With my car in the hands of Chris and Dave at Rotary Performance for her once-a-decade refresh and facelift, one of my wildly eccentric ideas was to have multistage boost capability. Something like wastegate [stock] – Low [350 whp] – High [400 whp] controlled from within the car. I know, crazy.

Dave recommended that I try to find a GReddy Profec Type S – simple, reliable, old-school but proven. But like many things of its era, I’m not having much luck finding a complete/nice one from a seller that is respected or just doesn’t come across as shady.

Much of what I’ve found on the topic is from over 10 years ago and many of the other options mentioned seem unavailable as well. While I will ask them what else I should look for if I can’t find the top choice, I figured I’d ask here in case time and experience have yielded some new advice.

My current build is a single turbo, PowerFC at 400 whp. The current boost controller is a simple Turbosmart Boost Tee under the hood. PowerFC will remain in control after this refresh/update.

What options should I be considering?

 

The technology has not drastically changed so for the most part you are getting very similar features with ones that have been around for more than a decade. If you however want one from this decade with a plethora of features pbc-pro from plex tuning is amazing but it is pretty pricey. If its in your budget I highly recommend it.

 

Independent boost controller tech isn't as diverse as it once was since just about all modern standalones handle it internally. The profec s isn't what you want or should even be looking at. The profec b spec 2 is THEE boost controller of choice. We've tried others and some are just needlessly complex, cryptic or expensive. The bspec 2 is relatively easy to use, has high and low settings, easy to find and install and it has great control over delivery as a whole.

Its a powerful controller that's does a lot

 

My friend has one of the more recent HKS EVCs, and say what you want about the cost, complexity, and excessive features, it looks really cool in your cabin.

I have an EVC IV, but I mostly use it as a boost gauge, since the original owner only installed it to improve turbo response.

You can switch between high and low boost with press of a single button, and even install a scramble boost switch, so there's effectively three boost level settings you can use.

 

Not heard of that before. Looks like it's discontinued as well. A bit outside of the budget I had in mind, but I'll keep that on the list.

Interesting. General consensus of opinions in my random and haphazard searching here seemed to point to that was the one to avoid. I'll have to give it another look.

 

could just be they don't want to take the time to learn how to use it. it will reliably and easily hold whatever boost you set it at within 0.1bar. we have installed many of them with the same result on every car. not just rx7s

 

I had one on my MR2, but they don't seem to actually make them any more. The solenoid is nice and compact, as is the controller itself.
Are you suggesting he find a used one? It's not actually from this decade, of course. Or do you actually mean the current Greddy Profec?

 

Not the current profec. The b spec 2. The one that looks like the turbo timer of the same era. It can be used with the greddy branded solenoid or a Mac valve. Used is the only option. Of the places that list them as "new and available" , the prices are so high we never tried actually ordering one to see what happens.

We briefly interacted with the new profec and didn't care for it. The design of the unit is definitely indicative of its operation...... busy and all over the place. If we spent more time with it maybe the opinion will change. It's design alone is enough of a reason to not want to use it.... its ugly lol. It may be really good for all we know but the profec 2 is so great, we haven't had a reason or a need to explore any other options.

 

i did not know that it was discontinued. i suppose its no surprise from a relatively small company like plex tuning, but they are saying that a new one is coming. I am only going to assume that it would be just as good with perhaps a color display like their dashes.

I had used the plex boost controller with the dual egts, AFR and fuel pressure while i was using the PFC and you can set these as boost-cut parameters. While it is not like the protections you get from a modern ecu, it was as close you could get to that.
The monitoring features were just great and with all of these features it was incredibly easy to use once you understood the menu concept.

I had used the eboost2 before the plex. i figured mounting it would be a lot easier but the eboost2 i thought it was complicated and not very user friendly especially if you needed to do something on the fly. The boost by gear concept was pretty much useless.
Greddy Profec B, HKS- EVC-S and BLITZ SBC-R I-color are all good choices and i have used all of them.
Personally, I prefer boost controllers that use the mac-valves as opposed to the solenoid boxes because i am running braided lines with AN fittings for my vacuum hoses for that little bit of extra safety.

 

May want to think about the Apexi AVC-R. I love mine, have had it for 15+ years, rock solid.

You can get VERY detailed on what it can do but if you want to keep it simple you can. Set what boost you want, make a few pulls, and there ya go. Or get in the weeds with the RPM boost maps, boost by gear, scramble boost input.....it's basically the same interface as the PFC Commander so if you can use one you can use the other.

Dale

 

Apexi AVC-R available here:
https://www.rx7club.com/market/1161563

 

AVC-R is a great option !

 

Slowly but surely you're going to end up with all my money.


Thanks, everyone, for all of the advice, experience, and expertise! Going to need to have a sit down with the guys and see what the plan is.

 

The Power FC itself can control boost by plugging into the precontrol solenoid and turning off sequential turbo control. The PFC Commander lets you select a high or low boost setting. It's definitely not as flexible as an AVC-R, but it can actually log your solenoid duty cycle with all your other engine parameters (rather than a separate box from which you get no integrated logs). However most people don't take advantage of the additional features, as it requires a pretty in depth understanding of how solenoid based boost control works (duty cycle maps, gain settings, based on rpm and throttle). If you want maximum capability I'd go with an AVC-R. If you want integration with the ECU, go with the PFC Commander, but understand it is less flexible than an AVC-R.

The AEM Tru Boost is pretty simple: Tru-BoostX Gauge-Type Boost Controller | AEM (aemelectronics.com) . It has no feedback though - it is open loop only, which is simple but limited. On an AVC-R you can adjust the gain up and down in fine increments.

Long-term testing with Power FC single turbo boost control - RX7Club.com - Mazda RX7 Forum


Electronic Boost Controller Comparison Chart - RX7Club.com - Mazda RX7 Forum