Big cam 304 Tuning help needed

[AngelMarc]

Seen some of that wall wetting stuff, never messed with it. Could explain my bodged CB450 setup having finicky idle. Sounds reasonable; I'd rather use a narrow injector than tune a bunch of wall wetting formulas that might include acceleration enrichment. The only predictive math I want is the VE table.
And when you say diminishing returns, are you talking race and drivabiliity, or you talking passing emmissions/mileage, or both? Heard a few people talk about no cats smell going away with delayed EOIT on fat cams.

[immortality]

Sounds like ECU swap time.
P01 or P59 and mount a 24x wheel to the crank like myself and other have. Somebody here did that on a Jeep; I did it on a motorcycle engine. I bodged the shit out of that setup.
Verifying crank sensor readings- https://www.youtube.com/watch?v=yv8rvb0K32Q
Actually running it- https://www.youtube.com/watch?v=g_Q6pFgmySY

On the off chance your willing to build a custom PCB, I'll mention my other project.
viewtopic.php?p=132802#p132802
Going to try an engine test again soon; hopefully next couple days I be able to show proof it works pretty good. All the bench testing looks good.

If it can't be full sequential EOIT adjustment, then I'd go with whatever spreads the spray out the most I guess, even throttle body injection, and probably just deal with some "weird" O2 reading and open loop only or something. Was going to say I've never messed with big cams, but many motorcycles do the same stuff.

Unfortunately the later PCM software doesn't have quite the same support as the earlier 808/424 ECU/PCM and many prefer MAP based software over MAF.

[AngelMarc]

The easy no MAF is to unplug it and set it to instant fail. The video of it on the CB450 is with no MAF and all DTCs disabled.
Free software and a $50 dongle. A bunch of stuff even HPTuners doesn't let you change.
I should add that my testing was limited, but I changed VE, and it behaved like I expected. Leaned it out, blue flames out exhaust and it revved a little higher; made it rich, orange flame.

[immortality]

Not that simple on these, the software is totally different. It would be brilliant if we could just unplug the MAF and run VE instead. These don't even have a factory fitted MAP sensor.

[vlad01]

Yeah there is far more work converting and supporting a newer system on these old engines, where the factory unit already has huge support and quite capable, not to mention ease of use and collective tuning knowledge amongst the community.

I'm sure these issues will be tuned out, good to also look at the overlapping sections of the main VE table and the idle stuff. Sort of related, I know Gareth had a serious hunting issue many years ago on his race car that was a delay induced feedback into the calcVE, so there was a rich and lean spike that the engine kept looping through, and the more he tried to tune it using the calcVE and WB, the worse it hunted and surged. Eventually it was obvious two spikes had gradually formed by the reinforcement of the feedback loop that was indued by the ECU, TP and WB delays. The delay made TP calc the VE for a cell based on data for another cell it had been on X amount of time ago, so that altered the cell, the engine rpm either rose or fell because of stall saver or the a stumble, that data was then for that condition which was delayed too, that fed the other cell, so each of the two cells were tuning off each other's WB data due to the x amount of ms delay. As that hunt grew, the faster and more extreme the swings from one end to the other, which round it went. So he just smoothed them by eye to what he though it should have looked like base on the surrounding map shape, the issue went away. That engine has a serious race cam and runs the 424 and 11P, that runs bank injection, so not all that different to batch. It runs and idles fine and all. It's cam is something like 250 deg + at 0.050", solid roller.

These areas also need to be the same level from the idle tables to the main, so when the ECU switches from idle to main running modes there isn't a sudden change in fueling as a result of them not being tuned the same, this upsets any engine, but especially true for big cams. Think back to what I mentioned about the main table decay setting that made my engine go lean for a given time and back, that hated that.

That reminds me, I need to post what that scalar is called, if it's a scalar? Can't recall for sure.

[buzzard]

Most tuners that work on both say that going to EOI sequential is diminishing return territory anyway and all that I've talked to say there is no diff over 1500-2k rpm which agrees with my experience as well.

That statement is somewhat dependant on the injector flow versus cylinder capacity. Also the port dynamics have a considerable effect. I have seen a loss of 30 rwhp at high rpm when changing from EV1 to EV6 injector for equal AFR as shown by NTK UEGO, tho I believe a gas analyser would tell a different story (BMW S50B30), with low rpm drivability favouring the EV6 injector characteristics.

[vlad01]

Yeah that's interesting with the loss up top.

My jist is the wider and newer injectors favor 4 valve heads so the fuel can be injected into the split port much better.

[immortality]

You know that you can get different spray patterns to suit the port/valve arrangement? Using the wrong type is surely going to make shit run worse.

I've seen some results where IOT changes have increased power.

I actually want to do some testing regarding this but I need to get different injectors and some more O2 sensors to test on a full sequential injection setup. I suspect you need a decently larger injector to reduce the injector PW at peak power to give a larger window to change EOI timing.

[buzzard]

I suspect you need a decently larger injector to reduce the injector PW at peak power to give a larger window to change EOI timing.

Yes, that is exactly what you need.

[buzzard]

Yeah that's interesting with the loss up top.

My jist is the wider and newer injectors favor 4 valve heads so the fuel can be injected into the split port much better.

Possibly, tho the BMW S50B30 is 4 valve, and preferred the pintle EV1 injector for maximum power. I would suggest there is no simple answer to this