View Single Post
Old 05-09-2008, 02:07 AM   #7 (permalink)
LostCause's Avatar
Join Date: Feb 2008
Location: California
Posts: 504

Thunderbird - '96 Ford Thunderbird
90 day: 27.75 mpg (US)
Thanks: 0
Thanked 7 Times in 7 Posts
The VX engine (d15z1) is the same anywhere in the world, as far as I know. People have swapped in JDM d15z1's and registered them successfully in CA.

The only difference is the O2 wire and ECU. The CA model uses a 4-wire narrow band O2 sensor while the Federal model uses a 5-wire wide-band (which is $$$). I believe the Federal ECU is the P07 model. Unlike most other Honda ECU's, it cannot be modded.

On GS, one member made the sensor/ECU swap on his VX and still easily passed his CA smog inspection. For those who care, NOx can be partially dealt with through a NOx adsorber as used on the Insight. The Insight entered lean-burn much less often (and less aggressively) and purged the adsorber through enrichment, but its basic operation would transfer over to a VX.

Most OEM lean-burn engines that I've seen increase charge turbulence and/or use a specially crowned piston to concentrate the gasses. Honda partially closes one intake valve per cylinder to improve what they call "swirl."

Extensively recirculating exhaust gasses accomplishes the same goal as a lean-burn engine without the emissions issues.

Originally Posted by diesel_john View Post
On a '91F250 302 for example the ECU is not reprogrammable is it?
You can probably build a MegaSquirt (w/ sensors) for $100-200 and gain much wider control over your engine. While it would cost more, I think it would be more worthwhile than tricking your ECU into lean burn. Just a thought...

- LostCause

Last edited by LostCause; 05-09-2008 at 02:15 AM..
  Reply With Quote