Exhaust mod affected rev range

[sammyhale22]

Changed my BIGGG magnex backbox for a much smaller single exit free flowing box and the car now feels quite flat in the mid range. Was thinking of taking it to RS Tuning in Leeds as its never had a remap since I`ve fitted the 182 mani or decat. I`m guessing now the exhaust system is much more free flowing its effecting the air fuel mixture???

 

[Gray]

yes.

 

[sammyhale22]

How does it affect it? and how can re-mapping correct it?

 

[mx1_champ]

you have already said how it affects its ie.. flat spot due to incorrect fueling....
how can it correct it... correct fueling..

basically they will either drop a generic map on there which is suited for cars with thos mod's or run it on wideband to see how far out the fueling mxture is and play with the ignition curve and fueling to gain near optimum performance from your setup

 

[sammyhale22]

I mean't what happens in the engine to cause the incorrect fueling? Like for example if i removed the rear section of my exhaust and ran it straight out of the decat, why does this affect the power in the rev range?

 

[Andyman]

Probably on the lines of the engine is flowing more gasses out from the engine thus changing the pressures in the head or / and the way in which the fuel and air from the inlet is mixed and disposed of quicker. Iv no idea haha