Tuning Gurus... Help!

[SCALILOU]

Hey gang, I have a question about my recent KB 2.8lc installation. Last week I installed the stage 3 kit from KB. It comes with a flasher and a loaded tune for the car (2008 GT500). Car starts right up, idles good and drivability is good. The only problem I am having is at WOT. At about 4000 rpm, and starting at 50% throttle, the car stumbles and bogs, basically falling on its face.

Car ran perfect before the KB install with my TVS and Lund tune.

HERE'S MY QUESTION....

The KB stage 3 kit is designed to be installed on a basically stock GT500. The tune that is included is also for stock components...

When I had the TVS I had installed 13-14 injectors (56#) in the car and figured they would be fine with the KB, but now I'm thinking if KB's tune is written for the stock injectors, wouldn't that cause some drivability issues?

Any help is always appreciated.

Lou

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[enormous]

Man, that engine bay looks awesome with the the KB on it !!!!
Sure someone will come right along and help you.

 

[SCALILOU]

Thank you. I worked hard on it lol. I think the problem is going to be the injectors, I forgot about them during the install and it's not easy to change them out with the KB. I'm removing it now lol

Man, that engine bay looks awesome with the the KB on it !!!!
Sure someone will come right along and help you.

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[HKusp]

You definitely need to account for the injectors and any BAP/voltage booster(s) you may have.

 

[SCALILOU]

Yep, I knew that but was in denial because I didn't want to take the blower off. But I did, knowing that was my only choice.

Pulled the blower,changed the the injectors, and buttoned everything back up.

I just got back from taking the car for a drive and scaring the shit outta myself lol. It's fast... Real fast. I have to learn to drive it really light footed, very crisp throttle response.

Thanks for the reply anyway

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[bg302]

I installed the same 2.8LC kit on my '10 back in March. I replaced my injectors with a new set of stock injectors, you're right, they would be a PITA to change after the fact. The larger injectors are going to cause you issues with the KB tune. The KB tune is written with the stock 47# injectors being used. You're likely running a tad rich.
I did notice with the KB tune in my car, when I launch at the track, there is a slight bog, no matter what RPM I launch at. Other than that, the KB tune works well. I recently did a Lund remote tune and at my last track session, no bog at the launch now. I'll load the KB tune back in after race season because I'll have to go through emissions at the end of the year. The KB tune has the CARB cert.

 

[Willie]

You definitely need to account for .... any BAP/voltage booster(s) you may have.

This is a myth. No changes to the fuel pump voltage table needed. The PCM learns and makes adjustments IF necessary. I know. I have the JMS which has a max of 22 volts, a 4.2 KB with the largest available pulley (4 inches) making 21 psig, and I tune myself.

Lou, I don't know what's included in the stage 3 kit, but I assume the Gimme 5 intake is. So I am confident saying that the only notable (important) differences in the two tunes are the MAF Transfer Function, and injector values. Any other differences are simply symantics and are not critical. Both injectors are Ford, data readily available for both and they are close in flow, so I theorize you can run one injector with the other's data, and because the difference is somewhat minimal, the PCM is within its parameters to adjust without throwing a rich or lean code. As for the MAF, no! Using data not meant for the specific intake would easily throw the AFR off. Note: Sometimes, two wrongs make a right. In your case, if you did not change the tune, a larger MAF tube would lean the mixture, but the larger injectors would richen it. The unknown is how much of each. It's possible but not probable, that both "wrongs" can result in one "right". Your AFR might be close to correct but derived from the two sets of data that are wrong but offset each other. And also important to note: If the MAF is off, so will your load calculations, which throws a whole other bunch of things off, so this is a no-no.

My tune is highly modified. Excluding the typical changes seen in any modded tune, it includes proprietary alterations (close to 200) specifically changed to optimize my methanol system. I have discovered, designed and implemented these changes so that I can modify my commanded AFR and timing with methanol WITHOUT affecting the before mentioned items when the methanol system is not armed (used). In essence, I have created two separate and distinct tunes in one, switched by simply arming the methanol system. The tune in conjunction with an interface circuit I built and installed allows the progressive methanol system to "send a signal" to the factory PCM saying, "I'm armed, switch tunes." Therefore, it is a 100 percent safe system with zero percent chance of "what if" occurring, i.e. the "wrong" tune, thereby eliminating the human factor. Methanol gives me the same advantages of e85 (great knock control / increased octane) with a few other advantages not seen with e85, and with NONE of the nasty drawbacks of e85. There are several, unfortunately these facts are oblivious to many.

No other tuner, professionals included, know about my tune accomplishment.... yet. Even with all the changes in my tune, the FP voltage table remains stock. This is a pic of it from my tune. Red values indicate higher than stock, blue is lower, and black is stock. Notice all are black. Processor code SXH1 (2008).