BT and A20A3 Engine

[Supatech]

I have a 86 LXi which means I have the BT engine rated at 110hp. The A20A3 engine in 88-89 LXi's have 120hp and this is due to their dual stage intake manifold if I'm correct? So could I just swap intake manifolds with an 88-89 to get the added power or are there anymore engine differences between the 86-87 LXi's and the 88-89 LXi's?

[k-roy]

There was some other things differant as as well. Like the ecu, higher compression pistons, exaughst manifold, two O2 sensors instead of one. There is probably some more small things but thats all I can think of at the moment.

If you want to get a new intake manifold I highly highly reccomend using This one
If you search through the board a few members have adapted a B16 intake to the A20/BT/BS head. I think k-mod sells them allready modified for the A20.

[shepherd79]

ok,
well lets start with what is the diff between the two engines.
first: the engines had diff compression ratio due to different cylinder heads.
second: intake manifold. on 88-89 it was dual stage controlled by a vacuum. on 86-87 it was single stage.
that is about it.
you can swap the intake manifold, but you will have to swap the ECU, black box, and a hole lot other things. it is pain in the ass for extra 10hp.

P.S. if you want B series intake manifold, you will have to figure out how to bypass the EGR valve without throwing ECU code at you. the best way to do that is get JDM black box and JDM ecu. they didn't have EGR in their cars.