The only way I will ever mod this car will be to spend money as I get it, as I can't save enough to do numerous mods simultaneously.

I am contemplating getting a larger dump and better cat as the first stage towards mild improvements with a tune. Has anybody freed up the exhaust like this while running the stock tune?

Easy driving I wouldn't think would cause a problem, but what actually happens when you boot it?

mate , I would start with a flash tuner and a custom tune .You will need this anyway before you start freeing up the exhaust.

Personally there is no way I would be doing the cat and dump and running a stock tune

it will overboost and most likely cost you an engine.

Why don't you just buy parts as you have the money? then when you have the money, fit it all and get it tuned! New and radical concept I know...

Why don't you just buy parts as you have the money? then when you have the money, fit it all and get it tuned! New and radical concept I know...

lol, Not a new concept, I just can't do it.

I don't get how it wil over boost with a functioning waste gate???

I want to get it tuned once, not each time I do a new mods which is why I want to try do it backwards

Because the wastegate is electronically controlled via the wastegate solenoid which has a pre loaded program which was set with the restrictive exhaust and high backpressure. Once you change the environment that the wastegate solenoid has been programmed to work in the values that are needed to control boost all go out the window and must be reset . The only way to reset the values is by trial and error on the dyno with a flash tune.

The wastegate is not very strong, so when the backpressure is dropped by the big dump the actuator will struggle to control the flow unless the wastegate duty cycle is adjusted to compensate

Or what he said ^^^

ive been thinking of getting a new cat for two reasons my car has 90000km and im guessing the old one is more than likely rooted

also I dont want to get the car tuned and have the cat crap itself and need another tune as well as trying to free things up a bit

now if I get the cat fitted and diconnect the electrical fitting on the boost solenoid , im guessing its a normally closed value my car will be safe from over boost to drive to sydney from wollongong for a retune correct ?

cheers trev

you'll be able to connect it and just drive it off boost to the tuner mate, shouldn't be too hard to do up the express way

I got a full ces 3.5" exhaust with twin dump pipe and drove full boost for a few months and didnt have the slightest problem, this was before I met everyone here and had no idea, the mechanic didnt tell me anything about needing a retune. you should collect the parts and get them all fitted and tuned when you have everything