GM Stand alone question

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05-05-2015
kbach

GM Stand alone question

I'm new to HPT and had a few questions.

I bought a hot rod a while ago that had a normally aspirated 5.3L Chevy truck motor in it mated to a 4L60E. The harness/computer is a 411 GM unit with a wiring harness/tune from CBM motorsports in Ontario, CA and is most likely an off the shelf tune from them as while it is good in some areas, it lacks in others. The engine setup as installed from CBM is (I'm assuming) a speed density setup as there is no MAF sensor installed. I do have a constant check engine light with MAF codes showing input voltage high and input voltage low (P102/103) as there is no sensor installed but that's another issue...

I am in the process of installing a Vortech supercharger and am now at the point of dealing with the tuning now that it is forced-air. The supercharger was not a kit, it was a custom build that I made all of the brackets, intake piping, etc. so there are no off the shelf pieces that will really help me out.

My plan with the addition of the supercharger is to go to a 2-bar SD OS using HPT.

Here are my questions:
Will I be able to utilize any of the existing map or will I need to start with a new base map?
With going to the 2-bar SD setup, what changes will be required other than changing out the stock MAP sensor with the 2-bar sensor? Any other hardware items that I'm not thinking of?

Go easy on me....I'm new to HPT but have some history with other platforms over the years.
05-06-2015
RonSSnova

When you convert to the 2 bar tune, you will get a bigger VE table. I believe it will be populated all cells the same bogus number. You will need to copy your orig VE values in the top non boost half. Then pick a number to populate the boost cells. Some tuning guides I've read say to put 175 in those cells. It will be dead fat though in boost.
A scheme I used was to copy the 105 kpa row and paste it to the 205 kpa row. Then multiply it by 2.2.
Using the interpolate function, interpolate all the rows in between 105 and 205 kpa.

For your 2 bar map. You will need to know the linear and offset values. These are entered under the diagnostics tab under airflow.

Ron
05-07-2015
kbach

Thanks for the info Ron, it's much appreciated!
05-08-2015
RonSSnova

Sure man. Hope it helps!
05-08-2015
Ranger6202

Since it's a custom supercharger build, don't forget to address your Crank pressure ports. I had to reroute my Passenger side valve cover VAC line to the suction of my turbo (super in your case). Otherwise you'll get a healthy dose of oil puff when you close throttle after Boosted WOT. Passenger side was pressuring my crankcase, throttle would close, and then my PCV would fly open carrying a healthy mist of oil right into my intake.
05-09-2015
kbach

Quote:

Originally Posted by Ranger6202

Since it's a custom supercharger build, don't forget to address your Crank pressure ports. I had to reroute my Passenger side valve cover VAC line to the suction of my turbo (super in your case). Otherwise you'll get a healthy dose of oil puff when you close throttle after Boosted WOT. Passenger side was pressuring my crankcase, throttle would close, and then my PCV would fly open carrying a healthy mist of oil right into my intake.

Good info, thanks!