Easy exhaust question???

[Ducal-dawg]

I have not seen a definite answer anywhere here, sooo... If i put on an FMF Q4 slip-on, do I lose the exup? ie: how long is the tail on the Q4? If the exup goes away, and you use the delete module, is there any negative effects? I see some people welding the exup back into their aftermarket pipes. I don't plan on changing the head pipe for a while. Although, if the exup is gone with the slip-on, I might just do it then as well. I will also do a basic programer as well at that point. Any thoughts from people just running the FMF Q4? Thanks guys!

[YamFloridaB]

If you put a slip-on on, you will lose the exup. Once you remove the stock exhaust, there will still be the servo that controls the exup valve. If you leave the servo in, you do not need the delte module. If you take the servo out, you will need the delete module. The delete module makes the computer think the servo is still there and it prevents any lights from coming on.

I think they are keeping the exup for more bottom end torque. Most remove it, there are only a handful of guys that have welded the exup on to an aftermarket exhaust.

[SwiftyWRX]

I hadn't heard of anyone else doing it when I decided to weld the EXUP back into the after market exhaust system (FMF Q4). I have commented about it in detail in other threads. Basically, like YamFloridaB said, it was to try and get a little of the low and mid ranged power back. I had tried the Q4 without the EXUP and noticed a performance loss in the ranges mentioned. It's not a HUGE deal but it is definitely noticeable and I think better for my commute. If you keep yours bouncing off the rev limiter then don't bother with an EXUP for sure. Here's a pic of the Q4 installed BTW (decals removed).

Swifty

[Ducal-dawg]

Swifty, have you done a programer? If not, are you worried about it running too lean? I will do a K+N filter as well so my research says yes to re-mapping. Any thoughts?

[SwiftyWRX]

Swifty, have you done a programer? If not, are you worried about it running too lean? I will do a K+N filter as well so my research says yes to re-mapping. Any thoughts?

Yeah, check the signature. FMF Power Programmer. My air box mods also made a noticeable difference. If you don't open up the air box somehow the K&N will be worthless.

Swifty