I recently purchased a FiST with lots of mods. I absolutely love it in every way except for the catless stench. From what I've read, it seems like going catless is more for sound and doesn't effect the power much until you get to crazy high output. So I'm considering swapping the downpipe back to stock or a catted aftermarket.
Here's the catch... I know absolutely nothing about the tune. I've driven stock FiSTs and this is a TOTALLY different car. Even with R888Rs on front, I have to be really gentle with the throttle through 2nd gear and sometimes even into 3rd or it just spins. I have no dyno data, but if stock is 200ish, then my mk1 foot dyno tells me this is easily 250. I'm both picky and very mechanically inclined as I build fast things for a living (not cars). The previous owner seems to have done everything "right." Everything I have inspected was done with quality parts and a quality installation. The mods I know about I stuck in my signature, but again, I know nothing about the tune and do not have a tuner.
So here are my questions:
1. Since this thing currently runs beautifully like a swiss watch, how much effect will changing the downpipe have?
2. I do not know what changes with a tune when going catless. If I went back to a catted pipe without touching the tune what would happen? I'm guessing the O2 sensor will be an issue.
3. Do I need to buy an Accessport or equivalent? And if so, can the existing tune be saved and tweaked?
Here's the catch... I know absolutely nothing about the tune. I've driven stock FiSTs and this is a TOTALLY different car. Even with R888Rs on front, I have to be really gentle with the throttle through 2nd gear and sometimes even into 3rd or it just spins. I have no dyno data, but if stock is 200ish, then my mk1 foot dyno tells me this is easily 250. I'm both picky and very mechanically inclined as I build fast things for a living (not cars). The previous owner seems to have done everything "right." Everything I have inspected was done with quality parts and a quality installation. The mods I know about I stuck in my signature, but again, I know nothing about the tune and do not have a tuner.
So here are my questions:
1. Since this thing currently runs beautifully like a swiss watch, how much effect will changing the downpipe have?
2. I do not know what changes with a tune when going catless. If I went back to a catted pipe without touching the tune what would happen? I'm guessing the O2 sensor will be an issue.
3. Do I need to buy an Accessport or equivalent? And if so, can the existing tune be saved and tweaked?