stangkillin

i know that some years the ls1 had the smaller cam, does anyone know the reason why?

MeentSS02

iTrader: (11)

I think you are referring to the '01 and '02 models - '01 was the first year they got rid of EGR. The smaller cam helped them do this.

justin hover

Advances in year to year technology...Their was alot more than a smaller cam between a 98 and an 02....cam, intake, manifolds, ect.

arock24

iTrader: (4)

When they switched to the ls6 intake for the 01-02 models, they gave them a smaller cam to offset the power gains, so the 98-02 would all have similar power off the line.

green28

iTrader: (8)

Negative. See post number 2 for the correct answer.

arock24

iTrader: (4)

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..

RPM WS6

iTrader: (3)

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.

S8ER95Z

iTrader: (3)

The 01-02 cam is a truck cam if I'm not mistaken. I thought they literally tossed it in to utilize the ls6 intake (no egr provision).

arock24

iTrader: (4)

so a 98-00 cam in a 01-02 would not pass emissions?

RPM WS6

iTrader: (3)

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.

14k

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??

homerz28

I thought GM said Uh Oh, the F bodies are now approaching the power of a corvette, and gave them a smaller cam to make the vette perform better in straight line performance

S8ER95Z

iTrader: (3)

You be troll'n man. lol

homerz28

nope.
so did GM put a smaller cam in the corvette too that year, or was it just the f bodies that got shafted?

MeentSS02

iTrader: (11)

Not sure on the Corvette portion, but do you really think you'd even notice a difference in power given the specs we're talking about here?

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.

MeentSS02

iTrader: (11)

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.

S8ER95Z

iTrader: (3)

How did we get shafted? Torque went way up.. and horsepower also increased do to changes. Very minor bumps in power but we certainly didn't lose anything.


http://corvetteactioncenter.com/spec...01perform.html

homerz28

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)

S8ER95Z

iTrader: (3)

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).

MeentSS02

iTrader: (11)

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.