Supercharged FC ECU options
 

before i start, i know half of the forum is gonna say "just get a stand alone or an rtek". this advice is all good and well, but, i am not planning on going standalone, and rtek IS a strong possibility, but not for a bit since i just got done financing a rebuild complete with new everything (rotors, housings, irons) minus the e-shaft and the front cover...

i am currently running a street ported s4 13b with a paxton sn89 strapped to it (or i was till i blew the rear rotor). all engine and fuel control is stock with the exception of an safc II. my main goal behind upgrading to an rtek in the future would be to electronically control timing. i was wondering if for the time being throwing a TII ecu, MAP and AFM in there would be nice. before i blew the motor, the na ecu (with the help of the aforementioned SAFC) along with the stock na MAP and AFM was doing just fine, but i started thinking about 6 port turbos. ppl normally swap these three parts so that A) the ecu will actually kno when its in boost and B) it can retard timing automatically when it is. would my setup benfit from this???

heres my relevant mods:
large streetport
paxton sn89 with high flow impellar (its safe around 8-9psi)
550cc all around
walbro 255
vortech fpr
safcII
corksport "cone" intake
rb headers
rb presilencer
apex'i gt spec catback
Turboxs BOV

i think thats it.....THANKS in advanced

I would think that a REAL aftermkt standalone would be the ONLY way to go for an application like this. Turbo's and superchargers create boost in very different ways and have very different effects on the intake pressures and more importantly the exhaust pressures. The only way that you are going to be able to maximize this setup is to go with a standalone. I think that if you keep dicking around with mickeymousing stock ECU's and piggybacks the exact same thing is going to happen - blown motor

your advice is duely headed, but it is not my belief that the ecu had anything to do with the blown rotor. the s/c i have is meant to run 5-6 psi on a stock na motor. since i had both the upgraded impeller and pulley, i was regularly pushing 10psi, 12 being the most i ever hit. this was all NON-intercooled. i *believe* (but admittidely could be wrong) that the blown rotor came from the combination of HOT HOT intake (i plan on solving that with water/meth injection the beginning of the year) and high compression rotors (compressing hot air only makes it hotter and more volatile, thus risking preignition). this has also been addressed since i replaced my na rotors with TII rotrs during the rebuild.

however, you are right that a full standalone would be ideal, and you are VERY right about the way s/c's and turbos build boost in completely different ways. this is one of the reasons i stuck with the stock na ecu: the s/c builds boost INCREDIBLY linearly. thus adding fuel with the safc based on an rpm curve is very easy since the s/c acts so predictably in almost evry gear. still, this does not address the issue of timing, which is what i hoped the TII ecu could help with until i got an rtek, but i guess that wont work either....

that actually raises another question for me. i am not too familiar with rteks, but since the 2.0 (or 2.1 or whatever they are at) allows for fuel AND timing control even on the na version, wouldnt it be just the same if i got my current ecu chipped by them OR used a TII ecu. are there extra features with an rtek'd TII ecu over an rtek'd NA ecu??

A good & properly tuned ECU could've retarded the timing based on hot AIT's and EGT's. Therefore, I stand by my statement that it was your ECU that blew your motor. That being said, an ECU is only going to be as good as the person operating it until the person operating it is smarter than the motor and the ECU. Meaning that if the person tuning your ECU doesn't know enough to retard timing based on those factors than you could have a fully optioned & setup Motec M820 with harness that'll run you ~$8-9,000 and your motor will still blow.

I don't know enough about the Rteks to speak intellegently on them. If they can be programmed to retard timing based on a few inputs than it could be a viable option. Don't dick around with stock ECU's. You're not running N/A, and you're not running turbo. Therefore you'll be mickeymousing shit together that will more than likely cost you more in the long run. Doing things quickly generally ends up taking longer, and doing shit cheaply generally costs more in the end

Yes your setup would benefit from TII ECU/AFM/MAP. The NA ECU does nothing when it senses pressure, no timing retard, fuel enrichment, nothing. The ECU is also energizing your injectors assuming they're the factory 460cc's so thats more tuning required on your part. Aaron cake ran your setup for a while and while not the best it definitely works.

In order for you to be able to use the stock ECU you need to get your setup as close to a TII as possible. Your setup differs in the following ways:

9.7:1 compression vs. 9.0:1
Different airflow characteristics than 4 port

To counteract these you can run the following safeguards. 93 vs. the expected 87 octane fuel, added fuel enrichment (FPR+255), retarded timing curve using the CAS (if you want to be extra careful), and meth/water injection.

As far as the AFRs you are directly in control of them with the SAFC and wideband. With an extra $120 you can get the RTEK 1.5 or 1.7 (720cc sec. preset) which removes fuel cut and retards timing 1*/1psi above 9 psi. With this setup I would assume that you are good to go unless you want to upgrade the supercharger and/or run more boost.

Edit: And the RTEK + the TII ECU is superior to the NA for your setup because it allows you to adjust timing based on boost levels and not just RPM/load. The NA will work, but the TII will be safer.

this is very true. i see what you mean now.

im not entirely sure either, but i believe that the tuner can set up a timing map based on other inputs.

i took care of this. when i rebuilt the motor i used Tii(low compression) rotors

...very true....

i always use shell v-power(93 octane). i have an fpr and a walbro 255. i plan on water/meth after the first of the year.

do you kno if these have complete fuel/timing map customizability(?) like with the newer (2.0+) VERSIONS??

AWWW, makes sense... thanks!

Asking all the wrong questions, not liking the answers?
 

I have *no* experience with the Supercharged rotary, but I can tell you that there has been mostly pain, lots of pain with SC rotary setups. If you go to a turbo ecu, add the boost sensor etc., the timing retard may help you preserve your motor. The fuel maps however, being set for turbo boost will likely not match your needs for the SC, so you will still be using the safc to patch the limitations. It will still be a hack, no matter what.

You already know first hand there is not much room for error with a SC rotary and preignition. One more rebuild and you could have had a standalone with a fine tune. My opinion is that you are going to pay the price one way or the other.


The only question is whether you have a working car when you are done? Or if you will post a supercharger for sale thread and an FC roller for sale thread...

Good Luck, you are going to need it.

I couldn't agree more.

Depending on the damage done a used standalone would be way cheaper than a rebuild. Shit, even a new Motec M2R would be cheaper than some rebuilds.

ok then, 2 Q's. i am not particularly familiar with any of the popular standalones (megasquirt, haltech, wolf, aem, etc). with this is mind:

1) what would be the main advantage of a standalone vs an rtek w/safc? bear in mind that the new rteks give the user the ability to make his own timing and fuel maps and adjust them as well. of course we all kno what an safc does.

2) which standalone do YOU reccommend? personal experience with any particular unit, or even multiple units?? keep in mind that price is an object in this case and i would like to spend as little as possible, but on the same token, if i am already spending $800 on a standalone, i would be willing to spend an extra $150 to get a superioir unit. however, i am not willing to spend an extra $1000 to get a far superioir unit.

thanks

why dont you have a wideband?

I don't know much about the RTek as I've never used one. Primarily because they are designed to plug into a stock wiring harness. To me, that makes it worthless as the second biggest benefit of a standalone is that 20+ year worn out harness gets replaced.

Without knowing the specifics of the RTek, I'd say a standalone gives you much finer control over everything.

Entry level Haltech or Microtech. You can probably get the basics for $1000, but you'll be spending several hundred more for wiring supplies.

great point.

so barics would include the actual unit and sensors?? and i assume that that much money in wiring supplies would be because all the wiring is to be done by hand??

thanks for the info btw

The only downsides I see of the RTEK is the max 720/720 injector preset, though you can put bigger injectors in and tune out the difference yourself, that and the restrictive AFM.

The <2.0 models do not have any tunability, thats why they are only $100. Few people go with the chip and an SAFC II if they can find good used ones. As far as standalones I believe the APEXI Power FC is a plug and play unit with the stock harness if you don't want to do any wiring, quite a few have run big turbo setups pushing 400hp+ with them. I'm not too educated on superchargers, how much power do you plan on putting down? Anything less than 350 and I'd go with an RTEK over a standalone...

The wiring supplies would be so much because of all the new connectors, shielded wire where needed, any tools required and then just all the wiring.

If money's such a problem you should look into the Megasquirt, but be warned, it's a definite DIY type thing. But you're trading your time and effort for a lower price. Other than that you'll be lucky to get anything decent for $1000.

You gotta pay to play.

although never on a dyno, based on dynos by two others that had the same s/c as me (the P.O of the s/c and another i met on this forum) i was making ~225rwhp. i have a video of the other guys. he did 230rwhp @ 6psi on an s5 vert with some similar mods. by that i took off 20hp for the s4 to s5 difference, then added on a few horses the high flow impeller (i easily hit 10psi). however, now i have a full exhaust (headers, straight pipe, catback, and a pretty large street port. im pretty sure that ill make over 250rwhp, but i would be estatic to make 275rwhp or more athough i dont see that happening. i just dont really kno since theres no real model for me to compare the setup to.

haha. very true

heres a link to his thread from a while back:

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/230-whp-supercharged-vert-complete-dyno-car-video-sc-comparisons-431570/

I won't comment much on superchargers because its off topic but even a stock turbo at 12psi with water/meth will make 300+ comfortably on a 6 port with stock compression. Chris Ludwig (I think) made 253whp@8psi on one of his customers' cars with a stock S5 engine.

this is true, but i think it is mostly a matter of airflow rather than boost. also, i plan on using the water/meth more for cooling rather than extra power since there is no inter cooler. althou the extra power is welcome :)

also, anyone have any experience with the zems (megasquirt)??