LS9 cam not good with turbos???
01-30-2016, 04:37 AM
#62
My thoughts as well. It would have been neat to see.
Then I started to really think about it. Certainly extrapolations could be drawn from a specific application standpoint, but I was led to the conclusion it may not be entirely indicative of a universally applicable outcome.
Obviously the mass flow rate would vary at the same manifold pressure but an operational stasis between drive/ driven pressure would be largely dependent on each sides mechanical efficiency at given flow rates/pressure ratios.
For example, if the cam change moved mass flow into, or outside of, given compressor efficiencies the mechanical work required to make those flow rates vs pressure ratios would change based on a given turbine Enthalpy value.
Then I started to really think about it. Certainly extrapolations could be drawn from a specific application standpoint, but I was led to the conclusion it may not be entirely indicative of a universally applicable outcome.
Obviously the mass flow rate would vary at the same manifold pressure but an operational stasis between drive/ driven pressure would be largely dependent on each sides mechanical efficiency at given flow rates/pressure ratios.
For example, if the cam change moved mass flow into, or outside of, given compressor efficiencies the mechanical work required to make those flow rates vs pressure ratios would change based on a given turbine Enthalpy value.
Last edited by gtfoxy; 01-30-2016 at 04:48 AM.
01-30-2016, 09:45 AM
#63
TECH Fanatic
Since this thread has some miles on it here is an article by Super Chevy that ran the LS9 vs a bigger LJS Stage 2. That way we can get another example of how it performs in a specific turbo application. For a $100-130 cam, I'd say it performed quite admirably.
One thing that has me curious is the difference in positive manifold pressure from one to the other. I surmise this is because the gate controller only looks at preset duty cycles rather than actual manifold pressure... I never used a turbo smart controller so I am not sure.
http://www.superchevy.com/how-to/eng...ged-ls-engine/
One thing that has me curious is the difference in positive manifold pressure from one to the other. I surmise this is because the gate controller only looks at preset duty cycles rather than actual manifold pressure... I never used a turbo smart controller so I am not sure.
http://www.superchevy.com/how-to/eng...ged-ls-engine/
10-13-2017, 10:33 AM
#64
Teching In
Join Date: Jan 2016
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
Bringing this back up, I have a LS7 cam I got for free. Will most likely use it in my 5.3 that I'm planning on using a 76 or 78mm turbo on low boost for now. I have the timing cover, gear and extensions from my LS2. The timing set I have is keyed for 2* advance/retard. Would advancing this cam 4* be more beneficial for the 5.3 and boost? Will have ported 243's, LS6 intake and TB. Thoughts?
pretty sure my cam motion 230/234 115+1 will be more detrimental than helpful on the 5.3
pretty sure my cam motion 230/234 115+1 will be more detrimental than helpful on the 5.3
10-10-2018, 10:10 PM
#65
Got a ls9 cam for free that had some ..basic surface rust. Shined it up. Going in my 6.2 l92 sbe with self ported 243s. W a pair of twins. Had a cam gear alredy. And just got a new chain n oil pump and im good. Cant beat free.
some shop had it from a takeout engine.
Customer went w bigger custom cam
was headed to the scrap yard.😳
some shop had it from a takeout engine.
Customer went w bigger custom cam
was headed to the scrap yard.😳
10-11-2018, 12:57 AM
#66
TECH Fanatic
Join Date: Aug 2005
Posts: 1,004
Likes: 0
Received 0 Likes
on
0 Posts
Got a ls9 cam for free that had some ..basic surface rust. Shined it up. Going in my 6.2 l92 sbe with self ported 243s. W a pair of twins. Had a cam gear alredy. And just got a new chain n oil pump and im good. Cant beat free.
some shop had it from a takeout engine.
Customer went w bigger custom cam
was headed to the scrap yard.😳
some shop had it from a takeout engine.
Customer went w bigger custom cam
was headed to the scrap yard.😳
