[Z06] 385 to 405 hp
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Dec 6, 2022, 02:46 PM
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2 things that I know of for sure are:
1: A higher lift cam, and
2: An air filter housing with a larger opening. There may be some other things I'm not aware of, or have forgotten.
HOWEVER!! If you run 1.8:1 rockers on an '01, it will make a bit more power than the '02-'04. The '01 cam actually has a tighter LSA, and a bit more duration, than the later cam. But it has only .525" lift, where the later cam has .550" lift. If you do run 1.8 rockers, you'll end up with .556" lift, and need the later LS6 valvesprings, at the least. Hope this helps......
1: A higher lift cam, and
2: An air filter housing with a larger opening. There may be some other things I'm not aware of, or have forgotten.
HOWEVER!! If you run 1.8:1 rockers on an '01, it will make a bit more power than the '02-'04. The '01 cam actually has a tighter LSA, and a bit more duration, than the later cam. But it has only .525" lift, where the later cam has .550" lift. If you do run 1.8 rockers, you'll end up with .556" lift, and need the later LS6 valvesprings, at the least. Hope this helps......
Race Director
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2 things that I know of for sure are:
1: A higher lift cam, and
2: An air filter housing with a larger opening. There may be some other things I'm not aware of, or have forgotten.
HOWEVER!! If you run 1.8:1 rockers on an '01, it will make a bit more power than the '02-'04. The '01 cam actually has a tighter LSA, and a bit more duration, than the later cam. But it has only .525" lift, where the later cam has .550" lift. If you do run 1.8 rockers, you'll end up with .556" lift, and need the later LS6 valvesprings, at the least. Hope this helps......
1: A higher lift cam, and
2: An air filter housing with a larger opening. There may be some other things I'm not aware of, or have forgotten.
HOWEVER!! If you run 1.8:1 rockers on an '01, it will make a bit more power than the '02-'04. The '01 cam actually has a tighter LSA, and a bit more duration, than the later cam. But it has only .525" lift, where the later cam has .550" lift. If you do run 1.8 rockers, you'll end up with .556" lift, and need the later LS6 valvesprings, at the least. Hope this helps......
Last edited by grinder11; Dec 6, 2022 at 03:50 PM.
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From a quick search of your question "What was done by the factory to take the C5 Z06 from 385 hp to 405 hp?" using Google I found this info
1. The cam his a bit higher lift
2. The precats are gone
3. The MAF has no screen and is tuned for that
4. The airbox has a larger opening
1. The cam his a bit higher lift
2. The precats are gone
3. The MAF has no screen and is tuned for that
4. The airbox has a larger opening
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Really good info. 
Le Mans Master
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Or just put a real cam in the car and not worry about it. 
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Seems to me I’ve read more than once that the 385 number may have been sandbagging.
Don’t real cam’s pretty always require new springs, tuning, and quite often an increase in ptv clearance?
Don’t real cam’s pretty always require new springs, tuning, and quite often an increase in ptv clearance?
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The same would be needed for rocker arm change too. The piston to valve clearance would DECREASE as the higher lift puts the vale closer to the piston.
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I’ve got the 2004 base coupe with the baby cam, A4 trans,etc. someday I’ll get a heads and cam kit. I already got the headers, gear, and converter. Be thankful they put a little something better in the Z06.
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I've worked with some of the lead managers/engineers from the c4 and c5 (in non-corvette related contexts), and over beers was told -- and this really shouldn't be any surprise-- that the 405 number was a big point of ego for the original z06 team. while the zr1 was revolutionary, it was embarrassing that the "king of the hill" was developed by lotus and built by mercury.
getting 405 out of a traditional cam'd, LS motor was a point of pride for them -- and should be no surprise that the later versions of the z06 hit that very specific number (it was especially interesting the point of view of the c4 managers vs the c5 managers :-) )
getting 405 out of a traditional cam'd, LS motor was a point of pride for them -- and should be no surprise that the later versions of the z06 hit that very specific number (it was especially interesting the point of view of the c4 managers vs the c5 managers :-) )
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This will give you all of the info you are looking for plus more: 2001 - 2004 Corvette Z06 Tech Center - Corvette Action Center
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I've worked with some of the lead managers/engineers from the c4 and c5 (in non-corvette related contexts), and over beers was told -- and this really shouldn't be any surprise-- that the 405 number was a big point of ego for the original z06 team. while the zr1 was revolutionary, it was embarrassing that the "king of the hill" was developed by lotus and built by mercury.
getting 405 out of a traditional cam'd, LS motor was a point of pride for them -- and should be no surprise that the later versions of the z06 hit that very specific number (it was especially interesting the point of view of the c4 managers vs the c5 managers :-) )
getting 405 out of a traditional cam'd, LS motor was a point of pride for them -- and should be no surprise that the later versions of the z06 hit that very specific number (it was especially interesting the point of view of the c4 managers vs the c5 managers :-) )