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Chris86NA2T

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About Chris86NA2T

  • Birthday 09/29/1983

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  1. The turbo ecu and injectors in an NA car is a bad idea. The fuel and timing maps in the turbo cars ecu are far too rich and far too retarded to make good power in a non-turbo application. Your best bet is to use the turbo injectors, and a programmable ecu via nistune. You can take your existing ecu and put a nistune board in it for about 400 bucks. It doesnt matter if you have an NA ecu because it will now be fully programmable with nistune. In fact, you will have a much easier time using your existing ecu because there will be no O2 sensor and idle control wiring issues to change. All you would have to do is change a few values (most notably injector K value and null time) in the NA ecu's program to make it work properly with turbo injectors. By far, this is the best and most cost effective solution. I think its a really bad idea to have someone "map" your ecu without having a running car to work off of. Nistune is only 400 bucks which is less than most places will charge to reprogram an ecu. After this initial investment you have a fully programmable ecu that you can change however you want. At that point, if you dont feel like making the changes yourself, you can drive the car to a dyno and have a program written based on feedback from your cars performance, not some generic off the shelf tune. If you go this route let me know. Ill be able to help you get the basics setup.
  2. The concept of altering AFM voltage is basically what the super afc does. While it may work well on certain cars with different EFI systems, its a terrible idea on a 280 or 300zx efi computer. The efi computer uses AFM voltage as a major part of the load calculation. By reducing this voltage you effectively reduce the calculated load value that the computer is using to choose the correct cell on the fuel/timing maps. Now this can lead to nothing or it can lead to disaster. It all depends on which cell is selected with the new voltage. For instance, suppose you have an AFM output of 3.5 volts while under full load. now you reduce that voltage to 3 volts, the load scales in the maps shift backwards (left). Take a look at this picture.. This is a stock timing map from a z31 (i forget which year exactly).. The rpm is obviously vertical, and the top numbers represent engine load. This is a calculated value. If you are interested in the exact formulas its described very well here: http://ztechz.net/id10.html The cell values are actual degrees of ignition timing, lets look at the cell that corresponds to a load of 80, and 4400 rpm.. At this point you are in the middle of a full throttle run. If you were to drop the afm voltage then you would effectively moved the calculated cell to the left. Suppose the voltage drop at the afm shifted you 3 cells over, look at the timing you would be at.. You jump from 24 to 35 degrees. Regarding the change in air fuel ratio, take a look at a stock fuel map: As you can see, the same thing applies here. A reduction in voltage does not always correlate to a richer AFR. I used to work on a kids r32 skyline with an RB26. He had more money than brains and decided to try and make the car fast. He took your idea to the extreem and used a safc to "compensate" for 720cc injectors. It took me an hour of math to explain to him that because of the changes he made he was running 14-1 AFR's and over 40 degrees of advance which resulted in the holes in his pistons. This is an extreem example. He was basically cutting the afm voltage in half and screwing everything up. Small changes to AFM voltage that only shift the load scal by one cell will generally not hurt anything. It also will not help anything as it is a completly unpredictable alteration. Your best bet is to spend the 400 bucks on a nistune daughterboard (need to have a z31 ecu conversion). This will give you full control over the stock ecu with complete predictability and repeatability.
  3. i did the same thing. i did it once with bolts and once with C clamps. my problem is not the inability to close the case. i can get the screws to engage without a problem. my issue is that i can not draw it down evenly enough to keep the tabs straight and have them slide back into the grooves in the case. the tabs end up sliding to the side and getting pinched between the case and the cover. im trying to find out if other people have had the same problem. do my first pictures with the tabs sticking up look normal? has anyone else had difficulty with the tabs moving out of place while trying to secure the case? if other people have found this to be an annoyance then i know its something i just have to live with. if nobody else has experienced this before then ive probably screwed something up with my setup. as far as flipping the springs, id like to know if anyone thinks that will be a problem. like i said, i cant see how, but maybe someone sees something i dont. thanks
  4. i have a question about the spring disks on either end of the clutch pack. when my unit is assembled the tabs of these disks stick out above the top of the case as pictured here: now according to the service manual these pictures show the spring plates oriented correctly with the cupped side facing towards the outside of the case. the problem i have is that i can not get the case closed with these tabs sticking up like that. they never want to slide back into the groove that they normally sit in, they tend to slide left or right and end up getting pinched between the case and case cover as i pull it together. has anyone else had a difficult time with this? when i flip the spring plates over it looks like this: in this configuration i can assemble the case with no problems at all.. with no shims using kendall LSD gear lube i got a reading of 60 foot pounds with no shims and 75 with two .004 shims the service manual clearly says to pay close attention to the orientation of the spring plates. while i do see how it would be very important to have them all oriented the same way, i cant see how reversing the orientation of all 4 spring plates will cause me problems. i currently have it assembled with the spring plates' "cupped" side facing toward the center of the case like in the last pictures. id like to install it this weekend, so if im missing something critical and there is good reason to not put it in like this please let me know. thanks
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