I'm hoping someone out there can hook me up with a chip for my '87 4+3, I don't know of anyone who can burn chips in my area. There are only a couple things I would want changed.
What I'm looking for is an otherwise stock chip (the car is a daily driver, don't want any fancy stuff), but I would like the chip to default to have the OD off upon startup rather than the default on, and I'd also like the fan turn on point bumped down from the rather high stock 226F to say 212F, keeping the stock turn-off point.
The OD off at startup is not a programmable feature. BUT with that said..... I have been shown how to hex edit the code to turn it off. I have not tried it yet to see if it works. I do have I think all the 4+3 stock BINs for 87.
I run a modified version of the ABTR chip in my 88.
To disable OD by default, you can simply adjust the upshift points (with tunercat etc) to some high speed like 125 mph, which is a reasonable speed to upshift from 4th to 4th od anyway with 3.07s. Note: It is possible to tune the 1st ,2nd,3 rd-> od upshifts, separately from 4th-> od upshift if you want. I have played with several od upshift strategies. Haven't tried Scorps approach, but Im sure its possible, I haven't found away to do this yet looking at the disassembled code....
You can still engage OD manually, but it requires two pushes on the switch, since the first push really turns od off, then the second push turns it back on and commands an upshift. Normal kick-down function is maintained. I use this technique for my strip versions, in case I stall during a burnout and forget to hit the button again. Also beats having to switch od off on every ign cycle.
Also setting the fans is no problem.
If you can't find local help, I could always edit and send a chip to you, but you would need to have your memcal socketed so you can replace the EPROM easily, since I don't have any extra complete memcals. Check your existing memcal for a sticker with an 8 digit code something like ABTR 4753. The first 4 letters will identify your original chip. Hopefully Scorp can provide a virgin copy for editing, if needed.
Corvette Store
Looking for a chip - 87 4+3
