Why Only 275 Horsepower? - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Bonneville GXP/ Northstar Powered Cars Discuss your Bonneville GXP and/or any other Northstar powered Olds or Cadillac... Including the 3.5L Twin Cam V6 (Short Star ) 4.0L and 4.6L Northstar V8's. Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

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Old 05-24-2004, 12:38 PM   #1
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Default Why Only 275 Horsepower?

Thinking about buying one of these this week...

Does anyone know exactly what differences derate the horsepower from 300 (in the Cadillac) to 275 (GXP).

Anyone?

Thanks,

Scott
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Old 05-24-2004, 01:57 PM   #2
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Apparently its the 275HP Caddy SLS tuned 4.6L Northstar...not the 300HP STS. Mikey explained it pretty well in one post.
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Old 05-24-2004, 04:40 PM   #3
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the original n* was 270hp, gm felt the pressure to make it to the magical 300 hp mark, so they screwed the camming all up to make it 295hp, but less tq (in 95 they redid the intake manifold to bump both up 5hp). throughout the entire RPM band the 275hp version makes more hp and tq than the 300hp one, but where the 275 one levels off, the 300 one keeps going. to make up for the huge lack of tq in the 300hp, they put in 3.71 gears, the 275hp one got 3.11 gears. even with the worse gearing the 275hp accelerates quicker. they further handicapped the 275hp one by giving it a 6,000rpm redline, the 300hp one got a 6500rpm redline.

so with the GXP they got the best of all worlds, the stronger 275hp engine, the better 3.71 gearing, and less restrictive exhaust so it kept the 6500rpm shifts (so its probably more like 280-285hp since it has a higher redline and free-er flowing exhaust)

so if you get one, does this mean we can expect intense to start releasing some Northstar performance parts?
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Old 05-24-2004, 04:46 PM   #4
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hey jim, with how many people ask, you should make a sticky as to why pontiac using the 275hp version was a better choice

whats even funnier, is the big "reason" is because the 275hp version looks worse on paper, cant have it shinning on cadillacs parade, but its actually a stronger setup than the STS/DTS setup, untill of course they go with RWD, 5speed auto, and VVT in the STS in 2005 (XLR'* drivetrain)
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Old 05-24-2004, 05:34 PM   #5
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Valid reasoning... we can sticky this thread and discuss the reasons why the GXP is only 275HP
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Old 05-24-2004, 06:16 PM   #6
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Quote:
Originally Posted by Jim W
"Aurora Snow"
You know who that is, right?
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Old 05-24-2004, 06:41 PM   #7
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Took you long enough Fuddy and yes I do
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Old 05-24-2004, 11:31 PM   #8
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Quote:
the big "reason" is because the 275hp version looks worse on paper, cant have it shinning on cadillacs parade
That was my uneducated guess.

Quote:
so if you get one, does this mean we can expect intense to start releasing some Northstar performance parts?
Anything'* possible, and you know me...

I did locate the car I want today, and managed to negotiate it down to within $920 of what I would like to pay. Best guess is that I'll probably pick one of these up by the weekend...

Scott
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Old 05-25-2004, 12:45 AM   #9
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To bad BadSSEi didnt break 10'* you could strip it down and trade it in on BadGXP

I gotta come get pictures when you get it Hey bring it to the dyno this weekend and we can test her out!
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Old 05-27-2004, 12:29 AM   #10
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I just brought home a new GPX and I have two comments:

1) Damn, is this thing SLOW!

2) Other than the above problem, this is one of the nicest cars I've ever ridden in, driven or seen.

Maybe I'll have to focus a little on the first issue...

Scott
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