BellaRSport

what is the difference between b18a and b18b motors? they both seem the same to me. is it just ecu software? TIA

punkindrublic

the b18b's have more torque

90hatchsi

Don't forget the b16 has more ponies and VTEC, whereas the b18 has no VTEC.

[1sL0CiviC]

dude...they are talking about the b18a and b18b

Import Racer

But it's not a big difference where you'd actually "feel" it. Probably 2-5 pound feet of tourque difference.

KS-R

B18A is from 1990-1993
B18B is from 1994 +

Supposedly the B18B head has better flow and slightly better cams. The manifold looks a little better, possibly better flowing too.

Other than those I believe they're pretty much the same

BellaRSport

thanks. i was actually talking about physical similarities. heads, pistons, etc

Jugglez

Heads are the same, diference is in cams and intake manifold only. Everything from the block down is identical, pistons, crank, rods, bore, cylinders walls, etc. etc...... all the same.

BellaRSport

Jugglez you're the best. i owe you a coffee or beer

ryuujin

jus bring him to WAGG

90hatchsi

Ooops I need glasses. hehe

[1sL0CiviC]

Jugglez

No no bring me to a massage parlour, ryuujin knows all the best JDM ones in town.

BellaRSport, i missed the part of question about the ecu's 1st time around...

here's a break down.

90-91 B18A ecus are non-OBD and labelled PR4
'92-'93 B18A ecus are OBDI and labelled P74, possibly P75 also but these are rare.
'94-'95 B18B ecus OBDI and are labelled P75
'96-up B18B ecus OBDII and are labelled P75

as you probably know OBDII ecu's are impossible to chip, so if you've got some heavy mods on an OBDII B18B and decide running a re-programmed chip is the way to go (either custom or pirated) you can get an OBD I conversion harness installed, which will allow you to run either a P74 or P75 OBDI ecu... and you'll be able to chip these without probelms.

There are also very small differnces between the OBDI and OBD II B18B's... like valve cover and location of PCV valve.

BellaRSport

actually i'm might get a PnP b18a head for a b20b block and be running the b20b ecu. looking at a setup that includes short ram, Skunk2 intake man, DC Sports 4-2-1, twinloop style muffler, AEM fpr and AEM fuel rail. then i might look into an ecu upgrade. just gotta figure if i want to run b20b or b18a cams