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.

all you have to do is watch the boost, if you start getting creep then at that point yes, you have to do fuel mods or highflow. Im just saying that its possible that the wastegate can hold the boost at 10, and if that is the situation he will need no further mods

Gotcha....and he does have a PowerFC, and those maps should give him a small amount of safety, certainly more than he would have if still on the stock ECU, like some have done https://www.nopistons.com/forums/pub...IR#>/wacko.png .

Still, I would think he better watch it closely.

Thats all fine and dandy until he gets on the boost on a cold day and gets a nasty boost spike. You can watch for creeps but one good spike to 13psi and he could easily break that engine. I've seen it happen more than a few times over the years at local meets etc.

It's always been my experience that when you add a mid pipe your playing with fire. If you want to be more safe and less sorry then don't play the odds. Either leave off the mid pipe all together or get some larger secondaries and re-tune the maps. I would worry less about your boost gauge and more about your air fuel.

If your running power FC all you have to do is set your boost 25% lower than the max you want to run. IE my boost on the power FC is set to 9.5, it will creep higher, but when I hit 12.2 it will cut.

What will cut? The fuel? Why anyone would want to set up a car to hit cut fuel as opposed to doing the mods so that you can floor it with out having to hit a fuel cut is beyond me. If you talking about the wastegate then you already said yourself that works up until a point.

All I am saying that if you run a mid pipe without adjusting your A/F's properly your asking for trouble.



Your going to want some larger injectors. Then re-tune with a wide band. A fuel pump only increases the abilty to run more fuel it will not automatically compensate the map for you.

I never said a FP would increase fuel? I have my injectors and fuel pump coming in a few more weeks. Yes I do have the fuel cut set like that, simply because you can never be too safe. Sorry If i didn't do my mods fast enough for you, but everything will be sorted out over time. As for now, I like to keep my motor running if I have the need to drive it at WOT, which 99% of the time doesn't happen. And well if that 1% does, I have the fuel cut to warn me to back the hell off https://www.nopistons.com/forums/pub...IR#>/smile.png

The reply to the fuel pump comment was directed at Ben and not you. He posted that he thought it would be ok to run the mods that he listed with only a Power Fc and a fuel pump.



nopistons94, I'm not knocking your fuel cut as a temporary fix. I think it's a good idea as a just that " A temporary fix" I just don't think one should plan to modify a car backwards. So long as you understand that setting up a fuel cut is sort of a band aid over the real issue which is trying to run a mid pipe on stock fuel. You can mod your car however you like obviously but the smartest way is to leave the midpipe off until you can supply the needed fuel to run with it on the car and not risk breaking your ****.

Sounds like the split air pipe comes off the back of the manifold..

Right I`m off from college now so I have had a chance to have a proper look at it. It goes from the cat to a braded hose which goes up into the car, It then goes to a plug under the carpet, I cant follow it any further.





Thats why I was asking the questions buddy!! I didnt really know.



Anyway what secondaries do I go with? I want to go single next year and try and get around the 500bhp mark, if I can, so I dont really want to buy more than I need to.

500 bhp translates into roughly 425 at the wheels. Not an authority, but to do that safely, it will be hard NOT to buy something you need. I envy you and the money you must have while in college. I drove an old Malibu and worried about having enough for gas (OK, and beer too https://www.nopistons.com/forums/pub...DIR ) from day to day.

Yeah I know its going to need more to go single what I mean is I dont want to have to buy stuff to get it running now and then buy the better versions of those parts again to cope with 500bhp.



The car is for my college course which is motorsports engineering so I get help with the money which is nice.

Well the cars running again and I love it. Its wet here at the moment and greasy as hell but it all good fun https://www.nopistons.com/forums/pub...#>/biggrin.png



I did get a boost spike though of about 17psi so I cant push it yet. I found this website http://opus.bloomcounty.org/~patrick/pfc/ and one of the guys on there, David Ieroncig, has pretty much the same mods as me. Would it help if I was to copy his ignition and fueling maps to my PFC?



What does detonation sound like in a rotary? Is it like a sort of rough deep ticking noise? If so I`ve heard it once.