Hey everyone. I am having an issue of which tuning to buy. I currently have a horrible tune by Mika, their 550cc tune. I was planning of buying the Chris Tapp 630cc tune, but a friend of mine has that and it runs pretty bad at idle, and runs richer than I would like it to throughout the rpm range. So I got to thinking......
I am going to build a microcontroller to control an extra set of injectors that will be mounted in the manifold behind the stock injectors. Using a voltage clamp on the mafs, the controller will turn on when the stock ecu would usually read fuel cut voltage from the mafs. By finding out the relation between the voltage sent from the mafs and the mass flow rate, I can use any mafs on the market. Using a wideband o2, a data logger that stores and calculates values from the mafs, a map sensor in the manfold, injector pulse width, fuel pressure, cam and crankshaft position sensors and the knock sensor, the controller will add fuel as necessary so that the car wont run lean, and it will run like stock when you are not under load. Building the controller will be easy, the coding shouldnt be too bad(C is pretty simple) and mounting the injectors will just take a couple of hours...and I already have the spare manifold and 630cc injectors. I have already discussed this with a friend of my dads who builds/tunes VW racing engines for a living, and he was telling me that someone had already done this a while back.
So what I want to know is if anyone has ever heard of this, and if so, the company that did it. I am curious to see how it worked out for them. Also your opinions are welcome.

 

I would either dump it for another chip of just get a full ems. What was the Tapp a/f like? The idle could be caused by incorrect injectors, which is the case 90%+ of the time.

 

Nope, correct siemens injectors, a/f using wideband around 10:1. I pland on being around 12.5-13.0:1. I am not saying that his tune is bad, but from what I have seen, I would rather go standalone, but that is, to do it right, around 2-2.5k.
I think Im going to build it. I see no reason why it wont work. And if it does, then I saved 500-800 dollars, since the parts cost less than 100 dollars.

 

dont be going past 12-12.5 in boost, your asking for trouble over that.

 

lol....the mika tune is running about 14.0:1 right now.....it is truely horrible.