Running cooler with straight through pipes

[fastandcurious]

Apart from the obvious audible advantages of straight through pipes, I've noticed my car seems to be running cooler in traffic since I did the conversion.
Has anyone else found this, and does anyone know why?
Curious CRAIG.

[Roberto Rica]

Hi

I suppose if you've reduced the back pressure the heat in the exhaust is getting away better.

Do you notice any change in power/torque - there is a theory that removing back pressure will take the edge of bhp and lb.ft - any noticeable difference?

Rob

[that daddy]

if you decatted it as well then possibly,if you just done the silencer mod then no purely coincidence.

[fastandcurious]

Roberto Rica said:

Hi

I suppose if you've reduced the back pressure the heat in the exhaust is getting away better.

Do you notice any change in power/torque - there is a theory that removing back pressure will take the edge of bhp and lb.ft - any noticeable difference?

Rob

Hi Rob.
No noticeable drop in power or torque. It's easy to be mislead into thinking it's going better because it sounds better. But I am sure, if anything it's less lumpy at low speed.
I don't think I have reduced back pressure by changing the perf tubes for straight tubes because the path for the exhaust remains the same. It was always straight through.
I'm assuming that back pressure can only be reduced by increasing the diameter or shortening the length of the exhaust.
I would apreciate any expert feedback on this.
Many thanks CRAIG

[fastandcurious]

that daddy said:

if you decatted it as well then possibly,if you just done the silencer mod then no purely coincidence.

Cat and pre cats still in. I can see where you're coming from on that. Cats get very hot, hence warming up the engine bay.

[97octane]

After having the straight through conversion I have noticed this too, but also the engine seems to 'breathe' easier and revs slightly more freely. I'm not sure about true performance, but it certainly feels nicer alll round.

Alan

[spend]

I've never really got my head around this back pressure issue. I do agree from experience that the less obstructions in the exhaust system the more freely the engine seems to rev.

Even if back pressure is required wouldnt it be similar to the inlet system where the critical lengths set up wave pulses?

Dave

[GreenV8S]

spend said:

Even if back pressure is required wouldnt it be similar to the inlet system where the critical lengths set up wave pulses?

I don't know how far down the system pressure pulses reach, I'd have thought that the cat would act as an effective reflector and isolate the engine from effects downstream. But that's only my guess.

[spend]

GreenV8S said:

I'd have thought that the cat would act as an effective reflector.....

Ooops, wheres that darned cat now?...

Dave