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needs to know cheap way to gain 20+hp

5K views 29 replies 19 participants last post by  Pepsibottle1 
#1 ·
Hi I have a stock motor in my 07 focus and want to know whats the cheap way to gain 20 or + horses¿
 
#6 ·
Some research into 'hot' side thermister resistances and math will be needed along with a fifty cent resistor spliced inline between ECT & ECU will give you 5-10hp, but as it's been said already, save for the turbo; you're half way there already.
 
#12 ·
Hell yes I believe it, I've done it twice already! It feels like when you add a K&N cold air system; just a slight difference in performance... and probably more of a mental upgrade. No error codes, no pending codes.

Let's work out the logic: If the PCM is told it's running a few (and that's VERY important, if you eff-up your math and get it wrong by twenty degrees = not good) degrees cooler than it's been programmed to run 'optimally', it does what?! adds air and fuel to warm it all up; the net result is more power and a slight loss of mpgs.

I'm working with a friend to solder up a few different resistances on a few different ECT sensors and pulling with each on a dyno to get concrete numbers... to prove to everyone else what I've already realized.
 
#17 ·
And also if you put a potato in the tail pipe the exhaust will build up enough pressure in the cylinder to where it compresses the air and builds boost. Waalla...boost without the hassle of the turbo system.
 
#24 ·
A light weight Fly on the Focus you cannot tell it revs faster and it adds little to no power

As for making telling the ECU that its 5 to 10 deg cooler then it is wont do a thing on the Focus 20 years ago with the early ECU yes you could see some changes by doing it and in the end it spark knocked most of the time from the added timing , 10 deg now would add maybe .5 to 1 deg and it it wasent needed the ECU would pull it right out because of other things it is looking for

You are correct to a point adding more fuel does cool the Cyl but if you add more fuel and it isnt needed you loose power , just because you add fuel and cool the cyl doesnt mean you are going to make more HP or TQ

Tom
 
#26 ·
A light weight Fly on the Focus you cannot tell it revs faster and it adds little to no power

Tom
granted it doesnt add power, but shaving 16 lbs of rotating mass can be felt, and seen, and heard, lol. my car does spin up a fair bit faster than a stocker, and it also doesn't hang at rpm anymore. it jsut drops right off. (unless the throttlebody is dirty again.[?|] )
 
#25 ·
Since this thread started out with a Duratec, all of my comments below pertain to the Duratec. I assume the Zetec is not much different, but I have never worked on one.

Let's work out the logic: If the PCM is told it's running a few (and that's VERY important, if you eff-up your math and get it wrong by twenty degrees = not good) degrees cooler than it's been programmed to run 'optimally', it does what?! adds air and fuel to warm it all up; the net result is more power and a slight loss of mpgs.
I agree...lets work out the logic!
1-The PCM/ECU is programmed to react to the actual ECT and ACT by adding/subtracting timing.
2-It does not add air or fuel based on temperature. At WOT, fuel is added based on the mass of air the MAF sensor detects, not ECT. If the actual air temp entering the engine is lowered, the MAF sensor will detect a greater mass and will adjust fuel to match this amount of actual air.

adds air and fuel to warm it all up
It simply does not work this way. The ECU does not have a target temperature and does not add air or fuel to change anything. If you trick the ECU into thinking the ECT or ACT is colder, all it will do is add timing. The problem is you dont know how close you already are to detonation. You might add a few degrees and be fine, or you might activate the knock sensor which can pull more timing than you added, taking a step backwards. Bottom line: Without careful datalogging, you really dont know what is happening!

the net result is more power and a slight loss of mpgs
I am almost at a loss for words. I assume you are thinking that you added more fuel and this is where your power gains are from. This is kind of irrelevant, because what you are doing will not change the A/F ratio. For arguments sake, lets say you did add more fuel. How could you say you will gain power when you did not know the A/F ratio to begin with. Maybe it was too rich to begin with. How many stock engines have you datalogged? I datalogged mine when it was 100% stock and the A/F ratio at WOT was so rich it went off the range of my wideband at 10:1! If it was any richer, I think it would have died. Most naturally aspirated engines make their peak power around 13:1 A/F ratio. Chances are that your stock ECU is already running richer than this.

based on it, and other sensors, the computer reacts to change a/f ratio to suit for the optimal setting in the stock maps
Once again, the ECU does not adjust A/F ratio based on ECT

a cold engine creates more NOX and other pollutants, Ford engineered efficiency into the system for emissions sake, not power
You are correct in the above statement as it pertains to idle and part throttle cruising(Closed Loop Operation). Once you go WOT(Open Loop Operation) everything changes. The ECU is not programmed for emissions at WOT, it is programmed to run rich enough to be safe and is most likely too rich for max power to begin with.
 
#30 ·
Like the others have said, there's really no "cheap" way to make big gains in horsepower so be prepared to put a little in if you want to make power. I'd say start with the FSWerks stealth exhaust, CAI and race header (take it off when before you inspect cause it's not street legal, lol) with the flexpipe. Those should be your first mods, as opening up that exhaust and intake will give you a much better base to work on if you decide to do anything else. Plus too, if you went the turbo route, the gains seen there would noticably better compared to sticking with the constrictive stock stuff. Start with that first before you go any further because it will help you out in the long run when you do decide to get into the serious stuff.

If you can, I'd also recommend trying to find a local shop and dyno. The place I help out for charges $80 bucks for a run, not too much but prices can vary between shops. It's worth getting that baseline and being able to track progress. See how much an ecu tune would go for as well. The tough part is finding a place who has knowledge in Duratecs, as Honda shops will probably frown upon you in the Focus. It's unfortunate but I see it all the time. There's not a lot of domestic love around my area :(

After the exhaust and intake upgrades and you want to go further (that stuff will only give you 10-20 hp at the most), you need to decide whether or not you want to go turbo or N/A. Either way, some headwork will help you out a lot in either area. You won't see much of a gain in a stock engine as the Duratec already flows pretty decent out of the box but if you combine a higher flowing head with a turbo and a decent camshaft, you've got a winner. Then just upgrade your internals, valve springs and probably clutch. Concerning a flywheel, you won't see any noticeable horsepower gains but the lower inertia will help throttle and engine response

But for right now, start with the simple stuff and don't get carried away with the radical stuff. A better exhaust and intake builds the base for more serious upgrades down the road. Listen to 1turbofocus, he is Yoda regarding the Focus.
 
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