DIY EFIE for less than $5.

[omgwtfbyobbq]

The only people I've heard of running electric prelubers, oil pan heaters, and blockheaters w/o 100% needing 'em are gearheads.

Originally Posted by rh77

So, let's say it's 20F. I start the car, and immediately place it in "D4". Ker-chunk, and we're off. Letting the vehicle idle along until some signs of warmth has been my style since I started tracking mileage. Cold start idle guzzles the fuel, but is the engine taking a huge hit then?

Not any more than normal. If ya give it gas it may warm up faster, but it'll still rev relatively high and have the same rich mixture till the emissions system is up AFAIK.

[trebuchet03]

Hrmmm.... I could be wrong... but I do remember from the EE course I took a few semesters ago that raising the ground voltage without raising the input voltage just lower the deltaV... I assume the mfr's practice good EE skills and the O2 sensor input is isolated...

I've done a cheap hack with computer power supplies to get 7 volts from a combo of the 12 and 5V lines.... Make your 12V + end your positive and the 5V your ground -- the difference is 7V... Not exactly a "proper" current loop, but it works

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IIRC, that's a basic voltage divider... so R2/(R1+R2) *Vin = vout.... So (10/1760)*13.8=+.0784V

I have these components in my parts bin... perhaps I should just mock it up to confirm

[MY02WRX]

yes, letting your vehicle warm up plays a very important role in engine life. Putting a strain on cold unlubricated bearings is bad. Also, you driving and putting a load on your engine will cause certian engine components to warm up quicker than others, this causes expansion, if for instance the pistons get hot and expand faster than the block/cylinder walls you will freeze you pistons to the cylinder walls, seen if a bunch in 4 wheelers and motorcycles, because people start them and rev them, not good.

You have to look at the long run, even though you save a buck or two on gas today, whats it going to cost you in 30k when you spin a rod bearing? or freeze a piston. To me, making my engine last 300k over 100k and using a few more dollars in gas is well worth it.

The gas that is wasted in warm up is very very little, honestly I think you would use more gas at 20-30mph driving in an optimum gear, rather than just idling.


I understand this sites desire for mileage, but when you make fun of ricers and such, some of them, not all of them, but some of them actually take better care of their engines than the average person does. An exhaust or intake will NOT hurt the engine, yea it sounds like **** and looks like a coffee can, but I can about bet you 85-90% of them will tell you they let their cars warm up when its cold.


My brother has a 94 civic Ex Coupe with a JDM B16a, AEM Hybrid intake, JDM ITR 4-1 header, and full exhaust - cat (bad for emissions, but we are in IL, so no worries). Anyway even though he has an LSD close ratio 5 speed, that runs right around 5 at 80mph and around 3800 at 55, he still gets 35-40mpg, because with all the stuff hes done to it, yes its a ricer, but he had it tuned, via Hondata, and the result was more power and better mileage. The point is he changes his oil with synthetic every 3k, and trans with synthetic every 10k, checks plugs every 5-10k, air filter just as often, he is a service freak, but when its cold, that car does not roll without the temp being off cold, no way no how.

If you want to increase warm up time, make sure the heat is off and no blower is on when you start the car. For oil sake, make sure the car is on a flat surface when its cold started, and if you really want to take this to the limit, buy a block heater, they are fairly cheap, but your cold starts will be more like warm starts.

This is all the info I can give you, I know only little about mileage, but I can tell you more power*** more power efficiently*** and efficiency will net you higher mileage. Less weight, setting lower AKA Lowering it PROPERLY! ricer stuff can actually create better mileage in a Civic.

Don't flame me, I've tore up civic's rebuilt civics. Drove Accords, and worked on about every other Honda. If your worried about fast idle at start, you should probably consider going to a psychiatrist because the little amount of fuel you are using during a cold start is not enough to make more than .1 mpg on a full tank of fuel.

If you save $500 this year on fuel, but spend $500 next year on an engine or a rebuild, what have you gained? You have lost time, plain and simple.

Last, use synthetic oil in transmission! Redline is probably the best.

All in all, your engine is about 95% of its maximum efficiency, especially if you drive a VX, Honda left LITTLE behind in its design.

[MY02WRX]

If you rev your engine to create heat so it warms up quicker, you are taking hours and hours off of its life.. But hey, its your engine not mine. My WRX warms up for 5-10 every morning.

[MY02WRX]

Also dry sump is an electric oil pump, your performance cars use them. Actually the 2007 Corvette z06 uses dry sump from the manufacturer.

It is designed to scavenge oil quicker, reduce crankcase pressure and deliver oil to vital engine parts better and quicker.

All in all dry sump is unbeatable in anyway, but very expensive.

[MY02WRX]

exactly, your internal alloys are also designed to work in conjunction with heat, so one does not expand more than another or quicker than another, but heating it to fast will sure make em do what they were designed not to do!

[omgwtfbyobbq]

What what what?

[skewbe]

A blueprinted race engine might have clearances that require careful warmup procedures, but your typical commuter engine won't care.

[skewbe]

Anyway, csrmel and treb, anyone

if your car has a wideband o2 sensor, and you want to adjust it lean, it may a no-brainer. You can do it with one variable resistor like this


According to the following graph, the lower the voltage is going to the ecu, the richer it thinks the mixture is, and the leaner it will make the mixture in response:

[trebuchet03]

Originally Posted by skewbe

Anyway, csrmel and treb, anyone

if your car has a wideband o2 sensor, and you want to adjust it lean, it may a no-brainer. You can do it with one variable resistor like this

Yeah, I got that... Just the reasoning in the OP seemed backwards to me:

if you change the ground to be +0.07v instead of ground then the o2 sensors output now becomes 0.45+0.07=0.52V!

~Just making sure my memory isn't totally relapsing