ZaphodB

A friend of mine has an '85 Vette with the 1226870 ecm, the old one used on the very first TPI cars.

We took a closer look at the chip from his car, and of course there are much less tables/settings than the 1227165 ecm, the question is would it be a waste of time to try to modify the chip for the 1226870 ecm?

Would we be better off upgrading to the 1227165 ecm or maybe even a MAP system with a 1227730?

Anyone have experiences with the 1226870 ecm, some comments about it would be really nice!

james_85Z28

I have swapped from the '870 to the '165 and now to the '730 ECM. The '870 to the '165 requires less pin swapping but you have to splice into a lot of wires for the 2 relays which is messy and you add the two relays. The '165 to '730 was basically all pin swap, removing all the splices created for the two relays. The '730 ECM uses a much different pin layout but the overall wiring changes from the '870 is neater and cleaner requiring few splices if any. At first glance the swap to the '165 appears easier but in reality the '730 is easier, better and cleaner. Both will take some study time and about 4-6 hours to swap pins and check everything a couple times. The '730 is a lot easier to tune and I am much happier with it.

So knowing what I've experienced I would go directly to the '730 from the '870.

ZaphodB

Okay.... Then the '730 would probably be the best route to go...

I suppose the factory calibration should work right out of the box on a non-modified car after the MAF to MAP system conversion?

james_85Z28

it will run but you will notice flat spots and it will be rich and lean in places depending on mods. Use can use VEmaster to get it close enough. Since you posted it on this board I assume you have chip modding, burning, and scanning capablity.

https://www.thirdgen.org/techbb2/sho...hreadid=117674


You will get a better result using the above than by swapping to the '165 with minimal bin changes.

ZaphodB

The Vette is 100% stock, no mods on it yet. And yes, I have been burning chips for some time, just trying to help a friend get started doing it too...

But since I still have a '165 in my IROC I have absolutely no experience with the '730 yet. But I might do a swap on the IROC as well when winter comes and it goes to garage hibernation

james_85Z28

I swapped because my MAF sensor went out. I had a hard time getting my calibration good after I went to a T56. When I had an auto the ARAP was very close. Makes you think, but I did use the appropriate bins for the different tranny types.

Converitng was pretty easy. What makes the swap to the '730 hard is that the you have to use different ECM connectors so all the wires will be re-pinned. Other than that it was just a about 4~6 of time to do it right and get it running.

I started my modded car with a stock AXXD bin (manual) with just changing my fan temps, idle, and cylinder displacement. It drove good enough to drive on for a week. But I eventually ran VEMaster and that cleared up a few flat spots and running a tad rich at idle.

I'm no tuning guru but I like that I can target specific load/RPM points for tuning. My car idles a lot smoother now. Tuning the '730 is better and easier. All I ever did with the 6E code was adjust my injector constant for tuning and some timing points.