Can a turbocharger with light boost (5 to 7 psi) improve fuel efficiency for unmodified stock engines like the F22 (low compression), not being raced or driven erratically? If so, would it need to be tuned with an after-market computer? I have heard that the factory ECU can compensate for light boost.

Also, if you were to decrease the compression of a higher compression engine like the B16 to 8:1 and added a turbo, would the stock ECU compensate for that much of a change and run reliably?

 

Fuel milage depends mostly on the driver. Turbos do increase the volumetric efficiency of an engine, making it easier to make power with less effort. So I think its possible to increase mpg's, but kindof unlikely; it all depends on how much time it spends with wot and in high rpms...

As for tuning and ecus; you MUST have your computer tuned for it to work properly. Factory computers do not like it when the map sensor sees boost, it will likely set a CEL. You also mentioned you want "reliability", I would definately have your ecu chipped (assuming its obd1) and tuned, you wont regret it.

 

Correct, but turbo's also increase the Brake Specific Fuel Consumption value.
In N/A trim, you're F22 may have a BSFC of .45
Boosted, you'll see a BSFC closer to .6, if not over .6

The bottom line is: there's no such thing as "free" power. It always costs fuel.

 

lol get a insight if you want to save gas!

 

lol not every car needs to be fast, the highway is not a dragstrip, and older hondas are extremely unsafe in accidents (just watch some crash test videos on youtube, they fold up like paper). When I want to go fast, I have a bike, but a bike isn't going to transport me, my wife, my kids and luggage from ohio to florida, and I'm not spending money on a POS.

Thanks.

 

^ wait bikes are POS or honda's?

 

All hybrids are POS. No matter from what company. They're seriously weak, the batteries are expensive, and they cost too much new. I'd rather have a turbo diesel VW to be honest, but I'd rather stick to what I know.

 

How much gas are you trying to save? Any modern 4 cyl is good for 30+mpg when driven conservatively.

 

I've heard of someone getting upwards of 40 to 50 mpg with high compression (14:1 or higher) using water injection to increase the detonation threshold. I didn't really believe it. I was just wondering how a turbo would affect fuel mileage if driven casually. If it would boost fuel mileage up to 10% on the highway (cruising speeds) that would be worth getting a cheap turbo for me. Going thru the hassle of tuning on a dyno is just too much.

 

I have experienced equal or better fuel economy in all of my turbo civics. Keep in mind this is when I try to get good numbers.

Diesels have high compression, more btus in the fuel and no throttle plate. Most of them have small ports with high velocity.

There are losses caused by a gas engine fighting to draw air through the throttle plate. Running low low boost under low load situations allows the air to be forced into the engine instead of pulled in. Tuning and driving style are the best things you can do. Run very lean and as much timing as possible in low load situations.

Thats just my experience

 

it's all in the tune. i get better gas mileage after installing turbo because im tuning or my driving habit.