78lb vs 75lb Supertech Springs
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From: Boston, MA
78lb vs 75lb Supertech Springs
I posted this in jbody.org as well but thought more people would see it here. Some of this information is already floating around but not all in one place:
I've been doing a lot of research lately and felt this is another good piece of information to share with the community. It may have already been posted but I didn't find it. I wanted to know what the difference between the 78lb kit and the 75lb kit are from Supertech. The 78s were discontinued for ecotecs a few years ago and replaced with the 75's. Though, they still make the 78s and they can be had if you call Supertech directly (I needed to replace just one from an otherwise good kit). I called Supertech today and this is the information I got:
The only changes between the 78lb kit and the 75lb kit are the retainer, the seat pressure of the spring, and installed height due to the retainer differences. The springs are identical in physical dimension. The reason the retainer was changed is because in some cases they slightly contact the machined lsj followers. Dave made a thread about this HERE.These followers can also be found in 2005 l61s, I believe only on the exhaust side. Any 02-04 eco will have the stamped followers that, while supposedly weaker, should not have this issue. In no documented case I could find has this contact ever lead to a failure, or even any noise, but the scoring can be seen visually when you pull the cover. Most report that you can't even feel the scoring with your finger because it's so slight.
That being said, the 75lb retainer is dished a little more to eliminate this contact and moves the installed height to something like .010 shorter(I can't remember exactly). That's why the spring is lighter. Moving the installed height down increases the seat pressure.
So, the 75lb Supertech retainers CAN be run on 78lb Supertech springs but since they reduce the installed height and therefore the seat pressure, the springs become more like 82lb (guestimate from the Supertech technical associate). Also, since the retainers are titanium they're about 200 bucks directly from Supertech for 16 of them. The other option, as many have done, is to clearance the machined followers ever so slightly to eliminate this potential contact. Although it's not much I personally find that a little scary as these followers are still pretty weak as it is.
Anyway, that's the deal. Hopefully this helps some people out in the future if they come across the 78lb springs.
An yes, before posting this I realized there will be replies such as, "ZZP valve springs FTW", I decided to post anyway.
I've been doing a lot of research lately and felt this is another good piece of information to share with the community. It may have already been posted but I didn't find it. I wanted to know what the difference between the 78lb kit and the 75lb kit are from Supertech. The 78s were discontinued for ecotecs a few years ago and replaced with the 75's. Though, they still make the 78s and they can be had if you call Supertech directly (I needed to replace just one from an otherwise good kit). I called Supertech today and this is the information I got:
The only changes between the 78lb kit and the 75lb kit are the retainer, the seat pressure of the spring, and installed height due to the retainer differences. The springs are identical in physical dimension. The reason the retainer was changed is because in some cases they slightly contact the machined lsj followers. Dave made a thread about this HERE.These followers can also be found in 2005 l61s, I believe only on the exhaust side. Any 02-04 eco will have the stamped followers that, while supposedly weaker, should not have this issue. In no documented case I could find has this contact ever lead to a failure, or even any noise, but the scoring can be seen visually when you pull the cover. Most report that you can't even feel the scoring with your finger because it's so slight.
That being said, the 75lb retainer is dished a little more to eliminate this contact and moves the installed height to something like .010 shorter(I can't remember exactly). That's why the spring is lighter. Moving the installed height down increases the seat pressure.
So, the 75lb Supertech retainers CAN be run on 78lb Supertech springs but since they reduce the installed height and therefore the seat pressure, the springs become more like 82lb (guestimate from the Supertech technical associate). Also, since the retainers are titanium they're about 200 bucks directly from Supertech for 16 of them. The other option, as many have done, is to clearance the machined followers ever so slightly to eliminate this potential contact. Although it's not much I personally find that a little scary as these followers are still pretty weak as it is.
Anyway, that's the deal. Hopefully this helps some people out in the future if they come across the 78lb springs.
An yes, before posting this I realized there will be replies such as, "ZZP valve springs FTW", I decided to post anyway.
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