Hey guys, I have a question for the experienced tuners in here.

I am in the process of building an engine and swapping to a 5-speed in my 89 iroc, I'll tell you the engine combo, maybe that will help.

L98 bored 40 over
24 lb LT1 injectors
vortec heads
SD vortec intake base
ported slp runners and plenum
ZZ4 Cam
Underdrive pulleys
Air Foil
Edelbrock TFS headers
Hooker cat-back

Now, from the research I've done, I've found that its probably best to start with a 305-5-speed bin file. In 89, it looks like there are two with federal emissions. One is APYX (3.08 G.R.) and ANYX (3.45 G.R). My first question is, I'll be running 3.23 gears, does it matter which one I use? I'm running a camaro, so it does not have a VSS. I would think that either one could work.

Secondly, I've read that you can take the 305 bin, and update the values of the maf tables and scalars to the 350 bin's values. What 350 bin should I use as a guide? ARAP or AUJM? Exactly what values/tables should I copy from the 350 bin to 305 bin?

I'm completely new to this, but I trying to learn. I appreciate any advice you guys are willing to give.

 

Stick with a 305 5-speed bin and work with it rather than a 350 Auto bin. There are more issues to make a 350 auto bin work well than a 305 5-speed bin.

Gear ratio is not that important of a factor. Shorter gears tend to have a quicker spark table in the low-mid range rpms. So I would start with that and then tone it down, as needed.

89s do use a VSS.

 

My 89 iroc has a speedo cable. I think camaros switched to VSS in 90, Firebirds in 87. I wish it were VSS, as the t-5 I bought is, so I'm going to have to try changing it over to cable.

Question, do I have to change my memcal to a 5-speed one, or can I just change th eprom chips with my original?

 

Just the eprom.

 

I can not find either of these bin files. I've tried moats web site, and the GM-EFI file repository. Any other ideas where I may find this thing? I'd rather not buy the whole memcal if I dont have to.

Thanks

 

The VSS is used and necessary for the ECM. As for locating those particular bins, make a separate post requesting those particular bins. Hopefully someone will see it and post them for you.

 

I'm confused here. I dont remember any wire on my auto transmission that would have been a VSS. The t-5 I took the electric speedo sensor out and replaced it with a cable setup. Where would a VSS be on a 5 speed iroc before they switched to an electronic speedometer?

 

There is an optical pickup on the back of the speedometer. A 3-wire cable from that to a buffer box (lime green or yellow) that is attached to the back of the cluster. From the buffer is a wire to the ECM, and a wire to the cruise control.

RBob.

 

Thanks for clarifying RBob. Grim, I'll try another post asking for the 5-speed bin files since the databases did not have them. Thanks for that suggestion.

 

I think that ANZA.bin is the latest 1989 305 5 speed bin. ARAP is pretty radical in the timing curve.

 

ANZA is cali emissions, does that really matter?