.259
Fourth
0.823
0.823
0.937
0.937
Fifth
-
.694
0.771
0.771
Reverse
3.153
3.153
3.153
3.153
Final Drive
3.888
2.95/3.25 (CA)
3.888
4.250

For those of us with newer Civics refer to the following tables (gears from these two tables are mixable but not final drives or complete transmissions):

92-95 Civic DX/LX/S
92-95 Civic EX/Si
92-95 Civic CX/VX
96-00 Civic LX/DX
96-00 Civic CX/HX
96-00 Civic EX
Clutch Type
Hydraulic
Hydraulic
Hydraulic
Hydraulic
Hydraulic
Hydraulic
Trans. Code
S20
S20
S20
First
3.250
3.250
3.250
3.250
3.250
3.250
Second
1.761
1.900
1.761
1.782
1.782
1.909
Third
1.172
1.250
1.066
1.172
1.172
1.250
Fourth
0.909
0.909
0.853
0.909
0.909
0.909
Fifth
0.702
0.702/0.750 (HB)
0.702
0.702
0.702
.702
Reverse
3.153
3.153
3.153
3.153
3.153
3.153
Final Drive
4.058
4.250
3.250
3.722
3.722
4.250/4.058 (HB)

For those of us with even newer Civics use this table:

01-05 Civic DX/LX
01-05 Civic HX
01-05 Civic EX
Clutch Type
Hydraulic
Hydraulic
Hydraulic
Trans. Code
First
3.462
3.461
3.143
Second
1.870
1.750
1.870
Third
1.241
1.166
1.241
Fourth
0.970
0.857
0.970
Fifth
0.711
0.710
0.757
Reverse
3.231
3.230
3.231
Final Drive
4.111
3.842
4.412

With these go to this gear ratio calculator and take a look at cruising RPM and shift points that various transmissions will afford you.

There’s not much more I can do to arm you with information, so at this point I will give you some statistics from my own swap and some other information I’ve dug up over the ages. Here is what my gearing looks like across the board (you can see how high it is, my transmission top speed is something like 220 MPH): Now, you must be thinking that with such a transmission acceleration would be brutal, but this is not the case either! My shift points are as follows:

  • 1 –> 2; 1500 RPM, 8 MPH
  • 2 –> 3; 1500 RPM, 20 MPH
  • 3 –> 4; 1250 RPM, 25 MPH
  • 4 –> 5; 1250 RPM, 30 MPH


That leaves me in 5th gear accelerating from 30 MPH. Sure it’s slow, but the fuel economy is amazing, so I don’t mind. My lifetime automatic mileage was 35.8 MPG, and so far I have managed 51.2 MPG with the 5 speed CRX HF transmission; quite the difference, if I don’t say so myself (40%, beat that, acetone)! You can check out my online gaslog here at www.ecomodder.com.

Another forum member, named Darin (MetroMPG) swapped to a transmission with longer gearing and saw what he approximates as a 5-6% gain. This may not seem like much, but when you’re pumping out 75 MPG tanks and 117 MPG segments, it’s nothing to scoff at. You can check out his findings and process in his swap thread here.

I also helped another member upgrade from his 4 speed STD transmission to a 5 speed CRX HF transmission. Not only was the swap a lot of fun, but look at his gaslog. His driving isn’t exactly consistent and he doesn’t drive for great mileage, but the improvement is there. He’s gone from 38.8 MPG before the swap to 43.9 MPG after, an improvement of 13.2%. You can also see a correlation between engine off coasting and gas mileage, but that’s something for another article.

There will be more success stories to come! If you have any questions about parts, prices, or procedure feel free to email me and I’ll give you all the advice you need.

PS: If you’re wondering how to determine which transmission is which for EF Civics/CRXs, check out this picture:

11 responses so far