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Discussion Starter #1 (Edited)
Hello guys,

I'm actually trying to understand some things about our v6's. I previously got a CF1 GTV with a CF3 engine that was very very strong with a wide torque spread at all rpm. All the car was stock, from intake to map & exhaust. The benefit of being on a CF1 car is that the throttle body diameter was 80 mm. The previous owner, who did the engine swap, told me that the CF1 engine was not as strong (timing was OK).

Now i've got a CF2 engine with mods (squadra remap, 3.2 cams, 74,5 mm TB, ACT plenum, ELFP and decat) and it don't feel as torquey, except on the very end of the rev band (6k to 7.3k rpm). Is there any upgrade done to the CF3 engine to counterbalance new emissions regulations and the precat that would explain the big power gap when fitted in a CF1 engine and ECU ? I see that the pistons and head gaskets differs (or is it only the TS ?). Maybe the CF3 engine got more compression ? I know that only the cf2 cars got a DMF but does it make this much difference ?
 

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I can't answer the technical questions, but I can say that the difference between DMF and single mass flywheel is big. It's so much more willing to rev with the SMF, it really makes the engine 'zing', if you've had all the other mods done then it's well worth having the DMF to SMF conversion done, and an LSD (Q2 or Quaife) too, transforms the corner grip and how you can deploy the power.
 

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Discussion Starter #3
It's maybe the SMF effect indeed, + the throttle by cable which is very responsive. Of course, the timing is spot on onn my CF2 actually and the maf readings suggest a little more power than a OEM 3.2 V6. I will probably go for an AHM lightweight flywheel ASAP.
 

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Hello guys,

I'm actually trying to understand some things about our v6's. I previously got a CF1 GTV with a CF3 engine that was very very strong with a wide torque spread at all rpm. All the car was stock, from intake to map & exhaust. The benefit of being on a CF1 car is that the throttle body diameter was 80 mm. The previous owner, who did the engine swap, told me that the CF1 engine was not as strong (timing was OK).

Now i've got a CF2 engine with mods (squadra remap, 3.2 cams, 74,5 mm TB, ACT plenum, ELFP and decat) and it don't feel as torquey, except on the very end of the rev band (6k to 7.3k rpm). Is there any upgrade done to the CF3 engine to counterbalance new emissions regulations and the precat that would explain the big power gap when fitted in a CF1 engine and ECU ? I see that the pistons and head gaskets differs (or is it only the TS ?). Maybe the CF3 engine got more compression ? I know that only the cf2 cars got a DMF but does it make this much difference ?
I know this is an older post however can you explain a bit more on your previous GTV as you quote had the CF3 engine I am assuming still 3.0 not a 3.2 however had the benefit of 80mm throttle body. So are you saying you combined the CF1 Plenum etc with later engine?
 

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Discussion Starter #5
Yup, exactly. CF1 plenum and ECU with CF3 engine. It seems like the CF1 plenum as a longer throat behind the TB.
 

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This has me thinking, would a CF1 plenum with a Cayenne Throttle body perhaps be the answer? Larger plenum intake as you say 80mm , The CF2/3 plenum is 72mm. Some people have used the Ferrari F360 throttle body on CF2/3 as is 75mm. Porsche Cayenne 78mm throttle body can be bought fro a fraction of the more traditionally used F360 throttle body. It is still plug and play. I also think a F430 Also works but is more expensive again.

I had an adapter made for me by Totally Alfa with a taper from 78 to 72. However was not convinced this done what I had hoped. Will try back to back testing next summer on Dyno. I can see a similar adapter could be made with a taper 78mm to 80mm.

Only thing is I suspect the smaller opening on Plenum may have been done for emission control rather than performance. I also need to think about how air flow rate, velocity would work. Most of all if would fit? Not sure if vacume pipes etc all the same? Pics of mine with Cayenne TB and below is a CF1 engine picture from Google. Looks like it would be very tight with coolant tank however is angled more than CF2 so possibly?
930165
930166
 

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Discussion Starter #7
I switched to an 78 mm TB. On the OEM plenum, with throat enlarges : no difference.
On the carbon plenum act : huge difference.
I still don't have the low end grunt of the CF1, but the high end is enormous now, with 268 hp on last test. I saw that the dual mass flywheel weigh a LOT and reduce greatly wheel hp. It's maybe just that, like someone said earlier. I'm waiting fir my clutch to go to swap a 3.2 flywheel that i bought
 

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Discussion Starter #8
I switched to an 78 mm TB. On the OEM plenum, with throat enlarges : no difference.
On the carbon plenum act : huge difference.
I still don't have the low end grunt of the CF1, but the high end is enormous now, with 268 hp on last test. I saw that the dual mass flywheel weigh a LOT and reduce greatly wheel hp. It's maybe just that, like someone said earlier. I'm waiting fir my clutch to go to swap a 3.2 flywheel that i bought. I recently tested a 3.2 147 GTA stock, so maybe 250 hp and it felt like my GTV from 3k rpm. The only difference besides cc, is indeed the flywheel
 

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It was interesting that the Conrero Challenge was also a CF1 intake. I do wonder if the volume of the Plenum on the CF1 Plenum as actually larger than the CF2 onwards. I suspect reduced just due to emissions. I am assuming your ACT plenum has a larger volume than the standard one. It would be interesting to know internal volumes of each. Interesting as the increasing throat diameter as you did alone did not improve, thus conclusion must be power improvement is due in some way to volume of plenum.
22BA7F53-8271-4ADA-B177-182F587FE07C.jpeg
930174
 

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Discussion Starter #10
The OEM cf2/cf3 plenum is given for 2.5L. The ACT is measured at 3.5L.
The CF1 management in France is also known to give 5 more bhp than the others, but with the squadra remap, they all lines up together normally. Maybe my CF1 was also chipped (it was as strong as the 147 GTA i tested at low rpm, maybe a bit more).
CF1 flywheel are in fact the lighters of them, with only 6 kg compared to the 8 kg from 3.2, 8.7 kg from the 2.5, and the 14 kg of the CF2.
 

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Discussion Starter #12
Yes, it is very well made on this aspect, and that explain probably a good part of the gains seens.
 
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