How much power with no emissions control?

[malazn mafia]

Do emissions gear on modern motors help performance or hinder it? If one was to tune up, for example, a current Ford i6 NA, with no regards for emissions whatsoever and all emissions gear removed, how much power would it be realistically chasing? Weren't cars back in the 60s and 70s pulling some figures that would rival todays emission-controlled motors?

[flappist]

Huge amounts, at least 1,000,000kw......

XY GT 351 made just slightly more power than a standard FG I6.....

[geckoGT]

I think you would find that the ECU would have a fit because of some of the sensor inputs that would be out of whack.

[93EB_SXR6]

Originally Posted by flappist

Huge amounts, at least 1,000,000kw......

XY GT 351 made just slightly more power than a standard FG I6.....

...you beat me to it.

[TheInterceptor]

Well back then they pulled jack all power compared to today. Exhaust systems and air intake systems are the only restrictors that make any difference.

Make the car breath in and out easier and you gain power and efficiency, but nothing overly spectacular.

[BAGT514]

The ECU controls the car so much better now and gets the air fuel ratio's to just about spot on. However - the ECU is made to be safe so no engine damage will occur - say the intake air sensor pick up very hot air the ECU reacts by adding more fuel in to make it richer (and therefore stop your pistons from melting and your valves burning). Same when a MAP (Manifold absolute pressure) picks up low vacuum - add more fuel to make it safe. The richer the air fuel ratio is the less power you make.

Apart from tuning perameters, the only real emission nasties we have are the cat converters which create a flow restriction on the exhaust. The unburnt exhaust nasties are burnt on the superheated catalyst to stop all those carcenagenic substances poluting the world. Removing the Cats will probably make you 10 kW's on some cars but the $50k fine for doing it isn't worth it.

[aussie muscle]

i think pollution gear severely affected 74-78 cars as the period between the regulations were more restrictive until the makers sorted out how to get power with them.

[flappist]

Originally Posted by aussie muscle

i think pollution gear severely affected 74-78 cars as the period between the regulations were more restrictive until the makers sorted out how to get power with them.

No actually the regulations were much LESS restrictive.

The problem was that the engine designs of the time (clevos and carb I6s) were rather primitive and inefficient and had to be "bandaided".

It was not until electronic fuel injection and later improvements in valve timing technologies were deployed into mainstream that the power and torque increased while the fuel usage and emmissions decreased.

[Mr Hardware]

flappist i think you and aussie muscle just said the same thing, albeit his was less legible and more open to confusion

[malazn mafia]

Originally Posted by BAGT514

The ECU controls the car so much better now and gets the air fuel ratio's to just about spot on. However - the ECU is made to be safe so no engine damage will occur - say the intake air sensor pick up very hot air the ECU reacts by adding more fuel in to make it richer (and therefore stop your pistons from melting and your valves burning). Same when a MAP (Manifold absolute pressure) picks up low vacuum - add more fuel to make it safe. The richer the air fuel ratio is the less power you make.

Apart from tuning perameters, the only real emission nasties we have are the cat converters which create a flow restriction on the exhaust. The unburnt exhaust nasties are burnt on the superheated catalyst to stop all those carcenagenic substances poluting the world. Removing the Cats will probably make you 10 kW's on some cars but the $50k fine for doing it isn't worth it.

Cheers, makes sense. May I ask why a car running rich produces less power than running lean/stoich? Theoretically, if engine blocks/pistons were made of diamonds, could they make more power by running lean and high temp?

[jcxr]

Originally Posted by flappist

No actually the regulations were much LESS restrictive.

The problem was that the engine designs of the time (clevos and carb I6s) were rather primitive and inefficient and had to be "bandaided".

It was not until electronic fuel injection and later improvements in valve timing technologies were deployed into mainstream that the power and torque increased while the fuel usage and emmissions decreased.

Wasnt the pollution Clevo 6 degrees retarded on the cam timing?

[ebxr8240]

These days they require the pollution controls to make them run right...
Even taking the cat off doesn't [really] make more power...

[BAGT514]

Originally Posted by malazn mafia

Cheers, makes sense. May I ask why a car running rich produces less power than running lean/stoich? Theoretically, if engine blocks/pistons were made of diamonds, could they make more power by running lean and high temp?

When you run at stoich you are running at the "perfect" air fuel ratio where you will make the best power. Running richer means the flame propergation is slower (so less initial burn and power) and you end up with unburnt fuel running out the exhaust.
Go leaner than stoich and you start creating more heat which eventually ends up in engine damage