[Wyteboii86]

So I have a fully forged 392 3.0 whipple with nsr cam and 2 inch lth. Making about 6-7lb right now with stock damper and 3.5 pulley. Thinking about going with the 18 percent over damper but got 2 concerns. 1. How much more boost will that make, I want to to around 10-12. And 2, will running an overdrive pulley give me more boost but also Rob me of power because of running the AC compressor and water pump harder? Would it be more efficient to go with a 6 percent overdrive and smaller blower pulley?

 

[MXS67454]

So I have a fully forged 392 3.0 whipple with nsr cam and 2 inch lth. Making about 6-7lb right now with stock damper and 3.5 pulley. Thinking about going with the 18 percent over damper but got 2 concerns. 1. How much more boost will that make, I want to to around 10-12. And 2, will running an overdrive pulley give me more boost but also Rob me of power because of running the AC compressor and water pump harder? Would it be more efficient to go with a 6 percent overdrive and smaller blower pulley?

Off the top of my head I don’t think you can get to 12 PSI with a 6% OD and a 3.5 . If it were my car I would use the 18 and then you would need a pulley larger than the 3.5 to get the boost down where you want it. either way the 3.5 will have to go. with the 18 and say a 4.0+ you’ll have much better belt wrap and much less chance of belt slip than the 6% and say a 3.0 or 3.25.maybe Whipple can help ?.. I’m not familiar.. does the 3.0 have dedicated drive ?

 

[Wyteboii86]

Off the top of my head I don’t think you can get to 12 PSI with a 6% OD and a 3.5 . If it were my car I would use the 18 and then you would need a pulley larger than the 3.5 to get the boost down where you want it. either way the 3.5 will have to go. with the 18 and say a 4.0+ you’ll have much better belt wrap and much less chance of belt slip than the 6% and say a 3.0 or 3.25.maybe Whipple can help ?.. I’m not familiar.. does the 3.0 have dedicated drive ?

Actually I only made 5.8lb earlier when it was 95, maybe 150 Iat. and tonight it made 6.4 pounds when 81 out, 125 degrees iat. Hhp told me the 18 percent will give me about 3lb gain. So Thai alone would put me at about 9-10lb. Plus a 3.25 pulley would bring me up 2lb more. No it's all one single belt. I ordered a 18 percent over damper and a 3.25 griptec pulley so I'll see what my tuner what's to try first.

 

[MXS67454]

Actually I only made 5.8lb earlier when it was 95, maybe 150 Iat. and tonight it made 6.4 pounds when 81 out, 125 degrees iat. Hhp told me the 18 percent will give me about 3lb gain. So Thai alone would put me at about 9-10lb. Plus a 3.25 pulley would bring me up 2lb more. No it's all one single belt. I ordered a 18 percent over damper and a 3.25 griptec pulley so I'll see what my tuner what's to try first.

Well my guess was way off…with the 18% being almost 1.5 inch bigger than stock I would have guessed it way more than a 3PSI gain .all combos are different but with an 18% and a 3.4 on a D1X I’m making 14 PSI @6400 on my Scat .

 

[Wyteboii86]

Well my guess was way off…with the 18% being almost 1.5 inch bigger than stock I would have guessed it way more than a 3PSI gain .all combos are different but with an 18% and a 3.4 on a D1X I’m making 14 PSI @6400 on my Scat .

Nice, on pump gas? What kinda power?

 

[MXS67454]

Nice, on pump gas? What kinda power?

Yes on 93 . 755 whp… 9.5 comp HC short block . FI cam and stock heads etc. nothing special . hindsight.. I wished I had done my 392 @10.5 comp rather than what I have . coulda, shoulda …

 

[Wyteboii86]

Nice. Stock trans? I wanted to do the 392 so the badges don't lie when I beat people lol.

 

[MXS67454]

Nice. Stock trans? I wanted to do the 392 so the badges don't lie when I beat people lol.

Built trans ..the mods were originally done in 2017 before trans tuning was available . I could write a book on the random problems I chased for 18 mo before finally figuring out I had a corrupt Diablosport PCM . here’s one example.
driving down road @70 mph on cruise or foot when the car was coasting or no power needed situation it would come out of gear and go to idle and then go back to normal in gear when power was needed to maintain road speed all without a setting any codes . without the PCM problems I would probably not have a built trans today.

 

[Wyteboii86]

Built trans ..the mods were originally done in 2017 before trans tuning was available . I could write a book on the random problems I chased for 18 mo before finally figuring out I had a corrupt Diablosport PCM . here’s one example.
driving down road @70 mph on cruise or foot when the car was coasting or no power needed situation it would come out of gear and go to idle and then go back to normal in gear when power was needed to maintain road speed all without a setting any codes . without the PCM problems I would probably not have a built trans today.

So I put 18 percent lower on but didn't change the upper yet, making 9.7 now with iat at 120-130. Not sure if I'll make too much for my fuel pump if I go up 2more psi.