need computer chip information

[karl24]

Are there advantages to replacing the stock chip? Where is the chip located and can anyone recommended a place to buy one? I'm a new member as of a couple of days ago and feel at home w/ other 81 vette owners!! I'm not a mechanic but willing to learn and thanks for any help w/ this question.

 

[LannyL81]

When I went looking for a stock chip, I could not find one. GM dealership told me "discontinued"....so I could only go aftermarket. Have no idea if it is worth it or not as the OEM one was dead. There are two available that I know of; a street and a strip versions. I got the street.

The chip is located in the top of the computer which is in front of the battery. Have to remove the computer to get to it. Not hard...about four screws and a sore back from twisting in that position....

Hope this helps you out

 

[motorman]

Are there advantages to replacing the stock chip? Where is the chip located and can anyone recommended a place to buy one? I'm a new member as of a couple of days ago and feel at home w/ other 81 vette owners!! I'm not a mechanic but willing to learn and thanks for any help w/ this question.

contact these guys for a chip reprogram. www.pcmforless.com

 

[karl24]

Thanks Lanny, will check it out tomorrow, see if I can find it. I've got a pretty strong back, have been detailing cars for 17 years!!! Karl.

 

[Hib Halverson]

contact these guys for a chip reprogram. www.pcmforless.com

Uh...if you'd read the web site content, first, you'd know they only go back to 85 so that's useless advice in this case because the car in question is an 81.

As for whether or not an aftermarket calibration will improve perforamnce of an 81, it is possible, depending on what spark schedule is in the cal. you get, that there might be a noticeable, but modest, change in performance.

The challenge, of course, if finding a "chip" for an 81.

 

[Sensei]

Hypertech thermomaster:

AutoZone.com | Vehicle Selection - Year

God bless, Sensei

 

[karl24]

Thanks Sensei for the information, will let you no how it turns out. Do you think there is much to gain here? Karl

 

[LanceB]

I changed mine years ago (and like an IDIOT i threw the stock one away, what was I thinking?). I put the "strip" one in and noticed nothing. I put the different thermostat in at the time too. I tried to convince myself I noticed something but who knows. Be careful to install the new chip EXACTLY like the old one is in there.

 

[Peer81]

As far as I know the Hypertech is the only one out there to replace the 81 chip.
I've been bussy with a different ecm (from a late Monte Carlo, last one with a E4ME). The ecm is much faster but you need some mods on the wiring harness, that is where I'm with this project. For this ecm there is a differend prom (ZZ4 prom, original for the camaro with E4ME), I have the Bin file but I don't know if this works on the early 81 ecm's.

The ZZ4 promnumber (without ESC) is 24502457. Maybe you have a change looking for that number. The instructions say this prom is to be used with a 700r4 (lockup) but who knows what you can make of it.

Groeten Peter

 

[LannyL81]

I still have my stock one...but from what I remember, the Check Engine lite stayed on when it was installed. I never put it back in since I got the one from Hypertech. I do not know how to test the PROM to see if it is any good or not...anyone have a PROM reader..

 

[topless82vette]

Aside from the L-69 having a knock sensor and maybe a baro sensor I wonder how the ecm and chip from one could be adapted to a L81 harness. I know it's spark tables were pretty agressive. Carbs were used till about 1987 and I believe this L-69 lasted till then so maybe you could get the newer pin style ecm.

 

[Peer81]

Easiest is changing the entire wiring harness. There are a couple of things dirrerent between the two and it isn't an easy fix (for example the 81 VVS gets 8v power and the later style gets 12v).

Greetings Peter

 

[Hib Halverson]

The amount of time and money necessary to change the wiring harness and/or upgrade the ECM will far exceed the benefit of the small performance gain you'll get by changing the "chip" on a stock 81.

If you want modest gains, I suggest looking elsewhere, particularly reducing restriction in the exhaust system. Also, you might consider some modest engine mods.

If you want significant gains, first replace the 81 with an older vehicle not having computer controls. Considering PA's emissions testing, that will probably give you a better chance of enhancing performance yet also passing the test.