bucking under 1500 rpm stage 4 BTR cam need a little help

[Gpargament]

I am helping a friend with his 2014 camaro ss, he has longtube headers, catless exhaust, stage 4 cam 233/248 619/595, and upgraded valvetrain and pushrods. from 1600+ rpms the car actually runs really good and even 1500 isnt bad if we are in 4th gear or above. however 1st 2nd and third do not enjoy steady light throttle at 1500 or below. I understand I might not be able to eliminate it completely, but I was hoping to get it a little better than it currently is. We started with idle tuning, it sits at 975 with a wonderful lope, steady maf and pretty consitent spark, then we did VVE tuning followed by MAF tuning, all of this was done with the short term trims histogram, we wont have the wideband untill this weekend. I have attached our last drive around, and last tune. All help is greatly appreciated.
latest brad ss.hpt
brad ss latest.hpl

[lukearmstrong1990]

look at your main spark tables at 1600RPM in idle and cruise section. there is a massive jump. blend that much better. I get you're trying to match your idle tables into the main, but you need to make that transition smoother than a 23 degree jump in 200RPM.

the issue you're trying to fix is spark smoothing.
set the max torque delta to 35nm and halve both the low and high torque gain tables.

turn off injector desoot and disable fast torque exit.... and zero out burst knock too

[Gpargament]

Absolutely awesome thank you very much will be trying it tomorrow

[sgod1100]

I've read to not match your idle table with your main spark advance table due to your overspeed/underspeed spark tables not being able to adjust properly? i've never tested this theory though

[Hib Halverson]

My choice with the idle spark table is adjust the spark in the cells where the engine idles for best idle quality. Then, to those idle spark numbers, I add the maximum park/neutral overspeed spark addition and calibrate the high and low octane spark tables with that number.

For example, if my best idle comes with 19-deg BTDC and my max. P/N overspeed addition is 8-deg, then I enter 27-deg in the high and low octane tables in same cells as I entered 19-deg in the idle spark table.

[Gpargament]

i wanted to ensure this thread can help others, tightening up the spark table between 1200-2400 made a huge difference with the stage 4 cam, I also adjusted spark smoothing max torque delta, removed burst knock and lowered the min airflow after 1200 rpm. I have attached both files the before and after in case anyone else faces what I did you can see exactly what I did.
latest brad ss.hpt
brad ss latest.hpl
brad latest after spark tightening.hpl
brad latest after spark tightening.hpt

[lukearmstrong1990]

did it work?

[Gpargament]

yes it did, however i needed the spark to be parallel to the idle table in idle cells, but also about 8 degrees above it at the same time. This way when you give it very light gas, the spark jumps up and the motor does not bog. This is the latest tune which has it running good under 4k and under 50% throttle, we have not done WOT tuning yet, but for a BTR stage 4 cam i am very impressed with its street manners and drive-ability.
base spark 8-13 higher than idle low octane minus 6 accross the board.hpt

[07GTS]

u could still clean it up a little more with some EOIT changes to suit that cam also

[Gpargament]

I've actually never played with the end of injection target tables before(assuming that's what EOIT stands for), if you can give me a little more clarification I will gladly make the changes and post here for others as well. whats the goal? what table would you start with? would you lower the values? and if so what affect should I notice, less gas smell? smoother driveability at low rpms, easier to come out of first? smoother transitions between shifts? and what areas should this be used for, idle under 4krpms, wot? thank you in advance.

[07GTS]

End Of Injector Timing, so with a cam and overlap stock is injecting on a closed intake valve then the overlap draws some raw fuel out the exhaust causing a fuely smell if u adjust it so injection waits until the exhaust valve is closed then u get more fuel in the chamber and it burns better and helps all round , bottom of the fuel, general tab "injection timing" if u know your .006 cam specs i can work some out for u

[Gpargament]

awesome, really appreciated. I will also search for an EOIT calculator and see if i can come up with the same numbers as you do, I plan to do more cams in the future and would like to eventually be able to work out the numbers as well. The attached jpeg contains all the cam specs.
560.jpg

[07GTS]

to start with try your "normal ect" to all 80, and zero out the normal rpm, let it warm up and u may have to remove some fuel if trims show richer then before and also driving u may have to remove some form the cruise areas also, there is a big read here for it and the calculators also find the last one is usually the best
https://forum.hptuners.com/showthrea...ance-Requested

[Gpargament]

again very much appreciated, I have made the changes, i did read through the link and agree the last excel file posted is the best, however i find it a little difficult, i have currently gone with your recommendations and will follow up on the results this weekend. out of curiosity is that standard starting point you have used before, or how did you get the 80 across the board for normal ect? from the calculator? also if its too lean afterwards would I add a little back into the normal ect table?

eoit tuning from forum help.hpt

[07GTS]

usually most cams will be round the 80 - 90 range to get idle injection after EVC i used your specs in the calc to check it, what u can also do is with that stock ect table lower it until u see trims stop going richer then u are getting most fuel in cyl and use that number, u can leave the cooler temps higher if u want but i found out can help with cold start also but check the cold throttle response if it goes different just increase it in the lower temps till its back to good, with my settings get it warmed up and then
adjust fueling idle then re check cruise, what u can do once ur doing the WOT side is adjust the boundary table as rpm increase above 2000rpm u can delay it a little more if it helps power as the rpm and IPW increases or it could be fine on all 520, increasing boundary delays injection

[Gpargament]

Phenomenal thank you, this is my first cammed vehicle I am tuning and that info will be of great value for many cammed cars to come. Really appreciated

[Widebody06]

+ 1 on EOIT, Dave Steck did us a huge solid with his info, major fix for driveablity issues and the dreaded startup fumes issue.

[Gpargament]

updating the results, the cold start is much better, the smell of fumes has been lifted and for a stage 4 cam it drives as close to stock as anyone could hope. Overall the car runs great. I did have to redo the ve and maf tuning after the changes which is to be expected. thanks to all for the help.