loss in torque with exhaust

[F80_javi]

Hey guys, for those running a Dinan free flow, straight pipes, or awe track non resonatated exhaust system, do you guys feel a loss of low end torque? I'd like see some dyno numbers if possible.

[allinon72]

The loss of back pressure is always a concern when opening the exhaust up. But I don't see it being discussed as an issue on most reputable exhaust systems on this platform.

[Pauldunlop13]

Originally Posted by allinon72

The loss of back pressure is always a concern when opening the exhaust up. But I don't see it being discussed as an issue on most reputable exhaust systems on this platform.

I have a Dinan exhaust installed on my 2019 M4. I previously had it on my 2015 M4 as well and notice no loss. I drove both for about 2 weeks stock before installing it

On my 2016 228, I dyno’d before and after install and got
+9hp and +5tq
(Also Dinan exhaust, but single sided)

[chmura]

Originally Posted by allinon72

The loss of back pressure is always a concern when opening the exhaust up. But I don't see it being discussed as an issue on most reputable exhaust systems on this platform.

I thought turbo cars don’t like back pressure?

[gatorfast]

Originally Posted by chmura

I thought turbo cars don’t like back pressure?

It's a fine balance. Some pressure will help low end torque but restrict high end power. With a more straight through exhaust you may lose some of that low end torque but ultimately gain more top end power.

[BIGW0RM]

Originally Posted by gatorfast

It's a fine balance. Some pressure will help low end torque but restrict high end power. With a more straight through exhaust you may lose some of that low end torque but ultimately gain more top end power.

Yup. I noticed a small dip in torque on every car I put a free flowing exhaust on. But like you said, it made up for it in mid to top end.

[Chris@VargasTurboTech]

The turbine will give you all the backpressure you want (plus some ). Free flowing wins every time in every category on a turbo exhaust.

[Tangent]

Originally Posted by chmura

I thought turbo cars don’t like back pressure?

No car likes backpressure. What they like is good exhaust gas velocity and the scavenging effect it produces; that's what can potentially be lost with too large a diameter of exhaust pipe.