MazdaRx7Racer4Life

My exhaust arrived, yes, my complete exhaust, DP, MP and catback. ON the way is my Profec B Spec II Boost Controller. I have heard this around and wanted it confirmed by the experts (im no expert myself) If I keep the boost at 10psi or lower, can I put on the full exhaust, I also have intake and will also have a fmic and hks ssqv in the future, but the next mod (going on the credit card) Is the power fc, until I can get the credit though, I can't dish out that cash, am I safe or not

Mahjik

iTrader: (1)

https://www.rx7club.com/showthread.p...hreadid=261340

MazdaRx7Racer4Life

damn, so I need to port the wastergate too? Not just get a boost controller.

Snook

iTrader: (12)

the only problem is that no matter what you do the boost may go past 10psi at the lowest setting because of creep. the only thing you can do for that is take out the turbos and port the wastegate bigger. so its easier to get a computer and run 11-12 psi instead of doing all that work

oh and I could make you a very good ball and spring boost controller for 20 bucks instead of wasting so much money on the profec b. its nice, i have one but you dont need it especially for what you are doing

Flipn

Once you get the Power FC... couldn't you just use that as the boost controller..? Or do you need additional things?..

RxSeven1

iTrader: (2)

the boost controller feature in the PFC isnt the best from what I heard and you do need to buy an addtional piece...i forget what its called.

MazdaRx7Racer4Life

So wait, i don't need to port the wastegate if I get the power fc? Can that reduce creeping?

Snook

iTrader: (12)

no it cant reduce creeping
a wastegate is there to route exhaust gas to the exhaust instead of to the turbos to spool them up more.
When the wastegate is getting rid of all the air that it possibly can to the exhaust but it is too small and theres some still going to the turbine then you will get creep. It will be all the way open but still as your rpms rise your boost will as well.

now with the pfc you can just decide to run 12psi and then you wont see creep because 12 is about what it would creep to. without the pfc youll have to set it to 10 and then in the higher rpms of 2nd 3d 4th 5th youll see it going to 11 12 maybe 13psi and the stock ecu has fuel cut at 10psi at various rpms so you cant do this safely.

get it??

JhnRx7

iTrader: (12)

it is safe to rune full exhaust and intake as long as you can keep the boost at 10 lbs. i ran my car that way for 5 months without a problem....in fact my car was running extremely rich. (although i did have a ported wastegate). every car is different though.

MazdaRx7Racer4Life

Thanks for the help you guys, atleast now I understand the concept of a wastegate.

Sprockett

Stock ECU - need to port the wastegate to prevent creeping

PowerFC - can remap fuel and everything so that creeping isn't a problem (I think)

TwinTriangles

I used the PFC wastegate duty cycles to contol boost at 14psi for 2 summers without any other boost controller, I never had any creep or spikes, in fact it worked real nice but now I did buy an AVC-R for when I go single...