94EG8

Tonight I was reading a post and someone mentioned the 3 Stage Vtec D15B, and i remembered that it requires a special P2J ECU to operate the second vtec solenoid. Then i got thinking. I recall reading a long time ago that people were reprogramming OBDO ECUs to use either the AC clutch circuitry or the Automatic transmission lockup solinoid circuitry to control vtec. Does anyone know if its possible to reprogram an automatic P28 so that the circuitry that controls the automatic transmission lockup solenoid so that it controls the first vtec solenoid that controls the 12/16 valve operation? I have no plans to do this swap, i'm just curious to know if anyone either thought of this before, if anyones tried it, or if anyone thinks it may or may not work. Heres a link to one site about reprogramming OBD0 ecus to use the AC clutch for vtec just in case it helps explain this a little better.
http://www.xenocron.com/te.php?page=TEvtec

94EG8

Kind of an update, i've been thinking a little more on this and i'm pretty sure there would be no way to get a 5 wire O2 sensor and lean burn to work with this setup. but does anyone have an answer for my original question? or any other thoughts or ideas? I just thought it would be neat to be able to run this engine without having to get the proper ecu.

Relic1

you can use eCtune and use one of the unused outputs to activate a relay to open the second VTEC solinoid, then shift to the secondary maps when you open it.
Should be fairly easy to do.

You can also go with the P72 base in Crome, then add the IAB Control circuitry in the ECU. Tie the IAB output to the second VTEC solenoid and tune from there.
(at least that's my plan when I get a chance to mess with this setup)

94EG8

Thanks, thats the kind of info i was looking for, i figured if i ever had a chance to play with this, which is highly unlikely, i'd control the solenoid for vtec-e with the automatic transmission lockup solenoid and control regular vtec solenoid, mostly because the regular vtec solenoid adds more fuel and i believe changes the timing, as far as i know vtec-e only almost completely closes one intake valve per cylinder to create a vortex that allows more efficiant combustion, someone please correct me if i'm worng on that. As I said i don't have any plans to do this. But i keep seeing these engines for sale and i never really hear anything on them, they look cool though.

Relic1

all about VTEC-E --> http://www.b18c5eg.com/VTEC/sohcvtece.html

which output controls which solenoid doesn't really matter, both ignition and fuel change with the activation of each.
the only main factor is the lower RPM switchover vs higher RPM switchover.

I've always thought that picking up one of these and having a completely custom cam made for it. Normal first stage for mpg, slightly more aggressive second stage, then outrageous third stage. That with some head porting, more compression and a little more lower end work to sustain the higher RPMs.... it would be a lot of fun to pull down really high hp #'s for a N/A SOHC yet remain in the 40+mpg range.
The ultimate weekend track engine IMO.

94EG8

Thanks, yeah I always thought even stock the engine was pretty cool, i don't know why they never used them here in north america, personally i think its pretty neat engineering.

Relic1

honda is a much different company in Japan as it is in the US.
They got to see a lot of different cars and engines than we did.