What Springs?
05-31-2008, 03:35 PM
#3
I would use the PAC 1218. PAC used to make spring for comp until comp switched and has been having trouble ever since. I have the PAC 1218 for $155 delivered. This is the comp 918 equivelant. pm me if your interested, I also have the 1518 which is good to .650 lift, same beehive style drop in spring, nitrided for added strength, true drop in no need to replace seats and seals.
06-01-2008, 02:02 AM
#7
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I would use the PAC 1218. PAC used to make spring for comp until comp switched and has been having trouble ever since. I have the PAC 1218 for $155 delivered. This is the comp 918 equivelant. pm me if your interested, I also have the 1518 which is good to .650 lift, same beehive style drop in spring, nitrided for added strength, true drop in no need to replace seats and seals.
I agree, either the 1218s or the 1518s by PAC. Trending Topics
06-01-2008, 10:17 AM
#10
:
The beehive design has a few advantages over a standard style spring. The smaller coils at the top allow for a very light retainer. The steel retainer for a beehive spring is about half the weight of a standard steel retainer. The beehive springs are resistant to harmonics due to the fact that the coils have different outside diameters and the wire is oval and not round.
The smaller coils at the top also allow the valve train to start moving easier and gain lbs per inch of lift at a much greater rate. This allows for greater control of the valve train.
The beehive design has a few advantages over a standard style spring. The smaller coils at the top allow for a very light retainer. The steel retainer for a beehive spring is about half the weight of a standard steel retainer. The beehive springs are resistant to harmonics due to the fact that the coils have different outside diameters and the wire is oval and not round.
The smaller coils at the top also allow the valve train to start moving easier and gain lbs per inch of lift at a much greater rate. This allows for greater control of the valve train.
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less valvetrain weight (which should result in slightly less parasitic losses and better hydraulic lifter operation) and improved valve spring harmonic control.
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less valvetrain weight (which should result in slightly less parasitic losses and better hydraulic lifter operation) and improved valve spring harmonic control.
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WIth a beehive spring it's like having 3 different springs in one. At the bottom is your damping coils that help control spring surge. THose close out first and then the rate will jump up and be sorta linear with the center coils. As those close out, you get to the top where the rate becomes very progressive. This allows you to have lower seat loads, but still keeps a good amount of load over the nose.
Then there's the weight difference. A PAC-1218 with steel retainer is 20 grams lighter then a patriot/prc with a Ti. retainer.
Less mass generally means you can turn more RPM. And anytime you can take seat load off and keep you valvetrain under control you will make more power. Which is what that progressive rate allows you to do.
:
WIth a beehive spring it's like having 3 different springs in one. At the bottom is your damping coils that help control spring surge. THose close out first and then the rate will jump up and be sorta linear with the center coils. As those close out, you get to the top where the rate becomes very progressive. This allows you to have lower seat loads, but still keeps a good amount of load over the nose.
Then there's the weight difference. A PAC-1218 with steel retainer is 20 grams lighter then a patriot/prc with a Ti. retainer.
Less mass generally means you can turn more RPM. And anytime you can take seat load off and keep you valvetrain under control you will make more power. Which is what that progressive rate allows you to do.
I stock them both now, ... lighter weight, better valve control
