1st gen Piggyback showdown, EMU+SplitSecond vs AEM FIC

So for context, 1st gen 5vzfe Tacoma with TRD S/C, I bought the truck used and it had zero fuel mods, IMO maybe why the owner was selling as it was very very pingy (carbon buildup maybe? As I assume it ran 'good enough' for at least a while like many here that have not gone the next step and added EMS)

I had already played around with piggybacks and standalones in the past and geek out on reading the spec and feature sheets of EMS, so rather than go with an established solution like a smart person would, I wanted to dabble with newer stuff that per spec sheets, looked to possibly be the better solution, so I bypassed URD and IMO am the first or around that time- early AEM FIC adopter.

The AEM FIC was a hard cookie to crumble, AEM had to release a firmware for it to work better with Toyota A/F sensors, and it's cam and crank circuits are horribly filtered and you have to install bridge resistors or have serious timing issues- I lived with the FIC for years and years... and years- dang its been a long time- BUT I really like the Greddy EMU (on my other car) but did not run it on the 5vz because it lacked o2 sensor controls, but I broke down and got a split second unit to shore that up. A bullet brake down:

AEM FIC Pros:
- for what it is, very affordable
- tunes by directly intercepting injector signals, allows you to very easily control much larger primary injectors
- includes, built-in, wiring and software features to tap and manipulate primary o2 sensor signals- something that is crucial to 5vzfe s/c tuning
- switch allowing one to switch between two maps, I used this to switch between a 91 octane and E85 tune
- Intuitive software- the tuning software is a breeze, also the USB cable powers up the unit, it does not need to be installed in the car with key on, or using a power supply on a bench to turn on and add tunes
- software works on modern windows, no need to run VMs like with the Greddy EMU

Cons:
- lots of soldering playing around with cam and crank wiring orientation and resistor values. After helping some friends installs I found there wasn't a "one resistor value cures all", otherwise would post up what it is and one could install the resistors inside the box- easy, clean, harness stays un-touched.
- some would argue the injector lag feature is not up to par in comparison to the EMUs
- increased cranking time-- AEM's approach seems to require the piggy to 'sync' before it will pass through cam and crank signals, so you get about 2 more seconds of cranking time
- No feature to retard timing even further when the auto tranny is shifting, causing ping during shifts.

Enter the EMU, why? Being a EMS geek following a lot on the interwebz, saw a Canadian tuner post up very strong evidence how the EMU seemed to have more accurate timing control over the FIC-- they go about it very different ways, the FIC simpy intercepts and offsets the cam and crank signals like older piggies, but the EMU intercepts the IGTs along with cam and crank. I suppose the OE ECU does a little bit of calculated guess work on timing and so there are windows of time only using the cam and crank to affect timing is not that effective- anyhow, my 5vz being the ping whore that it is, I wanted a little more accuracy, second is you can advance timing with the EMU-- get some MPGs back from using 91 octane all the time (5vz ECU does not use knock feedback in low revs so does not optimize timing like many more modern cars) and third (but not least), the EMU has an A/T shift feature, something I was craving after getting ping during shifts and finding out Toyota ECUs advance timing during AT shifting, the EMU can retard that when properly setup.

But a big problem, the EMU does not have built in o2 sensor feedback control, and for a little while they did make a very expensive add-on box that did, but discontinued it. But I had an EMU sitting around and finally said fug it, got a split second to take care of the o2 sensor issue and would tune around it with the EMU-- IMO a sin many tuners likely try to avoid as it adds complexity, but I wanted the EMU bad.

First couple of custom maps didn't start it up, so I loaded a known working map for a 2jzge, cranked, it started, and I have worked from there.

Pros:
- faster cold start, doesn't have the syncing delay the FIC has, or maybe has a faster processor, as it is cutting time off of it.
- A/T shift feature, time to fully defeat ping
- has a map switching ability, but requires some modding.


Cons
- not as intuitive software but with practice it gets there
- have to power up the unit to send tune to it
- costs more and doesn't seem to be getting updates from Greddy, but AEM doesn't update the FIC either, so equals there
- no o2 sensor control, have to get additional units
- No map switching ability in the same remote fashion as the FIC, but that was fixable
- need to be a little computer savvy, run a WinXP virtual machine for the software.

So to shore up some of the EMU shortcomings, I de-soldered a microswitch setup on the board so that I could solder on a header and harness so that I can use a three position OEM looking rocker switch to switch between fuel and timing maps to retain a 91 and E85 switching ability.

Initial impressions (just slapped the EMU in a few days ago, did just a little driving)

- EMU cranks/starts faster.
- Does suck to have to play with split second settings via rheostats, not having it all in one software setup.
- no need to add resistors, IMO the EMU is being more accurate with signals-- the truck just seems that much more smoother, tip-in is back to what it was like OEM, ping already seems less frequent even with less aggressive timing retard and fuel enrichment- but could all be placebo.
- overall really happy because I had been meaning to do this for a very long time, finally put the foot down and did it.

I still need to wire the a/f gauge output to the Greddy, tune the split second some, and do LOTS of logging to dial things in and hopefully get the A/T shift feature fully doing it's job.

Its the most expensive piggy option for the 5vz as the EMU is already pricey, and you have to add to that the Split Second-- but IMO you get what you pay for, I am controlling 625cc injectors flawlessly, starts and runs great, no CEL-- it is one of THE most modern piggies out there even though there are piggies that are getting much more development now, IMO they still don't stack up to the EMU. I didn't consider the MAPECU when I saw it still tunes fuel via MAF signal manipulation, IMO to be considered a modern piggy you need to do two things:
- intercept injector signals directly
- and now I feel IGT should be intercepted as well, not just cam/crank

Its getting long winded so I'll wrap it up, but overall I'm stoked I finally put this gear that was sitting around to use-- as the pic will show I kind of have a thing for EMS, I have Megasqurit stuff, AEM, Greddy etc just sitting around-- I like to tinker with the integration and tuning. This was a long time coming and its already delivering, getting rid of some odd gremlins from the FIC and running smooth.

 

How much increase in mpg with timing advance? I suppose you can go even farther with that on e85 as well?

 

Not sure yet, just pumped it with gas and haven't even advance vacuum timing yet. For E85 it should be really fun, with the AEM FIC the best i could do was zero out all timing retard in boost- that made a butt dyno difference for sure, and IMO there was still room for timing advance, E85 is just amazing.

Talking with a bud, I think it would behoove me to get some kind of engine knock gauge. I'm hoping that though the 5vz is too noisy for the OEM pezo, gauges that use more modern sensors can be effective. IMO aftermarket knock detection is going to be 'loose' at best, but hopefully better than just using audible knock.

 

It would be pretty cool to modernize the 5vz. I was just reading a study on direct ethanol injection in tandem with normal gasoline injection at high loads and the detonation suppression is truly amazing. Screw flex fuel, dual fuel gets me vote.

Interested to hear results with your setup. I'm probably going to make an e85 map once the weather turns around myself. Might have to follow your lead with the emu.

 

The FIC can do an E85 map as well, though IMO the EMU will get more gainz as it can advance timing. I have one of those super pingy 5vzs that require a lot of timing pulled, lots of fuel added, so just zero'ing out the timing retard made for a huge difference- wish I had the time and $$ to dyno it just to see what that difference is- if I had to take a swag at it, IMO ~20hp gain by adding 4-7 degrees of timing back in and not being anywhere near the ping threshold- nice smooth burns.

Its been a long time since I looked into knock sensing stuff. I remember J&S so started there, not really sure it was for me, so googled around--- WOW what a arid vast desert of nothingness. I guess it makes sense, its really hard for a company to claim they have a one size fits all knock sensor setup.

* Edit- totally overlooked the EMU's built-in knock sensor input feature because the OEM fixed frequency sensors are not useful below 3K even with Toyota's know how, but I can install a newer broadband knock sensor/s and run that to the EMU. Unfortunately the EMU only uses that for logging, it does not have a retard map that uses the input-- IMO if they were still making firmware updates it would/could have it, but logging will have to make do...

** I think I felt the A/T feature kick in this morning, had to drop the pedal to merge into another lane, truck was already in 1st (hardly moving, bumper to bumper) and when it shifted to 2nd while in boost, I could feel a very noticeable power droop which kind of sucks (but is to be expected with that feature working) but the good news, no ping when shifting!! I guess that puts a valve body upgrade up higher in the mod priority list haha

 

Good thread.

 

Oh forgot to mention a big pro-- the EMU does have the ability to auto tune air fuels. There are a lot of catches though of course, due to being a piggyback-- the big one is don't enable this feature within OEM ECU closed loop regions. But set up the settings correctly so its only used in open loop regions, and its a great way to ensure a consistent WOT/open loop air fuel.

The SplitSecond enricher takes a 0-5 volt input if you don't want to use the internal MAP- if only the EMU had a 0-5v aux map--- the AEM FIC DOES and that is how I was running water/meth via the AEM FIC-- if only the EMU had it as well, I could just use that aux map to then give the EMU the ability to control closed loop air fuels just like the FIC haha-- that would have been pretty cool. Oh well... for someone more enterprising than myself, a PWM/frequency to 0-5v translator would do the trick here-- might even be some generic little circuit on ebay that does this, or a nice little arduino micro project.

The EMU is so powerful, I found a website back in the day (now gone I suppose) in Thailand or somewhere, where tuners figured out a way to make a few dummy signals to feed into the EMU, to then basically use it as a standalone haha.

 

When do we get to see you try your hand at a Haltech?

 

For the price, I've never really been interested in Haltech as to me the budget standalone was megasquirt, and when you felt the need to pay up, go AEM or ProEFI. But the later gen Hatlech stuff looks really good-- one thing I really geeked out on with them is the software definable bias resistor value vs. older AEM and MS stuff you had to make physical mods to the boards-- this is a useful feature when you using a standalone on a newer car so the pretty standard route was you do not get rid of the OEM ECU, but mesh the two together- the standalone controls spark and fuel, some setups even VVTi, and the OEM stays there for DBW. Things like IAT and Coolant you would parallel to both ECUs, and the standalone you need to basically remove that sensor circuit's bias resistor and put the OEM value into the software. On Haltech if I remember correctly, you didn't have to make this physical mod. Oh another pro thats just the bias in me after traveling there, its an Australian company hahaha.

 

So I just realized from an old MS2 to MS3 build I did, I have a knock sense circuit and LED just sitting in a parts box!!! The old school looking website is still even up haha - http://www.viatrack.ca/ Totally forgot about them and the device I had, and google didn't pull up this site when I was searching.

So I can use that to send a signal to the EMU, and also have an LED giving me something near my gauges. I didn't need it for the EMU, but it will be nice to have something visual at all times like a gauge.

Another con for both systems, not having secondary MAP sensors to account for elevation changes. Elevation changes will mess up both piggies tune's. Good standalones have dual MAPs for compensation, or at least a calibration setting on startup (not much good when in one drive cycle your changing thousands of feet in elevation).

 

Debating, I will likely have NO use for the MAF wiring/air flow correction map and could likely just wire the MAF to bypass the EMU and then use the EMU's MAF wiring and map to send a mappable 0-5v to the Split Seconds 0-5v input (v2), so I don't have to mess with the rheostats on that thing at all anymore and tune via the EMU...

 

I have run into this here in CO with my AEM. I still need a ton more tuning especially closed loop partial boost. There is a lot of that going up mountain passes around here.

 

So yet another improvement project I'm thinking of but will likely not do-- Arduino build that corrects for this.

On MegaSquirts, you can have dual MAP sensors, one is just there on the board getting ambient (right term?) pressure so the software can make barometric corrections. I want to get an Arduino, dual MAP it, likely find the coding somewhere that needs some tweaks on the inputs, and send a 0-5v output to the EMU and Split Second--- thankfully both of them accept external MAP signals.

That way, it should be possible to have a 'MAP Sensor' as far as those two devices are concerned, feeding them, but its also smartly correcting for altitude adjustment.

 

finally mounted the emu behind kick panel and installed the map switch mod so I can switch between e85 and 91. Oh and ran the option 2 harness so with a quick solder the emu will get aem wideband input- with the emu this isn't just good for logging, but you can enable a closed loop air fuel target map in the emu as well*

* don't enable it in closed loop ranges, or you will have the battle of ECUs on your hands

Need energy to install ping led and sensor haha

 

So I'm a little scared my Greddy unit might suffer from an infamous flaw the earlier gen units had (though I really doubt mine is an early gen board), where the ignition chips desoldered over time due to vibrations. Two times now when I've really flogged on it off-road, where I'm on it about 50%+ throttle boosting, and then quickly let off, the engine will stall. One time it was because the vacuum hose popped off of the MAP sensor, but this time around I got an ignition CEL code- really weird. The EMU has a lot of sensor options such as offset settings for the crank sensor, so I think there is some playing around to be done to make transient ignition timing changes better...