Hello everyone!
 

Just popping in to say hello to all you guys on gassavers! I have a 1992 Civic VX with a 1994 Civic Si drivetrain. See my car's profile for more info.

Hopefully the Gaslog feature you guys have here will keep me on the straight and narrow - and stiving for more mpg. As I registered a 47 mpg just recently, I really want to get to 50. Look forward to reading some of your experiences and suggestions.

Currently I employ the following tactics for better mileage:

Higher tire pressure (40psi)
The car is lowered
Large front lip (2.5")
Short-shift at ~ 2000 rpm
Drive at or below speed limit (65 for majority of my commute)
Throttle-shut coasting down grades (lovin' the fuel injector shut-off!)
Allow loss of momentum on some uphill grades
Occasional drafting (but maintaing about 4-5 car lengths)

Glad to find some like-minded nuts. 8)

Welcome Welcome... it looks
 

Welcome Welcome... it looks like the take over of the Honda owners has gained more momentum.

Tell us a bit more about yourself. How long have you been a fuel economy nut, etc.?

Glad to see so many Honda
 

Glad to see so many Honda guys around.

Well, I have been a fan of efficency for a long time. Doing more with less is a personal motto.

I remember trying to amaze friends with my 1986 Trans Am when I was in junior college - I was able to get 28 mpg (which isn't too shabby, but not really that great). That particular car was the low output V8 with 2.73 rear gears and a TH700R4 overdrive transmission.

After getting married and being out on my own, I started looking for something that got much better mileage. I still wanted something fun to drive though. Initially I wanted an Si hatchback, but the VX came available first. It lacked performance up front, and because of a failing O2 sensor, the mpg wasn't awesome, but it contented me (38-40). I had every intention of upgrading things as they broke. And that I did - at 215k miles, the repair/maintence bill on the D15Z1 was such that I could replace it with a lower mileage 1994 Si drivetrain for about the same price (at the time, the VX engine needed the $380 O2, was ready for a timing belt, the input shaft bearing on the transmission had just went...). So out came the D15Z1 and in went the D16Z6. I really wanted it in there for performance, and actually expected some loss in mpg. Little did I realize that I would actually better the old Z1's figures with the Si drivetrain. \

So now I have a fun commuter that does decently well at autocrossing, runs a low 15 sec quarter mile, and has gotten as high as 47 mpg (although not all of those at the same time lol).

I'm an engineer (systems by trade, mechanical by training), so I like to try and apply learned principles as much as I can to my hobbies/interest). I have several ideas that I'm working on, and hope to be able to report back to you guys with better detail in the near future.

Thanks for the interest, and thanks for the welcome.

Re: Glad to see so many Honda
 

Hurray for more engineers! I'm an ME by schooling as well...about to take on the role of Manufacturing Engineer.

*sigh* A civic VX...I'm
 

*sigh* A civic VX...I'm jealous. If only I'd been smarter as a teenager and bought one. I actually went to look at one since I was so amazed by Honda's 72 mpg (Imperial gallons...damn Canadian resellers) claim.

Sweet - more analytical
 

Sweet DaX - more analytical types means we can debate crap till the cows come home. :evil: My wife hates that. lol

Hey haven't I seen you before? Honda-Tech maybe? Yeah, that's it! I don't post much there, but it is a great resource. Most of the time I'm over on sohchonda.

95metro - yeah, I like the VX and I really got it for a steal ($2800 about 5-6 years ago.). I hope to rebuild the D15Z1 with a few modifications in the future. Finally found time to remove the head and it's kinda crusty (carbon - I believe the valve guides were leaking as well as slightly worn rings). My brother-in-law has a 90's Metro also - and he loves it.

yeah, the vx quotient here
 

yeah, the vx quotient here is getting pretty impressive. (and welcome to the site!)

Re: Sweet - more analytical
 

Yeah, my fiance hates it when we get together with some fellow students and start yammering on about this and that technical mumbo-jumbo. :)

Yeah, I used to be all over H-T. I kind of stopped going there once I found this site, as I had already blown my turbo motor twice and was already on the fuel-conscious path. I thought I recognized your username from there. It's still a great resource, but when a few of us tried talking the mods into creating a Mileage forum, we got lots of flack. I still plan on building a high horsepower setup someday in the future, but for the time being, this efficiency / mileage kick is pretty good, plus it's (a little) easier on the wallet.

Anyhow, glad to have you and looking forward to hearing your input on discussions.

Re: Sweet - more analytical
 

Welcome fellow N-gin ear.

so what have you done to
 

so what have you done to make it such an avid auto-x car?

and what mods do you have to run low 15s?

EDIT: when re-reading my post it looks like im doubting you, but i am not, i just want to know your setup.:)

No problem - I like
 

No problem - I like skepticism lol.

Well, I wouldn't call it an "avid" auto-x'er, but I do enjoy it. Here's the modifications that I have done:

Modifications:

1994 Civic Si Hatchback engine/trans/ECU/exhaust

Dynatech 4-1 Exhaust Header

Flowmaster 50 series muffler w/ 2.25" rear section

Omnipower adjustable coilovers (448lb front, 336 lb rear, lowered ~2)

KYB GR-2 Shocks front/rear

Air intake resonator removed

Stock air intake box/pipe with K&N panel filter

15" Kosei K1 Wheels (light - 14.2 lbs each)

195/50/15 Tire size ( tire brand does vary :) )

"Home Depot Front Lip" spoiler (2.5" plastic edging attached with self-tapping screws)

So, I really have an Si in a VX body. The VX weighs less than the Si (by about 250lbs), so that's part of why I am able to outperform a stock similar generation Si - in both acceleration and gas mileage. Not to mention the mild aero tweaks that come with the VX (partial block-off of radiator, some underbody panels that reduce turblence and drag).

no skepticism, just
 

no skepticism, just curiosity. your setup is similar to mine.

i have a d16z6 in a cx, but i still have the pea shooter exhaust
my full setup is listed here:
https://thecarspace.com/thisisntjared

the dynatech header looks super nice, how do you like it?

i love my setup as well, super fun to drive and easy on the wallet. i picked up the shell for 1100 and the motor for 300 then i sold my 4door for 1400 hahaha.

Your car looks excellent.
 

Your car looks excellent. And it is very similar - execpt that I don't have ANY sway bars. Hence my comment about it not be "avid" lol. Very similar setups indeed. You have a much nicer car than mine though. Do you like your suspension setup? I need at a minimum a rear bar, and some sticker tires for auto-x.

I really like the Dynatech unit. Read my review here: https://www.sohchonda.com/forums/inde...showtopic=3018

Yeah, if you do it right, Hondas can be economical all the way around - nice buy!

thanks on the compliments,
 

thanks on the compliments, im sure in person your car is just as nice, right now my car isnt looking too pretty since i still have the winter rims and tires on(hx rims are waiting for something sticky)

btw the cf hood is gone, i have a factory red hood with paint that is flaking on there now, much less undue attention

picking up my sway bar setup was the best thing i did for the handling. i had the stiffer springs for a while, but putting on the sway bars makes it feel so much more stable going into and coming out of turns.

i LOVE my suspension setup, but if your on a budget just go for the good old integra 14mm rear sway bar without having the front. it leaves the same bias as my setup and rolls more, but it is still a HUGE improvement over turning barless. i drove for 2 years without any sway bars, then i had just the 14mm rear bar for 6 months before i upgraded to the 21mm/22mm setup for the passed 3 months.

i would say just go for the itr rear setup, but it does get scarey if dont have a front, like with brake oversteer and even throttle lift oversteer when daily driving.

where are you located? i have 2 14mm rear swaybars. all you would need is the lcas.

nice write up on the header, it looks like its a good couple steps above any dc sports header.

Thanks for the offer on the
 

Thanks for the offer on the sway - but even with you being in Southern NJ, and me in Northeastern AL I think we are still quite a ways apart. :D

I think I will eventually get a rear bar, as I feel the setup could really use it. I've heard so many people say how much of a difference they saw with the addition of the bar.

Yes, the Dynatech is a very nice piece - although I can't compare it to DC sports since I've never had one.

I'm concentrating now on improving my mpg - when I finally saw a little over 47, I felt the need to get 50 ;) After that goal is reached, I'm sure 55 wouldn't sound too bad either.

Thanks for the warm welcome.

If you really want to see
 

If you really want to see some sizable gains in mpg, aeromods, LRR tires, and synthetic transmission oil are where it's at.

You could be getting over 60 mpg.

I recommend the following:

-rear wheel skirts
-custom rear spoiler for improved fineness ratio(You'd have to design and build it. Aftermarket spoilers are by and large for either looks or downforce, not reduced drag coefficient)
-shaved door handles
-covered wheels
-FULL underbelly, not a partial one like you currently have!
-FULL grille block
-low rolling resistance tires for 15" wheels
-tweaked gears so you only need 1500 rpm for the highway speeds you drive
-synthetic transmission oil


Not only would you have a sizable increase in gas mileage for very little additional cost(well, the new gear ratio might be expensive!), you'd have a dramatic increase in both passing ability above 60 mph and in top speed from the reduced aero drag provided you still have access to your original gear ratios used to get up to those speeds.

Aeromods would shave 0.1-0.2 seconds off your ET and add 3-4 mph to your trap speed very easily.

CF hood
 

I was wondering how much less those carbon fiber hoods weigh? I was thinking of getting either one of those, or there used to be a kevlar racing hoood that used origonal latch and hinges on E-bay, it might still be there.
I've noticed that alot of the "CF" hoods on E-bay are really fiber glass over a plastic skeliton, with a layer of carbon fiber on the surfice just for looks.
the hood I have on my vx right now is rough, between someone backing in to a corner of it, and the whole thing haveing hail damage, it's one of those things that I've thought about, but I of course would want to repaint it to match the rest of the car.

the cf hood was half the
 

the cf hood was half the weight of the 35 something pound oem hood. the 'oem looking' hood on my car weighs like 5lbs less than the actual oem hood, however the paint on it sucks.... get a light weight battery, pull the ps/ac, get an aftermarket header first.

Re: the cf hood was half the
 

who makes a light weight battery? I was thinking a few small gel cells would most likely work, and be smaller and lighter for the same capacity, but is there something better?
I already pulled the a/c and the civic vx never came with power stearing, I didn't think any of the hatch backs did.
An after market header? all of them that I've found were intended for 1.6 engines, and woudl detune a 1.5 and would be really bad at low rpm's because of how much larger diamitor they are.

I think Jared speaks from a
 

I think Jared speaks from a weight and performance standpoint on that one, because his dc header lost him so much weight.

Re: Sweet - more analytical
 

Yup. I drive trains too. Mechanical.

Re: Thanks for the offer on the
 

Hurray! Another Southeasterner!!!

the starter only needs
 

the starter only needs something like 220 cranking amps. so i went to walmart and picked up the lawn mower with 230 ccas. i then went to the home appliance section and threw it on a scale to see if it was worth it. 13 lbs. yah its worth it. it took off more weight than the hood

so ive been running a $20 lawn mower battery for a year now and it weighs as much as a 'race battery' but is 1/4 the cost.

the difference between the 1.5 and the 1.6 is really marginal, but you are right about losing your sub 2000rpm power. i never ever, 3V4R |V3V4R drive at that low of an rpm, ever.

Hey jared, what type of
 

Hey jared, what type of battery is that? I'd like to find it not at wal-mart, :p

Re: Hey jared, what type of
 

each battery has the cranking amps, I think even lawn mower battereis, so you just need to find one that has posts that you can use, or get bold on posts.

I would still be temped to get a gell cell, is there reason not to go with a gell cell?

Here's a thread detailing a
 

Here's a thread detailing a small battery - https://www.honda-tech.com/zerothread?id=695215

The one there is a Hawker EP-13. It weighs 10.8 lbs vs. the stock 30 lb battery. Cost is about $40 for that one - if you can still find it. I did a breif search and can't find that one anymore. But I did find a similar battery here:https://www.stealth316.com/2-dynabatt.htm

But it's like $80.


Toecutter:

The gearing mods may not be that hard to do - I still have the OE VX transmission but it's in need of some r&r (input shaft bearing needs replacement). I saw the Keeps on Rollin' CX that had many aero modifications - the mpg blows the mind. I do plan on doing a belly pan at some point and I'm gathering materials now.

Has anyone done experiments on the rear wheel skirts? I know they are benificial, but I wonder how much and if they depend on other areo mods to be effective.

This is a great site!

Re: Here's a thread detailing a
 

There's a thread on here (with pictures) somewhere about my complete R&R on a CRX HF transmission.

^ Sweet thanks - I'll do a
 

^
Sweet thanks - I'll do a search.

That's an L3 trans though - how much different is the S20? I mean, aside from the hydraulic/cable and mounting issues? I've seen Mista Bone do a hybrid trans using mix-n-match components...

I talked to bense and if you
 

I talked to bense and if you feel like not doing the working he'd be game to do whatev with your tranny. He can custom build them or blah blah rebuild or whatev, that's all he does, :p

Bense! I talked him into coming over to SOHCHonda.com and sharing his research on the HX/GX engines/valvetrains. Great guy - I'll have to keep him in mind if I decide to go custom. I'm sure between Mr. Bense and Mr. Bone, I could get 'er togther.

On the bellypan note:

I've heard that there are some of the performance types that have tried this and ran into heat problems associated with the exhaust. Something about boiling gas in the tank? :o

I know some of you guys have done the bellypan - have you noticed any problems like the above?

Remind me what an S20 is. I've rebuilt numerous Honda manual transmissions, and all of them are VERY similar. I have yet to rebuild one that uses a cable shifter, but I really want to do this.

L3 - 88-91 cable transmission

Scroll down to see the ratios HERE

S20 - 92-95 hydro transmission (aluminum shift forks)

Mista Bones Page HERE

S40 - 96-00 hydro transmission (steel shift forks)

Note that the S20 is stamped P20/A000 (small diff bearing, CX/VX/LX/DX) or P20/B000 (EX/Si).

Here's another link on the ratios (I haven't checked accuracy though):
HERE

If you've rebuilt several Honda trans, you probably already knewn this. The stamps are what some people go by, but they are also known by the "S" designation (any appliques have S20... on them for the P20 stamps). The hydro/cable that I was referring to was just the clutch, not shifter.

Yeah, I've done an S20 rebuild before. What I was saying is that I haven't rebuilt any H/F series or any K series transmissions yet. My bigest gripe about D-series transmissions is that the shafts don't break down by hand...you'll need a press or puller setup to break them down if you're going that deep into the rebuild.

No problems here.:D

I wish I can pay a guy and he'll do my car highly optimized for FE.

I'm one of those suckers that will pay to achieve efficency. I do it all the time in life.

Hey, I know a guy selling gas pills that you might want to talk to. they need money for their defense fund :P

Didn't you have this idea of phill's as a type of dealership where you got FE cars or supped up other cars to make 40+ mpg?

I can share with all that care. phil is a hard study. he has grasped and worked on his skillz harder than anybody I know on the net or in person.

I expect him to be my mentor in short order!

psy

I'm glad someone is here to stand up for him, he's always being made fun of (I actually can't think of a single occasion, but mehbe I'll start).

Uhm, yes, I had that idea, but what does it have to do with me poking fun at the guy selling gas pills?