Ok, I've got a '91 CRX Si wit a SOHC ZC in it. I recently got offered a Z6 head in mint condition for 100 dollars. I would really like to do this swap and have looked into a good bit, theres one thing I'm a little confused on though. I know my car is OBD-0, I'm not sure which ECU I have though (I'll check tonight). But my question is, will I need to source a new ECU or will a V-AFC work fine for controlling VTEC. Any other tips would be much obliged. Thank you very much.

Chris

 

Bump

 

source a p28, and convert to obd1. you will be much happier and the motor will perform better when vtec is wired it up right.

 

I see this posted all the time and my advice is do it right the first time. IMO source a P28 ecu, OBD1 distributor, 4 wire O2 sensor, and a OBD0->OBD1 conversion harness. Just using a switch or VAFC to control VTEC does not account for the change in fuel and timing maps when the engine is running in VTEC. Just run OBD1 and you will be glad you did.

 

Yup yup, http://www.rywire.com
We'll be getting Z6 Distributors anyday now.
We've got your 4-wire O2 for $75, chipped P28 for $225 and the wiring is all on this page:
http://www.rywire.com/sitodvtec.shtml

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rexwreck &raquo;</TD></TR><TR><TD CLASS="quote">So I would say convert to OBD1 if you have money... If not try and chip the ECU.. If you dont mind the setup running kinda rough tune with VAFC.
I'm going through the same exact thing you are right now, and this is what I've come up with.</TD></TR></TABLE>

Ok, So the cheap way to do it right now would be to use the VAFC if I'm short on cash. What if I were to use the VAFC right now and then later on convet to OBD1? Would the VAFC still function? And If it did, could I still use it to fine tune VTEC even with the p28?

Chris

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rexwreck &raquo;</TD></TR><TR><TD CLASS="quote">This setup would run best by getting the proper ECU for the head (P28), which will require an ODB0-OBD1 conversion. You will need the P28, a conversion harness (check out rywire), the Z6's dizzy, and a 4 wire O2 sensor. Or you can stay OBD0 and try to tune it properly. I'm sure if you took the time you could get it to run just as good as the P28. You can use the V-AFC to control VTEC, but you also need to consider the greater VE of the Z6 head. You could try tuning with the VAFC but it doesnt tune "fine" enough. Another option is to have your ECU chipped to support VTEC and tune the fuel/ignition tables. This can be done on turboedit, and VTEC can be engaged by running a wire off the unused A/C clutch relay or automatic solenoid. The tables will have to be adjusted for a basemap, and it is recommended you then at least street tune the car with a wideband O2 sensor. Check out pgmfi.org... So I would say convert to OBD1 if you have money... If not try and chip the ECU.. If you dont mind the setup running kinda rough tune with VAFC.
I'm going through the same exact thing you are right now, and this is what I've come up with.</TD></TR></TABLE>

I'm in the process of doing this right now. I'll be using TurboEdit on an A6 bottom end with a Z6 head, in an MPFI'd STD chassis. This is with a PM6-A09 ECU.

FWIW, it's cheaper than an AFC, too. All of the parts for chipping/datalogging and three pre-burnt basemaps from Xenocron was $71 shipped.

Engine is still being built, so I won't have it running for another month or so.

 

Yes. The newest edition of TE has a ver simple interface for VTEC engagement. No splicing code together. It's just a couple of menu items, now. The biggest issue is the fuel tuning. TE-VTEC is a fairly new concept. There are no MiniMe basemaps yet. So I guess I'll be one of the first.