turbocharging 2000 civic lx for FE?
 

i have a few parts left over from my mustang 2.3 project upgrades and was thinking that since i went from about 15city/22hi-way n/a to 20city/30hi-way with conservative driving, whats left on the table for my civic? compression is 9.4:1 so boost would be 5-8psi max, and a boost referenced FPR to raise FP with boost to decrease chances of detonation. also to decrease pumping losses and increase power to the point that merging into hi-way traffic or passing wouldnt require more than 3/4 throttle. does anyone have any experience with d-series engines and turbocharging? i went to d-series.org, but the vast majority of the guys there could give a flip about FE and most are in it to make over 400hp and almost always give ricerish responses... i have started a thread after research ,but as i said most are in it for max hp. the parts i have are a .48AR t-3 turbo, manual boost controller, intercooler piping, and silicone adapters. i can make a log type turbo manifold from schedule 40 steam piping and pre cast steel weld ells, a laser cut head flange, and a laser cut turbo flange. i have made another one for my mustang with good results. any help or opinions are welcome and openly invited! thank you!

It's hard to get FE advice on forums like that. It's hard to even ask questions related to FE, even if you don't mention it at all.

I don't think adding a turbo to an engine will increase your FE. The way I understand that turbos help is by allowing you to use a smaller, more efficient engine for normal driving (which can then go into boost when you need more power).

The FE issue with gasoline turbos is that you have to run a little too rich when in boost to safely avoid detonation (or at least that is my understanding).

Adding turbo to a diesel would likely work for FE.

thats exactly what i am needing. in your opinion would a person use more gas at 1/4 throttle with small amounts of boost (5-8psi) and slight increase in fuel pressure, or 3/4 throttle and the trans kicking down 2 gears, rpms going up 2krpms to even accelerate 5mph? i might be purchasing and installing a wideband o2 sensor and gauge and tuning by "ear".

With an automatic it can be hard to reduce pumping losses, because you can't just lay on the gas pedal. However, using a turbo to pressurize the intake wouldn't reduce pumping loss at all; it would increase pumping loss, and merely move the loss to the exhaust instead of having it on the intake.

How about a modification that just prevents kickdown? If your vehicle is old and has a throttle-operated kickdown cable you can just adjust that cable. If it's newer you might be able to reprogram it, or you might be able to install a switch that cuts off the kickdown signal...that last idea is just a guess.

if you are handy with motors (which it sound like you are) just put a d15z1 motor in it.

For the spark ignited ICE, manifold pressure is what's important. Once you go over a couple psi past ambient, you really need to richen up your ratios to avoid detonation and keep piston temps down. You could drop the static compression way down, but then you'd be depending on the turbo for all usable power, then under lower manifold pressures flame speed would be so slow that part throttle efficiency would be terrible.

Higher static compression seems to be the preferred way to go.

what years did these engines come in? my car is and will stay obdII and i get tested yearly, so the engine HAS to be from the same year or later to stay legal here in vegas. apparently only clark county and las vegas smog and carry the same regulations as california. thanks!

EDIT- i just googled this engine and it is from an older obd1 car (92-95), and has far less hp and torque which is a huuge consideration for me.

you are correct about that. I think it was rated 92hp and was from before obd2 but it was also rated 50+ mpg and many on here have attested to those numbers and better.

it was an idea but i understand about the whole legal thing. have you considered playing with the trans? maybe using one with a different running gear (5th gear)?

im fully capable of changing the trans and ecu to 5 speed gear, its just lack of motivation.. not to mention the 95 ex i had many moons ago had little to no rpm advantage over this automatic.. if i remember correctly the 5 speed was almost 3k rpms @ 70mph, the same as my current set up. i know manual transmissions have a mpg advantage over autos, but its generally no more than a couple of mpg difference which is fairly negligible to me.

On manual vs. auto: Manuals only produce a couple MPG difference for EPA estimates, but for hypermilers they make a huge difference. They allow you to control your shifting separate from your throttle; and they allow you to EOC (Engine Off Coast).

However, I think BEEF was suggesting that you change your high gear to a taller high gear, not that you change your transmission type.

I always get the wording messed up so I tend to not word it right.

I did mean one with a taller 5th gear (higher or lower, I don't know) but I was thinking of the CRX HF trans. I think they are taller than normal ones.

there was a guy that took a firefly (canadian geo metro) and swapped in the trans from a 4 cyl into his 3 cyl. the 3cyl had a shorter running gear because of the lower power. he actually lost city mpg but gained highway mpg. overall he gained 5% I think.

metrompg he is a member here though I haven't seen him in a while

Yes- the CRX hf trans is geared like the civic VX trans - I put a crx hf trans in my civic- I run 2200 rpms at 70 mph in 5th gear.

hrrmmm.. is the vx a d15 or d16? i wonder if itll bolt up to a d16, anybody know?

the VX motor is the d15z1 but not sure about the trans. the compatibility of one with another would be hard for me to say.

there are hard core honda guys on here and hopefully, they will pop in and say one way or the other.

PROBLEM. :thumbdown:

You won't make boost at 1/4 throttle. Especially w/ a .48 A/R turbine and that tiny engine. You'd need a SAAB (KKK) turbo, or Audi unit and you still won't make boost unless you put that engine under enough load.... which will require more than 1/4 throttle.

Ditch this idea.

Also noteworthy... you don't tune by "ear" if you have a WBo2 and gauge... you watch the gauge and adjust fuel accordingly. LC1's will run you anywhere from $180 used to $300 new. Worth it?

Then we get to the tranny. Best bang for your buck w/ this car is to swap out the auto trans for a manual and just learn to drive it differently.... seriously. Abandon all other ideas.

yeah, i know tuning with a wbo2 isnt by ear, thats why i typed "ear", i dont consider tuning one system really tuning.. it was more of a joke.. i did figure out how to adjust ignition timing though (painful 2 hours of wading through hondatech junk).. i advanced timing max amount allowed by the dist housing and drove it full throttle and got a little valve rattle at 4600rpm and over, but acceleration is vastly improved at hiway cruising speeds. i know what valve rattle really is, so to keep from detonating (and to test the butt dyno) i retarded the timing all the way and retested, definately no power there, especially from stop/low speeds. i re advanced the timing and backed it off a couple degrees and retested: no rattle/ knock/ pre ignition, and crisp acceleration to redline! i might still toy with a turbo because im a fabricator and cant leave anything alone, but if mileage goes down morethan a couple mpg, the snail gets the axe! thanks for all help, opinions, and constructive criticism!!

Well dragging this back from the dead.. lol.. I didnt get to the turbo because I was too busy daily driving it 500 miles a week but 3the spun rod bearings forced me to tear into it. Long story short, the oil pump pressure relief valve was hung open causing starvation, spun bearings, bent rods, and severly scuffed pistons. This time around it got h-beam rods, floating pin pistons, .5mm overbore, .006" deck, and .012 off the head. I found a dirty cheap log manifold, t25 turbo, cheap air to air intercooler, etc. Next up will be an hx transaxle swap..

You do know that swapping that car from auto to manual does require you to cut out some parts of the floor board underneath the car. As the shifter linkage will not be able to go to the trans their is a hump of metal something in the way. Once you go manual with this car i hope you don't plan on going back. Also have been messing with Honda's for a while now and just going for mpg. I don't think your parts list is their for mpg and you need a 5 wire o2 and a good computer tuning system those are parts in the correct direction.