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-   -   Apexi intake = overboost???? (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/apexi-intake-%3D-overboost-609786/)

ghost-rider 03-11-07 04:40 PM

Sorry, I'm just trying to understand, if I have a dp, cat-less mid pipe, an rb cat back, in my case HKS intakes, stock ECU and on top of this a mild/street port, an electronic boost controller won't help with controlling boost spikes? Am I getting this right? I'll need something like PFC? or will I need to port the waste gate and run a boost controller.

dontlift 03-11-07 06:34 PM


Originally Posted by ghost-rider
Sorry, I'm just trying to understand, if I have a dp, cat-less mid pipe, an rb cat back, in my case HKS intakes, stock ECU and on top of this a mild/street port, an electronic boost controller won't help with controlling boost spikes? Am I getting this right? I'll need something like PFC? or will I need to port the waste gate and run a boost controller.

The boost controller or a PFC can control boost spikes; porting the waste gate will limit the boost creep you'd get with that setup. A boost controller can not solve boost creep.

Narfle 03-11-07 09:56 PM


Originally Posted by Wompa164
Technically that's not true. Boost controllers operate on the basis of 'tricking' the wastegate source pressure into thinking it's lower than it actually is by bleeding off pressure, keeping the wastegate closed longer and allowing higher boost pressure to build up.

You cant fool the wastegate spring which combines with the wastegate sizing is the ultimate decider of boost. BUT the aftermarket solenoids definitely work more precisely and more quickly than the aging FD solenoids. There is no question that an aftermarket boost controller set to 10psi will work better than the stock system at maintaining safe boost levels.

ghost-rider 03-12-07 01:25 AM


Originally Posted by dontlift
The boost controller or a PFC can control boost spikes; porting the waste gate will limit the boost creep you'd get with that setup. A boost controller can not solve boost creep.

That's what I was looking for, thanks. While the boost controller can't solve boost creep, it can control it. At least until I get my wastegate ported.

DaiOni 03-12-07 01:44 AM

Someone back in the mix (page 2?, anyway...) stated that you need the add-on module to control boost with the PFC. Not sure if that was clarified, but just in case - this is incorrect. The module is only required if you have a high-boost application (typically: a single turbo). It's fine for what 99% of us do with the OEM twins.

I have a 321rwhp sequential twin set-up using PFC for tune and control - and I have switchable high (0.8bar) / low (0.7bar) settings which have been rock-solid, even in 0-degree weather.

My tuner (one of the best in Japan) laughed when I wanted to use the profec B II (which was already installed) - he told me not to waste my time, and that the PFC was all I needed. In saying this, his workshop promotes Trust gear - so he wasn't trying to sell me on the PFC (which, in any case, I had purchased elsewhere, and was already installed).

PFC = thumbs up from me.


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