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C6 Z06 cam/head recommendations for occassional daily/weekend warrior
C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
Just for reference, when installing Johnson 2116LSR (with BTR 4) I measured zero lash to be 7.835-7.855, so I'll be running pushrods in the 7.875 range (I ordered custom rods from Manton, various lengths).
Always measure. My intake preload was different from exhaust by 0.020. With a .035" +/- 0.005" preload for the Johnson lifters, it almost requires custom pushrods (not expensive at all BTW).
On the up side, I gained 10whp going to the Johnson from stock.
Just for reference, when installing Johnson 2116LSR (with BTR 4) I measured zero lash to be 7.835-7.855, so I'll be running pushrods in the 7.875 range (I ordered custom rods from Manton, various lengths).
Always measure. My intake preload was different from exhaust by 0.020. With a .035" +/- 0.005" preload for the Johnson lifters, it almost requires custom pushrods (not expensive at all BTW).
On the up side, I gained 10whp going to the Johnson from stock.
I love my Johnson lifters, between they and the combination of my other parts that I used in my build, I've never heard such a quiet LS7 or any LS motor, for that part. I'd believe it on the extra power. I spoke with the Johnson product manager and he explained to me the advantages of Johnson's Slow Leakdown Rate lifters.
Essentially, slow bleed-down lifters describe the ability to maintain lift without collapsing, or the repeatability in the common rotation of the cam. In other words, if you had a .630" lift cam but your lifters bled down .030" as the lobe of the cam rotates, you'd essentially only be getting .600" of that lift from your cam. He said they measured the OE GM LS7 lifter and they maintained their lift about 50% of the time, whereas the Johnson SLR lifters maintained their lift 95% of the time. That's potentially a lot of power left behind if you're not using the right lifter.
OK sorry for the delay, but I've got the car running and been driving for the past few weeks. I had it street tuned and then dyno tuned, as you can see in the video below:
The car runs and drives great, and the power is almost too much for the street, or street tires for that matter. My builder ended up staying with TSP's recommendation of 7.800 pushrod length after measuring. The car does seem louder now, and has more vibrations and rattles, but I attribute that to the cam and the lighter/smaller ATI pulley. I do have a slight exhaust leak and rattle at the rear that I need to tweak, but otherwise the engine sounds great and I don't hear any excessive lifter noises. I wasn't chasing any specific numbers with this build, other than fixing the heads and getting the most bang for my buck while I was in there, so that I could have a badass and (hopefully) worry-free track toy :-)
I would add back in the ~15% driveline loss for an estimate of about 680hp at the flywheel.
No, your STD correction factor usually results in somewhat inflated RWHP numbers. The industry "gold standard" is SAE, which gives a more realistic and comparable RWHP number. Dyno operators like to post STD numbers for customer feel good and bragging rights.
EDIT: 15% is also a bit high. It's actually closer to 11.5%
No, your STD correction factor usually results in somewhat inflated RWHP numbers. The industry "gold standard" is SAE, which gives a more realistic and comparable RWHP number. Dyno operators like to post STD numbers for customer feel good and bragging rights.
EDIT: 15% is also a bit high. It's actually closer to 11.5%
What you see is what I got, but I was told this dyno is typically conservative compared to others. Like I said, I wasn't chasing numbers, but rather just making sure I got what I paid for 👍
I would add back in the ~15% driveline loss for an estimate of about 680hp at the flywheel.
He means the SAE correction standard instead of STD (what you are showing). STD correction reads about 4% higher because it corrects to a lower temp and higher pressure than SAE. Most dynos correct to SAE. You aren't really producing either of these numbers. These are what you hypothetically would make if the conditions were what the standard is correcting to.
What you see is what I got, but I was told this dyno is typically conservative compared to others. Like I said, I wasn't chasing numbers, but rather just making sure I got what I paid for 👍
I wasn't implying that you obtained those numbers to "fool" anyone, just that some dyno operators do that on their own for the aforementioned reasons. Either way, as said, nice numbers?
He means the SAE correction standard instead of STD (what you are showing). STD correction reads about 4% higher because it corrects to a lower temp and higher pressure than SAE. Most dynos correct to SAE. You aren't really producing either of these numbers. These are what you hypothetically would make if the conditions were what the standard is correcting to.
Very nice torque curve and overall chart!
OK I gotcha.
Yea the torque curve matches really well with what TSP advertises for this cam, which is why I chose it. I really want that broad, low end torque for street and road course use 😁
Very nice... I have a friend here locally running the PRC 265's... Rode in his car and it pulls HARD!!! I am thinking of stepping up to these myself.
I've also been thinking about doing this. I wonder what the hp/tq increase would be over ported oem heads... Someone local recently added some goodies to his existing setup that already had PRC heads and he was unable to use AHPs PM guides due to fitment issues. DRM used Bronze Ferrea guides instead which almost seems like a step back in the reliability aspect.
I've also been thinking about doing this. I wonder what the hp/tq increase would be over ported oem heads... Someone local recently added some goodies to his existing setup that already had PRC heads and he was unable to use AHPs PM guides due to fitment issues. DRM used Bronze Ferrea guides instead which almost seems like a step back in the reliability aspect.
If this is the same guy/thread that was posted I while back I thought that AHP was able to use their moldstar 90s? I did some research for AHP on this as I have the PRC 265s and am contemplating the Moldstars too. The guide OD on the PRCs are the same as AHP's moldstars. The only difference in the guides are the PRC guides are stepped larger on the top. All that's needed to rectify that is the correct ID spring perch. I've already researched and purchased the perches.
If this is the same guy/thread that was posted I while back I thought that AHP was able to use their moldstar 90s? I did some research for AHP on this as I have the PRC 265s and am contemplating the Moldstars too. The guide OD on the PRCs are the same as AHP's moldstars. The only difference in the guides are the PRC guides are stepped larger on the top. All that's needed to rectify that is the correct ID spring perch. I've already researched and purchased the perches.
Hopefully AHP will chime in on this...
Kohle said he thought he would be able to...but I haven't heard anything else either.
10-14-2017, 12:28 PM
