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Hi all, just wanted to ask if anyone had modified their flow system and what is regarded as the best exhaust mfr in the US for performance exhausts.
I have used K&N air intakes in the UK and got impressive performance.

Thanks

Andrew :)
 
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Don't throw away your money!

04' GTO has all the factory installed, best and most efficient airintake/exhaust system, period. You go ahead and put some KN airintake and you will have your LS1 gulping hot less dense air. Your parameteters will go bezerk and probably end up contaminating your system with oil. Your LS1 pistons will take in air by negative pressure and, as it is, it has all the air availbale it can handle. You don't need anymore because the GTO takes air in through the air dam, plenty of cold , dense air and routs it through proper diameter ducting into the airbox with a nice filter and then into your manifold where intake diameter gets much smaller so it does not matter what else you do outside. All sensors and software is designed for specific dimmensions of your system. The GTo electronically adjusts itself for the proper fuel/air mixture (See your silver GTO catalog that explains all of that). The KN airintake system, as well as all others, what it does for you is to spoil the whole design to allow hot, under the hood, undesirable useless air into your car's engine probably shortening its life.

The GTO exhaust system has been carefully designed to maximaize air flow from your engine. GTO engineers went at great lenght to design this system. Please, don't spoil it with some off the shelf magic pill type of solution. Don't fall for these aftermarket useless ideas.

Only way to actually increase significantly your vehicle's hp is to modify the engine which would take some finely tuned engineering to design, build and mantain. Unless your last name is Ford, Holden or GM don't get into it. Keep your GTO as it was designed for the job it was designed and take your money to enjoy a meal out with your gal. It is a powerhouse and a fantastic car as it is. It is a beautiful piece of engineering. If you still want more power get an 05' GTO.

Have fun driving it! I do.
 

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.......or........

Belive the dyno and install headers and a free-flow exhuast. There are only a few full systems out right now, but I haven't seen all the numbers, but any of them will be better then the stock system chock-full of flow robbing pinch points. I persoanlly like the looks of the side dump exhuast (and side skirts) offered through arrowheadperformance.com.

While adearmas is almost correct in saying that adding an entire intake system, with open element air filter, will suck in more hot air then the stock set-up, once moving, that effect is not nearly as pronounced. Add just a simple drop-in panel filter and you'll be doing yourself a favor.
 

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I don't have the slightest idea about intakes because they are all sucking air from under the hood. Get one the sucks air from outside the engine bay and we'll talk.

As for exhaust, cut the stock exhaust off after the cats and add you own choice of exhaust. The stocker has a creese no more than a few inches from the exit of the cats. After the mufflers there is another creese in the exhaust and the two pipes cross over one another. I guess this is for equal length and sound. When my exhaust goes from 2 1/4 or 2 1/2, what ever is stock, down to a size no larger than a 1 1/2 creese you are creating significant back pressure and choking you engine.
 

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I think I remember reading somewhere that the two pipes never actually 'cross-over', they are compeltly seperate from each other. The peice that looks like the x-over is actually welded shut....at least, thats what I read. Forget the reason stated as well, but it was a typical manufacturer's excuse.
 

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Tiger said:
While adearmas is almost correct in saying that adding an entire intake system, with open element air filter, will suck in more hot air then the stock set-up, once moving, that effect is not nearly as pronouncedQUOTE]

Will the new hood with the scoops help bring cooler air into the engine compartment?
 

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Tiger said:
I think I remember reading somewhere that the two pipes never actually 'cross-over', they are compeltly seperate from each other. The peice that looks like the x-over is actually welded shut....at least, thats what I read. Forget the reason stated as well, but it was a typical manufacturer's excuse.
I wasn't saying there was anything such as a x or h-pipe type of design. I was stating that the two tubes actually are crossed over one another. The passenger exhaust exits on the driver side tipe and vise versa.

For the new hood, it is not going to so to speak bring cold air in. It is going to allow hot air from the engine to vent or escape.
 

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"Will the new hood with the scoops help bring cooler air into the engine compartment?"
No! They're blocked off.

"For the new hood, it is not going to so to speak bring cold air in. It is going to allow hot air from the engine to vent or escape."

Wrong again !! see above. If you were to unblock them, they are holes straight into the engine bay. I would hate to see what the engine would look like after driving in a rain storm or worse yet SNOW, with open hood scoops....The scoops are forward facing not rearward.
 
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Where you get that info. from. I read somewhere that it provides for engine ventilation.
 

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More air (cold) into and out of the engine at any RPM will get you more horsepower. As long as the ECU can keep up by keeping the mix correct(not to lean).
Cheep----- K&N filter with after cat exaust.

Bucks----- Hi-Flo cold air intake with supercharger and intercooler with fuel management and headers with complete dual 2 1/2" exaust.

With the money you can save on a 2004 before Nov 1st, do the bucks upgrade and blow the doors off any 2005 that might pull up.

A good supercharger kit should give you 100+ hp to the rear wheels.
 

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SLP's ram air hood is functional, sealing to the oem air box.

they call it "ram air" but really it's more of a a plenum when compared to real ram air muscle cars of the 60's & 70's

now , this is good topic here, and it was and is also, on the SS owners forum.

for my 02 SS Camaro with the "oem" SLP ram air hood, it added 10 hp on paper.

but all the discussions, inlcuding that of SLP engineers, was that it only helped at high speeds as the fbod's were "bottom breathers" similar to the GTO

I noticed gains on the SS (seat of pants & dyno) by dremeling out some plastic that restricted air into the air box, K&N filter, and smoother air lid (MTI Clear) They were each small but still a gain. Also had exhaust cut out with electric power plate. with cutout open lost a little on the bottom, but gained more at the top. cutout was after the cats but before muffler
 

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GTO TOO said:
"

Wrong again !! see above. If you were to unblock them, they are holes straight into the engine bay. I would hate to see what the engine would look like after driving in a rain storm ...
That was my main concern. And how do the "Ram-Air" GTO's from the '60's address this problem?
 

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TexasRealtor said:
GTO TOO said:
"

Wrong again !! see above. If you were to unblock them, they are holes straight into the engine bay. I would hate to see what the engine would look like after driving in a rain storm ...
http://www.ultimatecarpage.com/frame.php?file=pic.php&imagenum=4&carnum=2084

http://www.ultimatecarpage.com/frame.php?file=pic.php&imagenum=6&carnum=2084

You may want to look at these. The scoops that are on the cars coming out are going to be open. Even though they do have the honey comb look to them, they are not blocked off. When you will drive in a rain storm, you will get a little water in the hood. Whether or not it makes it to your air filter is an entirely different subject for we don't have answers yet.
 

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The electric cut-out sounds like a good idea. I had a QTP electric cut-out on my 02 Camaro with a SS hood.

I am new to the forum but not new to F-Bods and want to mod my 04 GTO.

Saying to sell the 04 and buy an 05 was joking right? That is silly of course. ;) I can't drive a totally stock car hehe never have been able too.

I'm sure there is a way to get some more power out of this car without going FI or N20 and I was looking at exhaust and air intakes first as I always do.

I haven't looked real closely into this yet but their has to be some restrictions in the intake and exhaus somewhere?

Also are there any ECU mod's out yet or does this ecu learn pretty well when you adjust the A/F? I had the Hypertech on my prior F-Bods and loved it but I guess it isn't made for this car.

I had an 01 Pontiac Firehawk that loved modifications though and it had lots of SLP stuff on it straight from the factory.

What did they change from the 04 to the 05 to get that extra power does anyone know? Anyways that is where I will start by reading the exhaust thread links posted (thanks) and lurking here and reading.

Wanted to make my first post and say hi to everyone though.

Max from California.
 

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MaxHax said:
What did they change from the 04 to the 05 to get that extra power does anyone know? Anyways that is where I will start by reading the exhaust thread links posted (thanks) and lurking here and reading.

Wanted to make my first post and say hi to everyone though.

Max from California.
Hello and welcome,

The 05 GTO offers a 400 hp 6.0 liter.

Modern Day Muscle Cars offer a package to increase the HP on the 04 5.7. They have 410HP, 510HP and 585HP kits available for the 2004.
 
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