So I had my car dynoed at the end of last year on 91/e85 it's an 06 evo 9 my mods include intake, tbe, intercooler, intercooler piping 3port, injectors and fuel pump, question is I have to replace the resonator on my exhaust, if I simply replace it with 3in piping would it affect my tune ?? My exhaust is 3 on from the downpipe to the exhaust with no cat, and my o2 is stock thanks for any imput

 

Not enough to warrant a retune, but datalog after, send it (with your map) to Rick, and ask Rick to adjust it as he sees fit.

 

I would but I don't have a cable to datalog :/ only thing I have is a boost and afr gauge

 

No retune required. A resonator won't affect AFR enough to have to adjust fuel map.

 

Thanks for the input as long as the o2 stays the same the tune should be safe correct since that's the bottleneck in the exhaust

 

Are you replacing it wih another resonator or just normal pipe?

 

Monitor AFR's after the change to make sure but I doubt it would need more than minor adjustments to fuel if anything.

 

@ evojoelix I would be replacing it with just a single piece of pipe

 

You should be fine then depending on how restrictive the resonator was. If it was a straight through design i wouldnt worry about it, but if it was a louvered (sp?) one, its gonna throw the tune off a bit by leaning the car out much more

 

Yea it's a straight through resonator the piping is 3in from the downpipe to the exhaust it doesn't taper where the resonator is at

 

You will be fine.

 

Thanks man