New hi flow exhaust

Posts specific to the 2.5 litre NA engine

New hi flow exhaust

Postby Roberto-RX2.5 » Thu Nov 08, 2012 5:37 pm

hi guys i have a 2.5 rx liberty and i recently just got a hi flow 2 and a half inch exhaust from the extractors back i was wondering do you reckon i would have lost power?
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Re: New hi flow exhaust

Postby shav » Thu Nov 08, 2012 5:59 pm

2.5" on an n/a 4 cyl engine is over kill. You will lose some down low power but may have gain a bit, higher in the rev range. If you plan to fit a raptor supercharger on it later, it will be perfect. But as it is, you will probably notice it will be a bit loud at certain speeds and yes, possibly lost low end torque.
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Re: New hi flow exhaust

Postby bigBADbenny » Sat Nov 17, 2012 5:16 am

Not sure if this tip is applicable to your car but perhaps try resetting the ECU or if possible get a tune. :D
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Re: New hi flow exhaust

Postby turner_822 » Sat Nov 17, 2012 10:39 am

Hey, I only went a 2.25 inch system back from headers including a hi-flow cat and certainly would not have wanted to go any bigger. With NA I believe as said above: low-end torque loss, and a slight high-end gain

+1 on supercharger

I supercharged my 2.5i and it was good with the 2.25 inch system. I wanted to see how the car responded with hi-flow headers and even with the supercharger it was a BIG low-end torque loss (re-gained a bit through tuning) and a further high-rpm gain (that is still being improved on). However this is on my 2008 model which as it turns out has well designed stock headers...may be a better gain to be had on your model

Seems the NA engine needs to maintain its high exhaust velocity and increasing size allows easier flow but kills that high velocity.

If you haven't looked into it (and have a denso ECU) tuning will gain you some great low-rpm response
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Re: New hi flow exhaust

Postby Roberto-RX2.5 » Sun Nov 18, 2012 9:15 pm

sweet as man ill look into getting it tuned if i have a denso ecu the car honestly doesnt drive any different with the 2.5inch exhaust i was worried but i do feel it is a bit faster in the high rpm and speeds low end isnt much different the engine is in good condition so that could help things as well but over all im happy with the exhaust it started off loud but its slowly getting worn in and getting a bit quieter thanks everyone for the info :)
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