88´TransAM

Hi guys. Now, i am building a 383 setup for my 88´transam TBI. The shortblock is a 2-bolt-rollerblock with 1-pcs-mainseal, bored to 4.030" over. Eagle crankshaft with flattop-hypereutectic-pistons. The cam datas are:

Duration intake @0.05 224°
Duration exhaust @0.05 226°

Lift intake .502"
Lift exhaust .498"

Lobe separation 110°

The heads are AFR 195 with 65 ccm combustion chamber. With my head gasket, i´ll get a compression ratio 10.8:1.
My rockers are Harland Sharp roller rockers (stainless steel), ration 1:1.6.

My tranny is a TH700R4 with raybestos clutches, kevlar brake band, transgo reprogramming kit stage 2 (automatic version). Acc Performance Boss Hogg Nightstalker Level 2 converter @2200-2800 rpm stall....

My rearend is completely rebuild with richmond gears (49´series) @ ratio 3.23.

The TBI is from a 454 BBC with 80´injectors with turbocity´s vacuum fuel pressure regulator @max 18 PSI..


In my ECM works Rob´s great EBL.

Now, it´s time to get a nice bin file for my engine. I think, the right way is, to begin with a file from a 350 TBI. Suburbian or Chevy G20. Then, i plan to change the BPC, the SA-main-tables and adjust the VE-tables with some VE-Learns... What do you think ? What´s the right way to get the best bin for my engine ?

TZFBird

You are absolutely on the right track. I'm no expert at all, but have gone from starting fresh like you did to a fairly decent tune. I'm working on upgrading so quite a bit of it will go out the window and I'll be starting over again.

FYI... I believe the '88 LO3 used an ECM that is different and from what I could tell there is very little by means of definitions and support for them. If you are interested in keeping it I have a TunerCat file I purchased from them before I found out about TunerPro and ECM swaps. I'm not sure how it is over there in Germany, but I have an 8746 that I'm running now (it's decent), but will be going to a 6395 which is a step before the 7427.

If the engine is already broke-in...
The only words of advise I can give:
*Adjust BPC
*Start with a basic spark advance curve
*Work out idle VE both out of and in gear.
*Start taking it for a drive and slowly tuning the VE below 3Krpm under various load conditions.
*After VE is roughed in so BLMs fall around 128, continue and slowly play a game of add/removing timing to stay out of Knock while making as much power as you can. If that's what you are going for.
*Acceleration Enrichment will kick in and skew BLMs in lower vacuum/higher rpm cells.

I have yet to tune WOT, but the engine wants to pull so hard I have a hard time letting off before I hit the upper rpms.

88´TransAM

Ok. I had forgotten to say, i am also going with the Zeitronix ZT-2. Now, i´ll go with the 350 TBI suburbian BIN, change the BPC to my 383 cubicinches with 80´injectors. I think, it´s nice for a baseline-file ?! How can i change the cells in the VE-table after datalog ? How can i see, which cells should be changed ?

Ronny

iTrader: (1)

Does not RBob offer a .bin in the Utility file he gave you? Years back we were all given same EBL.bin but now I hear he has several EBL.bins to chose from. In his Intro To Tuning part2 I believe it explains what initially needs tweeking.

The cells are automaticly changed for BLM during VE Learn. You need to save the Learn.bin created and then drop it into ECU. Part 1 of Into explains that.

Yes the BPC is the first change needed plus BPC vs VAC. Again the Utility has a calculator for that.

TZFBird

I guess I need to start reading what has been posted in the last 5 years. I'm pretty far behind.

thomas1976

Great news 88', hope it will run great.

This is what you should know already https://www.thirdgen.org/forums/diy-...o3-lt1cam.html

Here the formula for changing injectors https://www.thirdgen.org/forums/post...012-post4.html (I have since this post, set idle timing to 0, runs perfect)

If no 383 TBI bin is available, I would start with a LO5 caprice bin. with fueling adjustments.

IAC probably needs some attention, with engine at operating themperature adjust trottle screw for around 5-15 IAC steps, turn engine off, restart engine werify IAC steps. Repet procedure untill 5-15 IAC steps at idle with A/C off and fan off.

VE and SA tables, highlight 1 ore more cells and ad or substract.






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