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HKS F-Con V Pro on JDM MK4 Supra Twin Turbo

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Hi Guys.

I am a newbie on here from South Africa with a MK4 Supra which I imported from Japan. Apologies for the long post.

I have been planning to map the car, but with these cars not being sold here, info/support is not easy to come by that is relative to my situation.

Given my location, we only have 95 octane fuel. We do get 98 race fuel and octane boosters, some local stuff is being used by the VAG community with good success.

My car is a JDM JZA80 RZ, BPU spec, 6 Speed, running on stock turbos.

Car is running 1.2 bar boost with a EVC6 and Gen2 Knock amp installed and all related mods.

I am planning to fit the HKS F-Con mainly because it is plug and play to my car, will link to my AFK Knock amp, I have the plug and play harness already, and running it in piggy back will keep the control of the sequential turbos, fuel pump ecu, A/C, power steering etc.

Previously HKS did not release the software with the F-Con, they are now doing so with the 3.4 & 4.0 version. See link below.


My plan for fitting the F-Con is to get the running properly on 95 & add map for high octane.

The mapper I am talking to is quite knowledgeable, taking advantage of HKS releasing the software with the 3.4 & 4.0, I can map the car locally. Hope fully once I finish the course on here I can map it myself!

My questions are:

1. Do I need to keep the Greddy BCC and SLD fitted or does the V-Pro have the functionality built in like the F-Con iS?

2. Will the 3.4 version suffice for the Supra? Are any of the newer features of the 4.0 worth having over the cost of the unit?

I know that this ECU is not popular on here, if anyone can help with this, would appreciate it.

3. Will I need the Optional pressure sensor & intake air temp or can the V Pro utilise the OEM Sensors?

The JDM has OEM sensors, will the VPro work with it?

I don't plan on changing the turbos anytime soon, so boost levels will be around 1.3bar max.

4. Should the Knock retard feature be activated? Some reputable ppl say not to as the Knock amp is finicky to set up correctly and the

OEM sensors don't detect knock very well being older tech.

5. The version 4.0 write up says "A/F & knocking measurement are added". Does this mean it does not have to go via the knock amp and the sensors can be connected directly to the unit? Are the factory knock sensors not functional?

6. Does anyone know if the Power writer on the newer versions is offered in English? I have emailed HKS, no response as yet.

7. Does the stock TRAC system still remain in place?

I do know that the F-COn is not the best choice for a modern car, but for the plug and play functionality on my old jalopy it makes it a simpler option.

Appreciate any help that can be given, apologies if some of the questions are trivial, I am new to the tuning world.

Thanks in advance.

I was an HKS pro dealer for about 5 years and dealt with my share of FCON V Pro ECUs, although admittedly the 3.2 and 3.3 versions. My single biggest issues with them was that the software wasn't available except to pro dealers (sounds like they've seen the light here) and that their tech support was beyond terrible - I highly doubt that has improved.

Compared to most current standalone ECUs, the V Pro (3.2 and 3.3) was clunky and awkward in its configuration and tuning. You could get good results but it was time consuming. In a piggy back installation (as most of these ECUs are installed), you also didn't have full control since the factory ECU was still controlling idle speed, fuel pump control, and dbw throttle where applicable. This caused some trouble with CEL's on later model cars due to aspects like STFT maxing out in one direction at idle.

The AF Knock amp in my personal opinion was a very poor product. I wasted a bunch of time with this product when it came out and found it to be next to useless. The knock detection was terrible, and the AFR reading was about 10% different to my Motec PLM. I spoke to HKS at length and got nowhere. About 18 months later they released the AF Knock Amp 2 and my HKS rep told me "Ah yes, AF Knock Amp verrrry bad product" - No jokes! Understandably I wasn't excited about the prospects of the AFK 2...

So in short, yes the V Pro will run your engine. I'd be suspicious of the knock retard function and make sure you confirm that it can detect knock and act on that information rather than relying on it. Provided you're not exceeding the scale of the stock MAP sensor, you can use it with the FCON. Likewise the FCON is compatible with any IAT sensor so if you have one, you don't need the HKS sensor.

At least with the 3.3 model you still needed a SLD. I can't speak for 3.4 or 4.0. The FCON deals with the boost cut though.

I had an english version of power writer for v 3.2/3.3 so I'd assume the same is available for the later versions. The stock traction control system won't function with the FCON.

Hi Andre.

Thanks a mill for your response.. I needed this kind of info to help with the decision.

Regarding the OEM ECU still controlling most aspects, with my novice skill & my tuners limited experience with F-CON, I actually view this as a good point. For a seasoned tuner like yourself, I can see why you would view the opposite.

Regarding the knock amp, I tend to agree on the knock side, I found it impossible to setup, it gives me knock in situations which it should not, eg. light throttle with high octane fuel and is inconsistent. I will check with the mapper if he has proper knock detection equipment before deciding. I am looking at investing in equipment as well.

The AFR side of it should be fine, it uses the Bosch UEGO sensor. Feedback from the US supra community is the AFR side works very well.

The MAP sensor is not too expensive, I may decide to fit it anyway rather than have issues with the install.

For the OEM Trac system, why does it not function? I thought that with the OEM ECU in place, the F-CON "fools" it and only take control of the fuel & ignition.

I will do some more research before making my final decision, but thanks for the help.