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I'll try my luck with TGO with this thread here for I've tuning questions wrt the 1226870 ECM in my original 85 IROCZ28 with a TPI-equipped/350 FT-cam'd/L98 intake/ZZ4 Al head LM1 swap (for anyone interested in the laundry list details of the swap, please ask).
While the power plant runs great (throttle response *is* snappy, no stored codes), I want to maximize its performance before I make the 1226870-to-1227165 ECM conversion. Using TunerRT 5.0, I'm reviewing the tuning export details for HLH and the HLK proms (the installed PROM is Hypertech Thermomaster 155332). While I'm not yet proficient enough in TunerProRT to make heads-or-tails of the BIN compare tool, in neither BIN do I find any of these details:
a) California emissions compliance
b) 5.0L vs 5.7L
c) Final rear drive ratio (I've a GU6, 3.42:1)
d) 700R4 (RPO MD8) vs manual (RPO MK2 or M39)
e) 9th-injector cold-start delete
Q: Where in these BINs would I find the above settings?
BTW, I've a 90-min datalog collected some time ago to analyze the engine's performance. As far as I can tell, total fuel trim (BLM+INT) did hit +20% at sustained speeds above 70MPH. Spark plugs #3 & #4 indicate a bit of soot (black, not brown). If any of the tuning experts here care to take a look at that datalog, please ask - I can sure use all the help.
That isn't how it works.
a) The emissions compliance is determined by the overall tune.
b) The displacement isn't used as the MAF directly measures the air flow.
c) final drive ratio affects the TCC lockup points and SA, and probably other minor areas.
d) manual versus auto is typically an option flag. Look for the TCC flag.
e) cold start is built into the system and tune.
That isn't how it works.
a) The emissions compliance is determined by the overall tune.
b) The displacement isn't used as the MAF directly measures the air flow.
c) final drive ratio affects the TCC lockup points and SA, and probably other minor areas.
d) manual versus auto is typically an option flag. Look for the TCC flag.
e) cold start is built into the system and tune.
Noted - thanks...I'll continue studying/comparing the two bins as the HLK prom was stock to then-85 5.0L TPI V8s in California.
Besides exercising TGO's search engine on all matters "1226870," what other useful threads or stickys should I consult?
Copy that, Tuned Performance...my game plan is to optimize the tune (as best as I can) with the existing 6870 ECM before making the 6870-to-7165 upgrade. My thinking here is is to achieve as much of an agnostic-to-ECM tune transfer I can get until I understand better how to tune. Thanks also for suggesting the sticky - any and all other suggestions/recommendations are most welcome.
The power plant's operating with the stock 19#/hr injectors (Bosch 5 235 047). The injector constant of which you mention applies to these injectors, not the injectors used in the '89 L98, right?
Seems kinda small for a zz4, yes the constant applies to the injector flow rate. You can increase the fuel pressure if you have a adjustable regulator. I wouldn’t go over 50 psi. That puts the 19#hr to about 20.4 . Which I think you should be at at least 24, I know for sure 30s will work fine.post 27, hp seems low but to is great. This was a zz4. https://www.thirdgen.org/forums/dfi-...rformance.html
Last edited by Tuned Performance; 11-15-2017 at 12:31 PM.
Btw if you don’t have a wb gauge you might want to read your spark plugs. Sounds like your excessively lean.
Funny you should mention that, as of an recent inspection, #3 and #4 spark plugs are a bit sooty indicating the ECM's adding fuel because my total fuel trim at sustained speeds over 70MPH is roughly +20%. If the ECM thinks the engine's running lean, it'll add fuel. If the existing tune (a Hypertech 155332) was designed for a 305 and 19#/hr injectors, the ECM would have to keep the injectors open longer to match the air charge to maintain stoich? Do I have that right?
I'll be back with a few calculations to make sure my thinking's on the right track.
Sounds like the 19#hr will work for the lower rpm if your running rich now. They will max out in the higher rpm. You can allways try to tune for them. Here’s some good information for the 165 but will apply to the 870. https://www.thirdgen.org/forums/atta...air-flow-tuned
Sounds like the 19#hr will work for the lower rpm if your running rich now. They will max out in the higher rpm. You can allways try to tune for them. Here’s some good information for the 165 but will apply to the 870. https://www.thirdgen.org/forums/atta...air-flow-tuned
You're absolutely right your suggested info is good - it's great!
It's also filling in a few holes as I align the $1F mask (HLK and HLH bins) to the $6E mask (ARAP bin) in the write-up and elsewhere.
I continue working some arithmetic to make sure my thinking's sound - will post for review as soon as I can.
I'll be sure to look at bins' idle speed settings as well in the current tune. IIRC, I set the base timing to 7 degrees and the engine's currently idling in Park at 600-700 RPM.
In reviewing the material you sent, I'm aligning how $1F and $6E masks compute LV8 wrt MAF settings. Straightaway, the 6 MAF tables in the $1F mask (counts-to-gm/s) are slightly different versus the 6 MAF tables in the $6E mask (volts-to-gm/s + MAF scalars). In the $1F mask, there doesn't appear to be an equivalent to $6E's MAF scalars.
I’d raise the idle 50-100 . You might want to start here after you datalog to see where your int and blm are. Create a spreadsheet and start tuning.
Hell of a great idea, Tuned Performance! The very same thought occurred to me after I read through the tuning guide. BTW, is the reason to massage MAF Tables 4-6 if one is only drag racing?
Ok, after spending some time this weekend with Tuned Performance's write-up and the HLK bin, I'd like to have my thinking reviewed wrt an injector constant exercise. Given 19#/hr injectors *and* no other tuning adjustments made, if 24#/hr injectors were to be used, the *new* injector constant table would take the form:
If I'm on the right track, then my total fuel trim (BLM+INT) would be the same as if 19#/hr injectors were still used. If that were true *and* my total fuel trim with 24#/hr injectors was still +20% after datalogging, I would reduce the 24#/hr injector constants by 20%, yes?
11-14-2017, 01:29 PM
