As the title states....I just acquired a '90 si drive train and wanted to swap it into
my HF...nothing fancy just basic swap one for the other ( for starters). I did not
know it would become a hassle....let me explain: I...like many of you have
very little free time...I work an average of 47-50 hrs a week as a retail sales
manager...You get the idea. I have not done a swap since I was a teenager
so I decided to let the pros do it ( hey they do it on the regular and they would
be much quicker than I ever would)....so I called few Chicago-land shops to
get an idea of what this would cost me....lets just say i got used to the "we don't
do that....*click*". Jeez I wanted to give them money...go figure

Okay this is where I stand....someone point me in the right direction on what
I need to have on hand to get this done....I'm more pissed than anything else.
I have a background in 12volt electronics ( I have been an installer for over 10
years..so I know my way around a tool box and a solder wand and multimeter )
This is what I have:

'89 rex HF....needs drive train pulled...engine still runs well
'90 rex Si...donor ( played duck duck goose with pole and lost)..complete
drive train with header except intake tube ( guy keep CAI)
Basic metric and SAE tool set...the Sears mechanics special
cheapo floor jack and various other tools mostly for electrical work.
will get jack stands in a few days.....

If anyone can guide me in the right direction on what to do..that would be great
appreciated...really it would..'cause with twins on the way my time is becoming
more and more precious every day.

Thanks in advance

 

First off, I would say get a Helms manual. It goes pretty in detail on taking the old stuff out and putting the new stuff in. Other than that I have the same questions as you, I'm going to attempt my first swap this summer...

 

Thanks...I plan to order one ( hey you can't have to many reference materials
available to you ). Keep the info coming. Those who have done this swap
before nad I know someone has,please share the wealth.

Thank you

 

its basically an easy swap
just get the engine out and slap the Si engine instead....
u can retina ir stock engine's mounts, shift linkage, axles, and inj resistor....
all u gotta do its take engine out.... and basically put the Si tranny and engine in there the same way u took the HF out.... the electronics are the same.... so ujust have to rewire everything back togheter..... as for the ecu u gotta use a PM6 from a 88-91 Si..... the si manifold should bolt to ur exhausdt system.
i say if u do have some mech background.... it shouldnt be that hard..... take ur time , it should take u 2 days alone......1 day with some help....
actually u dont have to rewire anything.....wich is good....good luck`

 

plug and play... replace ecus.. also remember that your wiring harnesses may not match.. from what I understand 88,89, 90-91 are three different harnesses... correct me if I am wrong.. Actually, just reuse your current hf harness..... you are set!

 

yea it goes hand in hand, take old motor, put new motor in. Just make sure you disconnect the speedo cable, throttle cable, shift linkage and harness before you take the motor out.

 

Thanks for the info and insights.....I was not aware i could resuse my HF axles
( or was it the hubs? duh). Are there any parts in particular that I should make
sure to save while doing this?

Thanks

 

A 90 computer will work in an 88 harness. No differences, just like a CRX SiR PW0 plugs in to a DX harness. Only diff between 88-89+90-91 ECUs is that 90-91 are a different style and support more chips.