Comp 918 spring question...who has checked a bunch of them?
10-22-2009, 02:51 PM
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Comp 918 spring question...who has checked a bunch of them? I have 2 sets of springs that have low miles on them. Both are "918" springs. But after making a home made spring checker they appear to be quite different.
Set #1 measures out to have:
~133lbs at 1.800
~320-330 at 1.200
OD of spring is ~1.300 but this spring seems to coil bind a hair sooner than spring set #2
Set # 2 measures out to have:
~115 lbs at 1.800
~310-315 at 1.200
OD os spring is 1.275 but coil bind seems to be a bit looser than the above spring.... probably right at the advertised 1.085
All of the springs measure out to within a few percent of each other for thier respective batch.
Question is...how many different variations of 918s are there? Any way to tell from the above info which spring has been the historically better spring? I know PAC used to supply Comp and now it appears that Comp has at least two variations lately.
Please dont reply unless you have specific info relating to the question. No replies of "well just get a set of XYZ springs and be done with it". That wasnt the question.
Set #1 measures out to have:
~133lbs at 1.800
~320-330 at 1.200
OD of spring is ~1.300 but this spring seems to coil bind a hair sooner than spring set #2
Set # 2 measures out to have:
~115 lbs at 1.800
~310-315 at 1.200
OD os spring is 1.275 but coil bind seems to be a bit looser than the above spring.... probably right at the advertised 1.085
All of the springs measure out to within a few percent of each other for thier respective batch.
Question is...how many different variations of 918s are there? Any way to tell from the above info which spring has been the historically better spring? I know PAC used to supply Comp and now it appears that Comp has at least two variations lately.
Please dont reply unless you have specific info relating to the question. No replies of "well just get a set of XYZ springs and be done with it". That wasnt the question.
Last edited by 383LQ4SS; 10-22-2009 at 03:04 PM.
10-22-2009, 05:28 PM
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the on with less pressure could be a 26915 spring.
If used on a very big cam (over 226 duration with over .580 lift) these bee hives springs die pretty quick and will lose pressure fast and even more so when crossing the 230 duration and/or .590 lift mark.
The springs with less pressure could have been set up taller with less pressure and died sooner or may have been on a more aggressive cam or spun more RPM killing them sooner. This would not explain why they coil bind at different points though and might lead me to believe they are 26915 springs instead.
Lloyd
If used on a very big cam (over 226 duration with over .580 lift) these bee hives springs die pretty quick and will lose pressure fast and even more so when crossing the 230 duration and/or .590 lift mark.
The springs with less pressure could have been set up taller with less pressure and died sooner or may have been on a more aggressive cam or spun more RPM killing them sooner. This would not explain why they coil bind at different points though and might lead me to believe they are 26915 springs instead.
Lloyd
Last edited by NightTrain66; 10-23-2009 at 09:20 AM.
10-22-2009, 09:14 PM
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Hmm...915's. That could be very likely. They seem to fit the specs a bit better. Of course the person whos car they came off thought they were 918s.
Funny thing is the suspected 915s only had a few thousand miles, setup at stock height on a ~580 lift cam with 224/228 duration.
Also after looking around a bit...I have seen quite a few variations on the 918. Probably no way to tell within a 100% certainty what the smaller OD springs are.
Thanks for the reply though...appreciate it.
Funny thing is the suspected 915s only had a few thousand miles, setup at stock height on a ~580 lift cam with 224/228 duration.
Also after looking around a bit...I have seen quite a few variations on the 918. Probably no way to tell within a 100% certainty what the smaller OD springs are.
Thanks for the reply though...appreciate it.