Valve float 52-5300 rpm. Than no issue.
08-01-2012, 08:44 AM
#1
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Valve float 52-5300 rpm. Than no issue. Got my car tuned on Sunday. There is an issue at around 5200 ish it sounds/acts like valve float then seems to push through it and rev on up just fine.
Tuner said everything was perfect. 11.4-11.9 A/F, 18-20 deg timing. Never did anything funny until that 1 rpm. He had also mentioned there were issues with harmonics that at 1 rpm or (pitch) they can act like a guitar string plucked to hard and almost go flimsy for a second than the pitch or rpm changes and it can handle the load again.
I just always assumed if the springs couldnt handle the load they couldnt handle it past a certain psi or rpm. Not just miss for a second and keep going no issues.
I figured the LS9 springs would hold 10-11 psi seeing how a zr1 gets 10 psi stock. I already have some Patriot Duals for it I was really just wondered if anyone else has experienced something similar. I am worried changing the springs may not fix it.
Tuner said everything was perfect. 11.4-11.9 A/F, 18-20 deg timing. Never did anything funny until that 1 rpm. He had also mentioned there were issues with harmonics that at 1 rpm or (pitch) they can act like a guitar string plucked to hard and almost go flimsy for a second than the pitch or rpm changes and it can handle the load again.
I just always assumed if the springs couldnt handle the load they couldnt handle it past a certain psi or rpm. Not just miss for a second and keep going no issues.
I figured the LS9 springs would hold 10-11 psi seeing how a zr1 gets 10 psi stock. I already have some Patriot Duals for it I was really just wondered if anyone else has experienced something similar. I am worried changing the springs may not fix it.
08-01-2012, 11:31 AM
#5
OP to answer your question, yes what you are experiencing is a very real situation. We list the frequencies in our catalog for a reason. Every engine at ceritian RPM's create a frequency. the object is to find a spring who's natural frequency is outside of the main operating frequency of the engine while maintianing correct loads and rates to control the valves.
Switching to a different spring will solve your issue. Now what spring you want to run is your choice.
Switching to a different spring will solve your issue. Now what spring you want to run is your choice.
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08-01-2012, 02:28 PM
#8
FormerVendor
08-01-2012, 02:43 PM
#9
Won't know till you try. if you have different rockers, heads, pushrods, lifters, motor mounts, drive shaft, transmissions ect, ect, you may not get it or you may get it at a different RPM.
