If you put a resistor and keep it there for a while, the long-term fuel trims WILL get adjusted and mostly negate your "adjustment". Adjusting the resistor and seeing how the car momentarily changes fueling does not tell you how it will run if you actually keep it on.

I can adjust my fuel pressure by 5-10 psi (which you have to admit is a huge change in fueling compared to what you're trying to achieve) and the stock ECU learns and adjusts for the change within minutes and runs just like before (oh and I have a wideband to look at also).

Screwing with ECT will probably affect the fans (they normally start at ~205F and stop at ~195F).

And monitoring O2 sensors? Lol, monitoring narrow-band sensors tells you very little. And monitoring them while the car is in closed-loop mode (i.e. anytime you're not under heavy throttle) is useless as the computer immediately adjusts fueling to cycle between lean and rich every few seconds or so.

Even if this worked, it would be a broke-man's SAFC, which itself is a poor-man's "piggyback".

 

You won't get any gains, but if you want to try to reinvent the wheel that thousands of others have of all models, be our guest, it's only your own time and money you are wasting.

Our engines run VERY rich stock. Adding more fuel to the fire won't do anything, and as Radu said, the ECU will learn around anything you throw at it anyways.

 

http://cgi.ebay.ca/97-99-00-01-03-05-07-Hy...=item4ced702007

 

<div class='quotetop'>QUOTE (JDN902 @ Feb 3 2010, 07:39 PM) <{POST_SNAPBACK}></div><div class='quotemain'>http://cgi.ebay.ca/97-99-00-01-03-05-07-Hy...=item4ced702007</div>
Thats very similar to what I made except the parts cost $2.99.

In response to RED ZMAN's post, I am not re-inventing something everyone else has done since almost all posts are for resistor only static temp value designs that will cause a decrease in performance when used in warmer climates. I was just offering my version and way of doing the mod. Time and money are nothing since it took me minutes of research to figure out which wire I wanted to intercept and since the part is $2.99 and the rest of the wire was already in my garage why not give it a try. And maybe your engine runs rich stock but mine doesn't with my current mods which make it run lean.

In regards to Radu's post regarding the long-term fuel trims overiding the sensor, I thought just like you did and that the o2 sensor made the final say in closed loop but from my tests running the IAT at different temps both above and below ambient outside temperature I got interesting results that support the IAT sensor has a slightly bigger role in fuel trim management on our cars than you think and I can drive for weeks without resetting the ECU due to performance issues which seems to be caused more by the way I drive the car at that time than anything. I also havn't played with the ECT sensor yet so I have no idea at all, if any performance benefit can be found by doing this, since I am more interested in controlling the fans than anything especially for $2.99. And who cares how much money you spend on your high end mods when you can you build your own for pennies utilizing stuff thats already there. At 172,000 on the original engine and tranny my car is running way better now than when it was new.

I will not deny the fact that this IAT mod does have performance benefits when adjusted right on "my" car in both closed and open loop operations. Who knows maybe I have a freak car or ECU that has bad wiring or something and this mod allowed me to bring the sensor values back to where the ECU produced the most power with my current mods which are only a performance air filter, better flowing exhaust, poly engine mounts, suspension upgrades, with good plugs and wires. I see that no one has it in them to try this for themselves since 95% of all posts on the internet are against this idea. If you lived near me I would love to show you the effects and difference it makes on my car in person, granted its not so much the increased HP thats worth it so much as the smoothness it brings back to the engine especially at idle and during gear changes and at WOT the car doesn't seem to struggle like it does using the stock sensor.

Since I have polyurethane engine mounts that cause horrible vibrations through the car and any change in the way the engine starts running increases the vibrations beyond a comfortable level. It used to suck sitting in line at a drive thru having to use your leg to hold pressure against your steering wheel to prevent it from vibrating so bad that you can barely hear what the person behind the window just asked cause your keys are jingling so loud. lol. At time the vibrations seemed almost as bad as watching the car idle with the MAF sensor disconnected.

The shaking started and progressed after I had installed a "new" IAT sensor a while ago. I didn't think much of it and troubleshooted tons of sensors in my search of these idle vibrations that would diminish @ 1,100 rpm or higher and ended up replacing a bunch of sensors only to find they didn't make much of a difference in the end. Thats when I started using my scanner and checked out my IAT and tested the old one only to see that it was reporting about 15degrees colder than ambient temp and the new one was right on the money. After I put my old sensor back in the car for testing, reset the computer and ran the car for awhile I noticed the vibrations were at a tolerable level so thats when i built an adjustable IAT that still functions normal like the old IAT only it starts off 15degrees cooler than outside air temp.

Oh well, I could go on forever on my theories about how this might or does work for "me" but im tired of typing.

 

It's your car dude, do what you want. You asked if anyone here has purchased them, and I can probably voice up and say no, no one currently here has.

Why?

Because the folks that did promptly sold the car and moved on because it didn't give them 55 WHP or mad game.

Most of us here have been here long enough to have had this same conversation, YES, the EXACT SAME CONVERSATION, at least a dozen times.

One out of ten new members, or maybe more, thinks the same way. "Oh, it'll be different because I'M doing it"! LOL No it won't.

So, go for it, do a before and after dyno. Then fix your wiring, throw the resistor away, and re register under a different name.

And I'm SPENT!

 

<div class='quotetop'>QUOTE (RED ZMAN @ Feb 3 2010, 10:59 PM) <{POST_SNAPBACK}></div><div class='quotemain'>It's your car dude, do what you want. You asked if anyone here has purchased them, and I can probably voice up and say no, no one currently here has.

Why?

Because the folks that did promptly sold the car and moved on because it didn't give them 55 WHP or mad game.

Most of us here have been here long enough to have had this same conversation, YES, the EXACT SAME CONVERSATION, at least a dozen times.

One out of ten new members, or maybe more, thinks the same way. "Oh, it'll be different because I'M doing it"! LOL No it won't.

So, go for it, do a before and after dyno. Then fix your wiring, throw the resistor away, and re register under a different name.

And I'm SPENT!</div>

Ahh. after a quick search I see your posts relating to megasquirt ecu's.

Why would someone who is hyping up ECU replacements and talking about custom fuel maps want some newbie to come into this forum and start talking about little ways to fine tune your sensor signals to squeeze out a few extra hp from your stock ECU. Its beneficial to people who have a few mods done to their car that are already bringing extra air in and could use a slight fuel bump that otherwise couldn't be obtained without a different ECU. And even megasquirt has on their website articles talking about using potentiometers to fine tune the IAT.

And I did search this forum only to find a few posts for the "Resistor" mod that takes the place of the IAT. I personally think thats a bad mod too. My idea is different than those posts since I mentioned using a Potentiometer to modify the existing IAT sensors signal just enough to make a difference. Sorry it doesn't achieve 55 rwhp but a mod that affects how my car runs that takes minutes to build and only costs a few bucks is a mod. And if the theory behind it made sense then I would have tried it myself. Does this forum have minimum horsepower requirement for a mod before it can be turned into a DIY post?

If you read my original post all I was asking was the resistance of one of those ebay joke chips cause I was thinking about making a DIY thread on it and wanted to mention that. But my bad for tossing out technical words which brought out the nay sayers on this subject. Besides its not like im trying to sell this idea or make any money off it, I was just going to explain to this forum how they would install the part from radio shack and how to adjust it by going off the short term and long term fuel trims. Thats all, no harm done.

Just trying to pass on a usefull mod that works on my tiburon even if the performance increase is minimal. It still works.

I never thought this topic would turn into such a touchy subject and get out of control like this.

Hopefully I don't get banned from here for this post! blowup.gif

 

It's cool dude, I'm sure you won't get banned. But when someone reads Ebay chips in the title they automatically come to tell you don't do it which is for good reason. However, if you can show some proof that it does work than that would be great. You get what I'm saying?

 

OH SNAP yeah that's it, your mod is going to hurt standalone ECU sales... lol
People who fork $$ for a standalone are people who are heavily modded N/A or run turbo setups, neither of which will resort to a resistor to tune their car.

If the IAT values would affect timing, then a resistor might do something. But for fueling, our car runs pretty rich stock, I am very doubtful that a lightly modded N/A would need more fuel. Less fuel - maybe (which is why some use 1.8 ECUs)

 

<div class='quotetop'>QUOTE (Bommello @ Feb 4 2010, 02:23 AM) <{POST_SNAPBACK}></div><div class='quotemain'>proof</div>

. . . does not consist of butt-dyno numbers. The placebo effect is strong with this type of modification. A/B/A dyno tests and fueling charts after several driving cycles without resetting the computer, so the ECM has time to learn what is going on between changes is the ONLY thing that will convince this crowd. Otherwise, as you have seen, you will get nothing but flak from haters and direction to proven systems from the helpful.

 

The subject isn't out of control at all, and i did read the entire thing several times.

The megasquirt has nothing to do with what you are talking about my man. If you looked harder, you'd find that there have been discussions on this subject for over 10 years in the Hyundai world.

You are brand new, have less than 15 posts, and are determined it will be different for you, or that you have a new twist!

You don't my man. Others have said it here too, you are wanting to try to tune your car in a basic manner with one of these modifications, using narrowband O2 sensors too.

Everyone is just trying to save you headache and embarassment.

As for what Radu said, he's right, no worries, your "performance chip" will have no effect at all on any sales from any vendor here. Your comments won't get you banned, but now folks see who you are even more so. I make no money from any of the MS sales, I just help do R&D for products and show to members here.

Let me go find the thread of the extensive mods you've done to your car. I did quite a bit before my Megasquirt, I mean a LOT, and my engine still ran VERY rich with the stock ECU. Don't know how yours doesnt.