I'm gonna change my '87 350 iroc to a manual trans, and for sake of clarification, what is needed in the prom? From what i've seen on Prom mods, it is a bit(byte) setting, I'm assuming it affects the idling control loops, or maybe timing. anything else? I never seem to see a definitive answer on the message boards, so I'm guessing it's not a critical change, guys seem to convert over to stick and never mention having an issue with changing the prom. Anyone have experience w/this? Since the 350 never had a manual behind it(except for vette) is there a specific binary image that is well suited to doing this? I see people talk about the ARAP bin, is this usable w/ the MAF '165?-thanks in advance

 

I compared the BUB bin to the BUA bin for the '86 vette and found over 100 bytes changed. The only difference between these two is manual (BUB) vs auto (BUA). There is no one byte that causes the ECM to adjust control loop etc. settings - the changes are individually coded in. Many of the changes have to do with TCC lockup parameters which you will leave disconnected anyway, but there may be tuning issues with the rest. Perhaps ARAP is better suited but I haven't looked at it yet.

 

I think your best bet would be to combine your current bin with a stock bin from a manual car. Graft the timing and fuel things onto the manual bin and take it from there as I'm sure you'll make changes with the new tranny. There is no magic switch unfortunately.

 

Exactly as hector has suggested. START with a manual bin or prom and then you will need to modify it to work for you. Trust me, I went the take an auto chip and modify for a manual tranny, doesn't work. well it does, but it sucks.. just plain stinks..
I rev controls, the IAC operations the cold start ups, open loop starts, everything.
Not just timing and fuel.

Brendan

------------------
1987 IROC-Z L98,SR,EB 6085's,LPE 219/219 SR Cam, Crane 1.6RR, EB TPI Base, 58mm TB, Stock T5, 30lb SVO, AFPR, K&N, EB TES, Catco Cat, 3" Borla Cat-Back, Accel cap,rotor,distro/other crap, Aluminum DS, 94 Disk Rear, Adjustable Prop Valve, Precision 3.73 Gears, Weld in Sub-Frame Connectors, Hotchkis LCA's, KYB Shocks/Struts, Poly Bushings all over the place, Moog Upper/Lower Ball joints and Tie Rods ends/Idler Arm, Big stereo, 730SD Conversion.

To see the ROC, Check out the webpage Here

 

Hmmmmm...i kinda figured that GM would do something like that, it would be too easy to just switch a bit and have manual code execute, but i guess for space inside the prom, it makes sense to just have two versions.. I'll have to get up to speed w/ burning proms(getting there, not quite, haven't actually burned one yet), and basically take a manual prom(from a 305) and add the tables for a 350. What software do you think would be the easiest to use? And the BUB is the bin I should start with? Again, thanks for all the help.

 

You want an 89, 305, T5, whatever axle you have, bin. The '89 code is the best, no point starting with older bins.

I show ANYS for the 89 305 with 3.45 axle.
APYS is for the 3.08 axle. Either of those should be a good starting point. If you are smart, you'll call the local dealer and double check my recommendation.

 

The IAC is very different.
With an auto, it's a fluid coupling, with alot of slippage in the lowere RPM area. So the timing and fuel will be different.

All depends on what you call OK. You can use a 6 cyl memcal, and the engine will run, sort of and in some cases not to bad, does that make it right?. Not in my book. There can be a huge difference from OK, to runs correctly, to runs it's best

 

OK, so now I'll start with the 89 305 w/manual, change the BPW for the larger injectors(along w/ the CID info), then tweak from there, referencing the old 350 tables in terms of timing and fuel curves. Does that sound like the best path? Does anyone have thoughts as to the prom editor i should use? I am going to buy Tunercat eventually(I guess sooner than later once i swap out the trans). Thanks!