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Tuning question after cam install??

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Old 03-17-2019, 08:49 PM
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Default Tuning question after cam install??

Hey guys, new member here. I have a nnbs 4.8 with longtubes, 4.10s , and a recently added 212/218 112lsa
tx speed cam. After the install I had the truck tuned. So far I’m extremely happy with the performance of the cam, but I do have a question about the tune in regards to the way the truck idles. In park or neutral the cam has a nice lope to it, but in drive, when I’m say stopped at a light it doesn’t lope at all, the rpm seems to be the same as when it’s in park but I just sounds higher. I’m new to the cam game but I know I’ve heard canned trucks chopping at a light next to me so I wasn’t sure if this was something that could be adjusted in the tune or if this is normal for this cam? Any info would be appreciated!
Old 03-17-2019, 09:15 PM
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Usually the In drive RPM is a little higher with increased base running airflow to keep it from stalling. You can adjust it but might worsen the driveability. If you spend a bit of time on it you should be able to get it to chop and drive just fine.
Old 03-18-2019, 08:42 AM
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Originally Posted by black04
Usually the In drive RPM is a little higher with increased base running airflow to keep it from stalling. You can adjust it but might worsen the driveability. If you spend a bit of time on it you should be able to get it to chop and drive just fine.

thanks for the quick reply bud, I’ll look into it
Old 03-18-2019, 09:23 AM
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Echo what black04 said.

It's the tune.

There isn't a reason in the world you shouldn't be able to get a 212/218 cam to idle the same in D as in P/N.

Usually your 230+ duration cams you have to have the idle set at 900-975.
Old 03-18-2019, 09:31 AM
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Originally Posted by madmann26
There isn't a reason in the world you shouldn't be able to get a 212/218 cam to idle the same in D as in P/N.
Not necessarily. Combustion stabilizes at higher cylinder air mass. In gear = more load = higher cyl mass. Idle improves.
Old 03-18-2019, 11:51 AM
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It could be a wide range of things, like higher timing in drive and/or changes to delays/decays in cracker and follower which will prevent adaptive idle from occurring.
Old 03-18-2019, 09:47 PM
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I’m not getting a lot of answers from the tuner that tuned it so I reached out to another guy that claims he can get it to idle the same in park and drive, catch is he’s twice the price, I just wish I could get in touch with someone with the same cam that has been able to get it to chop in drive with no problems just so i know I’m not flushing money down the toilet. Regardless I think I need my tune adjusted because I suspect my truck is running really rich.
Old 03-18-2019, 10:18 PM
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Ideally you should have a wideband installed because knowing your fueling is a good thing.

One to make sure that the tune is okay because you didn't do it and two, so that you can monitor it after the fact. Would be super easy to tell you have a major problem going on if for some reason it goes stupid lean from lack of fuel/vacuum leak or super rich if something with an injector went south.

It's cheap insurance on a modded engine.
Old 03-18-2019, 10:27 PM
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Originally Posted by FFDP
Ideally you should have a wideband installed because knowing your fueling is a good thing.

One to make sure that the tune is okay because you didn't do it and two, so that you can monitor it after the fact. Would be super easy to tell you have a major problem going on if for some reason it goes stupid lean from lack of fuel/vacuum leak or super rich if something with an injector went south.

It's cheap insurance on a modded engine.

thanks for for the heads up. That’s a good idea
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