New Cam tuning

[Daniel196]

I have a fresh build lm7 based engine. I have changed usual parameters for a cam swap but am having issues with idling still and have lack of idle control in my scanner when the engine is running too.

Engine is stock LM7 with exceptions of Summit 8706 stage 2 turbo cam, flat top pistons, and dual valve springs.
Cam Specs:
Summit Racing SUM-8706: Stage 2 Pro LS Turbo Cam. 226/230 Dur., 113+4, .600/.575 Lift, 3-bolt, 5.3, 5.7, 6.0, 6.2, 7.0, Vortec Truck, LS1 LS2 LS6 LS3 LS7 LQ4 LQ9 LS9, Each

This motor is in my crawler with a th400 and np205 behind it with 4.56 gearing. At this time, the motor will idle for a short amount of time and needs throttle to start. Only other issue I am having is slightly lower fuel pressure at 55psi, but that will be fixed soon.

At this point I have done a typical change to target idle tables and airflow tables; however, I did notice that at some points it will idle on its own without slight throttle , but does surge still. I am not sure if the compression increase is also causing problems to typical changes for cam tuning. Also, I do not have a wideband at the moment, but this rig does not see high miles and is typically slow moving or wide open. Jeep 1.hplJeep 1.hpl

[Daniel196]

CAMMY video tune 1 .hpt

Also, I have noticed that I am not able to change or find max/min idle rpm in my editor, but do have it in advanced mode. All I have access to in terms of RPM is the simple idle table and a few other things not seemingly related. Would anyone be able to possibly send me a file that may help. I have attached a link of my setup I currently have uploaded to the ECU, but it may be slightly screwed with out of my frustration.

[5FDP]

You're very lean based on the fuel trims. The 55psi of fuel pressure is pretty close to the 58psi that you'd want but that's not a huge issue at the moment.

The camshaft is bringing in far more air and it needs more fuel as well. If you are damn sure you have ZERO vacuum leaks and exhaust leaks pre o2 sensor you can make a quick change to the fueling to see if it helps being the fuel trims down.

Add 5-10% to the MAF curve and both VE tables. Highlight the whole table and multiply by 1.05 or 1.10 to add that amount of fuel.

I would also zero out the negative timing values in the ECT spark correction table for when the engine warms up, you don't need it pulling 4-8 degrees of timing. Also cut the under/overspeed spark corrections tables in half, it helps to not allow the timing to swing as well.

Go back and change the base running airflow table to stock again. Then just add a little bit to it, do not make the whole table the same value as that is not helping you. The main thing to get straight in fueling, then airflow tables will fall in line much faster. A wideband is a must here and it doesn't matter that you will not see a lot of miles. Be it idle time, low rpm cruising or full throttle, fueling needs to be correct otherwise you run the risk of hurting the engine with something like a chipped piston or worse.

There are no tables labeled min/max idle. Ideally when fueling/airflow is on point it will idle really close to the desired idle rpm as well as the idle timing set. Most cammed setups can be anywhere from 18-24 degrees sometimes.

The data logs are also missing lots of data. You need RPM, cylinder airmass, commaded AFR or Lambda (eq ratio), injector pulse width avg for both banks, knock retard, burst knock and anything else you think you need to watch.

[Daniel196]

I am not sure why I am missing so many values in my scanner. I do have a harness that has been cut down, but do have most things still plugged in or enabled. Do I not have RPM in my scanner due to not having the green rpm wire in the harness not running to the OBD2, or is that wire simply for a tach signal?

[5FDP]

You just are not logging those specific channels. Anything that you wish to log/see must be present in the main channels list on the left hand side.

[Daniel196]

Thank you, I will add those parameters and re-log some data. I appreciate your help very much!

[Daniel196]

I have logged some new data with the changes you suggested. It seems to need more throttle to stay running and does seem a little more choppy. I can also take and attach videos if needed.

Jeep2.hplJeep 2.1.hpl

CAMMY hptuners forum file 1 .hpt

[Lakegoat]

Looks like you don't have a working iat sensor or a engine coolant temp sensor.

[JoshuaGrooms83]

Following,
I have that exact same cam and am excited to run it! I'm either gonna put it in my current ls1, or my 6.0L engine build project. Either way, I'm curious how your tuning endeavor has gone on it. I'm slowly getting my feet wet tuning my current turbo build as it is with the stock 98 ls1 engine with a 2bar SD OS and turbo system for 10psi now. I've only been messing with it for a few months, trying to clean up the VE table and dial in timing now. Once I get real comfortable with this, I might swap out my cam this winter, and dial in the Summit pro stage two turbo cam. Seeing how it is very similar to several 226/230 cams, there should be an over abundance of similar repository tunes that could get you close without recreating the wheel.

Setting up your channels and graphing tables seems to be one of the few tuning secrets that often gets over looked, as well as how to apply your data logging to your tune, and how to interpret the data. There's recently been several videos on ls1tech that really got me going in the right direction. Probably basic to most experienced tuners, but damn did they really help me get my tune smoothed out. I sat through a few goat rope garage videos, which can be really hard at times as he speeds through so fast that sometimes you gotta rewind several times to see what hell he's doing, but some of his scanner setup videos for different parameters and user math histography's such as SD EQ error ratio helped me out.