change exhaust for more performance

Hello everyone!

Im new on this forum and so excited i finally found a forum for our beloved C3 turtles!

I have a petrol 1.4 8valve c3 2003 .
A little backstory on this. ->
I found this car in a friends garage abandoned for amlost 7 years. it was like a brand new car it just needed a good heavy service.

I managed to service everything and got that little baby running smoothly, the car back then had only 52.000 miles(85.000km) ( not much for a 2003 car especially in greece where im located ).

I will add up that in the big service i made the mechanic also changed the timing belt.

at 59.000 miles the timing belt broke 7 of its teeth that leaded the whole engine to brake, pistons, valves , etc, the mechanic took full responsibility since he understood that either it was a faulty belt or he did not place it 100% right, so the engine was serviced from the start ( not changed ).

The question ->
After this, i noticed that the car felt a little slugish and i couldnt understand why, i then decided to put a custom cold air intake located on the bottom of the car near the radiator . once i placed the cold air intake the car feels extremly good, i manage to get accelerations and speeds i couldnt believe it would be possible with the specific car.
So im asking you guys, based the backstory, if i change the exhaust ( full body or just the pipe ) or even if i place a racing catalyst , will the car run better or it will just consume more fuel without a better performance?

Sorry if i posted this on wrong section, i dont think there is another section for such questions.

Thank you all in advance!

Hi

Your custom intake isn't what makes the car better.

You had a fault and making the changes have cleared the fault.

You can undo your modification and see what the original problem was.


For performance improvements, they are possible with a better exhaust but with the cost and the small gains, most don't bother.

If you want more power, it is often just easier to trade in the small engine car for the bigger engine model. A lot less hassle.

Hello Arfur ,
Thanks for your reply.

I have taken off the intake and put back the stock one with a new filter inserted ( in case it was dirty ) but the results are not the same, not even close.

Trading the car with the one that has a bigger engine is not an option, changing the engine also not an option due to the high cost it will take.

Following that the engine has been opened and repaired once i believe that since it needs a custom air intake ( more air flow ) it may be good to also replace the exhaust so it can " exhale " more air.
is that right ?

While an improved exhaust system can potentially exhale more air, the exhaust valves are also a restriction and the size of the pistons and the distance they move in the bores all have an effect on the speed at which exhaust gasses can be removed.


I don't know how much more of an improvement you will get with a different exhaust.

It has to be worth a try if you want to go that far. Please report back with your findings

The intake shouldn't make that much of a difference.
It could be that the MAP sensor is not in spec and the intake is bringing the air/fuel ratio closer to a better stoichiometric value.
Could also be an injector "problem". Inspect the spark plugs. See if there is a difference between the plugs.
O2 sensor not quite right? You can swap the blue and green sensors over and see what happens?
I had 2 of the 1.4 C3's. One ran better than the other but there was nothing wrong with either of them (after I fixed them up)!! I sold one before I could sort it out.
So while they may be identical when they leave the factory, after a few years they are no longer all identical!
To get better exhaust flow will require removal of the catalytic converter. Or is that what you meant?