Tuning recent LT1 Build - Split BLM's
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Tuning recent LT1 Build - Split BLM's
Hey folks, I'm new to this forum (first Corvette forum ever actually). I been working on debug and tune of my '92 Black Rose C4. Build outline included below. I'm working with a seasoned tuner and trying to align the BLM's. I've done quite a bit of troubleshooting (new single wire O2 sensors), FP at rail. I've deleted the CATS and I'm running Exotic Muscle OT headers w/ O2's in collectors. I'd be happy to share log if anyone could perhaps provide some troubleshooting guidance. Thanks in advance.
1993 Black Rose Corvette (38k miles). Three years ago I started accumulating parts as part of a build plan. Included Dana 44 (3.45 gearing) , 4L60 build with 3200 stall, LT1 build (LE2 heads and 227/235 .565.579 110 LSA Cam, 1.6 Lunatti RR, LE2 ported intake, 58mm BBK, 30lb injectors, Exotic Muscle LT headers).
1993 Black Rose Corvette (38k miles). Three years ago I started accumulating parts as part of a build plan. Included Dana 44 (3.45 gearing) , 4L60 build with 3200 stall, LT1 build (LE2 heads and 227/235 .565.579 110 LSA Cam, 1.6 Lunatti RR, LE2 ported intake, 58mm BBK, 30lb injectors, Exotic Muscle LT headers).
Safety Car
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From: Glenbeulah Wi
There is not much that can be done about the split BLM's, just make sure there are no mechanical issues like vacuum leaks, header leakes, fouled plugs or ??. The 1992 is a batch fire car and the LT1 intake has some fuel distribution issues at light throttle low RPM. The later cars 1994 to 1996 had sequential fueling and they adjusted the pulse width by cylinder at low throttle to tune out this issue. Just make sure the mechanical issues are good and dial in the tune the best you can.
Last edited by bjankuski; Apr 29, 2020 at 02:43 PM.
Melting Slicks
Joined: Feb 2015
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From: Park Ridge New Jersey
Hey folks, I'm new to this forum (first Corvette forum ever actually). I been working on debug and tune of my '92 Black Rose C4. Build outline included below. I'm working with a seasoned tuner and trying to align the BLM's. I've done quite a bit of troubleshooting (new single wire O2 sensors), FP at rail. I've deleted the CATS and I'm running Exotic Muscle OT headers w/ O2's in collectors. I'd be happy to share log if anyone could perhaps provide some troubleshooting guidance. Thanks in advance.
1993 Black Rose Corvette (38k miles). Three years ago I started accumulating parts as part of a build plan. Included Dana 44 (3.45 gearing) , 4L60 build with 3200 stall, LT1 build (LE2 heads and 227/235 .565.579 110 LSA Cam, 1.6 Lunatti RR, LE2 ported intake, 58mm BBK, 30lb injectors, Exotic Muscle LT headers).
1993 Black Rose Corvette (38k miles). Three years ago I started accumulating parts as part of a build plan. Included Dana 44 (3.45 gearing) , 4L60 build with 3200 stall, LT1 build (LE2 heads and 227/235 .565.579 110 LSA Cam, 1.6 Lunatti RR, LE2 ported intake, 58mm BBK, 30lb injectors, Exotic Muscle LT headers).
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Burning Brakes
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From: Richmond Hill Ontario
Tune it as best you can in Closed Loop. Then run it in open loop and clean up the idle (BLM Cell 16, 17) Then leave it in Open Loop permanently...trust me .
Last edited by FrankieD; Apr 29, 2020 at 11:54 PM.
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Next steps on ECM Performance Tuning
Folks... any recommendations of Tuners that can help me get from "stable" to "optimized performance" on my '93 LT-1 build. While the BLM's seem to be a stabilizing, I need to get some help with performance tuning. Any help or a point in the right direction would be greatly appreciated. Thanks
Drifting
Joined: Jul 2004
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From: MA
Folks... any recommendations of Tuners that can help me get from "stable" to "optimized performance" on my '93 LT-1 build. While the BLM's seem to be a stabilizing, I need to get some help with performance tuning. Any help or a point in the right direction would be greatly appreciated. Thanks
Also check out this: https://ls1tech.com/forums/lt1-lt4-m...d-pp-tb-4.html
Good luck!
Last edited by grandspt; May 3, 2020 at 06:17 AM. Reason: link didn't work
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From: Ohio
Split BLM's
Thanks again.
One addition, I was just reviewing a LOG from earlier in the week in which the BLM's looked more closely coupled. I'm working remotely with a Tuner (unnamed) and the only changes were VE adjustments and physical TB idle position. See the dates on the files.
Last edited by BPontuti; May 3, 2020 at 08:22 AM.
Burning Brakes
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From: Richmond Hill Ontario
There seems something wrong with the first capture. You are only using BLM Cells 16, and 18, during the entire log. That's not right it should be using more Cells than that for fuel correction. BLM Cell 16 is only for Idle. And I believe Cell 18 is a special function Cell usually triggered during CCP ( Charcoal Canister Purge). From what I can tell you are not going into proper fuel correction. This happened to me whenever I lost VSS signal.( Is your Speedo working on your instrument cluster? )
Can you post whatever files you are using for datalogging. BIN File, XDF File, ADX File.
Can you post whatever files you are using for datalogging. BIN File, XDF File, ADX File.
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From: Ohio
There seems something wrong with the first capture. You are only using BLM Cells 16, and 18, during the entire log. That's not right it should be using more Cells than that for fuel correction. BLM Cell 16 is only for Idle. And I believe Cell 18 is a special function Cell usually triggered during CCP ( Charcoal Canister Purge). From what I can tell you are not going into proper fuel correction. This happened to me whenever I lost VSS signal.( Is your Speedo working on your instrument cluster? )
Can you post whatever files you are using for datalogging. BIN File, XDF File, ADX File.
Can you post whatever files you are using for datalogging. BIN File, XDF File, ADX File.
The Definition file is the following:
- $DA2 ECM Definition File fro Data C.A.T.S
- The "BPONTUTI8 BDBK YB auto.BIN is the latest tuner (ECM) program
I had been using Tuner PRO RT... The files I was using for that (previous to the logs posted) were:
- $DA3-16159278-V2_ALDLDroid_Modified.adx (you have to remove the .txt from the file name (I couldn't upload .adx without adding the .txt)
- $DA3-16159278-V2.1 (Again, remove the .txt)
Any help or insight you can provide would be greatly appreciated. I switched from TunerPro RT to Tuner C.A.T.S and Data C.A.T.S. because I was having occasional "synch" errors with TunerPro... the same problem occurs with Data CATS however so I just live with it.
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From: Ohio
There seems something wrong with the first capture. You are only using BLM Cells 16, and 18, during the entire log. That's not right it should be using more Cells than that for fuel correction. BLM Cell 16 is only for Idle. And I believe Cell 18 is a special function Cell usually triggered during CCP ( Charcoal Canister Purge). From what I can tell you are not going into proper fuel correction. This happened to me whenever I lost VSS signal.( Is your Speedo working on your instrument cluster? )
Can you post whatever files you are using for datalogging. BIN File, XDF File, ADX File.
Can you post whatever files you are using for datalogging. BIN File, XDF File, ADX File.
Thanks
Burning Brakes
Joined: Mar 2005
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From: Richmond Hill Ontario
Do you have hardware to burn your own BIN ( prom ) ?
If I send you a modified BIN can you burn it and place it in your ECM
Also, do you have a Wideband hooked up to your vette
If I send you a modified BIN can you burn it and place it in your ECM
Also, do you have a Wideband hooked up to your vette
Last edited by FrankieD; May 3, 2020 at 09:33 PM.
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thanks
i don’t have wideband O2’s.
Last edited by BPontuti; May 3, 2020 at 10:26 PM.
Burning Brakes
Joined: Mar 2005
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From: Richmond Hill Ontario
Ok that's great that you can burn your own prom. I already see issues with your existing BIN that I will improve on. Once I make some changes I will send it to you via Private Message.
I would highly recommend trying to get a Wideband installed. It will really help the situation.
I would highly recommend trying to get a Wideband installed. It will really help the situation.
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Ok that's great that you can burn your own prom. I already see issues with your existing BIN that I will improve on. Once I make some changes I will send it to you via Private Message.
I would highly recommend trying to get a Wideband installed. It will really help the situation.
I would highly recommend trying to get a Wideband installed. It will really help the situation.
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I can install wide bands no problem. I just installed new O2’s two weeks ago and when I inquired with the the guy that had been helping me with the mail order tune i was told the ECM can’t process the wide-band data. If that’s not the case I will order wide-bands and install.
Burning Brakes
Joined: Mar 2005
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From: Richmond Hill Ontario
The wideband will be useful for visual to see what is happening. (only 1 wideband needed on whatever side you choose) Especially great when dialing in WOT
Also, what fuel are you running? What is the Ethanol content % if any?
Also, what fuel are you running? What is the Ethanol content % if any?
Last edited by FrankieD; May 4, 2020 at 11:40 AM.
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Race Director
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From: NEwhere Ohio
Datalog your wideband (‘make sure it has 0-5v analog output)thru your ac pressure sensor harness or oil temp sensor harness
(You can plug back in those when not datalogging so the a/c or oil temp works fine again)
this will put your wideband afr alongside all your other tune outputs (rpm, etc.) will help in tuning immensely!
datacat even has a feature to convert the a/c pressure (or oil temp) readings into wideband afr
otherwise you need a simple linear equation to convert the a/c press (or oil temp) output into wideband afr
(You can plug back in those when not datalogging so the a/c or oil temp works fine again)
this will put your wideband afr alongside all your other tune outputs (rpm, etc.) will help in tuning immensely!
datacat even has a feature to convert the a/c pressure (or oil temp) readings into wideband afr
otherwise you need a simple linear equation to convert the a/c press (or oil temp) output into wideband afr