I have a 2.3 that i built for a street car and have a 2.3 with bc280's. Supporting mods include stage 4 head, 1mm o/s valves, si double ti springs and retainers, balanced rotating assembly, Magnus SMIM, rewired wally 255, etc, etc,etc. I had put a FP3065 with FP race manifold and changed my setup to a new FP 3582HTA with a T3 SLS exhaust manifold and .82 v band a/r with FIC 1050's. I am running pump with meth and am shooting for low 11's and 550+ AWHP on pump with meth. Car will be street driven, not a daily, but not a trailer queen either. Any advice on which is a better cam to go with? If i forgot to add any other necessary info on my build, please let me know.
Thanks,
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I run the 3x's. I believe you will have better results with the 3x's. As for mine, my car idles like stock at 800 rpm with the BS eliminated so these can be used for all types of set ups.
I run a 4G64 bottom end with BC280s. I run the same valve train you do. It is VERY lumpy idling anywhere below 1K. I really like the 280s, but I have considered switching to the FP3X's. If you decide to commit to the FP cams, you will need to swap your springs and retainers for FP's package. The SI's do not have enough seat or open pressure to run the FP 3X's.
I run a 4G64 bottom end with BC280s. I run the same valve train you do. It is VERY lumpy idling anywhere below 1K. I really like the 280s, but I have considered switching to the FP3X's. If you decide to commit to the FP cams, you will need to swap your springs and retainers for FP's package. The SI's do not have enough seat or open pressure to run the FP 3X's.
The SI ti double springs won't work with the FP3's?
The SI ti double springs won't work with the FP3's?
The SIs are not stout enough for the cam profile. FP recommends using nothing but their springs, however I believe there have been a few members using other spring packages that match or are above the spring pressures of the FP set.
has anyone used the si doubles with FP3X's with good success?
Maybe you should consider the application:
SI dual valve springs
80 psi on the seat
190 psi @10mm lift
14mm max lift
19mm coil bind
FP3X camshafts:
Be sure to install your springs with 280+lb over the nose. This camshaft has the highest valve acceleration that is allowable with our dual valve springs.
Intake cam lift on the 3X is .430". Now, at .430" lift (=10.92mm) FP recommends valve spring pressure @ 280psi +. If you do the math, SI duals @ 10mm of lift are only @ 190psi. If you consider the spring rate of the SI duals (11lbs/mm), @ 10.92mm of lift the SI duals would be @ 200.12psi. You are about 80psi under the recommended spring pressure @ max valve lift.
^^^ Thank you for the above information. When spelled out like that, it is very obvious that they will not work together well. Guess i will have to wait a while before proceeding with the cam upgrade.
