Standard Air Box

[Hq King]

Does anybody know how much hp a standard air box will support would modifying the inlet ie making inlet to airbox behind light bigger help ?

 

[Tryg]

Does anybody know how much hp a standard air box will support would modifying the inlet ie making inlet to airbox behind light bigger help ?

More air is good, but without a tune, not useful. You will essentially just lean out more.

 

[Forg]

More air is good, but without a tune, not useful. You will essentially just lean out more.

I think the ECU’s more capable (ie. than you’re inferring) of measuring the air going in & hence providing the right amount of fuel. Especially as the sensors are after the airbox.
Reading that back to myself ... I don’t mean you’d get more power from changing the airbox, I mean that it’s not going to make the engine lean-out at all (if you don’t mess with the ECU & sensors that is!).

 

[Tryg]

I think the ECU’s more capable (ie. than you’re inferring) of measuring the air going in & hence providing the right amount of fuel. Especially as the sensors are after the airbox.
Reading that back to myself ... I don’t mean you’d get more power from changing the airbox, I mean that it’s not going to make the engine lean-out at all (if you don’t mess with the ECU & sensors that is!).

Fact is...I never said run lean...I said lean out more. Any change the computer makes is to fix the lean condition. So, you use more fuel, but the outcome is two-fifths of eff-all. It’s a super-common change for every car owner, chasing power.

I think balancing the equation helps. Better in, needs better out.

I probably know less than most here, but I certainly listened to the professionals...who said just the same.

I’d save any minor mods, until it was a better package of mods.

My 2c.

 

[Forg]

Ah, I see what you’re saying!
I was trying to maybe be a bit more technical (while still pretty general ).
More air in doesn’t equate to “more lean” though ... I mean, yeah, more air in is a Good Thing (assuming more fuel can be provided to match); but the way the ECU works is to measure the air going in & apply fuel appropriately, so you get the intended air+fuel mix going into the cylinders. “Lean” or “rich” sorta applies to the amount of fuel in the air+fuel mix being inhaled by the cylinder, I just (from a “technical” point of view) meant that the ECU would keep that mix correct, so the change introduced by the airbox wouldn’t affect that air+fuel mix (you might get more air drawn in at certain revs/throttle but the air+fuel mix wouldn’t be “leaner” when ingested by the cylinders).
If that gets anywhere near making sense ...

 

[Tryg]

If that gets anywhere near making sense ...

Yes, I guess so.

But I’ve done so much I no longer have a MAF.

 

[07GTS]

any change in airflow in and or out of the engine will cause a change in AFR, the ECU will do its best with trims to correct for it and some trims like LTFT carry over to PE OL so u will be safe but if u have had a tune and LTFT disabled and ur only on STFT then u will be leaner PE OL by what ever the extra % in airflow error is because not many carry over any STFT error, all that airflow around the headlight is hot air so u may increase flow but it may also be hotter air and thus cause a timing loss for higher IAT's

 

[Forg]

any change in airflow in and or out of the engine will cause a change in AFR

I know this is veering further off topic, but how does the (standard) ECU setup use the airflow meter if not to drive AFR? Is it secondary to MAP or something like that?
[I’ve only ever fiddled with MoTeC stuff (and with only one source of “input air” data)]

 

[monstar]

Yes, 350 to 400 CFM.
Theoretically this supports 800 BHP from a 376ci V8 at 5700 RPM, assuming 100% volumetric efficiency. But there are more factors to the HP baro equation than CFM including some biggies like temperature velocity and pressure.
The Zeta airbox max CFM alone is not a restriction to near stock performance, rather the main factor is the Intake Air Temperature when using petrol as fuel.
Introduce cooler air, higher octane fuel and or cooler spark plugs and or lower thermostat and the stock tune will definitely adjust itself for better performance vs making the airbox entry a bit more noisey. In that regard there is no need to change the airbox or intake plumbing pre-throttle body for better performance.
Alternatively keeping the stock airbox and tuning will produce good results but reduce the knock margin and increase the safety risk. Whereas a Cold Air Intake will facilitate performance tuning without imposing undue risk (of catastrophic failure due to knock).
Gains from stock HP left on the table (for whatever reason) is huge, like 60 hp from increased VE%, not increased CFM beyond the max spec of the airbox.
Goals from porting / derestricting and installing devices in the intake (and exhaust) tract of a street car are not just more CFM as a priority, that’s overly simplistic and most important lessons learned in motorsports over 100 years ago.
Useful gains for EFI hipo street car is in terms of greater thermal and volumetric efficiency with cooler air at higher velocity, tuning tumble through the runners and pressure waves through the ports.

 

[Hq King]

Ok guys I think I should clarify what I was trying to do I was hoping to get around the 500 engine hp mark with a completely stock looking engine bay no big exhaust no otrcai no headers .I was thinking head porting ,mild cam ,maybe vvt and of coarse engine and trans tune and what ever else it might take. this is for my magnum ute I do not want a gas guzzler or loud exhaust or lumpy idol or harsh riding I have enough of them STOCK LOOKING STOCK SOUNDING STOCK HANDLING any suggestions about how best to go about this or do I just want to much lol