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Converting LS P75 to VTEC

Discussion in 'ECU's, Electronics, and Tuning' started by araychel, Apr 6, 2004.

  1. araychel

    araychel Junior Member

    I read somewhere that Hondata could convert LS ECU's to VTEC, but they don't anymore. I am going to be doing an LS VTEC and I already have 2 P75's so I would like to get them converted. I have a P28 to use, but why have 2 extra useless ECU's laying around? I am sure that if the P75's were VTEC someone would be able to use them. Anyway, does anyone know of a place to get a non-VTEC ECU converted?
  2. Slammed90Lude

    Slammed90Lude Senior Member

    first, this is wrong forum- second, why would you want to do all that? sell the two P75's and the P28 and just buy a P72 or whatever ECU corresponds to the head you're going to use- THEN get hondata to tune that ECU for your motor-
  3. bklyneg

    bklyneg Senior Member

    usually its like 150 to get it converted. call ericks racing they do it
  4. katman

    katman Member

    Your concern about 2 P75's leading a useless life is amusing, but to answer your questions, NO, you can't use P28 parts in a P75 ecu because the P28 motherboard & P75 motherboard are totally different.

    You might find this amusing tho -- Honda built the OBD1 P75 & P72 (GSR) ecu's on the same motherboard. So, its possible to turn a P75 into a P72-GSR ecu, with the addition of a knock sensor board and various components which are not commonly found on a P28 ecu.

    You're better off selling the P75 ecu's in their stock form (or reprogrammed) rather than spending time on trying to convert them to VTEC.

    just my $.02

    PS: yes, hit up Erick's Racing, he's pretty gifted in the ECU department.
  5. cycloneb18c3

    cycloneb18c3 Senior Member

    they usually rig it up with a msd rpm activation switch, which is ghetto
  6. araychel

    araychel Junior Member

    First of all the reason I put the original post in the "hybrid" section was because this was for an LS VTEC swap into an EG Civic, I failed to clarify that initially.

    Second, I didn't say that I wanted to put P28 ECU parts into a P75 ECU, I have 2 P75's and a P28 that I could use. However, in taking out the D16Z motor for the current B18B that I have in there I obviously have the P28 ECU as a spare. I know that I can use that and have it converted, but I want to sell my D motor and the ECU would help me sell it. I have a few B18B motors and a B16 but I don't have any "usuable" DOHC VTEC ECU's yet that is why I wanted to know about conversions. I am planning on doing the LS VTEC and since I have 2 P75's I figured why not have one converted to VTEC if possible since I have to have one of my ECU's chipped anyway.
  7. radnulb

    radnulb Senior Member


    ignore the bullshit.
    You can convert a P75 to a P72. If you are going to use a B16 head or a GSR head w/ skunk2,etc. manifold and you do not need the IAB (intake air butterfly) valve control, it is marginally simpler to convert to vtec. If you have an auto P28 and you convert it to manual, you can use the leftover parts for the P75->P72 conversion. You might be lucky and have two SK5151 transistors in your P28, even if it is a manual ECU. You can remove one, install J10 and again have your parts for the conversion. DON'T USE SK5050S for P75 conversions... they don't work reliably in my experience.

    Katman, I'm surprised at you on this one. You can indeed take P28 parts to do this conversion. :angry:

    The rest of you are just plain ignorant. Spend some time learning before you start preaching about ECU crap so the PGMFI commandos don't come and school your ass. If you have extra ECUs and you have extra parts, then why waste your money buying another ECU? :ph34r:
  8. katman

    katman Member

    bah...spec overload!
    I haven't got around to converting a P75 to VTEC, its almost not worth doing. I've only gone so far as converting P05 & P06 ecu's...kinda gave up on them as a whole though.

    Thanks for the clarifying Blundy ...
  9. araychel

    araychel Junior Member

    radnulb thanks for the link, it appears to be somewhat confusing but I think that I can figure it out. I am glad someone backed me on converting those 2 P75's because I don't think that I could have sold them for much and P72 pricing is so inflated!! I also didn't want to have to use the knock sensor. Anyway, thanks for the info. It appears that you have done this conversion before, how does it turn out?
  10. radnulb

    radnulb Senior Member

    works like stock when done right. I have 50+ cars running on vtec conversions.

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