Pontiac GTO Stock HP/kW?

[vxtreem]

What is the stock fwkw ?

I thought it was only 245kw

Pontiac website did a dyno shootout between old skool GTOs and the new GTO.

http://www.highperformancepontiac.com/features/0407pon_engine/

2004 pulled 297 hp thats around 226 kw
So fwkw would be around the 280kw

[Drizzt]

I'll hazard a guess but wasn't it around 255-260fwkw (340-350fwhp)?


Drizzt

[SSbaby]

They use a Dynojet dyno over there, which is around 11% optimistic.

[clixanup]

The figure quoted in Pontiac's advertising is 350 FWHP

[Dacious]

Lotsa guys with manuals have gotten around 290-300 rwhp so the 350 hp advertised is right. Someone on the LS1GTO board did some research and basically the car uses the exact same programming as the SIII Monaro - the 15hp difference is accounted for by the lower-restriction exhaust and the PCM 'learning' it while running in.

[clixanup]

Isn't there is more to it than exhaust? I think that their standard cam is a tad "lumpier" than ours. From memory their heads are different too....

[Dacious]

Isn't there is more to it than exhaust? I think that their standard cam is a tad "lumpier" than ours. From memory their heads are different too....

I can't confirm, but I suspect we get the exact same engine, from the Series II VY and Series III Monaro on. The peak torque on the Monaro moved down to 4,000 rpm as per the GTO, from 4,400 previously published. We also got the revised LS6 shortblock and intake as per the GTO.

Someone who has seen the valvesprings could confirm - the GTO has lime green paintmarks on them, indicating an LS6 spring to cope with the lumpier cam.

Someone who has been in an early Monaro and mine said mine felt stronger especially down low - I don't know, could just be differences between cars.

[Sid447]

You get,

more American horses to the Kilo than we do.

--- Sid447

[Malcolmsp]

An interesting article that should help out with any BS sessions starting "Back in my day the cars were a lot more powerful than this modern crap blah blah blah..."

cya
Mal

[clixanup]

I can't confirm, but I suspect we get the exact same engine, from the Series II VY and Series III Monaro on. The peak torque on the Monaro moved down to 4,000 rpm as per the GTO, from 4,400 previously published. We also got the revised LS6 shortblock and intake as per the GTO.

Someone who has seen the valvesprings could confirm - the GTO has lime green paintmarks on them, indicating an LS6 spring to cope with the lumpier cam.

Someone who has been in an early Monaro and mine said mine felt stronger especially down low - I don't know, could just be differences between cars.

As per this thread:

http://www.ls1.com.au/forum/showthread.php?t=12823&highlight=casting+head

The casting numbers on the heads of mine (December '03 built VYII) indicate that they're LS1 heads, not LS6 heads.

I think the 235fwkw and 245fwkw Holden engines are the same, with the only physical differences being in the exhaust.

I doubt very much that a VYII has the same camshaft as a GTO, because the guys on LS1GTO talk about how lumpy it feels while idling. Mine idles like a 6 - smoooooth. Don't get me wrong - I'd like to believe that I have the GTO engine, but I don't think its true.

I'm hoping somebody can prove me wrong here.

[Sid447]

Nobody,

On this Forum has been able to verify with absolute certainty, what the stock LS1 cam specs are, and whether there is more than just the one or not in use on LS1.

Maybe Crane Cams Australia (Tech Helpline) could help, being as they are the o.e. supplier.

--- Sid447 ---

[VX2VESS]

their was talk that the GTo was to have a beefier cam to satisfy the market. the aussie VY uses an older spec ls6 cam hence able to produce better numbers to the VT/VX. they must bring in two spec ls1s if thats the case, one for the GTO. be good if a few got mixed up.

be good to get hold of a VT2, VX, VX2, VY1 and VY2 cam a get them all measured up for specs.

those that have access to a parts manual, look up the cam for all models is the part number the same? EG can a VY2 cam fit a VT2. i know they fit, but if the cam is different holden won't list it for the other motor as the tune will be effected on a stock car.

[Dacious]

As per this thread:

I doubt very much that a VYII has the same camshaft as a GTO, because the guys on LS1GTO talk about how lumpy it feels while idling. Mine idles like a 6 - smoooooth. Don't get me wrong - I'd like to believe that I have the GTO engine, but I don't think its true.

I'm hoping somebody can prove me wrong here.

I certainly don't know for sure - speculation on my part - BUT conversely my Monaro DOES idle lumpily! It's got a slight shake at idle similar to what the US guys describe.

I know our cars have LS1 heads, as do GTOs. But the peak torque RPM spec for up to '02 Monaros are different. Whether it's just a typo or a correction to an earlier one I don't know.

I am going on info from here:


GOOD NEWS! GTO heads have the latest LS6 valve springs, Old Goat your source is perhaps misled or information was mixed up. Intiallly 2001 LS6 springs had a blue stripe for .525" lift superseeded by Yellow stripe on the 2002 springs and puke green color stripe on the 2003 LS6 valve springs rated for .550" lift.

Have our US friends got it wrong? Does the Monaro have GTO internals and a different engine to the SS? Doesn't seem likely.

Link here (http://www.ls1gto.com/forums/showthread.php?t=3308)

[vxtreem]

Well this is what "high performance Pontiac" state at the bottom of the article

Cam Specs: Hyd. roller, 196°/207 dur. at .050, .479/.467 lift, 116° LSA

Can anyone confirm our specs.

Also I noticed the rubber on them are BF goodrich.... not Bridgestones???????

[Dacious]

Also I noticed the rubber on them are BF goodrich.... not Bridgestones???????

That's because GM NA decided the yanks might find the 18" wheel ride too firm. So they get the previous 17" SS wheels. The cars are also limited to 155mph because of that. So they're more powerful but slightly slower.

[Sid447]

Well this is what "high performance Pontiac" state at the bottom of the article
Cam Specs: Hyd. roller, 196°/207 dur. at .050, .479/.467 lift, 116° LSA
Can anyone confirm our specs.
Also I noticed the rubber on them are BF goodrich.... not Bridgestones???????

Good call vxtreem,
That looks suspiciously like the stock LS1 cam, that makes it something very close to a 260/270 (total duration @ .004").
It just doesn't make sense to make several different o.e. cams for a mainstream production V8.
I think the only difference is in the PCM.
For people to say it seems lumpier at idle means nothing.

As far as different rubber is concerned, different markets dictate it I s'pose. All the Middle East production comes on Yokohama for example; this is purely Marketing.
And as far as PCM's are concerned M-E stuff has been officially rated at 250kw since MY2000.

--- Sid447 ---

[Sid447]

They found that Yokies offered a higher quality-control standard than the others and it solved lots of after-sales problems for them.

I'd heard that. Though have no issues with the SO-3's I've been running.

They (UAE) have strict tyre inspections at the yearly Registration Renewal tests. Anything that's more than two years old is rejected in most cases, regardless of remaining tread depth.
The heat ages and degrades rubber dramatically.


--- Sid447 ---

[Thunder]

the 15hp difference is accounted for by the lower-restriction exhaust and the PCM 'learning' it while running in.

Can't be the "Free Flowing" exhaust because they are running 4 cat converters - 2 daewoo VY2 cats up front as well as 2 VX-VY1 cats underneath.

It only has the front mufflers and no rear resonator, but with 4 cats, that's all they need.

[Dacious]

Iv'e heard one of these things in traffic - they are a lot louder than a Monaro. If it's not exhaust, what it is then - if they have the same PCM program plus the same CAI. Only other difference is no crossover on the pipes. Either way, they dyno higher than a Monaro. If the cam info above is correct, then it appears it is the same cam.

One of the GTO guys on that board who has an LS1 Camaro says they're the same. Yet Pontiac states they're different. :confused:

[derf]

Iv'e heard one of these things in traffic - they are a lot louder than a Monaro. If it's not exhaust, what it is then - if they have the same PCM program plus the same CAI. Only other difference is no crossover on the pipes. Either way, they dyno higher than a Monaro. If the cam info above is correct, then it appears it is the same cam.

One of the GTO guys on that board who has an LS1 Camaro says they're the same. Yet Pontiac states they're different. :confused:

It was about marketing. The people in charge at GM didn't want the Camaro/Firebird to tread on the Corvette's toes. So the published rating was lower than actual output to make the Corvette look better. However, I've seen 2002 model Firebirds that dynoed at about 325 wheel horsepower in stock form. Then again, some 2002 Firebirds and Camaros dynoed at 285 wheel horsepower so who knows what the actual rating was supposed to be.

Bob Lutz, the new guy in charge decided to change the lowering of the rating for the sake of the Corvette. When you consider that the Z06 comes with 400+ horsepower, it doesn't matter if the GTO matches the "base" Corvette engine.

The GTO supposedly gets a Corvette camshaft that's slightly modified to give it more low end torque. I don't know the details about how they did that though or even if they made a real change at all.

My GTO dynoed at 305HP and 326 lb-ft with 900 miles (about 1440 Km) on it. And it came with 245/45ZR17 BF Goodrich KDWs tires. (sorry, tyres... :p :D)