Just back from new camshaft tuning Question

Tech discussions on the L77 6.0L V8.
Post Reply
VintageIron41
Posts: 90
Joined: Sun Nov 18, 2018 8:23 am

Just back from new camshaft tuning Question

Post by VintageIron41 » Sat Nov 30, 2019 5:47 pm

Hello and thanks for taking time to read this.

Per the topic, I just got my 2014 PPV back from the tuner after installing a Texas Speed Stage 1, 225/236.629"/.615" camshaft. The AFM delete was done both mechanically and in the tune.
Solo Exhaust axle back at 2.5" was also done, the car sounds really good at idle, not too loud but has a good snarl to it under load.

My question(s) is/are, while everything is fine above 1200 RPM, the car idles at about 800 RPM now, and has a tendency to stall coming off throttle, coming up to a stop light for example.
Too, the converter lock up seems odd, again, while coming to a stop, it will lock up and lurch the car forward randomly, this generally is accompanied by the engine spooling up in RPM without my foot on the accelerator.

What do you think is causing these issues?

Okay, please understand, senior citizen here, this is my first experience in LS engine customization, so pardon if I am asking newbie questions.

Thank you!

Dave

Ilikemtb999
Posts: 184
Joined: Thu Feb 07, 2019 5:49 am

Re: Just back from new camshaft tuning Question

Post by Ilikemtb999 » Sat Nov 30, 2019 8:51 pm

You need a better tuner. That’s a baby cam and should work just fine with a stock converter.

VintageIron41
Posts: 90
Joined: Sun Nov 18, 2018 8:23 am

Re: Just back from new camshaft tuning Question

Post by VintageIron41 » Sat Nov 30, 2019 9:51 pm

Ilikemtb999 wrote:
Sat Nov 30, 2019 8:51 pm
You need a better tuner. That’s a baby cam and should work just fine with a stock converter.
Any tips from your experience?

Silversled
Posts: 269
Joined: Fri Aug 12, 2016 12:13 pm
Location: Tampa, FL

Re: Just back from new camshaft tuning Question

Post by Silversled » Sun Dec 01, 2019 2:20 am

The tuner probably didn't spend a lot of time working the idle areas or verifying the minimum idle RPM for that cam. The surging you're experiencing is many times having too much idle and coast down timing which have not been optimized to the required airflow. It also sounds like it needs more minimum idle airflow as it want to stall. I've seen many tuners just bump the minimum idle airflow to what they think it should be but forget to verify the ECT multiplier table which depending on the stock tune actually lowers the effective airflow in the table. A responsible tuner will not accept this and fix it without charging you!
2014 Chevrolet Caprice PPV
2014 Chevrolet Stingray Z51
2016 AMG C63
2015 BMW X5 iDrive 50i

VintageIron41
Posts: 90
Joined: Sun Nov 18, 2018 8:23 am

Re: Just back from new camshaft tuning Question

Post by VintageIron41 » Sun Dec 01, 2019 4:42 am

Silversled wrote:
Sun Dec 01, 2019 2:20 am
The tuner probably didn't spend a lot of time working the idle areas or verifying the minimum idle RPM for that cam. The surging you're experiencing is many times having too much idle and coast down timing which have not been optimized to the required airflow. It also sounds like it needs more minimum idle airflow as it want to stall. I've seen many tuners just bump the minimum idle airflow to what they think it should be but forget to verify the ECT multiplier table which depending on the stock tune actually lowers the effective airflow in the table. A responsible tuner will not accept this and fix it without charging you!
Silversled-
Thank you very much for that concise information!

Silversled
Posts: 269
Joined: Fri Aug 12, 2016 12:13 pm
Location: Tampa, FL

Re: Just back from new camshaft tuning Question

Post by Silversled » Sun Dec 01, 2019 5:10 pm

VintageIron41 wrote:
Sun Dec 01, 2019 4:42 am
Silversled wrote:
Sun Dec 01, 2019 2:20 am
The tuner probably didn't spend a lot of time working the idle areas or verifying the minimum idle RPM for that cam. The surging you're experiencing is many times having too much idle and coast down timing which have not been optimized to the required airflow. It also sounds like it needs more minimum idle airflow as it want to stall. I've seen many tuners just bump the minimum idle airflow to what they think it should be but forget to verify the ECT multiplier table which depending on the stock tune actually lowers the effective airflow in the table. A responsible tuner will not accept this and fix it without charging you!
Silversled-
Thank you very much for that concise information!
Good luck. Please report back if you were able to resolve it.
2014 Chevrolet Caprice PPV
2014 Chevrolet Stingray Z51
2016 AMG C63
2015 BMW X5 iDrive 50i

VintageIron41
Posts: 90
Joined: Sun Nov 18, 2018 8:23 am

Re: Just back from new camshaft tuning Question

Post by VintageIron41 » Mon Dec 02, 2019 7:03 am

Will do and again, thank you!

VintageIron41
Posts: 90
Joined: Sun Nov 18, 2018 8:23 am

Re: Just back from new camshaft tuning Question

Post by VintageIron41 » Sat Dec 07, 2019 7:53 am

Silversled wrote:
Sun Dec 01, 2019 5:10 pm
VintageIron41 wrote:
Sun Dec 01, 2019 4:42 am
Silversled wrote:
Sun Dec 01, 2019 2:20 am
The tuner probably didn't spend a lot of time working the idle areas or verifying the minimum idle RPM for that cam. The surging you're experiencing is many times having too much idle and coast down timing which have not been optimized to the required airflow. It also sounds like it needs more minimum idle airflow as it want to stall. I've seen many tuners just bump the minimum idle airflow to what they think it should be but forget to verify the ECT multiplier table which depending on the stock tune actually lowers the effective airflow in the table. A responsible tuner will not accept this and fix it without charging you!
Good luck. Please report back if you were able to resolve it.
Silversled-
Went to the tuner today, ( a different one ), he showed me on his laptop those things he wanted to change before and side by side after, the first tuner had put a lot of low rpms, 650rpm to be exact, in the tables, along with higher numbers in other tables. These were found in base rpm, at idle and in gear. They were in the tables that were based on coolant temperature, and also in the tables referencing the MAF, and VSS. The result, the ECU was getting conflicting control data. As you surmised, the first tuner had not spent enough time with the idle numbers, just plugging in generic low numbers in several of the tables. The result, the shop owner of the tuner I went to today, drove the car with me as passenger, and did several "panic stops" to test the new tune, the result was much different, no stalls, the transmission downshifted without "blipping". The car now is much better to drive in traffic, and as the ECU is adaptive should only improve as I drive the car over the next several days and it learns my driving habits.
This is my first experience with a modern engine, my 1969 Oldsmobile with a 1972 455ci has no computer. It was staggering to see the amount of data collected on the 2014 Caprice by the computer, and the many many tables to access and change that data, obviously ( now ) a good tuner knows where to make changes and all the places he needs to.
I hope the information I have provided is useful if only generically to someone else combined with your above reply to my post, which, again, I thank you for.

Dave

Silversled
Posts: 269
Joined: Fri Aug 12, 2016 12:13 pm
Location: Tampa, FL

Re: Just back from new camshaft tuning Question

Post by Silversled » Fri Dec 13, 2019 12:59 am

VintageIron41 wrote:
Sat Dec 07, 2019 7:53 am
Silversled wrote:
Sun Dec 01, 2019 5:10 pm
VintageIron41 wrote:
Sun Dec 01, 2019 4:42 am


Good luck. Please report back if you were able to resolve it.
I hope the information I have provided is useful if only generically to someone else combined with your above reply to my post, which, again, I thank you for.

Dave
Awesome to hear you got it solved Dave!

Unfortunately I've seen a proliferation of tuners lately who just don't know what an engine needs and how to get there. Too many laptop commandos these days. LOL. I've troubleshot 3 bad tunes already this week.

Vic H
2014 Chevrolet Caprice PPV
2014 Chevrolet Stingray Z51
2016 AMG C63
2015 BMW X5 iDrive 50i

VintageIron41
Posts: 90
Joined: Sun Nov 18, 2018 8:23 am

Re: Just back from new camshaft tuning Question

Post by VintageIron41 » Fri Dec 13, 2019 7:31 pm

Vic-
Thanks again, for your insightful reply to my post. Yes, I learned a lot, and believe I have found a competent tuner now.

Post Reply