Sport mode - Does it alter exhaust flow/sound?

[Darren M]

Darren, refering to the quote above re: your rare BMW and the "crucial piece" - may I ask what exact is this piece are you referring to? Does that mean all the cars fitted by H&S will have this "crucial piece" missing? Again, is this referring to the full system or just the back box?

Hi funkdude,
No, the piece is not in every exhaust. In this case it was an "x" piece close to the manifolds (the two exhausts merged briefly before separating again). They simply didn`t use it in their exhaust design - it was very crucial to that car in particular (pulses, exhaust scanvenging and all that - way above my head to understand).

I think you might be okay with the backbox. I`m not saying all of their exhausts for all cars are no good, but you can`t beat BMW parts............I think the back box won1t be too risky -not too much performance can be lost.

Maybe you should get your car to a good dyno and get it tested afterwards. Ideally, before and after results are the best way to prove or disprove an exhaust. If you live in the South, I can recommend someone. I`m thinking about organising a dyno day for a laugh later near Wiltshire.

 

[funkdude]

Cheers Darren,

Thing about Dyno is that in order to compare the effects of an individual component accurately, you must ensure all other conditions of the car are at constant... so the car must be operating at the same condition / same temperature etc. Also it will have to be the same car, same engine etc. There is no good comparing my car with the fitted back box with another standard car cause it will not give a fair test as every car is unique. I cant really run dyno on my car with standard box then change it and run another dyno with the car again with the new back box cause again that will not provide a fair test as the car wouldnt be operating in the same condition in the two tests.

For that reason I think it will be pretty hard to find out whether a change of back box will have any minor impact on the car's output. Unless ofcourse the impact is significant. But then any significant impact would've been picked up by test driving the vehicle without the need to dyno test it anyway!

Since my car is already there with them I trust that it is being look after by safe hands... afterall they have vast experience dealing with proper race cars and I am sure they are aware of all these concerns regarding lost of power. As you say, in the end of the day I am only replacing the back box... unless it is a true mechanical disaster it shouldnt really have any notciable impact on the power + or - anyway... so I hope.

=)

FD