Will I Need A Retune After Cahanging My Catalytic Converter ?

[Tweaky]

Just bought a Venom 500 series hi flow cat with a 100 CPSI flow for 3 inch exhaust system. I am running a Microtech Lt x12s ecu , will i need a retune once i fit the new catalytic converter ? At the moment it has a ceramic cat fitted to the exhaust system , which has had a few bumps & bruises !!! So i thought i would replace it with a stainless steal one , which will last longer & have better flow. Will the extra flow cause the fuel / air ratios to change ?

[ClutchBurndout-:(]

no

flow speed wont be noticable

Edited February 9, 2011 by Clutch

[Tweaky]

no

flow speed wont be noticable

But if i'm going from 400 CPSI cat to a 100 CPSI cat flow sould be alot better ! If not what would be the point in changing cats then ?

Edited February 9, 2011 by Tweaky

[Moodles2]

The point of changing the cat is to relieve backpressure, with a freeflowing cat the exhaust velocity is maintained (where it might have been slowed down when caught in the 400cpsi) which helps helps turbo response.

[Tweaky]

The point of changing the cat is to relieve backpressure, with a freeflowing cat the exhaust velocity is maintained (where it might have been slowed down when caught in the 400cpsi) which helps helps turbo response.

So once the new Hi flow cat is fitted & there is better flow , will that be enough to upset any current tune settings on the ecu ? Will the car have to go back to my tuner for any slight adjustments ?

[ClutchBurndout-:(]

But if i'm going from 400 CPSI cat to a 100 CPSI cat flow sould be alot better ! If not what would be the point in changing cats then ?

are you expecting amazing things from changing cats? unless your running high numbers it doesn't really change much

ive tried more cats than an 80 year old chinese cook

Edited February 9, 2011 by Clutch

[Sunkist]

if anything

you would come on boost earlier, causing a lean of fuel in certain rev ranges.

but this would only happen if your tune was shit to begin with ie running TOOOO lean..

shouldnt be a problem, unless your fussed about 1 or 2 kw's..

[Tweaky]

O.k thanks guys , just wanted to make sure ! Better to be safe then sorry Car is making the 290rwkw mark at the moment , the guy who sold me the cat recommend i get a tune after it is fitted. Thats why i'm double checking The last tune was done 3 months ago & car is running great , anything i think the car would be running on the rich side.

Edited February 10, 2011 by Tweaky