turbocharging 2000 civic lx for FE?

[hi tech hillbilly]

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!

[theholycow]

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).

[GasSavers_Erik]

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.

[hi tech hillbilly]

Originally Posted by theholycow

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).

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".

[theholycow]

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.

[GasSavers_BEEF]

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

[greasemonkee]

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.

[hi tech hillbilly]

Originally Posted by BEEF

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

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.

[GasSavers_BEEF]

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)?

[hi tech hillbilly]

Originally Posted by BEEF

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.