Valve spring suggestions

[TurboTdr3.8]

PAC-1201
1.260
0.860
Yes
0.770
140
@
1.750
437
@
1.200
540
1.115
0.550
NA
PAC-R349
NA
NA
Small diameter to fit stock SBC pocket without machining.
PAC-R649
Single Spring with a Damper. High rate for aggressive cam.
PAC-1201X
1.260
0.860
Yes
0.770
150
@
1.750
460
@
1.200
540
1.115
0.550
NA
PAC-R349
NA
NA
Additional RPM Processing to allow for Extreme Use and
PAC-R649
Endurance over Traditional PAC-1201 spring

 

[Pronto]

The 1201x looks like the one to go with. Thanks everyone!

 

[Pronto]

Springs installed. Now pulls cleanly to 6000+. Solved that issue but still have the knock spike at about 5100. Going to try swapping the ECS next.

 

[cstavro]

Why no love for the beehive?

Where are your hp/torque peaks? Do you have a dyno graph?

Do you believe the sensor is picking up false knock, or some other mechanical noise? What is the rpm band where you detect knock? Is it intermittent, or does it appear every time?

 

[Pronto]

We believe it's false. Plenty of octane, fuel pressure, good tune, nothing hitting, knock sensor torqued correctly, etc, etc. Comes on pretty consistently at about 5100 or so and spikes to 14 then decays even as rpms keep going. No other knock is detected. Pulls clean and hard. No dyno yet. We are looking at the chip and any internal mechanical possibilities first and then dyno.

 

[Dreamn4GN]

Sorry to hijack but sheesh, a lot goes into choosing a valve spring, more than I ever thought. Any recommendations for an all stock motor? Looking to put new springs in mine over the winter. Again sorry for the hijack. TIA

 

[larrym]

Comp 980

 

[ZNix]

Comp 980

*installed at the correct seat pressure using shims if necessary.