stock numbers?

[jerrad]

i know everyone says are cars were underrated hp/tq wise so did anyone ever take a low mile new Gn and put it on a dyno to see the real numbers? thanks jerrad

 

[BLACK6PACK]

consensus seems to be right at 275 hp and 350 lb/ft of torque to the rear wheels.

 

[2QUIK6]

My TTA with 14k miles stock dyno'd at 235 rwhp and runs mid-high 13's in the 1/4. The advertised hp is the flywheel hp not rear wheel hp...so add another 20-25% for drivetrain loss and thats would be around 285 or so at the flywheel...a littel higher than the advertised 245hp....wasn't it 245 that was advertised for the GN anyway, I think the TTA was 265??

 

[jerrad]

i though the trans am had the exact same engine and trans but because of the weight and aerodynamics it was faster.

 

[UNGN]

Originally posted by jerrad
i though the trans am had the exact same engine and trans but because of the weight and aerodynamics it was faster.

It actually had different heads, headers, pistons, intercooler, stock boost setting and the exhaust was completely different.

Some are better, some are worse.

Weight is about the same, aerodynamics are better, but that doesn't have as much effect as most people think.

 

[jerrad]

all that and only 20hp? oh well thats cool though

 

[turbo2nr]

The turbo was almost the same as the GNX. The Gn had a .63 A/R turbine housing, the GNX and TTA had a .85. That's why the GN had a torque peak around 2000rpm, and the GNX was around 3400rpm, or something like that. Of course the GNX had the ceramic turbine wheel. The heads on the TTA are no better than the GN, it used them because of clearance under the hood.

 

[2QUIK6]

The heads on the TTA make it have a little bit higher compression, they were used to clear the strut towers and are for the front wheel drive 3.8. Eprom program setting are a bit different to compensate for the different compression. Don't think making a ton more hp than the GN motor was GMs goal when the TTA was conceived, just a few improvements in crank shaft oiling, and making it work with the different heads and tight constraints of the TTA body design.

 

[mygrain]

TTAs had different pistons with more dish than GN pistons.