Hi guys, im new both to the forums and also rotary's. I just purchased a 1987 rx7 TII and im getting the RB complete dual exhaust(DP,presilencer,y-pipe, and mufflers). I have searched and read multiple posts but none have answered my question. If i have an HKS manual boost controller in my car and i set it to low boost do i still need to purchase and FCD? or can i run safely without one? From what i understand, if i get the RB complete exhaust i have to: 1) port waste gate,2) buy an Rtek or FCD. like i said, i have searched these forums many times and im sorry if i missed what i am looking for - send me a link or share your knowledge with a noob. I also have an HKS intake! its an awsome car i hope to see you local guys around, i have seen some at the 99 ranch meet in artesia ca on monday nights! p.s. - i hear a FCD is harmful?...so i kinda dont want to go that route but what do you guys think?

this is not a daily driver, its a project car that i am aiming to get around 250whp safely......FOR NOW AT LEAST .

THANKS

 

i would go with the boost controller...do you have a boost gauge?

 

not an after market, just the stock one. it still works fine but im not sure about accuracy. i keep the boost controller on low all the time and it goes 1/2 way up on wide open throttle which is ~ 5 psi (on low) i believe, medium setting took it all the way up to 40 on the stock gauge which is ~ 7 or so psi. (this is all according to my handy pressure conversion calculator http://www.online-ambulance.com/calc...Conversion.htm)

 

You have to search harder and read up on rtek. Port wastegate and get a rtek 1.7 with 720cc secondaries.

 

A boost controller cannot lower boost. No matter whether it's a $10 DIY bleed valve or an over-priced Japanese electronic one, the amount of boost you have with no controller if the lowest you can get.

Fuel cut is at 8.6psi. If you improve the wastegate flow enough to get boost below that, you don't need any electronic mods. If you want more boost than that, you need something to eliminate the fuel cut.

The ECU retards timing as boost increases to keep a safe margin away from the point where detonation occurs. A FCD tricks the ECU into seeing a boost reading lower than the point where fuel is cut, so above that point the ECU is no retarding the ignition any more. The higher above the cut point boost is, the smaller that safety margin is. So unless you run mixtures rich enough to suppress detonation, you risk engine death.

 

Yeah a boost controller won't help you, as stated above it can only raise your boost, not lower it, a fcd and a heavily ported wastegate should keep you safe, just make sure you have an accurate boost gauge to keep an eye on things.