General HKS VPC/GCC Tuning

[flybyricer]

Ok I have ready everywhere and probley missed this so sorry if this has been answered. I have vpc 550 chip and gcc combo running 660's. What should I be shooting for inj pulse width. I have heard it should be around 13 give or take 1 or so. I am getting like 12-18 knock when I get it around that though. In order to not get much not I am using the gain nob almost all the way over and gcc rich all the way. Power is ass at this setting and my inj pulse width is like 19+. I have my reasponse knobe turned to the right almost all the way in order to keep knock down. Any ideas here I am a newb sorry so to flame to hard

 

[1LE]

Response seems to end up at about 3 o'clock, give or take a click or 2 on 1g's (1g goes fairly lean on tip in and this compensates). 2g is exactly opposite, goes bigtime rich on tip-in...

The GCC should be set to all 0 to begin with. Just use it to fine tune settings (unless you're QUITE sure you know it should be different). If you're trying to run the car off of it, you will get some weird results.

Which way do you have the gain turned? Running a VPC w/550 chip on a 660 equipped car, my "guesses" would be that if your car is fairly stock (internally) that you'd end up way on the lean side of the gain and would probably have to subtract a little more across the full GCC range. A modified engine might result in a gain near 0 with GCC settings near 0 as well.

My recommendation is that you get a 660 chip for your VPC and *then* try tuning it with the gain first (and GCC zeroed), then use the GCC to fine tune the RPM ranges... The fact that the VPC chip does not match the injector sizes *may* be screwing with your injector pulse width readings. With a proper match, you should be able to ignore that and tune on knock/timing...

Of course, all my experience is on my 6-bolt 2g, so YMMV, FWIW, and if it blows up it's not my fault

 

[Merciless]

I was told that there is no 660 chip for a VPC.
Where can I find one?

 

[1LE]

Well, there *was* They're no longer made (like most of the VPC components). Buschur used to have some, but it's not listed on his website anymore. Wouldn't hurt to call him though.