do performance valve springs add hp or do they just raise rpm's?

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a vtec a day will keep the doctor away

They won't raise your rpms but perform better at higher rpms. You wont see and hp increase either. They may be a bit lighter than stock.....but thats about it.

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Apexi Boost Gauge, Apexi Meter Control Unit, RMR C/F Gauge Pod, Blitz Fatt DC III, Rexpeed Apex VG

high performance valve springs are part of a whole package that you should do all together. if you replace the valves, springs, and retainers, then yes, it will raise your redline( I assume thats what you meant by rpms) and in itself, you will see marginal or no hp gains, as the stock cams will choke out the motor at higher-than-stock RPMs. the power is found in high performance cams, hi-po valves, springs, and retainers, along with a computer mod that will allow you to move your rev limiter up to utilize the bigger cams. the springs are a means of making more power, not a power mod in themselves.

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Yes, there's a "Replacement for Displacement". Its called Volumetric Efficiency.