well, i wouldnt go as far as saying that boost pressure is totally irrelevant...

but for example, in some cases, a turbo that makes 10 psi on a stock motor might loose some pressure if the engines volumetric efficiency is increased... say, by adding a less restrictive exhaust system.. the boost pressure might go down to 8 psi, yet the engine is actually making more power than with 10 psi with the stock exhaust..

BUT, the fact that boost is present gives the tuner the ability to control fuel enrichment by way of whatever fuel controller is used...

my point is that once you have a normalized boost pattern, you CAN create a fuel map based off of it AND using a boost dependent system such as what I described above or any aftermarket one will give you dynamic fuel enrichment which I would prefer over a static fuel map which doesnt account for some of the normal driving conditions that one would experience on a dialy basis such as going up and down hills or parking garages....


smile.gif

 

You basically raise the same point as me back in that old discussion, and I was holding to that point very hard; until the moment I understood that the ECU is there do to it's job.



Say that a car ALWAYS used the SAME amount of fuel; completely absurd, but say it was the case anyway. Then your points would be, at least in part, valid. You could use the input from the map to somewhat gauge your fuel delivery, but it would be FAR from perfect. Like you pointed out, 10psi going up the hill and 10psi going down the hill doesn't represent the same LOAD.

LOAD is what is important in a fuel management system. When you use an SAFC against RPM and TPS, you have a good idea of what the load is. Same with RPM and MAF. But neither are perfect.

But still it WORKS; how come? Because the ECU is doing it's job, and it can ADJUST itself.

The point is this; you do not have to



... as this is the job of the ECU. You do not use a piggyback to do the ECU's work; you use it to compensate for things for which the ECU wasn't programmed for. But it's still the ECU that does most of the work. And it's allright.

Try this; reread your post and change any mention to boost to actual airflow. You should understand that you can do all what you want to do when you know the actual airflow entering the engine, and that be knowing the amount of air entering the engine, you actually know a LOT more than what a single pressure reading can tell you.

 

ok good point smile.gif


that is one reason that I like 5th injector setups...

as long as you have good distribution, you can do wonders and still idle like stock ! smile.gif

 

Yep. An additionnal injector (or two) or a second fuel rail is actually a solution I like wink1.gif

 

Agarwal,

From personel experiance just reflashing our ecu is a waste of time. I had same code as the person above this was when Real ECU tried tunning the ecu for my RD plus mine was s/c'd hehe.. Well technically it worked but always threw that code annoying as hell. Plus everytime I went to the dyno it was reading differant numbers and a bunch of other crap. So it got ditched and went back to unichip.
Anyways I am not all that educated but completly rechipping the ecu would be the only way with this type of ecu. It would actually be nice to have a rechipp then tune/program when every we want sort of like a standalone. Am I wrong in assuming what I said about the ecu. laugh.gif Or is there alot more involved.

 

Reflashing and rechipping basically achieve the same goal; it changes the firmware in the ECU to what we want, so rechipping is not an "upgrade" to reflashing. We basically rechip when we don't know how to flash the firmware directly through the OBD2 port wink1.gif

The code you got, was it the same as LeadFoot, ie (IIRC) P0605 Read Only Memory Error? If so, the problem is the same as with LeadFoot, and I have a good idea of what the problem is. Granted, knowing what the problem is doesn't actually fixes it wink1.gif But it's a step in the right direction.

Like I said earlier, it would be possible to provide a little software to tune the ECU yourself, but I don't know what I'll do about it just yet. I see 2 main problems: first is the fact that I don't know how to flash the ECU through the OBD2, meaning that I'd have to provide a programmer and that the user would have to get the chip out of the ECU, program it, then put it back in the ECU each time he wanted to make a change. The programmer would also keep the cost up. The second main problem is the possibility of "making" chips for their friend, actually giving away my work. Call me selfish, but that's not really what I have in mind.

So, until I know how to flash through the OBD2 port, I don't think I'd offer "user tunability". Makes the product less attractive, but could fit some users needs anyway. I was thinking of offering more than one single chip for each user, more like 3-10, not necesseraly programmed at the same time. Meaning that the user could buy a chip from me, wait 6 months and add a turbocharger, then ask me to burn a new chip which I would do for free. Or he could just get 5 chips at the same time.

Anyway, you guys know that it's still a project, but without projects and ideas, nothing new happens wink1.gif I'll actually make some tests with one of my own tuned chips in my turbo tib pretty soon, so I'll keep you updated on that.

 

you also said you wouldn't need to "retune" because the ECU can adjust itself after its been flashed.. now you are saying you may have to reflash it or fine tune it..
so which one is it? you should have just said its unnecessary to reflash or rechip it, because thats what you told me. :roll:

 

Oh nooo... please reread my posts, *again*.

It is obviously necessery to update the fuel map and the timing if you go from stock to turbo. You also need to be fine tuned enough so the ECU is in the range to get it "perfect". Like it would be for a standalone. There's no magic involved. The ECU can adjust itself to some extent.

You know about fuel trims, right? If not, google for engine management and obd2, and read about that.

 

yeah i know about fuel trims but i said you would still need an S-AFC with it and you said it wouldnt be necessary, now you jsut said it would still need fine tuning... oi vey

 

There's no magic?
What! Ive been lied to my whole life. 02.gif