What is the difference, internally between the two that makes for the 20ish hp difference that they have. Just wondering.

 

fule econimy based i guess and the one with more hp (b1?) has upgraded internals

 

I'm pretty sure that the b2 has more hp. Both are DPFI, correct?

 

both are dpfi, b2 has more hp, difference that i know for sure are the restrictor plate under the t/b on the b1 and the b1 had a weaker cam. not sure if the ecm had a different program.

 

Do you mean that there is a restrictor plate in between the tb and the intake manifold? If so, can I just remove it?

 

From what I know, the differences are the cam, ecu, restrictor plate. There is also a restrictor plate inside the litte box that sits on top of the throttle body.

 

NON 88 d15b1 and all d15b2 = 9.2:1 c/r
slight difference in cam
header
intake manifold
d15b1 has a restrictorplate in the tb only allowing for 1/3 air flow of the tbody. removing it may make the motor lean out. im not sure about this... you only have 2 injectors

88 d15b1 had 9.6:1 c/r stock. same im and header as the other d15b1's w/ the restrictor plate.

 

So if I went MPFI, I would get a lot of the same gains as if I converted a DX motor?

 

you will get gains exceeding a stock si motor.

 

ok. thanks