Tunign the ITB

[Anonymous]

Ok lets see if I understrand this correctly.

So the ECU controls how much fuel the motor gets, and keeps it so the air/fuel is dead on. Now with the independent throttle bodies, my mtoor will eb able to get a lot more air. But the ECU can only ocmpensate for so much, becuz the injectors/fuel system can't keep up. Therefore if I put in bigger injectors and a new Pressure reg, boost the pressure a bit, assume the pump is good enough, then the ECu will eb able to add enough right?

So as long as I add the injectors and regulator, it shouldn't lean out? Or do I have to tell the computer, by tuning, that it can give more gas.

I thought I knew a lot about our MPFI system, but I guess I do not. I know the basics and how it works, but not how to modify it.

Thanks a lot for any help!

(btw:I ordered the 6 throttle bodies and 50mm air horns and the fuel rail to the tune of a lot of money, they will be in next week. My flanegs are being cut as we speak and should be done around the same time, maybe a few days later. I have found tapered pipe, and will order that soon.)

PICS WILL BE UP AS SOON AS I GET THE BODIES

[RacerX11]

I don't have time to go into everything right now, but the quick answer is you will have to retune. The bigger injectors and higher fuel pressure will alter your air/fuel ratio EVERYWHERE (idle included) so to make it rich enough at the top end, you will be running too rich everywhere else. With the ITBs, you are going to drastically alter the shape of the power curve (ever seen Michael Smith's dyno plots?), so simply shifting everything up or down won't cut it.

With all the time and money spent on the intake/TBs, don't skimp on the ECU...get a real good retune done on the stock ECM, or consider an aftermarket control.

Marty

[Anonymous]

I want to leave the stock ECU in it for now.

Will I be able to tune it enough with just a chip? If so that won't be a problem since ben will be able to help.

I have seen his curve. BAD low end loss, but it climbed all the way past 7500. Kinda what I want, just not past 7200 or so just yet. So having longer runners will help.

I'd appreciate if you went into it deeper when you get a chance.

Hey Ben can you add your comments please?





Hahahaha, spelchek, hahahaha

[Anonymous]

I also ordered a Halmeter, basically a air/fuel gauge.

http://www.halmeter.com/

I will put this in the car and make it not look ricey. And then i will get the TBs on, and start the car. I will adjust the screws to set the idle. At idle I shouldn't have a problem with leaning out. Then I will drive around and let the rpm's slowly climb while I slowly add throttle, and see when it starts to get lean. Then I will stop. I think this will eb my first step.

[RacerX11]

The Halmeter is just a narrowband oxygen display. You can do the same thing with a multimeter, or buy a 10-segment LED $35 air/fuel gauge from Summit and use your stock sensor. The 30 segment Halmeter display doesn't give you any more resolution, as you are limited by the narrowband sensor output.

Marty

[Anonymous]

Honestly I'm ordering it more becuz it will look good in my car, it is square and I can mount it in front of my shifter, not on my A pillar.