Toyota Celica GT/GT-S Tuning on the AEM Infinity

For a little change of pace I want to discuss the AEM Infinity retrofit we did on a customer’s Toyota Celica, what really prompted this change and the features of the AEM Infinity we implemented on this platform — as well as a few others that are available.

The Background

We had the customer’s car in the shop for a fair amount of time — installing the Monkey Wrench Racing turbo kit he had purchased with the engine management package. The turbo kit did require quite a bit of customization to fit, but we took care of all that and the car was ready to tune.

I spent a good 3 weeks on the stand alone ECU that was included with this package as I was never quite content with the drivability of the vehicle with the included engine management. I don’t want to name any names, but it is the “accepted go-to” EMS for this platform — with fairly hefty price tag (customer paid something like $1500 for it). Unfortunately it is not a very good EMS and is very dated — it’s comparable to running something like an AEM V1.

Did the car make power? Sure — it’s not hard to make power. However this EMS was plagued with random misfires and quite a bit of time was spent chasing the misfires (hardware, coil dwell, sync, etc) and eventually they became very rare — but not quite gone. When taking the car off the dyno and on the street no misfires were apparent — I’ll get into that more later.

After the car was off the dyno, I put in a week of street tuning for drivability — cold start, cold start driving, warm start, warm start driving, the works. The transient response that was achieved with this EMS was not remotely what I would call “great” — warm or cold. Many would consider it to be “acceptable”, but in my book if the car doesn’t put a smile on my face from the moment I fire it cold and tear off down the street without giving me weird moments of hesitation — it’s simple crap. Why? Because I work with dozens of different EMS and dozens of different platforms — I have a very intimate understanding of what “great” drives like.

And before people start questioning — yes, all the cold start, post start, throttle pump, throttle enrichment, delta tables were tuned, every single parameter that was exposed was tuned to try and improve overall drivability.

Finally we had no choice but to let the customer try the car out and see what he thinks — and we went in not at all happy with the results this EMS let us achieve.

So What Now?

Sure enough, he brought us the car back a week later as agreed to let us fit a much more modern and advanced EMS on the car — an AEM Infinity.

Before I go into the details of this EMS, let’s go into what we expect to be able to do with our EMS and how it compares to what the previous EMS (these are some basic features as this car was run at 10psi on wastegate — no boost control):


As can be seen, the basic features look quite similar (the AEM Infinity is capable of much more — including traction control and DBW), so why would the Infinity be so much “better”? Let’s look into a few bullet points.

The Misfire Issues

This is the most annoying part of the previous EMS — once we retrofitted the AEM Infinity on the vehicle, we did not experience a single misfire. The AEM was sync’d and tuned without experiencing a single misfire during the tuning session. This leads me to believe the previous EMS was having trigger sync issues and/or problems running the coils/injectors. The coils & injectors themselves were not a problem (and neither were the cam/crank sensor) as they all functioned perfectly on the AEM Infinity.

VVT-i Control

A picture is worth a thousand words. Yes it works with the AEM Infinity — just requires proper install & configuration. Not a “big deal” to get it working. And the feedback/control is completely adjustable.


Closed Loop Fuel Control

This was extremely lacking on the previous EMS — in fact I’ll go so far as to say it was completely junk. When you’re paying $1200 or more for an ECU you would expect a modern EMS to have wideband O2 control already without having to pay extra and depending on a narrowband O2 sensor — which amounts to slow feedback and inaccurate feedback (fueling swinging back and forth, etc).


As you can see, with the AEM I configured feedback well into boost (in fact the system is so fast and accurate you can run it full time on high boost applications as well).

The previous EMS? It simply didn’t have this ability — and I wouldn’t trust it using an analog input into the ECU. It’s not accurate and the EMS has no control over the O2 sensor directly (since it requires a separate controller) — so if the sensor has a fault the EMS would know. The AEM *does* control the O2 sensor and is very quick to detect a fault (from experience), and you can chose to put the ECU into protect mode if the sensor faults. Fantastic.

Knock Control

Two words: It works. Here’s a short clip from the street tuning session with the AEM while I was out touching up the car (IE: drivability adjustments, finding any spots it may knock with “real” load on the car on the street).


This is just a small glimpse at the control — we also have the option to enrich lambda during knock events and individual cylinder knock thresholds.


This was a real source of frustration with the previous EMS — 8 channels of datalogging (and not real time at that — you have to record and then view) is horrible. To use the term “unacceptable” is an understatement — the more data you have to view the better you can tune the EMS and you get a much better picture of what the EMS is doing if you have to do any diagnostics. Not enough data and you can be left chasing your tail — at the very least it takes up much more of your time as you’re stuck with scenarios of “oh I wish I had logged that parameter… but all 8 channels are already used..”.

The AEM lets you record everything. And the “on board” datalogging is expandable by the size of the USB drive you plug into it if you need “on board” datalogging. The fact an EMS company advertises “256K” of onboard datalogging is just laughable — that’s NOTHING and utterly useless (not enough data, or not enough data at meaningful refresh rates).


This was the biggest point of annoyance for anyone driving the car previous — the throttle response, transient response and drivability just wasn’t there with the previous EMS. Sure if you had a race car, you put your foot down and it worked fine. However with the new AEM Infinity installed and tuned (which I might add only took two days to fully tune on this vehicle — yes you read that right) the drivability of the vehicle soared to perfection.

No I’m not exaggerating — I could fire the car up cold or hot and stab the throttle immediately without any delay or hesitation. Off I went down the street to do further fine tuning.

The best part? I was able to deliver the car to my customer driving perfectly in every scenario. Awesome.

So What?

I guess what I can say about the faults of the old EMS lie in a couple of points.

  • Old outdated hardware.
  • Poor software — on the EMS and desktop (yes the software does matter).
  • The fuel film model in the EMS was basically non-existent or poorly modeled — this caused our drivability issues/concerns.

Does that EMS look good on paper? Mostly, yes. But looks and practice can be completely different things.

Why is this old EMS so popular? I think this mostly comes down to what select groups have learned and push adamantly on this platform — simply put they are stuck in their ways and either don’t know anything better or don’t want to try anything that could be better. It “works for them”, as I hear a lot.

However if you are looking for something better on this platform that can improve your vehicle — we have better options available that don’t break the bank.

jason_celica_aem copy

Deatschwerks DV2 1500cc Injector Review

Deatschwerks announced their DV2 line of injectors — 1200cc and 1500cc variants — not too long ago. I was fortunate to be one of the first to get the word about these injectors from DW and I was excited to get my hands on both sets to do some testing on my shop vehicle.

Foremost, I want to talk about the 1500cc variant — I’ll touch on the 1200cc set briefly later.

The test vehicle is a 2001 Honda S2000 powered by the F20C on an AEM Infinity stand alone. The fuel system is very simple — the OEM Honda fuel return system with completely stock fuel lines, with a Walbro 485 fuel pump in tank, an AEM FPR and AEM fuel rail sitting over the Deatschwerks DV2 1500cc injectors.

My goal? To make over 600whp (on a dyno that baselined 195whp for the car bone stock) with a Comp CT4x-5862 turbocharger.newmotor_20psi_pump_vs_24psi_e85

Mission? Accomplished. On E85 the vehicle put down over 600whp at 24psi and 525whp on 20psi running 92 octane pump gas.


That is fantastic power for a very simple setup — it’s a 2.0L bottom end with a 58mm turbo and only “drop in” fuel system upgrades (no plumbing new lines, etc).  The only fault in the fuel system is the high fuel pressure at idle — I’ll touch on that later — and the injectors have performed amazing nevertheless.

I am able to run a very wide range of power without swapping parts — no injector swaps, etc. The injectors DW supplied me have been more than plenty for my goal, with room to push to 700hp with a higher base pressure and a different pump/fuel line setup (the Walbro 485 doesn’t do so hot at high base pressures).

Unlike the 2200cc injectors we have been stuck with in the past if you wanted to do a 600whp+ flex fuel vehicle, the 1500’s don’t have the drivability nuances we’ve become so accustomed to — no insanely unstable idle due to the pops and misfires, no weird shuffling at light loads or on deceleration. Even on pump gas — where it is virtually impossible to get a set of 2200cc injectors to behave without running the vehicle at a super rich target lambda.

On E85 the 1500’s have a very slight pop at idle . On pump gas — they are a little “poppy”, but not so much that it deters from the idle or attracts unwanted attention to the car stop light to stop light. Much more than acceptable — they actually make the car very enjoyable to drive without having to put up with drivability nuances. In fact, whether it be on pump gas or E85 — squeezing the throttle rewards you with a smooth powerband, strong spool and very predictable power delivery without the odd “oops the motor missed” as you touched the throttle.

And if the biggest fault I can find with the 1500’s is that on deceleration in rare situations running pump gas I’d get some shuffle — I can easily blame it on the high fuel pressure at idle & low load. With the Walbro 485 in tank, the fuel volume is so massive the small factory return line can’t keep up when the engine doesn’t demand a lot of fuel — this increases the fuel pressure to over 70psi on this car, resulting in effectively a 1900cc injector in these situations. Yet — I was still able to fix the shuffling with a tuning trick, without going to the same extremes as a 2200cc injector.

Better yet — a fuel return line upgrade will bring the fuel pressure down to actual base pressure and clean up that behavior. This isn’t something I’m wanting to do on the car as I have not found it to be necessary — the drivability is fantastic and I just don’t want to change a thing at this point.

Short comment about the DV2 1200cc injectors: they are perfect. In every aspect. If you’re not looking for 600-700hp they’re a great choice as well. I made 575whp on E85 on the 1200’s squeezing them to 100% duty cycle.

Whatever you’re looking for — both injectors are fantastic and I would definitely recommend.  As with all the products I’ve tested and support, these injectors are on the VitTuned Store.