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View Full Version : 2005 GTO (AUTO) vs. 2005 GTO (MANUAL); 2004 GTO SUPERCHARGED; 2003 COBRA WITH MODS


moat2005
01-23-2006, 09:41 PM
Dear GTO owners,

I wanted to pass on some experiences I have had with my 2005 GTO. I purchased an automatic about 6 months ago and I must say that I have been totally impressed with the car. It serves as my daily driver during the work week and on weekends it is a very fun car!

First I would like to talk about an automatic versus a manual transmission. I know that I might spark a large debate, but I am confident that the automatic is faster than the manual. I have raced two different manual GTO's making 3 run's against both cars. I won all six races and it always seemed to be by about 3-4 car lengths. Obviously there are a lot of factors involved here, but I would love your feedback?

Second I raced a supercharged 2004 GTO from a 20mph roll and to my surprise he was only able to pull my by one car length. I do know that 05's put 351hp to the 04's 301 on the dyno. I know that the 05 GTO puts around 480 to the back wheels with a supercharger. Again it could have been the particular run, but I estimated that he had to be putting atleast 430hp to the back wheels. His set up was extremely nice and we had a nice conversation at the end of the run. I must say that once again I am impressed how a stock 05 GTO was able to run with an very strong car.

The final experience I will talk about is against a modded 03 cobra. I believe he was putting out atleast 470hp. I would love to see what an 05 GTO would do against a stock 03 cobra? It has been very difficult to find one that is stock. In my race against the cobra we first went from a 20mph roll. He easily pulled away and I would estimate that he won by 7-8 car lengths. Next we went from a dig and again he easily pulled on me. He was driving on drag radials and I was driving on all season's. So I was pulled on hard, but I walk with pride. In the stock form I believe the 05GTO is a force.

In closing, feedback would be great. Please share your experiences!

RandyW
01-24-2006, 04:51 AM
Most of the magazine tests had the auto car being slightly quicker both 0-60 and 1/4 mile, though the trap speed usually favored the m6 car slightly, indicating a small rwhp advantage for the m6.:drivin:

moat2005
01-24-2006, 10:48 PM
I didn't know that they trap higher? I guess it makes sense that a good driver can drive the manual to faster speeds. I have heard that the stick is very hard to work with.

I have noticed as well that my car has no wheel hop? I don't know if this is just a problem that comes with the manual transmission or what?

Please post some experiences about your cars out there? I think that we recieve a lot of negative press, but really these GTO's are absolutely awesome cars! The whole package!

quicky06
01-26-2006, 07:59 PM
I didn't know that they trap higher? I guess it makes sense that a good driver can drive the manual to faster speeds. I have heard that the stick is very hard to work with.

I have noticed as well that my car has no wheel hop? I don't know if this is just a problem that comes with the manual transmission or what?

Please post some experiences about your cars out there? I think that we recieve a lot of negative press, but really these GTO's are absolutely awesome cars! The whole package!


since when is not ahving wheel hop a problem?

an independent rear makes it fairly easy to plant the rears like the goat

moat2005
01-26-2006, 11:22 PM
To answer your question, I have not noticed any wheel hop from my car? Maybe you can tell me more about that? So it has something to do with the back suspension?

ctbeiser
01-27-2006, 05:04 AM
I have a probelm with wheel hop. It happens from a dig and then when I shift into 2nd under hard throttle conditions. Sounds like the rear end is about to come out of the car. Has anybody fixed the problem or looked into it? I am about pull the my Vehicle Dynamics book from college off of the shelf and design a set of traction bars. Might as well use some of that knowledge for good.

Deeavi
01-27-2006, 11:33 AM
Doesn't the auto and the manual have different rear end gear ratios?

The Gentlemen
01-27-2006, 11:52 AM
IRS should eliminate wheel hop!!!!

Deeavi
01-27-2006, 12:53 PM
I have a probelm with wheel hop. It happens from a dig and then when I shift into 2nd under hard throttle conditions. Sounds like the rear end is about to come out of the car. Has anybody fixed the problem or looked into it? I am about pull the my Vehicle Dynamics book from college off of the shelf and design a set of traction bars. Might as well use some of that knowledge for good.

A set of air bags will help. Need to stiffen up that suspension.

quicky06
01-27-2006, 02:38 PM
To answer your question, I have not noticed any wheel hop from my car? Maybe you can tell me more about that? So it has something to do with the back suspension?

wheel hop basicly, occures when your tire start to spin bt the wheels literaly hop the bounce up and down. this is a bad thing. you dont want this

snaggeltooth
01-30-2006, 12:59 PM
Yea , we will just keep raceing those 03 cobras. I dont think a factory SC is a good idea. I worked at a Ford dealership and all the Mech told me war stories of the supercoupe, SC T.Birds . And that was a V6. The 4.6 is a very good everyday engine. But to put that much hp to one. Only time will tell

NYTIGER
01-30-2006, 01:23 PM
The springs are a little soft in the rear causing the wheelhop issue. Airbags and/or stiffer springs will eliminate it.

hellhammer
02-12-2006, 08:26 PM
Automatics will have less wheel hop, because they can be staged to pre-load the suspension. I.E. brakes on and some throttle squats the car. IRS IS the problem for wheel hop, not the solution. The big problem with the GTO is that the center section is too low, statically the axles are straight, under load they over center. Ideal, per a retired GM engineer, would be to have the rear higher so that under load the axles would be straight or considerably less over center. The way the rear set up is in the car, raising the center section is not an option. He said that if I wanted to test it, start by putting 2 inch spacers at the springs to raise the car, thus the center section. He had concerns with stiffening the suspension because it would impair the weight transfer. A lot of people are trying the air bags now, so there should be some good feedback on it. The only semi consistant wheel hop preventer (at the track) is a set of sticky tires. My `05 does not have hardly any wheel hop issues, but my `04 is a nightmare with it.

Dave

surfgzr
03-11-2006, 06:24 PM
Launch technique and tires make all the difference. Stock 2004's with the A4 can get into the low 13's with a cooler air intake, upgraded street tires and a mail order tune.

Wayah-bird
03-11-2006, 07:14 PM
I think that we recieve a lot of negative press, but really these GTO's are absolutely awesome cars! The whole package!
Oh I don't think performance is the issue with the negative press. That would be completely unwarranted. I believe any negative press is about the body being on the 'unexciting side'. I personally feel that they are fine looking machines, especially the bright colors, that will knock the heck out of anything similar in the same price range. I would love to have one before they disappear later this year.:thumbup:

tafdil
03-19-2006, 03:02 PM
I have a 05 GTO. 6spd. I had a little wheel hop when i first bought it. The stock tires are pretty hard,220 tred whear. I put 18x9" wheels with 275/35/18 with Goodyear F1's.They are softer tires,180 tred whear. This will help with wheel hop. A harder tire will spin then catch, which causes wheel hop. Also the gas tank in the new GTO's is located right behind the rear seats. Pop the trunk and you will see where the trunk stops and the back seats begin. That's the tank. That pushes the weight distribution more to the front. The best thing to do is add the poly. Bushing's. I also have HAL adjustible shocks on the front and rear of the car. You can transfer the weight dist. with these. They cost about $1200.00 bucks. But I went from running 12.11sec. 1/4mi to 11.73sec. Just by adjusting them. ThunderRacing.com carries them. Question? I have The Corsa Sport cat back system. They sound ok. Does anyone know if the SLP Loudmouth, Loudmouth 2, Or Magnaflow sound the best? I am looking for a real deep sound not a high pitch sound like our Mustang enemies?

GoatRider
03-22-2006, 02:34 PM
tafdil,

Take a look at the GHL exhaust system. It sounds like the old muscle car rumble. Of course, I also have K&N cold air and JBA short headers which might enhance the sound.

Regards,

Chuck

carbuff
03-29-2006, 09:50 PM
Dear GTO owners,

I wanted to pass on some experiences I have had with my 2005 GTO. I purchased an automatic about 6 months ago and I must say that I have been totally impressed with the car. It serves as my daily driver during the work week and on weekends it is a very fun car!

First I would like to talk about an automatic versus a manual transmission. I know that I might spark a large debate, but I am confident that the automatic is faster than the manual. I have raced two different manual GTO's making 3 run's against both cars. I won all six races and it always seemed to be by about 3-4 car lengths. Obviously there are a lot of factors involved here, but I would love your feedback?

Second I raced a supercharged 2004 GTO from a 20mph roll and to my surprise he was only able to pull my by one car length. I do know that 05's put 351hp to the 04's 301 on the dyno. I know that the 05 GTO puts around 480 to the back wheels with a supercharger. Again it could have been the particular run, but I estimated that he had to be putting atleast 430hp to the back wheels. His set up was extremely nice and we had a nice conversation at the end of the run. I must say that once again I am impressed how a stock 05 GTO was able to run with an very strong car.

The final experience I will talk about is against a modded 03 cobra. I believe he was putting out atleast 470hp. I would love to see what an 05 GTO would do against a stock 03 cobra? It has been very difficult to find one that is stock. In my race against the cobra we first went from a 20mph roll. He easily pulled away and I would estimate that he won by 7-8 car lengths. Next we went from a dig and again he easily pulled on me. He was driving on drag radials and I was driving on all season's. So I was pulled on hard, but I walk with pride. In the stock form I believe the 05GTO is a force.

In closing, feedback would be great. Please share your experiences!

According to the pontiac sales brochures...
in 04 the M6 0-60 is 5.3 and the A4 was 5.4 making the stick a tad quicker.
in 05 the M6 0-60 is 4.7 and the A4 was 4.6 making the Auto a tad quicker.
the 06 Brochure just says 0-60 in under 5 seconds.
I hate speed shifting my 04.... so i can see why most would say the automatics are faster, the M6 imho is too notchy

carbuff
03-29-2006, 09:52 PM
Doesn't the auto and the manual have different rear end gear ratios?
NO
both auto and sticks for all 3 years carry the same axle ratio 3.46:1