Well I just got a sedan with blown motor.
I have a spare vx swap with tranny that I can swap in. I wanted to get the most mpg in the city & hwy.

<FONT COLOR="light blue"> I was worried that since the weight of both cars are different selecting a tranny might be a factor. I would prefer to use the VX tranny simply because it's already attached to the VX block... BUT if I used that would city driving be a PITA.

VX hatch MT = 2,094 lbs
LX sedan MT = 2,403 lbs

</FONT>

 

as long as you're cruising at a constant speed the weight means very little. lower R's = better MPG. (generally speaking of course)
Accelerating it all depends on how heavy your foot is. If you have a heavy foot the reduced power will frustrate you and you will be pushing the engine a lot, which will kill your MPG.

Also the VX uses the P07 ECU to get the good MPG that it gets, and it will light the CEL without the EGR setup and L1H1 wideband wired in. Just a warning if you didn't know that going in. (additional work)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Relic1 &raquo;</TD></TR><TR><TD CLASS="quote">

Also the VX uses the P07 ECU to get the good MPG that it gets, and it will light the CEL without the EGR setup and L1H1 wideband wired in. Just a warning if you didn't know that going in. (additional work)</TD></TR></TABLE>

I see, good point.
I'm doing the swap this weekend. Have the complete LX sedan. I also have the complete VX swap with engine harness, egr, 5wire o2, ecu.

how do I go about wiring up the vtec, 5 wire o2, and egr....

BTW what is L1H1.... don't know what that is nor what your referring to.

 

You'd save more gas by just driving 5mph slower than what you do now, and less aggression on the gas pedal.

Although the VX is geared lower, it's a Highway modeled car. It is not going to help you because you'll need that much more throttle to accelerate the way you do now.

Summary: Slowing down with the larger engine/tranny will save you more.

&lt;---drives a 23mpg Cobra.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Spade &raquo;</TD></TR><TR><TD CLASS="quote">You'd save more gas by just driving 5mph slower than what you do now, and less aggression on the gas pedal.</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Charlie Moua &raquo;</TD></TR><TR><TD CLASS="quote">Well I just got a sedan with blown motor. </TD></TR></TABLE>


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Charlie Moua &raquo;</TD></TR><TR><TD CLASS="quote">
how do I go about wiring up the vtec, 5 wire o2, and egr....

BTW what is L1H1.... don't know what that is nor what your referring to.</TD></TR></TABLE>
VTEC is the exact same as any other VTEC conversion you can read about in the sticky.
Here are the ECU pin #s to the things you will need to add.
ECU - function
A4 - VTEC solinoid
A6 - O2 heater control (orn @ O2)
A11 - EGR control sol (red/blu @ EGR)
D6 - VTEC oil pressure switch
D8 - O2 signal 1 (red @ O2)
D12 - EGR lift (wht/blk @ EGR)
D14 - O2 signal 2 (wht @ O2)
D16 - O2 reference (blk @ O2)
D18 - Upshift light (not required)
D20 - EGR reference (yel/wht @ EGR)


the L1H1 O2 is a NGK wideband O2 sensor that the VX ECU uses.
it's is wired like...
orange - heater control (A6)
yellow - heater ground (thermostat ground)
white - O2 signal 2 (D14)
black - O2 signal reference (D16)
red - O2 signal 1 (D8)

 

Thanks for the wiring info bro. That will definatly help reduce time on the swap.