# Mustang guy with GTO questions



## TorqueJunkie (Oct 10, 2008)

Hey there. I'm new here and just had a couple of general GTO questions and i'm sure there is no better place to get them answered. 

Could someone give me some basic specs on the cars?
Factory HP and TQ ratings (and at what rpm) for the autos and manuals, weight, trasmission types, factory gear ratios, factory suspension types. 

Did the 6 speed only come in the LS2? 
What year did the goat come back? 03...04?
Were both engines available in all years?
What were the price ranges new for fully loaded LS1 and LS2's?
What kind of rear axle assembly to they have? Differential set up?

I have a guy in my unit back home with an 06 LS2. He is the only fella in my unit that is into american muscle really. I enjoy our talks about our cars and the mods we've made and plan on (I'm a mustang guy).
I just got an email and he was telling me about his upcoming mods:
ported intake and TB
LS7 clutch upgrade
Dynotune
UD pulleys
Headers

He is wanting to go with pacesetters. I'm trying to talk him into getting a good set of SLP's or Kooks. I've had headers on a lot of my rides and i'll never get another cheap set. I have Dynatech long tubes on my 06 GT and i love them. Absolutely perfect fit and finish. He is on a bit of a budget and is trying to make the money go as far as possible.

I told him that for me, by far.....a gearswap was the best bang for the buck mod. He was telling me that it's a really expensive mod on a GTO. Why is that? Who makes the rear end assemblies? Is there something special that makes it an expensive mod. For me a set of gears is $149 and a install kit with alll the hardware, fluids, and friction modifier is another 100 bucks or so. 

Sorry to bombard ya'll with so many questions so soon. That's the reason i am here though is to learn more about the other american muscle on the streets. I respect these cars a great deal. Thank you for any insight to the questions i have.


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## Ninjured (Apr 28, 2006)

The goat came back in 2004 for a three year run.
the 2004 came with the Ls1 with 350hp @ 5200 rpm, 365 ft-lb @ 4,000 rpm, redline 6,000 @ rpm
the 2005-2006 came with the Ls2 with 400hp @ 6000 rpm, 400 ft-lb @ 4,400 rpm, redline @ 6,500 rpm

for 2005, they also added hood scoops, bigger brakes and split dual exhaust exits (the 2004 has dual exhaust, just both exits are on the same side of the car)

for 2006, they added lighted steering wheel controls, a door lock switch, the "smoker's package" as standard, and black tail lights

the only options for the GTO were A4/M6, 18" wheels, a Sport Appearance Package and the smoker's package

curb weight ~3,800 lbs and the retail price was ~$33,500 for all three years. The manual was actually more expensive but didn't have to pay the "gas guzzler" tax which put the auto back on top as more expensive...

Full independent suspension with a 3.46 LSD
Manual Tremec t-56 (top speed in a 2005)
2.97 (49 mph)
2.07 (69 mph)
1.43 (100 mph)
1.00 (143 mph)
0.84 (171 mph)
0.57 (252 mph)
Automatic Hydramatic 4L65-E M32 
3.06 (47 mph)
1.63 (88 mph)
1.00 (143 mph)
0.70 (205 mph) 

most m6 guys go for 3.91 gears while the A4 guys go with 3.73's
mods aren't quite as cheap as a Mustang (ok, not even close)


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## GTO JUDGE (May 14, 2005)

Did the 6 speed only come in the LS2? 
The LS2 6.0Lwas in the 05-06 model years.

What year did the goat come back? 03...04? 
The Goat came out in 2004 although it was available late 2003.

Were both engines available in all years? 
The LS1 5.7L was in the 2004 year only.

What were the price ranges new for fully loaded LS1 and LS2's? 
Both stickered in the 33K range.

What kind of rear axle assembly to they have? Differential set up? Gear 
Ratio is a 3.46:1 Dana Limited Slip Differential. 

As far as going with pacesetters, or kooks, you’ll get varying opinions on both. This question is better answered by guys who have either of those installed. 

Dana is the manufacturer of the rears for all 3 years. If the car is going to be modded out and raced, replacing the rear with the correct ratios would be wise. As far as the Friction Modifier, its not cheap, and it’s specific with its own part number for this rear however some have switched to I believe Royal Purple that has a F.M. in it. 

Hope this helps, and welcome to the Forum.


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## TorqueJunkie (Oct 10, 2008)

so the LS1 was only in the 04 cars and was replaced by the LS2 on the 05-06 cars? Thank you for the answers, exactly what i was looking for. So i'm confused, the expense of a gear swap is in the friction modifier? How much is a ring and pinion set for a dana rear end?


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## GTO JUDGE (May 14, 2005)

TorqueJunkie said:


> so the LS1 was only in the 04 cars and was replaced by the LS2 on the 05-06 cars? Thank you for the answers, exactly what i was looking for. So i'm confused, the expense of a gear swap is in the friction modifier? How much is a ring and pinion set for a dana rear end?


That's correct, the LS1 was only available in the 2004 model year.
As far as the expense of a gear swap being in the FM.. The FM is an additive that reduces noise. It is necessary in this rear, if you do a rear swap depending on what rear you use the manufacturer will have their own criteria. 

As far as cost for those parts, I have no idea what those parts run, and I don't know if GM would know being the rear end is one part number in their system. The rear end is a Dana part but warranted through GM. Its a sealed unit and they were not repaired but fully changed out. You can inquire with a Pontiac service center maybe they have a schematic with a part number for it but those will be Dana part numbers NOT GM. Maybe a Pontiac Parts center can help you out on obtaining a quote on those parts. If they can't maybe they can direct you.


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## AlaGreyGoat (Jul 6, 2006)

Hi, TorqueJunkie,

First, thanks for your commitment and BE Careful!!!

The GTO was a limited production run from Oz, with only about 44,000 total produced for the
three years.
The IRS rearend is a DANA 44 viariant, also from OZ. Only one company I know imports
the gear sets to the US and are super expensive. A gear set and major install kit is
upward of $700! 3.91:1 is the lowest ratio that will fit these housings.
With a 3.91, you only drop 300-500rpm on the shift points.

The LSx motors have a flat torque curve, with very good low end.
I've attached my dyno sheet. I have an 05 with a few bolt on-ons and tune.
I've got 325 ft/lbs at 2500 rpm with 368 max at 4700 rpm.

Here is a link to a speed chart:

http://www.gtoforum.com/f39/gto-m6-gearing-mph-chart-15718/

Larry

(Can't get the dyno sheet to upload from here, will do it at home tonight)
Dyno05orig.jpg - Image - Photobucket - Video and Image Hosting


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