HKS VPC to replace factory AMS/AFM

[JeffHarper]

Has anyone ever tried a HKS VPC to improve the air flow control?

VPC (Vein Pressure Converter)
This device allows the removal of the stock air-mass sensor. It simulates the signal that the air-mass sensor normally supplies the computer. It uses standard speed-density measurements to determine (estimate) the air mass being consumed. Speed-density works by factoring together engine RPM and manifold pressure. Barometric pressure and ambient air temperature also also fudged into the final calculation. The calculations are highly dependent on the volumetric efficiency of the motor. For this reason, the VPC needs to be "tuned" differently for engines that have different levels of modifications. Many people report that low speed operation and idle quality is adversely effected. While this is not always the case, it is an indication of the fact that this device isn't a "plug n' play" solution. Once the VPC is tuned to provide a reasonable facsimile of the signals that the stock Airflow Sensor previously provided, the major advantage of the VPC becomes apparent. The elimination of the stock (restrictive) air-mass sensor increases incoming airflow capacity substantially. It is credited with providing very substantial horsepower increases mainly by virtue of the reduced intake restriction. Some advantage is also attributable to the fact that the air-fuel mixture can be easily changed with the front panel controls. Supposedly, the output signals from the VPC are held within a range that won't cause the ECU to fall into a fuel-cutoff mode. (A few people report that fuel cut problems still exist however - despite their best efforts to cure them)



http://www.rit.edu/~sjb2096/dsminfo_pages/hks_vpc_manual.pdf

http://www.rit.edu/~sjb2096/dsminfo_pages/vpc-gcc.html


http://www.taboospeedshop.com/VPC.htm

It sure seems to have some potential.

 

[Zuffen]

Jeff,

Looks like you have everyone buggered on this thread.

We all need to do some reading then throw our 2cents worth in.

 

[JeffHarper]

Mmm I am trying to suss out if HKS actually made a kit for the 1UZ JDM version at all! or if they have a suggestion, except its Japanese festive time and everyone is shut in Japan.

 

[JeffHarper]

The way I see it, using this will allow bigger injectors with standard ECU.

 

[elhsupra]

This was fairly common with the Mk III/IV Supras. Have heard that HKS has discontinued it. Try this for some reading, applies to MkIII turbo but has the same type Karmann Vortex AFM. Select Engine mods then Fuel.
http://oldschool.supracentral.com/

 

[bloodypulp]

you can do basically the same thing with Greddy's E-manage, and then some.

 

[JeffHarper]

On a 1UZ? Have you done that, or seen it done?

 

[bloodypulp]

i've done it to 2uz. wiring is a little different between models, but it will work. it is a piggyback/interceptor and requires the original ecm though.

 

[manny]

The original question still stands - anyone know of anyone who has fitted a VPC to a 1UZ, particularly on a stock ECU?
Bigger injectors aren't a major issue for a NA 1UZ as the stock injectors have been proven more than adequate even in a low boost S/C'd 1UZ.
But the original questions still stands, will a VPC work on a 1UZ in an SC400 to allow eliminationl of the AFM for say fitting some ITBs, assuming the IAT sensor is relocated?

 

[SCV8]

That would be nice to know, haev been thinking about this for awhile as well.
I noticed in the hard-to-read, translated manuals for the Apexi fuel controllers that it may be possible to use a map sensor with that system, but who knows.
There's a company I've dealt with before called SplitSecond (splitsec.com) that makes devices to do this and that, you might try them too.

 

[Lextreme II]

I have splitsecond and SC400T will have it too.... SS can make either AFM or MAP...