So, why does Pontiac's website say it has a high lift cam for greater peak preformance and flat torque curve; and "...the GTO exhaust system is true dual..." AND shows a picture of the setup?



http://www.pontiac.com/gto/index.jsp?source=hmlnav

 

Who says we don't have a hi-lift cam with a flat torque curve?

In my defense, I don't understand any of those lift/duration/degree jargon for engine internals, though i'm trying to learn!

 

Just a little info,
The '04 GTO(V-body) uses camshaft part #12561721 same as 01-04 Y-body (Corvette),01-02 F-body, 01-04 K-truck (6.0 4x4), and, 03-04 N-truck (H2)
cylinder heads are the same as 99-current f and y cars.
It does have true dual exhaust with an h-pipe.
Ron

 

I think people get confused because the pipes are routed out the same side.

 

The H pipe is a dummy it is solid (no internal connection) and is there for rigidity.

 

Here ya go. Straight from the GM Press Media Site on the LS1/LS6 for 2004.

It is in an MS Word Document.

Hope this helps.

 

So that's kinda confusing. They say it's different than the f-body because they take the cam from the y-body. Yet the f-body used the y-body LS1. Now, unless the y-body started to use a different cam in 03, that is a bit contridictive.

 

From:
http://www.gmgoodwrench.com/gmgoodwr...283&section=ep

12480033 Camshaft "Gen 3" (Hot Cam)
The "Gen 3" (RPO-LS6) engine is used in all 1997 and later Corvettes, and 1998 and later Camaro/Firebird vehicles. This camshaft is comparable to the LT4 hot camshaft but for your LS1 engine. This kit includes 16 LS6 valve springs P/N 12565117.

12480110 Camshaft, "Gen 3" V8 (LS1)
The "Gen 3" V8 (RPO-LS1) engine is used in all 1997 and later Corvettes, and 1998 and later Camaros. This camshaft is designed for ASA racing and has .525" lift on 110º center line. Use with "Gen 3" LS1 engines only.

12565308 Camshaft, 2002-03 LS6 Corvette
This is the production cam for the 2002 LS6 Corvette. It features .550" intake and exhaust lift, 218 degree exhaust duration, and 204 degree intake duration at .050", and 117.5 degree lobe centers.

12560950 LS6 "Gen 3" Production Performance Camshaft
This camshaft is original equipment in LS6 Vortec engines. It features .525" intake and exhaust lift, 217 degree exhaust duration at .050", 207 degree intake duration at .050", and 116 degree lobe centers.

These are the 4 part number options from the GM performance parts website for camshafts (from link above - there is also a 'showroom stock' replacement part). That being said - I've looked everywhere for a part number of the GTO and can't find it. All is says is that it is 'revised' from the cam in the Holden spec LS1.
Dan

 

if look at the pontiac site it says it also has a 100MM TB and intake

is that true about the h-pipe?

 

Notice how the Goodwrench site says:

"12480033 Camshaft "Gen 3" (Hot Cam)
The "Gen 3" (RPO-LS6) engine is used in all 1997 and later Corvettes, and 1998 and later Camaro/Firebird vehicles."

and then says:

"12480110 Camshaft, "Gen 3" V8 (LS1)
The "Gen 3" V8 (RPO-LS1) engine is used in all 1997 and later Corvettes, and 1998 and later Camaros."

So, they are saying you could get a LS6 since 97 in the Vette, and 98 in the F-bod.

 

Yes it is true there is no exhaust crossover - completely dual from manifolds back.

 

you gotta change you exhaust man

 

Well, the initial plan is to keep her stock for a bit. The first thing I'll do when that 'bit' is up (I'm building a SBC for the summer to keep my tinkering focused) will be to do headers and exhaust back. At this point my only question is should I go for high-flow cats or dish them altogether. I should get some good (and bad) results from other people modding the exhaust to help me pick the right setup.

 

cant go wrong with long tubes, no cats, x-pipe, dynomax or magnaflow muffler, 2.5" all the way back into 3.5" stainless slash tips

 

Don't you guys forget that the Aussie LS1 come with a LS6 intake, i think that they would have changed the tune slightly as well which is what they do to our cars each year when a new model arrives. The LS1's started with 220kw standard in Aust now come as 245kw standard.

 

So has the North American LS1 since 2001.

 

man... that interior looks great!!

 

well trevor, has it been 30 mins yet? what are the dyno results.

 

As far as i understand, it has to connect somewhere. You want the Exhaust pulses balanced...

 

It does not connect. I have heard arguments that you can actually get more HP from a crossover exhaust due to 'pulses' helping to extract gas from the combustion chamber. As I'm not concerned about absolute optimum performance, I will probably keep it as a true dual setup. I'm partially waiting until next spring to get a good idea of what systems are better than others w/ the GTO setup. At that point I'll decide for sure. It definitely needs headers. I hate the look of manifolds in such an otherwise beautiful engine compartment.
Dan