hot air intake and 87 octane

[hydrastas]

if i did those two things and turned boost all the way down would there be a gain in mpg or would the engine self destruct? im thinking about rigging up one of the boxes for a cai, but would be as interesting to test a hai while im at it . i don't have a logger yet though, which is why im asking, any ideas?

 

[crimsondragon]

ECU will pull timing due to knock. You'll run shitty. That's about it.

 

[knochgoon24]

The drop in performance from switching to a lower octane might actually cause you to get less gas mileage. Your better off spending the extra 20-30 cents a gallon to make your car run right. You'll probably save money.

 

[c_riggan]

The car is designed to run on premium only (at stock boost). Turning the boost down and dropping to regular gasoline is not such a good idea, infact its a bad idea especially when sucking in hot air. Those three things will spell disaster. You will most deffinately get det (knock) which can melt valves, rings, and even your pistons. It would sound kind of like crumpling an empty chip bag when its at an audible level, and then you're already loosing it... The computer should shut you down when this happens, but not worth risking it anyway.

Less power does not always equal better fuel economy. With less power, the engine will have to try to pump more fuel in to work harder at moving, which could actually bring fuel economy down. Hate to say it, but if you need it that bad, go buy a cheap honda for a commuter or something and drive your DSM on the weekends.

 

[crimsondragon]

I've never heard of our cars shutting down when it detects knock. That'll be a bi*** especially with phantom knock.

 

[c_riggan]

Didnt quite mean shutting down, sorry, but backing off a bit I'm sure it will. Gotta have some wort of protection to it. Reason I said should, not entirely sure it the ECU will, but I'm sure it will pull back or something. If it doesnt, then deffinatelty dont even try to put it in the situation..... (I wouldn't anyway)

 

[BoostFrenzy]

if i did those two things and turned boost all the way down would there be a gain in mpg or would the engine self destruct? im thinking about rigging up one of the boxes for a cai, but would be as interesting to test a hai while im at it . i don't have a logger yet though, which is why im asking, any ideas?

Seriously...?

There is a reason why K&N filters guarantee an increase in both HP and MPG. Engines like COLD air. Turbo engines like that very same cold air, but also HIGHER octane fuel. The more off boost power your engine makes in a "stock" set up will yield better gas mileage as long as you don't romp on it all the time. *stock meaning fuel mods and engine internals*

If you do an intake mod, it helps your on boost power, but also your off boost power because it is getting rid of a restriction and making your throttle response better. Better throttle response in this case means more air for the same amount of gas creating a better AFR to create more power. A "bolt-ons" only car will run far better then any other form because it is not too much, and also not too little.

 

[crimsondragon]

Didnt quite mean shutting down, sorry, but backing off a bit I'm sure it will. Gotta have some wort of protection to it. Reason I said should, not entirely sure it the ECU will, but I'm sure it will pull back or something. If it doesnt, then deffinatelty dont even try to put it in the situation..... (I wouldn't anyway)

Like I said, it'll pull timing.

 

[4Motion4g63]

best perfomance downgrade you can make in a DSM is buy a 1.8 car........
I got mine for$100 bucks running and driving, and it drives for a year on a single tank of gass....

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[16g-2ndgen]

is there.. flames on your dd 4motion4g63? back on topic. If your worried about fuel economy, buy a honda or a geo.

 

[BubbleGumRacing]

Like I said, it'll pull timing.

This is correct. Your car will pull timing to compensate for the knock created by the inferior gas. You'll lose HP and Fuel Mileage. If you're after fuel economy keep the car as stock as possible and keep your foot out of it. Oh and do all of your required maintenance.