I have an '87 GTA and I want to use the ARAP EPROM (per many suggestions from others). My question is: is there a GM memcal that I can purchase that has a factory EPROM with the ARAP bin on it - like maybe for an 89 IROC/GTA?? I am planning on burning my own EPROMs in the near future but for now, money is very tight, so if one is available with the ARAP bin already on it, I would go that route for now. Any help is appreciated

Your 87 GTA doesn't have VATS and ARAP does. Your car wouldn't start.

[This message has been edited by Brent (edited April 18, 2001).]

There must be a way to dissable the Vehicle Anti-Theft System or I can take the module and tmbler out of my parts car (88 GTA POS) to make it work. !!!

The VATS system can be disabled with a simple circuit fed into your ECM. That said, if you're going to go to that amount of trouble, why not just have someone burn you an ARAP binary with VATS disabled?

GM part number for '89 ARAP:

16134193

This is for '89 Corvette with auto tranny. As others mentioned you'll have VATS troubles.... if you just want the bin, I've already uploaded it to the diy-efi ftp site... look for 89ARAP.BIN on incoming. Have somebody disable vats in that bin, and burn it to a chip for you.


Craig M.

Consider what Cmarcho suggested. Then you could just grab a used "Hypertech/ADS/Jet" piggy back eprom, have it reprogrammed with the ARAP and VATS disabled. Then you just plug your regular GM memcal into it, and you are off to the races.

Just remember that you can't "beg" or "ask" anyone to do this, on this board (House Rule). But, maybe some kind soul will contact you PRIVATELY and give you a hand; if you are still waiting for your eprom burning equipment. FYI, this is a REALLY simple thing to do. Great "first eprom" to start with. Good luck and feel free to contact me if you have any further questions on this matter.

Thanks guys, lotsa good ideas here.

Glenn, I have a question about the 'piggy back' style aftermarket memcals; how do you identify one? I got my 87 GTA used and someone put an ADS chip in it but I don't think it is this 'piggy back' style; it looks kinda like the GM memcal, except it's black, and it has an EPROM soldered into it (I assume that the piggy back style one must have one of those chip sockets (I forget what they call those things - brainfart ) on it for easy removal/installation). if this is not the proper one, can I modify it by removing the EPROM and soldering one of those sockets onto it?

Thanks...

Laterzzzzzzzzzzzzzzzzzzzzzz

The "piggy back" has an eprom on it (it may or may not have an eprom soldered on it..but often you can pry the eprom off); and then your regular GM memcal plugs into a set of "pins" so the ESC circuitry of the GM memcal flows through.

This is probably the most common setup as the "piggy back" allows the chip mfg to just "give you the eprom" and they don't have to include the ESC circuitry. Much cheaper to produce.

Truthfully, I believe you could use ANY piggy back "carrier" with ANY GM memcal, as long as it has the proper eprom (27C256 for SD cars, 27C128 for MAF cars though you can make a 27C256 work) and you have the proper number of pins to allow the ESC circuitry to flow through.

Also, the majority of these "piggy backs" generally do not solder the eproms in. You just have to pry on them (carefully) and the eprom will pop out. This is what I did with my ADS "piggy back" by replacing the 27C256 with an AT29C256 Flash Prom. Now I just erase/program directly through an "adapter" as described in Tim's "Prom Burning Introduction". I don't know if Tim got the pictures working, but I believe he had a picture of a "piggy back" and the "adapter" which costs about $5.00 and about 15 minutes work with a Dremel.

I have an 89 Iroc with the L98. Can I just go to a GM dealer and order that part number for the 89 Vette ARPA memcal part number 16134193, pop out my old memcal and replace it with the Vette ARPA memcal from the dealer? I assume that the spark curve will be more aggressive but will it be alright if I run 93 octane gas, set timing to the stock 6 degrees, and run the engine cooler with a 180 degree stat and 190 degree fan switch?

Thanks!!!

I purchased the ARAP bin and installed it, reset the computer and put the timing back down to 6 degrees.....But now I have a problem....the primary fan(the one on the drivers) side stays on all the time????? Any ideas? It didnt do it with the stock bin. On a good note the car idles a lot better and seems a bit peppier. Well that fan always running makes me think that the car is in limp home mode.....is there a way to check? When I turn the key to on but dont start it I get a solid SES light and no SES light while driving so I dont know.
Thanks for any help!!

I used the same memcal for the vette (16134193)and found that even after using tuner-cat to change the VAT and fan to normally open then fan would remain on. I swapped the chip to the 87 memcal and the fan problem went away. The limp home mode chips are appearantly not the same. For referance this is for an '87 Formula. In looking at the list of memcals available for the 3rd gens this P/N is not listed. This was probably already addressed but I missed it.
Later

The fan problem is not limp home mode related.... The relay is just different. You have to modify the ARAP by setting the fan relay to "Normally Open".

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Mike Metzler (Desert86Roc)[*] Check Out:SpeedWorldMotorplex.com[*] Check Out:Chevrolet F-Body Online Part & Illustration Manual[*] My 86 IROC 305 TPI Page (406 build in progress)

ET's @ 1250 ft[*] 14.28 @ 95.461 mph (uncorrected, NOS, no headers)[*] 15.362 @ 88.238 mph (uncorrected, headers, no NOS)
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Does anyone know how to set the fan relay to "Normally Open" in TunerPro?