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S550 GT350R Race Car Build Build Thread Profile - S550 Mustangs

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..Engine harness has to be re-pinned to change firing order...

Wouldn't it be safer to remap the cylinder order in the ECU calibration? There are a bunch of things, like the knock sensor, that are programmed cylinder by cylinder. For instance, the FPC ECU knock subsystem expects firing on opposite banks every time, but the CPC firing order fires same side twice out of every 8 sparks. The results may be unpredictable.
 
Why not go with a dry sump oil system?


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Looked at that, but the GT4 dry sump system drives a lot of other changes due to package, including the Multimatic blade style front sway bar.

Wouldn't it be safer to remap the cylinder order in the ECU calibration? There are a bunch of things, like the knock sensor, that are programmed cylinder by cylinder. For instance, the FPC ECU knock subsystem expects firing on opposite banks every time, but the CPC firing order fires same side twice out of every 8 sparks. The results may be unpredictable.

I had the same thought, but firing order can't be changed via the ECU.
 
1,246
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...I had the same thought, but firing order can't be changed via the ECU.

I never fiddled with the firing order in my blown 2011 Mustang GT, but I did a lot of other fiddling with the ECU cal tables in SCT Pro Racer. I have the VIN-specific SCT tuning license for my GT350 (which I don't plan to ever touch) and one day when I was daydreaming about a CPC swap, I looked at the tables for firing order, and they're definitely there and they're editable. Maybe call SCT and ask them about it. Somebody must have done this by now.
 
I never fiddled with the firing order in my blown 2011 Mustang GT, but I did a lot of other fiddling with the ECU cal tables in SCT Pro Racer. I have the VIN-specific SCT tuning license for my GT350 (which I don't plan to ever touch) and one day when I was daydreaming about a CPC swap, I looked at the tables for firing order, and they're definitely there and they're editable. Maybe call SCT and ask them about it. Somebody must have done this by now.

Thanks. I will do some more investigation.....
 
Let me know if I can help with that. I’m about to place an order.
 
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This build is really coming along nicely and looks excellent! I’m curious what series and class you plan to run the car, and where?

Also, I’m curious why you’re opting to go through the laborious process of a crank swap now, rather than ringing it out as is and refreshing as needed? Apart from vibration, do you feel the FPC just isn’t up to task?
 
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Thanks. I will do some more investigation.....
It occurred to me later that you might have to do both - rewire the connector to actually change the firing order and change the ECU coding so it knows which cylinder fires when. It depends on what those tables actually do.
 
It occurred to me later that you might have to do both - rewire the connector to actually change the firing order and change the ECU coding so it knows which cylinder fires when. It depends on what those tables actually do.

KohR Motorsports converted my FPC Voodoo engine to CPC. I’m sure he can shed some light on how he did it.


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Have you decided if you will be installing it yourself?
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Haven't decided yet. I've always done my own, but this is a little more extensive.....

This build is really coming along nicely and looks excellent! I’m curious what series and class you plan to run the car, and where?

Likely NASA ST2. Depends on where I end up on weight.
 
Makes no sense why ford went to all the trouble of engineering the voodoo flat plane crank 5.2 and not use it in the GT4 and FP350S. They did win and race with the FPC on the GT350R-C


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DFW, TX
Makes no sense why ford went to all the trouble of engineering the voodoo flat plane crank 5.2 and not use it in the GT4 and FP350S. They did win and race with the FPC on the GT350R-C


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I thought the GT4 cars were restricted and the CPC makes more power in the reduced rpm range the restricted engine runs.

Are you doing this for similar reasons to stay under a HP class limit in NASA? Or some durability concern?

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I thought the GT4 cars were restricted and the CPC makes more power in the reduced rpm range the restricted engine runs.

Are you doing this for similar reasons to stay under a HP class limit in NASA? Or some durability concern?

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Yes they are restricted do the run the CPC and GT intake. It’s not because of durability. Before GT4 class the were FPC


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I want to know why they are not using the FPC.
The CPC in the 5.0 does not make anymore hp / tq at any given rpm over the FPC 5.2.
It makes no sense.
To me it’s either because of vibrations or aftermarket parts supply.
I’ve been bugging ATI balancers for nearly 2 years for a balancer and they keep saying nothing is available yet.
I contacted Holinger transmission and they will sell me a transmission that is used in the GT4 (RD6) but I must use either the GT4 flywheel or a custom flywheel that they said they can make and the Tilton clutch.
I’m not comfortable using a flywheel or balancer from a CPC on a FPC.
The GT4 uses a stock balancer by the way.


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The GT4 is limited by class regulations/BOP and makes just a little over 400hp. It doesn't even use the GT350 Intake.

The FPC is engineered as a total system to manage the unique characteristics of that engine, including damping in the clutch/flywheel, external Transmission damping and dampers behind the Cats.

I wasn't prepared to take the risk of major changes to that system that are unproven on a race car and wanted the option of using FP350S / GT4 powertrain parts a they become available. This also allows elimination of the weight associated with the unique FPC damping, and other engine mods that are cheap insurance for a dedicated race car. I have every expectation of having to tune out power to meet ST2 Power /Weight limits.
 
The GT4 is limited by class regulations/BOP and makes just a little over 400hp. It doesn't even use the GT350 Intake.

The FPC is engineered as a total system to manage the unique characteristics of that engine, including damping in the clutch/flywheel, external Transmission damping and dampers behind the Cats.

I wasn't prepared to take the risk of major changes to that system that are unproven on a race car and wanted the option of using FP350S / GT4 powertrain parts a they become available. This also allows elimination of the weight associated with the unique FPC damping, and other engine mods that are cheap insurance for a dedicated race car. I have every expectation of having to tune out power to meet ST2 Power /Weight limits.

Yes they really neutered it for GT-4. Basically a 5.2 coyote and not even making current coyote level power. It’s a shame. Prior to GT-4 they were still using the FPS 5.2


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You are sure right about all the dampening under these cars. I was amazed at the dampening on the transmission mount. It was heavy despite being aluminum. The dampers on the cats must weigh a bit too.
 

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