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Discussion Starter #1 (Edited)
Looking for some input on the GCC with the VPC.

I've heard good things about this combination. In fact, I guess many have ripped out their S-AFCs and other fuel controllers and switched to the GCC to solve lower than expected RWHP and electrical interference problems...each causing MAJOR tuning problems.

How many of the BPU and Singled Supras are running the combination?

I would appreciate any feedback!
 

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Discussion Starter #2
King:

Thanks for the feedback...

I saw your car at the CA canyon run and I thought you had a APEX S-AFC mounted to the right of your steering wheel????

Did you replace it with the GCC? Or are you talking about other cars.


Also, am I giving up USEABLE functionality by going with the GCC that the S-AFC offers?? Not sure if the other features are needed.

Thanks again and I'm glad it wasn't you in the wreak that was posted!!!!

Anyone else have any input on the GCC??
 

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I have the VPC/GCC combo. It worked out fine for me. If you only want 1 fuel map it should be fine. It only has 5 adjustment points, but I'm sure it will be enough for most any application.

After adjusting the general fuel curve level, my car needed only a bit of adjustment around the 3000-4000 rpm range. I just picked a setting where I had an adjustment setting at 3500 and added a bit of fuel. Works great.

I think the other controllers have memory for different fuel maps, and some monitoring features. Some people may have a leaner more aggressive setting for drag racing, and a richer setting for road racing. You could do the same thing with the VPC/GCC combo by turning up or down the overall VPC level knob.
 

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Discussion Starter #4
Kevin:

Thanks for the reply.

What do you mean by general fuel curve adjustment...is this the VPC settings?

What settings are you running on the VPC? I was told to put all knobs up for starters until I can get it on the dyno. Can you share how your car ran with the different VPC settings as you were tuning? I've heard that the VPC makes the car run richer at low end and leaner up top in general.

I have to wait a week for tuning so I'd like to make double sure that the all knobs up setting will be ok until tuned.

Anyone else have good results with the GCC over other fuel controllers??

Thanks for the input!!!!
 

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We used the level knob on the VPC to lower the entire fuel curve. (It was rich throughout the range) Then we only need to add a bit more fuel between 3000 and 4000 rpms. We raised the point at 3500 by 2%.

Does that make sense?
 

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Discussion Starter #6
Kevin:

Yes it does...

So the GAIN knob was used to lean out the bottom with the VPC and the GCC was used to richen the top since the VPC leans the top.

Thanks!!
 

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Hboostn97TT said:
Kevin:

Yes it does...

So the GAIN knob was used to lean out the bottom with the VPC and the GCC was used to richen the top since the VPC leans the top.

Thanks!!
Well basically the gain knob on the VPC is the course, overall adjustment. When you get the fuel close, you fine tune it with the GCC. Depending on where you need to add/subtract fuel, you may have to flip the dip switches in the back of the GCC.
 

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Discussion Starter #8
Kevin Hoare said:


Well basically the gain knob on the VPC is the course, overall adjustment. When you get the fuel close, you fine tune it with the GCC. Depending on where you need to add/subtract fuel, you may have to flip the dip switches in the back of the GCC.

Got it. I'm installing the VPC tomorrow if Fedex delivers a missing piece.

Where is GAIN knob (and other knobs) set at on your VPC? I think I should keepthe GAIN a bit richer than your location until I get a fuel computer/GCC...but I'm curious about the other knobs as well.

Did you have to change any of the dip switches located inside the VPC for your engine?

Do you have an EGT gauge? What temps are you running?


Thanks!!
 

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Just keep all the VPC settings are 12 o'clock until you get it tuned. It'll be fine.

I did have to change dip switch settings. Off hand I can't remember. I think it had something to do with the number of cylinders the car had.
 
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for me it doesn't make sense to lean out or rich up the curve below 4000rpm because our ecu has a learn process below 4000 rpm. that means even if you lean out below 4000 rpm the ecu rich up (set back) our setting to the original factory level and rich up all above 4000rpm. if you rich up below 4000 rpm, the ecu will lean up the curve starting at your setting point below 4000 rpm to the top end, that means you have not enough fuel at the top end. never make fuelcurve settings below 4000 rpm.
I'm also using a vpc together with a safc and I'm happy with it. I was discussing with dusty about changing the safc to a gcc but I don't see realy an advantage to do this, becaus you have much much more posibilities to set a fuel curve in an afc than in the gcc. on an safc you can set at each 500rpm from - up to +50 % the right fuelvalue, you can set the low and hightrottle starting points in %. no I'm also searching a pro who can tell me some advantages from the gcc to the safc for a bpu++ car.
thanks
markus
 

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Discussion Starter #11
Supra500:

Why were you discussing a switch with Dusty? Are you having any issues that brought this up?

I agree that it's nice to have bells and whistles...but not at the expense of the primary issue of getting the A/F dialed in for MAX RWHP.

The GCC smooths the curve between settings so in a sense it has more than just 5 set points.

If you want the Bells/Whistles get the OBDII monitoring tool or HKS monitoring display that attaches to the in-car diag. port and will log/display all vital car stats including injector duty, timing, etc. This is much more info. than the AFC will give you.

However, I am still considering the Fields unit because it has 3 MAP settings. Not sure if I will ever use 3 maps, but several people have 2 maps.... for road tracks and the other for racing.

But, you can accomplish the same thing with the twist of a few knobs on the GCC/VPC. So, the multiple maps almost becomes a moot point.

Plus the GCC attaches to the VPC with a single connector!!!

Has anyone had bad experiences or been unable to tune properly with a GCC!!!

Thanks for the feedback!
 
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