MrJ

its just an idea I had. I've heard lately that the 305 TPI 5 speed chip has a better, more aggressive spark curve. If I were to do this I wouldn't leave that chip the way it is of course.... I'd screw around with the fan turn on temps and TCC lockup speeds, etc. I've got a friend on here who will burn a chip for me. So is this a good idea?

Oh I almost forgot. I heard swapping chips with a GM Speed Density ECM is a pain in the *** , because soldering is involved at some stage.... what's the story on this?

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91 Trans Am WS6
Bright White
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

Built on Wednesday

Kevin91Z

iTrader: (1)

You're better off with a 350 chip, because the 305 5-speed chip wont control the TCC lockup.

I can swap my chips easily, just remove the blue thing and replace it. Takes all of 5 mins from dropping the computer to putting it back into place.

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West Coast GM Shootout 2001!
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

Grim Reaper

MrJ...welcome to our nightmare..j/k.

I see no reason why you cannot take a 305 5speed eprom and turn the switch from manual to auto. I have experimented with this on my 350 SD auto bin (for someone that converted to a 5speed) and then setting it back to auto. The 5speed version worked fine for him, and when I reset it to auto, it was identical to the original I had when I use Binary Compare. The only thing may be that since it is starting with the 5 speed is that you will have to set the TCC locking/unlocking speeds. But since you have the original 305 auto bin, you can use that to determine the proper settings...in fact you can play with those... I have they do work.

I think KevinZ may have miss understood your question, I think he is thinking of the pulling the memcal from the ecm. I believe you are asking about the erasing and reprogramming the GM memcal itself.

You basically have 3 methods you can use:
1) directly erase and program the GM memcal
2) unsolder the 27C256 eprom from the GM memcal and re-solder a ZIF socket in its place to allow you to swap eproms at will
3) use an aftermarket "piggy back" chip like Hyperjunk or Jet that has a socket with a removable eprom in it. Becareful as not all aftermarket chips will allow this. My ADS has the eprom soldered in.

To use method 1 (direct erasing and programming onto the GM memcal), you have to rig the switch on your UV eraser to turn on (mine has a safety) so that you can place the GM memcal in the UV eraser. Just leave the end dangle over the edge.

To program the GM memcal, you need to get a $5.00 "header" from DigiKey and put in in the programmer (burner) so you can put the GM memcal into the unit. I enclose a link from Traxion's photo Gallery that shows what this looks like. I just modified it with a dremel (like Traxion did) so it had the proper number of pins (28) and cut the tabs off the end so the memcal fitted.
http://www.picturetrail.com/gallery/...2145&uid=96398

Here is the link to Digi-key part # CHW34G-ND...34 pin wire wrap connector that you need
http://www.digikey.com/scripts/US/DK...?KeywordSearch

Hope this helps

MrJ

hmmm...
thanks for the replies, guys. I wanted to go with the 305 5 speed chip because the spark curve is supposedly even more aggressive than that of the 350.

Blade

I can attest to that. I'm runing a 5 speed chip in my car. Well the 5 speed's timing and fuel curves anyway. I just copied them over to my auto chip and I definately felt an SOTP difference in parth throtle driving. WOT is still slow... but that's not something you can calibrate that easily.

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92 Z28 L98 350
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Ported stock heads, XR270HR-10 cam, TES headers, Crane AFPR, Flowmaster catback, MSD ignition components, #24 SVO injectors.
Best ET 13.3@107 mph
"Take that auto, drop it in first, hold the brakes, stomp the gas and grin from ear to ear! :-)
Click here to see my car at Truspeed.org

Check out TruSpeed at http://www.truspeed.org
Check out the Bin Archive at http://www.truspeed.org/bins.html