gnttype.org "bruce" Bruce was very active in the original gnttype mailing list, but posted only one message after they moved to a forum, unless they aged out any older stuff. Reply With Quote #2 Report Bad Post Old 03-04-2006, 11:16 AM Bruce Bruce is offline Join Date: Oct 2004 Posts: 1 Bruce is on a distinguished roadDefault Re: General overview on the ECM's program flow? Quote: Originally Posted by King_V Is there any sort of flow-chart or high level diagram or explanation that briefly illustrates the sequence of events in the coding? Basically, what sorts of things are done in what order in the ECM? Not that I know of. Being's that it operates on interupts, it's flexible about where things lead. There are some what might be interesting threads here, for you to look at. http://www.thirdgen.org/techbb2/for....php?forumid=16 __________________ 87 Black Car, not sure if it's a Monte Carlo or not. But,it has a Cotton's F/M, 60 PPH injectors, and a TA-62 thingie on it. A/C fell off, and the ecm has a few extra smoke holding devises installed. Mini-tubes, and improved brakes. ======================================================================= "Tech Area" article: MAF Relocation Mass Air Flow Sensor (MAF) Relocation Bruce Plecan Introduction The following describes and experiment in relocating the MAF to AFTER the turbo. The MAF used is the LT1 style 3" MAF with the Translator. This is divided into two page ... Phase 1 and Phase 2. This is my first relocation of a Buick V-6, MAF. From what I've been able to gather, the relocation should be OK. The electronics package is good to 120dC, and the operating temp of the *wires* is 70dC. In what testing I've done, I've never actually exceeded the 70dC, in MAT temps (even if the temp was over the 70dC, I'd imagine that allowances are made for that).. The housing itself shows no real weak stuctural places for failure, from boost. The Experiment and Results The *reason* for this experiment was that for at any air flow per Throttle opening the incoming air would be presented in the most repeatable manner possible. While this might have signifigant meaning for WOT, my primary motivation is for drivibility, and mileage. When using an open element, such as a K+N, the air can be rather erratic in how it behaves in the tract just prior to the MAF. While minor, at times, numbers seemed to vary more then what would make sense to me. I 've driven hundreds of miles with it so far, and like it. Like I said, I did this for drivibility, and in my opinion there is alot of difference, and all for the good. Trouble is that it turned cold, and I've had to turn the boost down because of road conditions. It's just all too easily blow the tires off. But, rolling into it and running at 15 PSI has all the grin factor of the past. Also, response in neutral seems markedly improved (much crisper), and idling smoother. How any reversion plays into the new equation is an unknown at this point. I think (as a hunch) think the turbos free running rpm is less of a factor. Like in a panic brake to 0, the immediate idle and recovery is better, but that is one chip area I have been toying with, so it just might be enhancing another variable Notes The MAF to turbo intake pipe clearance is close, even with the 3" MAF, but mine did clear. I'm currently running the Translator +, and extender chip. No adjustments were needed. The pics show, the current installation with a .5" plenum spacer, which changed the angles some, so it doesn't look as pretty. I'm getting ready for installing the 3.5 when the parts arrive. Using the tubing graft was an attempt of just cutting my loses in case it didn't work. Two, 2.5 to 3" hoses would look better, and fit easier. I'm currently waiting on some 2.5 to 3.5" hoses, for the larger MAF. I'm deliberately *risking* going too large, becuase I have a high level of confidence that with this new level of repeatability, might cover for the poorer resolution at the min air flow rates, with the bigger MAF. Engine notes: My combination includes: 206 MM hydraulic roller cam 40#/hr injectors Pocket ported heads (smoothed cambers) THDP ATR 3" single shot Enhanced turbo (the short list) Your results will vary. How much I don't know, nor can I forecast. This very well maybe illegal for emissions. You need to check your local laws for what is legal. I strongly suggest that you mock things together and try it before making any perminant changes. Not to be attempted without adult supervision. Have fun Finished installation - notice the extremely short MAF pipe and the shortened up pipe to the plenum (which necessitated the radiator hose rerouting) The following describes the second phase of the experiment in relocating the MAF to AFTER the turbo. The first phase involvd relocating the MAF to after the turbo (using an LS1 style metal MAF). Phase 2 involves shortening the old MAF tubing as much as possible, and that took reworking the upper hose. The hose was shortened almost 4 inches and it has resulted in better turbo spooling. The hoses used in the project were found by browsing the hose rack at the local auto parts place, and the chrome bits are 1.25" sink drain parts. Since the filter has been relocated, a much larger filter can be used ... no such thing as too large of filter on the intake side of a turbo! Phase 3 will involve putting the 3.5" center section in the 3" housing and installing an OEM blow off valve from another car. The picutres show a 280 ZX blow off valve, which may not be used in the final project, but it does illustrate what they look like. One thing to note is that there are several locating nibs that a dremel /file will make short work of, letting the 3.5 maf fit in the 3" case. When doing the above be sure to reset the Translator Sensor Option. Bits and Pieces Close up of the MAF installation just before the Throttle Body Close up of the 3.5" MAF Close up of the 3.5" MAF dissassembled Close up of the radiator hose rerouting Bruce Plecan Introduction Phase III installation - notice the Blow Off Valve (BOV) mounted just in front of the MAF and the 4" tubing The following describes the third phase of the experiment in relocating the MAF to AFTER the turbo. The first phase involvd relocating the MAF to after the turbo (using an LS1 style metal MAF). Phase 2 involved shortening the old MAF tubing as much as possible. Phase 3 incorporatates a 4" Air Filter to Turbo Piping (modified Eastern), and the installation of a 1st Generation Eclipse Blow Off Valve (BOV). The Eastern Piping originally had three bends in it, but to fit the 14" K+N meant cutting it up and refashioning things. The BOV in OEM form started to open at 10 PSI. To make it operate at a more respectable boost level, Bruce blocked the reference signal port to the bottom of the diaphragm (along side of the piston). Then he drilled a hole from the side to reference the diaphragm to atmosphere instead. At 22 psi, the valve is still closed that way. If you look at #5 plug wire, you can see how much more room there is without the HVAC box. In 2D it's hard to see how much more room there really is! While not fully sorted yet, you can see that Bruce has rewired the loom so it runs down the passenger side of the engine, right by the fuel rail. This makes access a lot easier. As part of the project, Bruce changed the 3" ATR single shot exhaust (too loud) to a Walker Ultraflow 17220 in place of the Pit Bull muffler and then installd the Pit Bull where the catalytic converter was. Now it's much quieter with no noticable loss in performance. ============================================