what base tune can I use for ls swapped heavy car

I have an ls1 in my 96 impala with 243 heads ls3 springs btr stage 3 truck cam (218/224-.553/.553-110lsa) flex injectors 2600 stall 4l80e tbss intake 92mm DBC throttle body longtubes. 27in tire with 3.73 gears.


the car was originally swapped with a lm7 with 02+ ls6 cam same injectors trans and intake and gear

the car will not stay running with the current tune and wanted to know if I should use a stock truck tune copied to my tune for a base tune. or does anyone care to share theirs with similar setup.

Attachment 93818

Midnight bump

Post a log.

Nothing is that tune should really stop it from running. It should stay running even though you may need to pedal it.

Without a wideband reading or log to look at I can't see if it's getting too much fuel, too little fuel or it needs more idle airflow to stay running. Or if something else is the cause for it not wanting to stay running. Either way one it runs it will need to be tuned in open loop with a wideband to fix the MAF/VE.

I will post a log tomorrow after I pick up the car amd drive it home. Going to pick it up but was asking if the stock tbss or Silverado 2500 lq4 or Escalade lq9 tune would be a better starting point to at least keep it running. I'll just take the expressway instead of the back roads to avoid having to rev it to keep it running at stop lights.

Attachment 93845

here is the current log

you wont find anything to drop in and call done. your going to have a hard time finding the right stuff in one spot.
the engine parameters, cam airflow, and tb dimensions would need updating but doing so would open a whole can of adjustments that need to be made.

if you have to know the lm7 has a cylinder volume of 0.6625 L/cyl which is a general engine setting in the ecu. The ls1 throttle body which would have been oem for the ecu file you supplied is 78mm not 92mm so the etc area scalar to correct this size change should be changed to 0.0178. the cam is larger than oem and will require more airflow at idle so to request this the braf should be bumped up to around 10 g/s in the high temperature range and interpolated from roughly 68*F to max temp. The more consistent idle may push on the converter some so you could apply a 10% reduction to the throttle cracker airflow table to reduce the initial push if there was going to be any. from here you need a wideband, and you need to tune maf or ve in one at a time and while doing so, you can work on adjusting the braf using russ K method. dont forget to check your warm idle IAC counts once the fuel is tuned in. you may need a mechanical tb stop adjustment. these mix and match combinations take a lot of work. sorry there isnt some drop in perfect solution.

Attachment 93852

here is the updated tune. it did not like the other one at all so I went back to the 5.3 tune I originally had with the old engine. and that log I posted previously is for this tune file. I will ad to the BRAF and see where that gets me.

Thanks

Quote:

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Originally Posted by cobaltssoverbooster

you wont find anything to drop in and call done. your going to have a hard time finding the right stuff in one spot.
the engine parameters, cam airflow, and tb dimensions would need updating but doing so would open a whole can of adjustments that need to be made.

if you have to know the lm7 has a cylinder volume of 0.6625 L/cyl which is a general engine setting in the ecu. The ls1 throttle body which would have been oem for the ecu file you supplied is 78mm not 92mm so the etc area scalar to correct this size change should be changed to 0.0178. the cam is larger than oem and will require more airflow at idle so to request this the braf should be bumped up to around 10 g/s in the high temperature range and interpolated from roughly 68*F to max temp. The more consistent idle may push on the converter some so you could apply a 10% reduction to the throttle cracker airflow table to reduce the initial push if there was going to be any. from here you need a wideband, and you need to tune maf or ve in one at a time and while doing so, you can work on adjusting the braf using russ K method. dont forget to check your warm idle IAC counts once the fuel is tuned in. you may need a mechanical tb stop adjustment. these mix and match combinations take a lot of work. sorry there isnt some drop in perfect solution.

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thank you :pray:

yes I know its a Frankenstein puzzle piece of vehicle. I will get a wide band asap I know it will be required. I will check and adjust all of the parameters you mentioned.

Any ideas on the fuel? The car is definitely running rich seen the stft at -21 at some points and sees some knock retard at higher RPMS

A wideband is needed so the MAF/VE can be fixed using that. With that you'd create a wideband error against the commanded fueling to show where fuel can be removed or added.

The knock could be fuel or timing related, it's just not easy to say.

It doesn't help either that the timing tables are exactly the same. So if it does knock, it can't do anything about it because the low octane timing table is telling it to use the same amount of timing. A stock vehicle would have anywhere from 5-10 degrees less timing in that table so it could pull timing when it knocked. Then over time using the knock learn factor it could blend the timing between the two tables bring the timing back in.

So should I copy a stock timing table over? Or reduce the low octane table by a %

Just minus like 5 degrees from the entire table.

Ok will do before I leave work today. I cant get the car to the tuner til about 10 days. Is it be ok to drive? I am also running 93 octane btw

here is the latest log and tune

Attachment 93893

Attachment 93894