smaller cam
That was the ONLY reason they downsized the cam? Negative..
MeentSS02 was correct for one of the purposes, but GM also wanted the hp output comparable to the 98-00 Camaros. If GM wanted to eliminate the EGR with a larger cam, they could have..
MeentSS02 was correct for one of the purposes, but GM also wanted the hp output comparable to the 98-00 Camaros. If GM wanted to eliminate the EGR with a larger cam, they could have..
Joined: Nov 2001
Posts: 34,647
Likes: 2,573
From: Schiller Park, ILL Member: #317
This doesn't make any logical sense. What does make sense is saving money by dropping the LS1 specific intake and EGR system, using the EGR-less LS6 intake (that was already destined for the Z06) for V8 F-body models, and picking a truck cam out of the parts bin to stuff in the LS1 as a means to meet emissions requirements without an EGR system.
Seems more like a cost savings measure to me. I've never heard anything about "limiting horsepower to earlier levels" as a factor for the cam change.
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Verdad Gallardo This doesn't make any logical sense. What does make sense is saving money by dropping the LS1 specific intake and EGR system, using the EGR-less LS6 intake (that was already destined for the Z06) for V8 F-body models, and picking a truck cam out of the parts bin to stuff in the LS1 as a means to meet emissions requirements without an EGR system.
Seems more like a cost savings measure to me. I've never heard anything about "limiting horsepower to earlier levels" as a factor for the cam change.
so a 98-00 cam in a 01-02 would not pass emissions?
Joined: Nov 2001
Posts: 34,647
Likes: 2,573
From: Schiller Park, ILL Member: #317
There are several types of emissions tests, ranging from state sniff tests to OBD scan only tests, to the FTP (Federal Test Procedure) that the OE manufacturers must pass. FTPs are far more comprehensive and accurate than a standard I/M sniff test performed at the state level for local compliance. Several cams that were not originally designed nor able to pass an FTP in a specific engine application may in fact pass local sniff standards in that same engine. As for OBD scan tests, anything can be made to pass those with proper custom tuning. In other words, local testing standards for a private consumer are less strict than initial tests for an OEM.
I recall the '01+ LS1s using the same cam as the LQ9/4 truck engines; I remember this being tossed around the 'net quite often back in ’01-’02 and was accepted as common knowledge.
Prior to 2001, the F-body and Y-body LS1s did not share an intake nor cam, with the Corvettes receiving a specific cam and LS1 intake without EGR, and the V8 F-bodies receiving a different specific cam and LS1 intake with EGR. Starting in 2001, all LS1 engines were standardized to the same cam (shared with trucks) and intake (LS6, without EGR) configuration. This allowed V8 F-bodies, and both base and Z06 Corvettes to share an intake as well, plus a cam sourced from the truck line for all LS1s.
I don't think there was ever a goal to reduce horsepower via a cam update just to offset gains from other updated parts, with the overall goal of limiting engine performance to previous levels on a newer version of the same engine; the whole thing would be one massive contradiction. I think it’s a safe bet to say that cost savings through a reduction in model specific parts in favor of standardization across several models was always the primary and probably only goal.
I recall the '01+ LS1s using the same cam as the LQ9/4 truck engines; I remember this being tossed around the 'net quite often back in ’01-’02 and was accepted as common knowledge.
Prior to 2001, the F-body and Y-body LS1s did not share an intake nor cam, with the Corvettes receiving a specific cam and LS1 intake without EGR, and the V8 F-bodies receiving a different specific cam and LS1 intake with EGR. Starting in 2001, all LS1 engines were standardized to the same cam (shared with trucks) and intake (LS6, without EGR) configuration. This allowed V8 F-bodies, and both base and Z06 Corvettes to share an intake as well, plus a cam sourced from the truck line for all LS1s.
I don't think there was ever a goal to reduce horsepower via a cam update just to offset gains from other updated parts, with the overall goal of limiting engine performance to previous levels on a newer version of the same engine; the whole thing would be one massive contradiction. I think it’s a safe bet to say that cost savings through a reduction in model specific parts in favor of standardization across several models was always the primary and probably only goal.
Last edited by RPM WS6; Jan 24, 2012 at 11:11 PM.
TECH Fanatic
Joined: Mar 2011
Posts: 1,050
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From: Odessa, TX
been asking this for like a week in another thread. since i have a 98 in my 01
so how can i pass emissions with the 98 in my 01 with !EGR !AIR and a rubber freeze plug on my 98 ls1 manifold? will i fail the sniffer test undoubtably??
so how can i pass emissions with the 98 in my 01 with !EGR !AIR and a rubber freeze plug on my 98 ls1 manifold? will i fail the sniffer test undoubtably??
Last edited by 14k; Jan 24, 2012 at 11:17 PM.
98-00 LS1:
Duration@.050 198.86 intake 209.25 exhaust
Lift .498 intake .497 exhaust
LSA 119.45
01-02 LS1:
Duration@.050 196.37 intake 208.72 exhaust
Lift .464 intake .479 exhaust
LSA 115.92
For reference, here is the '02+ LS6 cam:
204/218 int/exh @ 0.05" duration
0.551" / 0.547" int/exh lift
117 LSA
I dropped this one in my Camaro, and could hardly tell the difference.
And after some digging, I found the following on Corvette Forum:
Y Cars (Vettes) LS1
1997-99-----.479/.472 lift-------207/199 duration--------117 separation
2000--------.500/.500----------209/198----------------115.5
2001-03-----.479/467----------207/196----------------116
Based on this (unverified) information, it appears that the 2001 Vettes also got shafted on the cam. Get it? Shafted. Holy crap I'm hilarious.
Y Cars (Vettes) LS1
1997-99-----.479/.472 lift-------207/199 duration--------117 separation
2000--------.500/.500----------209/198----------------115.5
2001-03-----.479/467----------207/196----------------116
Based on this (unverified) information, it appears that the 2001 Vettes also got shafted on the cam. Get it? Shafted. Holy crap I'm hilarious.
Very minor bumps in power but we certainly didn't lose anything.http://corvetteactioncenter.com/spec...01perform.html
Last edited by S8ER95Z; Jan 25, 2012 at 11:32 AM.
Launching!
Joined: Aug 2008
Posts: 203
Likes: 0
From: Alabama
haha you have a point. so if you did swap from a 98 cam to a 02 LS6 cam, would you notice a significant loss of torque? like you wouldnt be able to climb certain hills in 6th that you used to? (i have no experience with cam swaps)
This should answer that somewhat... knowing that the 01+ car has more torque down low (and more peak torque) than previous years.
http://dl.dropbox.com/u/18487098/200...anvsLS1man.pdf
Honestly under 4000rpm I can't tell a difference in the performance.. once I hit around 4000rpm I can feel a noticeable difference over stock (the tires also start spinning right around that point on the street which it could never do stock).
http://dl.dropbox.com/u/18487098/200...anvsLS1man.pdf
Honestly under 4000rpm I can't tell a difference in the performance.. once I hit around 4000rpm I can feel a noticeable difference over stock (the tires also start spinning right around that point on the street which it could never do stock).
It behaves just like a stock cam until you get past about 4,000 RPMs, then you'll feel a slight power increase. Nothing more, nothing less.
That's why people don't like it much...it just doesn't make a big enough difference to justify the work required to swap it. People generally do it because it is an OEM tested/approved piece, it is cheap, and the valve springs that go with it are also cheap. Plus it is reliable...no spring checking/swaps in the future, just put it in and go. It runs okay on the stock tune too, and even better if you actually tune it.
Just don't do it if you are expecting to pull down 400+ RWHP cam-only.
That's why people don't like it much...it just doesn't make a big enough difference to justify the work required to swap it. People generally do it because it is an OEM tested/approved piece, it is cheap, and the valve springs that go with it are also cheap. Plus it is reliable...no spring checking/swaps in the future, just put it in and go. It runs okay on the stock tune too, and even better if you actually tune it.
Just don't do it if you are expecting to pull down 400+ RWHP cam-only.