Big cam ls7 tuning

[atomic vette]

I am tuning a 2010 camaro ss with an ls7 swapped in which has a large cam 24x/25x. The main issues I am coming across is getting the car to idle consistently. I played with the idle airflow and speed until it would idle fairly steady, except every 10 seconds or so the idle drop way down and then recover. I have used some diy I found to tune and set the timing based another similar set up I tuned except with a haltech ecu. The other thing I have been trying to figure out is tuning the ve table. I know there is some information on here about the virtual ve but I can't even seem to find the link for it. The other thing I was interested in is the custom os. Can I use the 2 bar speed density to get a normal ve table with my 1 bar na car? Is there any negatives to going this way?

[schpenxel]

Email support, request access to the 2.25 beta. It makes virtual VE tuning easy.

Yes, you can use the 2 bar OS on a non-boosted car, no problem. No real negatives that I can think of at the moment.

[Alex5.0]

Duration at .05 ?

this will need a idle near 950-1000 and RAF very high 18-22g , timing probably around 25 .

[RR46]

LS7 with RPM B3 cam.
Stock TB.
MSD intake.
Headers and exhaust. Standalone mode in a tube frame car.
EDIT: KEP small single mass flywheel and small Porsche pressure plate and clutch

Can't get it to idle, set airflow tables to 21-22 g/s, and it seems throttle signal seems static the whole time, it won't get more air.
2006 E38, Setting "Effective Area Percent Max" to 4.5 - 5% made it idle perfectly, but shortly after it just throws PCM/ECM internal error code and it can't be cleared.
Set back to 2.37% stock per advise from Alvin here in the board, and now the PCM/ECM internal error code is gone (thanks Alvin!), but sadly so is the airflow, rpm will just fluctuate a couple of times and drop out.

Log.
cold-start-log w effective area limit.hpl

Tune
LS7 restore point3 - starts idles great - with 2006 stock table resets except maf spark startup .hpt

How can I get more air to it when the area max is 2.37%? Or smth else to solve it?

[SultanHassanMasTuning]

LS7 restore point3 - starts idles great - with 2006 stock table resets except maf spark startup .hpt

try this

[RR46]

LS7 restore point3 - starts idles great - with 2006 stock table resets except maf spark startup .hpt

try this

Thank you! Tried it, no dice. Fires up then dies. I realize I forgot to add an important mod - the flywheel and clutch are single mass KEP and a small Porsche clutch. Much lighter and smaller rotating diam than LS7.

That's probably why it's hunting and dying. What can I change to fix this? I've started to try to limit the spark swings, but generally, it just seems to need more air.

When I could have the throttle area limit higher it idled at about 34% throttle, started and idled perfectly, super solid and no issues cold or warm.
Video here:https://www.youtube.com/watch?v=QqViv43-JYE

But then the ECM decided to start throwing codes due to the area limit, and now the max airflow no matter what I put into the tables is constantly capped around 27% and it will just hunt between 200-2000 rpm and die after a few swings. Began trying to limit the timing but even that doesn't have big enough of an impact.

Is this where drilling a hole in the throttle blade comes into play?
Or is there any table that will get around the allowable idle airflow limit?

06 os adaptiive idle change2.hpl

LS7 Restore point2 - restored reduced fuel added max area.hpt

[SultanHassanMasTuning]

stock injectors?

[hjtrbo]

Effective area % max / max brake is the upper limit of the TPS opening.

Another method to try, you can set the minimum air flow table to some unattainably high number (TPS will want to go to this air flow but will be clamped by the effective area max %) then gradually increase the area % max / max brake to till you kiss the amount of tps needed to get a stable idle. Hopefully whatever that % number turns out to be, it is somewhat lower than the 4.5 - 5% you found previously and the ECM doesn't fault out.

[RR46]

stock injectors?

60#, table has been adjusted to them.

[Sub8]

Is your MAF and VVE dialled in well? Absolute first thing you need before working on anything else.

[pannetron]

Try increasing the values in the columns of Idle/Airflow/Throttle Follower/Torque below your idle RPM. That may help the computer add more torque quicker when the idle speed drops below its set point.

[Gpargament]

I am hoping I may help. I also have a big cam (annihilator) ls7 (C6Z), i do have twin turbos but the tuning should be very similar
both logs that have been posted do not have the narrowbands running and you are in open loop, there is also no wideband that I could see. This makes it super hard to tell how your car is running, if I could see the stft max out, or the idle adaptive spark max out, it would easier to pinpoint where the errors is occurring.
I know you had questions about running SD, currently your tune does not show the maf failed and I could not see your intake valve temp, but normally you can adjust the open loop gains ivt gain gas and help dial in cold and warm starts after the maf and virtual ve are dialed in. these need to be dialed in separately, there are video's you can watch to enable maf only and then sd only, logging wideband vs these tables, you can make adjustments and be dialed in within about an hour or two.

The direct issue you are facing at the moment is your spark. you are requesting a very large cam to idle at 13 degrees of spark, that is probably pretty rough on the motor, and the table is not smooth. your cylinder airmass is higher with the new cam or at least different, check out your base idle table at .08 cyl airmass and 800 rpm - 1400 rpm, your spark which is too low and targeted at 13 allows for major jumps from 13 to 32 in less than 1k rpms, this is your first thing to fix before anything, if you look at your log you will notice you are at 400 - 500 rpms when spark is at commanded 13(again too low, try 19 or 20, if it runs too hot at idle go to 21 or 22) and when spark is commanded at 20+ you idle fine at 800 or so. I personally target 950 idle with about 20 degrees of spark at idle

after you adjust your idles spark make the cruise spark the same, it could probably be a tad higher but for ease of use just copy. I have posted photos of your table, your tune, and my tune in the areas that are causing your car to jump up and down, the adaptive spark cant keep up, and the AFR is off too(just a guess) some dont like having spark that low throughout but I do, also having the fast drop in spark when you let off the gas and leave it in gear should cause beautiful after fires, same for clutching in at about 4k(if you want the afterfires lower your main spark in those areas too, not as much though or you'll have no low end power.

Lastly you will not have good street manners until your main spark isnt such a large jump from your base idle, right now your car can jump pretty fast in spark once out of idle, even after raising your base idle and cruise idle there will still be too large of a gap and you will buck. ive attached a portion of my main spark table to give you an idea, remember SD uses low octane table, I always tune both just to be safe. good luck.

oh and you will never have a proper tune without a wideband, if you have one and i didnt see it in the tune my apologies.

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[RR46]

Huge thanks!

Gold TB replaced with Silver TB. Now works well enough to tune. Bucking is for sure happening.
Put a WB in it, finally populated the layout as well with tables that allow matching to the tune files.

Topic continued here.
https://forum.hptuners.com/showthrea...t-load-bucking