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Hi. I'm 17 and traded my gtp for a 95 caprice 9c1 because I love the b-body style.....my uncle has a 94 impala ss and says that the lt1 in my car is detuned and slower than the ss but I thought that the power output and gearing were the same.....if I posted in the wrong section I'm very sorry but I'm new to the forum and want to know if I stand a chance...
 

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Well I see that the drivetrain is identical but can't find info on computer calibration and weight differences
 

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Doug,

the 94's had a few things that were different, that infact made them slightly faster.

my 94 was always the fastest out of all my bbody (unmodded)

at least it was a 94 9c1, I am not 100% sure if the SS had the same items.

if I recall, they had different push rods, different cam, and a few other small differences.
 

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Well I don't kno how the caprice runs now but my gtp was slightly faster than the impala. . Hes telkibg me that not only does my caprice get less gas mileage but its slower and it was a dumb trade
 

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Well I don't kno how the caprice runs now but my gtp was slightly faster than the impala. . Hes telkibg me that not only does my caprice get less gas mileage but its slower and it was a dumb trade
well it really depends on the condition of both cars.

can we see some pics?
 

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Welcome to the forum and congrats on your car. enjoy it and look through the stickies here as there is a ton of info gathered over the years along with lots of helpful members.

as for which is faster.....The enlgines if they are both LT1's should be pretty much the same. Some 9c1s have the smaller L99 (4.3 vs 5.7) engine but all Impalas came with the 5.7.

Another factor in which car would be faster is gearing. I believe all SS's came with a 3.08 gear and some 9C1's would have a 3.23 or a 3.42 from the factory. If the engines are identical, I would think the car with a 3.42 would be faster.
 

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The only important engine differences between any 9C1 with LT1, and an ImpalaSS of the same year, would be the speed limiter in the program. Any other differences in the programs are either negligible and irrelevant, or nonexistent.

9C1s were limited to 130MpH only when equipped with 'H' rated 225/70R15 tires. Most of those were L99s, but some 9C1-LT1s were ordered with 225/70R15 tires.
9C1s were limited to 149MpH when equipped with 'V' rated 235/70R15 tires.

Impalas SS were limited to 154MpH, due to a driveshaft resonance issue.

Civilian Caprices [regardless of engine] were limited to 108MpH. The original tire spec for these would be 'S' rated 235/70R15.

All B-LT1 engines for a given year were identical, as far as the hardware is concerned.
This is the correct info. Many LT1 9c1's including my federal car were ordered with 225/70R15 tires. The speed limiter is easily removed when you have your PCM tuned. L99 9c1's have 3.23 gears, LT1 9c1's have 3.08 gears, the same as the Impala. The Impalas had Posi (G80) standard and it was an option on the 9c1's.

There is no significant performance difference between the LT1 3.08 Posi 9c1 and the same year Impala SS.
 

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fbi9c1 nailed it. I might add that the 91-93 TBI 9C1s are what had the 3:42 gears (with HD rear drums) and that was not available on the 94-96 PFI cars. Also the axle width and spring heights are different (doesnt affect performance) on the 9C1 vs. the SS. The SPID label in the trunk will tell you what options you got. Yes, there are lots of 9C1s with the 4.3, and non posi.
 

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Well I don't kno how the caprice runs now but my gtp was slightly faster than the impala. . Hes telkibg me that not only does my caprice get less gas mileage but its slower and it was a dumb trade
Well I would say your 9C1 has a lot more potential than the GTP. If your Caprice is not faster than the Impala then with just some minor Mods it could be. You are starting with the same car - but the 9C1 has life-time hoses and stiffer springs. In our club a 95 9C1 was the fastest at the 1/8th mile drags last year.
 

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Congrats on a great trade!

You might tell your Uncle that your car still has the "intercepter chip" and is, therefore, faster. :)


Sent from AutoGuide.com App
 

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its not true there were internal differences of the motor also...
There were differences in the 94 to 96 engines, but there wasnt anything that made one better than the other. I think the 94 calibration might be a bit more agressive. The 95's feel smoother to me, but could be the transmissions and the 96's were better yet and felt like they had a bit more bottom end torque.

The impala and the caprice are all "identical" for the discussion at hand. Physically the 9c1 should be quicker due to the impala with its 26.25" diameter tire and the 9C1's 25.34 diameter tire. Cams are the same, timing curves and fueling curves are the same. I can post screen shots of stock file tables. The biggest in the cal files are differences is in the shift scheduling. The 9c1 is closer to the vp4 cadillac cal and feels better to me.

OP, put a tune in your car and wipe the smirk off his face cwm4.

Chris
 

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i have a question for this discussion.Is there a weight difference between 9C1's and Impalas,or Caprices?
 

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There were differences in the 94 to 96 engines, but there wasnt anything that made one better than the other. I think the 94 calibration might be a bit more agressive. The 95's feel smoother to me, but could be the transmissions and the 96's were better yet and felt like they had a bit more bottom end torque.

The impala and the caprice are all "identical" for the discussion at hand. Physically the 9c1 should be quicker due to the impala with its 26.25" diameter tire and the 9C1's 25.34 diameter tire. Cams are the same, timing curves and fueling curves are the same. I can post screen shots of stock file tables. The biggest in the cal files are differences is in the shift scheduling. The 9c1 is closer to the vp4 cadillac cal and feels better to me.

OP, put a tune in your car and wipe the smirk off his face cwm4.

Chris
I remember us talking about the 94 9c1 and how it had reinforced push rods and some minor differences on the cam.
 

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i have a question for this discussion.Is there a weight difference between 9C1's and Impalas,or Caprices?
I would think that a 9C1 would be lighter than a Caprice or Impala due to the latter two having more options and "luxury" equipment as standard; can anyone confirm that?

And to back up what others are saying, my buddy compared his stock tune (1996 Impala) to my stock tune (1996 Caprice) because he, too, thought that the Imps got something special. Except for the speed limiter, we saw no difference in any parameter. He just wouldn't believe me until the numbers were in front of him :).

OP, for what it's worth I like your trade: I think the B-body is more stylish, and certainly more unusual, than a GTP. It'll probably be a more robust vehicle, too, if it's in good shape.
 
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