[chiefsotos]

Hello guys i have a question.. How do the catless downpipes give us more hp? I mean, i saw the dyno results and i know they increase the exhaust flow and reduce back pressure so make the turbos spin faster and achieve the desire boost earlier.
But finally as the desired boost will be achieved wouldn't be the same as without downpipes? Ex. in stock around 8psi and with a tune around 14psi
So without having an specific tune map, for dp, with higher boost, how do our car produce more power with dp and the same boost level?

[jhershorin]

It is all about restrictions and efficiency. When you have less back pressure the turbos aren't working as hard to create the flow which creates a more efficient production of compressed air (lower temps often, faster spool up creating a larger tq curve which leads to more hp, etc.). Similar to the way a restriction on the cold side of the turbo can choke some power but when free'd that extra flow can go a long way.

[scalbert]

The turbine of the turbo operates on differential pressure. To spin to the desired speed and create the desired boost, there needs to be less pressure on the outlet versus the inlet. If you reduce the pressure on the outlet by removing restrictions, the inlet pressure can drop the same or proportional amount. Less pressure on the inlet means there is less resistance to the piston to evacuate the exhaust gases on the exhaust stroke. Less resistance to the engine is an increase of power.

[ianthegreat]

good explanation guys

[Blind32]

Originally Posted by scalbert

The turbine of the turbo operates on differential pressure. To spin to the desired speed and create the desired boost, there needs to be less pressure on the outlet versus the inlet. If you reduce the pressure on the outlet by removing restrictions, the inlet pressure can drop the same or proportional amount. Less pressure on the inlet means there is less resistance to the piston to evacuate the exhaust gases on the exhaust stroke. Less resistance to the engine is an increase of power.

I love reading your posts. Great asset to the community.

[ar design]

Originally Posted by scalbert

The turbine of the turbo operates on differential pressure. To spin to the desired speed and create the desired boost, there needs to be less pressure on the outlet versus the inlet. If you reduce the pressure on the outlet by removing restrictions, the inlet pressure can drop the same or proportional amount. Less pressure on the inlet means there is less resistance to the piston to evacuate the exhaust gases on the exhaust stroke. Less resistance to the engine is an increase of power.

[badass1g]

Originally Posted by scalbert

The turbine of the turbo operates on differential pressure. To spin to the desired speed and create the desired boost, there needs to be less pressure on the outlet versus the inlet. If you reduce the pressure on the outlet by removing restrictions, the inlet pressure can drop the same or proportional amount. Less pressure on the inlet means there is less resistance to the piston to evacuate the exhaust gases on the exhaust stroke. Less resistance to the engine is an increase of power.

wow. you are one smart guy. nice work.

[chiefsotos]

Originally Posted by scalbert

The turbine of the turbo operates on differential pressure. To spin to the desired speed and create the desired boost, there needs to be less pressure on the outlet versus the inlet. If you reduce the pressure on the outlet by removing restrictions, the inlet pressure can drop the same or proportional amount. Less pressure on the inlet means there is less resistance to the piston to evacuate the exhaust gases on the exhaust stroke. Less resistance to the engine is an increase of power.

Thank's Scalbert... Your post was exactly what i need to know

[Mahhvinn]

Originally Posted by jhershorin

It is all about restrictions and efficiency. When you have less back pressure the turbos aren't working as hard to create the flow which creates a more efficient production of compressed air (lower temps often, faster spool up creating a larger tq curve which leads to more hp, etc.). Similar to the way a restriction on the cold side of the turbo can choke some power but when free'd that extra flow can go a long way.

Originally Posted by scalbert

The turbine of the turbo operates on differential pressure. To spin to the desired speed and create the desired boost, there needs to be less pressure on the outlet versus the inlet. If you reduce the pressure on the outlet by removing restrictions, the inlet pressure can drop the same or proportional amount. Less pressure on the inlet means there is less resistance to the piston to evacuate the exhaust gases on the exhaust stroke. Less resistance to the engine is an increase of power.

great explanation guys!

[X.X.I.V]

so with the better efficiency of catless DP's does the dealer think of it as a mod or as a better designed part that helps increase the life of its connecting peers?
Then with emissions folks what do they say about dp's

[e.n335]

Originally Posted by mario0573

so with the better efficiency of catless DP's does the dealer think of it as a mod or as a better designed part that helps increase the life of its connecting peers?
Then with emissions folks what do they say about dp's

as a mod and not emission compliant. you will need O2 simulators as well. back to topic.