Hello,

My tuner, who's been in the business for quite some time and has a lot of experience w/ Honda engines is telling me something I want to confirm.

I have a comptech sc installed with the esm.

However, he is telling me my setup cannot be tuned with the Apexi VAFC I bought a year ago because of the comptech ESM. He says as long as I have the comptech ESM installed, the VAFC will not work since the esm is already doing fuel management. Does this make sense or do I need to take my car somewhere else?

Any and all help is greatly appreciated.

Thank You,

PJ

 

The ESM is a Voltage clamp. It stops any MAP sensor voltage reading above 2.93V from going to the PCM. If the Stock PCM see's more than approx 2.93V, It has a nasty tendancy to go into limp-mode or backup. The computer allows the engine to run, But not very well. No VTEC, revs are cut at 5000. The VAFC manipulates the MAP sersor voltage to add or remove fuel. Therefore, if you add fuel with a VAFC in boost, (a voltage over 2.93) the PCM goes into backup. The VAFC negates the ESM. Seeing that most FI applications need to add fuel, A VAFC is pretty much worthless.

The ESM is not a fuel management device. It does not add fuel in boost, The Comptech FMU does.

 

Thanks for the reply Slows2k...

I guess I will have the VAFC removed and buy something else...

Much appreciated.

 

An Emanage or AEM EMS are 2 options. If you have the budget for it, Go with the EMS.

 

Yeah, I've been reading about the AEM system, but I'm not ready to spend that kinda cash plus tuning charges as I am not capable to do it myself.

Oh well... thanks again.

 

another option is microtech
www.microtechefi.com

If you are really short of cash, you can remove the comptech ems, and get the vortech blackboxes to work with your vafc. You will need to get the software for the timing box to monitor the timing

 

The AEM would have to be the cheapest/best value full replacement ECU. The plug and play ability will save loads of headaches as will the base maps. Microtech and Motec solutions are great, but the physical install alone will be much more involved than the AEM.

It's not wise to cut corners but if you're prepared to purchase the E-manage and have it tuned this is a much better solution than the VAFC. it'll drive the injectors directly and can control timing and isn't much more than a V-AFC.

 

The only diference between the Comptech and Vortech ESM's are the Voltage clamp level settings. The Compech is actually an adjustable unit, but not reccomended by Comptech. The Vortech timing controller is made by Split Second. It is not an off the shelf FTC1, but a custom unit spec'd for Vortech. It is a effective timing retard device, but doesn't control fuel. It has a internal MAP sensor that is used to retard timing based on boost and RPM.

As far as lowering the MAP Voltage Clamp setting to the Vortech Level of 2.79V gives you .14V to adjust with a VAFC. Decreasing the MAP voltage also moves the timing more advanced. This still gives you no control adding fuel in boost. Most SC owners need to add fuel. The Comptech FMU does have an adjustable static fuel pressure. This changes AF ratio over the entire rev range. You are limited to how far you can adjust static fuel pressure. I believe 55 psi is the max reccomended pressure.

I let you decide on lowering the MAP clamp voltage and adding a VAFC. I don't reccomend it, Neither to a few others on the board. I'm betting we'll hear from Aus2000 before it's all over.

Edited for accuracy

 

Way ahead of ya!!

If you want to know about VAFCs with SCs just ask Honda9krpm. And don't forget to ask how his engine rebuild is going!

 

Hey Aus, It took me a while to type all of that!