Slow speed surge - I'm out of ideas - help?

[JasonCzerak]

Hello everyone.

I'm clueless here. I've read dozens of different way to cure this surge and tried them all to varying levels of success (all fails...) I've fiddled with Transients, more fuel, less fuel, open loop, closed, ya name it.

How do I get rid of this crap! trying to maintains slow speeds is all. Very little if amy throttle input.
Screen Shot 2022-06-25 at 9.05.45 AM.png

Blower: YSI (peak boost 14psi ATM)
Fuel: e70
Intake: Stock LS3
Throttle body: Ported LS3 of unknown - <---- maybe this has been the problem all these years?)
motor: 408CI, 12:1
cam: .598/.604, 232/236, LSA 112, IC 108. I need to check with engine builder, but it should advanced
heads: PRC LS3 (forgot exact model, but the big Ls3 ones)


Per timing. I my old timing map was more flat and agressive, same results as the one in the tune. I have my suspecion that I need to better lay out the idle vs coastdown vs base timing.

I'm fairly sure the the ETC Area Scalar is wrong for this car. In reading, that number should be closer to 5500. I did try that change once and I'd be inclided to adjust the base idle as it was droping past idle, but drove fine other wise.

could my issue be that idle air transistion to idle?

Lastly, if someone can help with thoese lean tip-ins on shifts. that would be awesome as well

[dhoagland]

Have you tried EOIT?

[JasonCzerak]

I have in the past. Maybe with a better MAF/VE table, that might not be a horrible idea to start tinkering with again.

[JasonCzerak]

So, if I were to muck with that table. For a cam with decent over lap, what direction would I start toward? The docs on that always confused me and I'm still not sure which way would make sense.

[dhoagland]

https://forum.hptuners.com/showthrea...980#post690980

Here is the Post where Greg Posted his latest sheet