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Field SFC VTEC Controller - by FB


Once I purchased the Civic Type R (CTR) intake cam for my 1995 GSR Sedan, I had a huge hole in the midrange from 4500-5000 rpm.  The CTR intake cam usually kicks in around 5800 rpm, whereas my stock GSR ecu was telling it to switch at the factory 4400 rpm point.   This was too low of an rpm (not enough flow), so the engine bogged.  I had a few choices:  Get a new ecu (haven't heard favorable things about ecu's besides raising rev limiter, also not very flexible), wire my own VTEC controller (not a good idea with my duct tape and a hammer approach), buy a commercial VTEC controller.  The last option seemed to make sense to me, and many people have had good luck with the Field SFC VTEC controller, which also provides fuel tuning with the ability to richen or lean 20% from the stock baseline at 8 1000 rpm intervals (1K, 2K... 8K).  The fuel tuning actually "works" since it comes after the ecu.  Mechanical methods, such as an adjustable fuel pressure regulater, may only richen the mixture so much since the ecu will attempt to compensate (leave injectors on for a shorter pulse for example).   Finally, the Field provides an adjustable shift beep notification and can display your speed in Kilometers (oooooh).


Hank at HP Engineering   performed the install, which involves splicing into a few wires for the ecu.   The directions from Field were "okay," but their diagrams didn't exactly jive with my ecu.  Hank had to cross-reference a few service manuals and the Field directions to figure out which wire to splice.  I "mounted" the Field itself in the little shelf under the factory cassette radio (my Alpine deck and amps were "liberated" by some punks).  This is a great location since I can see and tune the unit quite easilly.


I set the Field X-over to 5000 rpm, left fuel at stock (all 0), and went for a test drive.  The annoying hesitation was gone, just a nice linear pull!  This was great, and made the car much more driveable.  Over time, I have found that the stock Honda ecu runs VERY rich, especially uptop (above 6000).  I am basically leaning at every point, by as much as 10% in the upper ranges.  The flexibility is ideal, since fuel needs can change depending on the weather (cooler=denser=more fuel) or even the situation (extended crusing=lean=fuel economy).  I vary the x-over slightly, but usually around 5000 is the best.  I have the shift beep to 8100, which is helpful when autoxing, so I don't have to watch the tach. 


What did the dyno say?   Well the ACS Racing Dynojet showed no increase in peak power, but the midrange was now about 7-10 HP stronger.  You can certainly FEEL this on the road.   Actually, I think the fuel tuning helped a little, but at the time I dynoed, I thought I had to richen uptop to make more power.  I got the most power with fuel at 0 uptop, but now lean a little bit and the car feels even stronger.  This helped me pull my best recorded dyno au naturel of 173.x HP and 124.X TQ.



copyright (c) 1997 Franz Bayog
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