Basic VPC Tuning Knowledge Needed

[Loewen21]

Hey guys, so my car came with a vpc and gcc combo already installed. So i'm wondering basically what everything does exactly in regards to the response, gain, and output knobs on the VPC. The idle is pretty self explanatory but if anyone could tell me exactly what these adjust to help me tune that would be great thanks alot guys.

[spinz4]

Set response to max and the gain helps you lean or richen the car up but since you have the gcc you can use that. Have you thought about going to HKS's site and reading a little? I would think that the instructions are still on their site. If not I have a set from a while ago that I could scan in and upload.

[Big Woo]

I would also suggest checking the HKS site, and downloading the manuals for both the VPC & GCC if possible. In the mean time I will look and see if I still have copies laying around.

The GCC is like a graphic equalizer for the fuel curve. If memory serves me correctly, it adjusts the fuel + or - 20% or so, at each of the specified (labeled) RPM levels.

The VPC converts the stock MAF (mass air flow) air measurement system to a speed dencity air measurement system. Again if menory serves me here the responce knob adjusts throttle tip in. This changes the rates and points at which fuel enrichment or leanment (sorry that is not a word) occur in relationship to the throttle. The output knob has to do with using other HKS products in conjuction with the VPC like the F-con or AIC. The idle knob adjusts the fuel curve up (I think) 1500 RPM or so. The Gain knob does the same but from where the idle knob stops and above.

I am just going from memory here so I would not suggest playing with things until you have a good understanding of exactly what each knob does. A wide band O2 sensor will help you greatly with tuning. Like I said above I will look and see if I still have either of these manuals around.

[Loewen21]

Ok great thanks alot guys. So what i'm understanding here is response does basically what it says and adjust throttle responsiveness?? And gain is for basically controlling your fuel during cruising and not at WOT while the GCC is for controlling fuel at WOT??

[b00stedAWD]

Not sure if you are still needing this information. Gain works in conjunction with response knob. Example: if you are needing quicker response time when tip in then you'll to go positive but if you need less fuel then you'll decrease the Gain vise versa..When I was using VPC with HKS AFR I had my gain -2 and my response -6. This prevented my car from falling flat between shifts.

[Slo TSI]

I just got the vpc/gcc combo in a car I purchased. Does anyone have the manuals for this setup. I tried on HKS USA Driving Performance - Homepage and it isn't available.

[turboglenn]

Here' a link to VPC info
VPC Instructions

I couldn't find a link to the GCC instructions