Anyone have the difference in AFR before and after replacing the catback system alone? How about for the cone type air filter? I'm planning for the mod. and see if I need to fine tune the AFR in order to release full power of the mod. I need the data as I dislike guess work. Thanks in advance.
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surely the engines closed loop lambda control will correct any fuelling discrepancys and after its been driven for a few miles and the ecu's learned the fuelling will be fine again...
there is pretty much no way of fine tuning AFR on modern engines short of getting something like a unichip fitted (or any other fully programmable ecu), even an adjustable regulator is like fine tuning with a 2lb sledgehammer its that clumsy
just let the ecu do its job and you'll be fine
there is pretty much no way of fine tuning AFR on modern engines short of getting something like a unichip fitted (or any other fully programmable ecu), even an adjustable regulator is like fine tuning with a 2lb sledgehammer its that clumsy
just let the ecu do its job and you'll be fine
As has been stated the ECU will pull fuelling back to stoich on cloosed loop lambda, but the ECU will run open loop lambda above a certain load/speed boundary, and take a preset fuelling algarithymn for maximum power (where lambda=0.88, NOT 1 (stoich)). But as Ben has told you, the AFR of your engine must be checked by YOU....its no good comparing it to another clio, even of the same spec. you need to check and adjust YOUR car accordingly....
well wot does it matter even if you have a reference?? the mapping will still have to be adjusted live, and so it will inevitably be mapped specificaly for your engine. i.e. if someone comes on here now and says their engine was at lambda=1.1 at max engine speed/load (with the same mods), YOU are still going to map it to max power....
Thanks for your reply. I know it should be remapped to provide the best AFR after every mod and my question is, anyone replaced the catback system only and measure the AFR? If it will mess up the AFR a lot, then I will give up. Of course, I can measure it up by myself and I have wide-band sensor too. Why I ask this question, the reason behind is that I don't want to buy it and measure it. I want to know in advance and I can make judgement on whether I should go for it.
Dear Stan, million thanks for your reply but I think you don't understand what I'm trying to ask. I know it should be remap after changing intake or exhaust. I just want to ask for the reference AFR after replacing the catback system alone. No more, no less. I know different car behave differently but I don't think same model car with same mode can run very rich and on the other hand, very lean. There should be problem on them.
BenR, I don't think so. Changing either intake or exhaust will make difference in AFR. Even changing the size of the backbox will make a difference too. I have wideband lambda sensor and play with AFR for over 2 years.
In my experience, on Lancer Evolution, changing the catback system alone will not gain any performance, loss sometimes without AFR fine tuning. See if it will happen on clio too. Thanks
In my experience, on Lancer Evolution, changing the catback system alone will not gain any performance, loss sometimes without AFR fine tuning. See if it will happen on clio too. Thanks
Changes are minute, and yes we all know about the effects of modifications on AFR's.
However, some are so non-influential that testing isnt required, especially with the majority of half arsed exhasuts on the market. If you stuck something remarkable on and it was of good design, then maybe it'll change the afr's enough to require remapping at the cost it stands.
As for evo's, if you look at the stupid systems they have as std, its no winder they do gain significant bhp when you swap the exhausts.
However, some are so non-influential that testing isnt required, especially with the majority of half arsed exhasuts on the market. If you stuck something remarkable on and it was of good design, then maybe it'll change the afr's enough to require remapping at the cost it stands.
As for evo's, if you look at the stupid systems they have as std, its no winder they do gain significant bhp when you swap the exhausts.
Agree !! I owned EVO for 3 years and play her as a testing platform. I owned Clio RS MKII for 2 years and still know a little bit on it. So I would like to seek for advice from the expert like you. I don't want to guess, I only trust the fact.
Before, I tried Jetex backbox replacement, it really gain from low end to high end. After that, I tried decat pipe with silencer, and I was not happy with the setup. Now, I run full stock exhaust and feel happy with it. Not as happy as that with Jetex backbox but keep the car low profile.
How about if I change the decat alone on the stock system? What gain I expect? Will it damage the mid-pipe due to emission? Please advice.
Before, I tried Jetex backbox replacement, it really gain from low end to high end. After that, I tried decat pipe with silencer, and I was not happy with the setup. Now, I run full stock exhaust and feel happy with it. Not as happy as that with Jetex backbox but keep the car low profile.
How about if I change the decat alone on the stock system? What gain I expect? Will it damage the mid-pipe due to emission? Please advice.
this is going round in circles.
How can we tell you the change in fueling from an exhaust that you dont have and that nobody has data logged?
Only way is for you to check, and the change from and exhaust, especially those avaiable is very very small.
Hundreds of people are running exhausts, i wouldnt worry, buy it, then check with yur wideband........dont be paranoid.
How can we tell you the change in fueling from an exhaust that you dont have and that nobody has data logged?
Only way is for you to check, and the change from and exhaust, especially those avaiable is very very small.
Hundreds of people are running exhausts, i wouldnt worry, buy it, then check with yur wideband........dont be paranoid.
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