This thing is truly insane. Throws massive flames, pops like bazookas and I'm pretty sure it'll peel paint off of walls! My only issue however is a major, major one. It idles VERY roughly, and the rev fluctuation is very annoying. Gone is the smoothness of the PDK and now it's pretty much a jerky ride in traffic every single time. The rev-liner drops to as low as 400rpm then when it's about to stall, it jumps back up to 2000 causing a massive jerk. It's all very embarrassing really.
Do I have to tune my car to adjust the system to the o2 spacers? Will a GIAC tune help?
Is this "normal" in a catless system?
What the hell should I do?

 

First off congrats on your new Fab Speed exhaust! I always say exhaust is the best feel good mod that really brings the car to life. With that said, I had those exact symptoms on my cat-less supercharged m3, as well as my buddies cat less f13 m6. i had a tune for my car and it still did it... removing the cats will turn the car into a different animal. It has that "motorsport" feel but to me it got very annoying after awhile not to mention the soot build up from the exhaust on the rear bumper.

I would recommend taking it to a proper tuning shop for their professional opinion, and if you do decide to get a tune i would do a custom dyno tune. The reason i say that is because most tunes offered on the market are "canned", meaning one tune fits all. Having a tune tailored to your car will not only make your car smoother, but it will yield you the most HP gains!

In the meantime, try not to do what this Gumballer did and light the bushes on fire!
http://www.youtube.com/watch?v=MhfkDvpkDrU

 

HOLY CRAP! :O He actually set the bushes on fire! LOL!


Thanks for the advice bro. I'm probably going to go ahead and order the cats because for now, the car is far, far too jerky.

 

Reach out to the manufacturer, Fabspeed, to see what they advise on the new system they sold you!!
Surely they have experience on test mules that can help you....

 

Go w/ the HJS sport cats, I've been very happy w/ mine on my fabspeed.

 

Agreed with the previous post in regards to taking it to a proper tuning shop. If a Dyno is available, they will be able what the cause is, but adding back some cats might do the trick.

Good Luck!

BTW....how about a video of the exhaust?

 

deleted...

 

Yes, fabspeed is going to contact my dealer in Dubai directly. Hopefully we can find a solution.

 

I already informed my dealer to order the cats if I don't find a solution. The cats sound *****in too!

 

Thanks. I'm planning on taking some videos today that is if my shorts don't catch on fire when filming

 

I was assured that the fitment of the system was correct and precise and as far as I know, nothing was wrong with my car prior to fitting (apart from the crank sensor which Porsche had replaced for me). It probably differs from manufacturer to manufacturer. My dealer tells me a gmg catless system he had fitted on a 997 turbo had the same issue.

 

I have fabspeed exhaust and headers , no cats and I havent had this issue

 

You should come up and get your car flashed...you've got a lot of HP left on the table

 

might have to

 

Let me know when. I'll get you in and out pretty quick.