EFI and more boost

[serpa4]

Can I just up the table for boost and not add timing or fuel? Would there be any benefit? I've been using my tow tune as my mpg tune since engine rebuild by dealer due to cracked (not holed) pistons. I'd like tad more power, no more smoke, afraid to play with timing now.

 

[Dozerboy]

No you need to start with more fuel

 

[Killerbee]

fuel is safer than timing. More timing can be added, if you increase the dynamic provisions for retard with increased cylinder heat.

 

[GeneralTJI]

More fuel technically needs more timing (assuming you didn't have too much timing to begin with).

If the truck is smoking under WOT then a little more boost may clear that up...

 

[SSchmi5519]

More fuel technically needs more timing (assuming you didn't have too much timing to begin with).

If the truck is smoking under WOT then a little more boost may clear that up...

Technically, more fuel (pulse) needs less timing. That is, to keep the injection event as close to its original percentage BTDC as possible.

 

[Killerbee]

I would suggest avoiding the paradigm, that a "percentage" of pulse needs to go this way or that side of TDC. This will kill a motor as quickly as anything.

Scant spreadsheets, supposed "tutorials" etc, that help calculate and timing number around CADeg, should be avoided if using them literally. They account for ONLY rpm, and do not consider all other combustion impacting variables, like fuel pressure, boost, IAT. In short these convenient spreadsheets are dangerous with large pulses, and even smaller pulses when thermal stress is high.

Yes, more advance is usually called for increased rpm and/or pulse, notwithstanding the effects of the other parameters. Air charge heatsoak is a big one, and not easily accounted for with even the peripheral timing tables, so step carefully.

 

[Dozerboy]

Way to turn a tread about a tad more power into rocket science.

 

[Akdiesel]

Seriously....I came into this thread thinking I'd learn something...speak English for us uneducated folks

 

[[email protected]]

I don't get why timing dosent follow a gas engine. Like the more efficient head or more airmass needs less timing, so peak torque requires the least timing then as rpms go up the air mass in the cylinder decreases so timing has to be advanced.

So besides the rpm time factor, why does increased boost need more timing.

 

[SSchmi5519]

I don't get why timing dosent follow a gas engine. Like the more efficient head or more airmass needs less timing, so peak torque requires the least timing then as rpms go up the air mass in the cylinder decreases so timing has to be advanced.

So besides the rpm time factor, why does increased boost need more timing.

It doesnt.

 

[Bustedknuckles]

Aaaannnddddd that's why idahorob is tuning my truck.....