Right so I am putting a mid-pipe on and have noticed a wire from the car onto a thin pipe leading to the cat what is this? Do I need it? What do I do with it? Its in the opposite side to the air pump pipe. My mid pipe doesnt have anything on it at all.



Right the final questions are.



The mods I have now are;



Mid pipe

Down pipe (Jspec so doesnt have pre cat)

Blitz SUS induction

SMIC

AVCR boost gauge (old type)

Air Pump gone

Fuel pump on its way

Power FC



Will the standard map on the Power FC be ok for these mods ie I can just plug and play? I think I saw on here somewhere on here but cant find it that I have to tell it I have removed the air pump?

Don't know for certain on JDM cars but the pipe sounds like emissions and I would assume it could just vent. I would trace and see what the source is if your that curious.



If you want to run a mid pipe on stock fuel levels be really careful about keeping the boost under 12psi or you risk breaking that engine. I would get it re-tuned and buy a wide band to keep an eye on your A/F's.



Good luck

You need more fuel with those mods.

not if he keeps boost at stock level

Would boost creep be a concern with the midpipe, even with a boost controller?

Yes it could be a concern. Every FD is different, some have problems with creep and some don't. Basically what happens is the exhaust flow is too great, and the wastegate gets maxed out at 100%. At this point, boost will start to creep due to the fact that the wastegate no longer can control the boost. Porting the wastegate is a option but its a PITA.



A Boost controller can not keep boost down once the wastegate is maxed out. A boost controller can only control boost within a wastegates operating range. Be safe!

Yes it would. You are asking a lot of the stock wastegate. I have similar mods, minus the smic and mid pipe, and on cold nights (like 30 degres F)i have seen the car come dangerously close to leaning out. The stock fuel system is going to have a hard time giving your engine enough fuel, the new maps in from the powerFC helps, but you might be coming close to maxing out the injector duty cycles. I would look at getting a A/F gauge and some slightly bigger secondary injectors.

If you keep the boost level to a stock point, you will have no problems with leaning out especially on a power FC which runs richer than a stock ECU anyway. Keeping the boost down is the hardest part though. Best thing to do IMO is just tune for higher boost levels and upgrade injectors and fuel pump, or stick a highflow cat on.

I`m only really getting rid of the cat because I took out the air pump. I`m a bit worried now I thought the power FC and a fuel pump would be enough, what secondary injectors should I get? What would I need to do to the power fc for this?



Sorry I`m such a "noob" at the moment, I`m working on it. This site helps a lot



Next year I`m going to go single anyway so I`m really just trying to have some fun with it for now but I dont want it to blow!!!!

This is why I asked the question, because as you pointed out earlier, the BC can't do anything about boost once the wastegate is a maximum capacity. So I was thinking that Sweet7 was right when he said that more fuel would be needed with those mods. Even if he sets the BC at 10 psi, if the wastegate gets overwhelmed due to the free flow of the midpipe, he could run lean. You've confirmed that when suggesting "the best thing to do" is to either leave Cat on, or upgrade injectors and fuel pump.

Never had a midpipe so I can't say whether it's worth it or not, but I always thought that putting one on caused a domino effect, requiring alot of other mods to safely support it.