I have used the advanced search and used these key words: +ej25 +na +n/a +exhaust +MY02 +catback +cat-back
I didn't get any good search results.
Firstly I would like to state that by my possible intention for a catback exhaust, I am not being naive, expecting big power gains out of a N/A engine. I also am quite familiar of the frequent indecision of getting an exhaust on a non-turbo car, be it a Liberty or something else. I want a CBE for 3 reasons:
1. functional daily driving (throttle response)
2. performance increase (even if it's negligible at best)
3. exhaust note
4. fuel economy? Not sure with this one.
I recently got a quote for a 2.25" catback setup and other exhaust options for my MY02 RX from Exhaust Technology (SA). The quote information is as follows:
$520 = 2.25" mild steel catback setup with small resonator, MS muffler and stainless tip, perhaps a Y pipe.
$550 = Unequal length headers
$300 = high flow cat
A fellow member who I have been discussing this topic with has owned a N/A Gen 3 with 2.5" catback and has driven a N/A Gen 3 with 2.25" CBE, with the former option being his choice though both are nigh on the same playing field.
I have been doing extensive research into this including multiple cost quotes and browsing various car forums via Google search.
When I told Mark (owner) about a member on this forum having experience both 2.25" and 2.5" systems, he still recommended 2.25" for controlling the noise. I am aware of a certain 'rule of thumb' that there are RECOMMENDED pipe diameters based on the engine size and whether the car has forced induction.
4 cyl = 2.25"
6 cyl = 2.5"
turbo = 3"
If I am off on the above information, please say so. I know it also comes down to the amount of HP your car is producing.
I am aware that one needs to be concerned with backpressure and that too large an exhaust can result in a loss of power rather than a gain.
I was told that by getting the CBE I would get some more torque in the low RPM ranges, however the other day I read on the web that you might lose power in the high RPM ranges. Can anybody verify this?
How can an extra .25" in pipe diameter from stock, provide the increase that motivates so many N/A drivers to getting a CBE in the first place?
I had a very similar topic to this posted up on OZ Liberty forums when they were still up and got almost a unanimous decision that it's a big waste of money to do these exhaust changes to a N/A car, and that if you want a better exhaust note, just to buy a muffler.
I would rather make a well informed decision NOT to go ahead with these plans, than to make an ill-informed decision to go ahead with these plans.
My apologies if this topic has been covered numerous times over (assuming it has) but I did make the effort to use the advanced search.
Thank you for your time reading this and I look forward to reading all of the replies you fellow members have to share.