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9c1 vs b4u

7065 Views 16 Replies 8 Participants Last post by  1BAD9C1
hi there i have a 95 caprice with the lt1 b4u and towing package and a friend of mine has a 94 caprice pc1 x rcmp car and he has flowmaster mufflers and k&n intake stock 3:08 gears and i have cold air intake and hypertech programer and running preium gas and i have 373 gears and true trac posi . Now i like my car but his seems faster than mine we have not raced yet but i have driven his and he has driven mine and we both think his seems fast buy the seat of your pants test . is the 9c1 tune different than the civi cars or am i just missing something. I can use his vin and tune a computer to it but is there any difference.
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No tuning isn't different between the two. My friend with a 96 SS thought my 94 9C1 with 120K on it was faster than his car as well, never ran them though. He is running OBD1 so there maybe some subtle differences with the tune, but I wouldn't think that a car with 3.73's and pretty much the same tune would compare to a pretty much stock car with 3.08's
9c1 goes 154mph and b4u goes 108mph max, thats the only tuning difference I know of.
i would have throught that with the 373's it would be a little more torquey than his. does the exhaust make that much difference mines stock his is just flowmater mufflers the rest is stock.I'm going 2.5 pypes x pipe flowmaster 40s and dyna max over axle pipes and chrome tails. will it help that much to be as quick as a 9c1?
9c1 goes 154mph and b4u goes 108mph max, thats the only tuning difference I know of.
Good call on that one, but I don't think that it is that high, I thought it was relative to the tires that were installed on the car. I could be wrong, I guess I don't remember on my 9C1 it being that high.

OP- the exhaust will make a difference, but nothing compared to gear swap. I don't know.
9c1 goes 154mph and b4u goes 108mph max, thats the only tuning difference I know of.
The production PCM settings for speed were set based on the spec tire used on a particular model.

I don't know if the 9C1 was 154 MPH or something else. V-rated tires, which were available on 9C1 (not sure if they were default/standard by specs) are rated to 149 MPH. Anything other than an unmarked vehicle would probably not get close to 149, let alone 154, due to increased drag, but I'm not saying it wasn't possible, either.

It might be possible to have a factory 9C1 tune applied to a B4U, but the GM flash process may require a VIN validation to match up the vehicle to the allowed limits, based on the PCM in the vehicle (in other words, GM's flash program data base should know which VIN's have which speed limiter settings, but I'm not certain). A B4U would not have the right gear (2.93 vs 3.08) for everything to work out "right". Tuners can do the deed, if a factory flash isn't possible.
Thanks for the clarification Bill, I had thought that they were programmed for type of tire but I wasn't certain.

I guess you could throw into the mis with this, and I thought or read this somewhere that the OBD-1 cars had a little more umpf due to the programming between the OBD-1's and 2's being different, I could be way off, but I thought that I read that somewhere.

To the OP- I reread your original post and it stated you have a Hypertech programmer, that may be half of your problem, ditch that thing, contact a respected tuner and get a GOOD mail order tune, you will be surprised. The programmers from Hypertech are junk and can cause more problems than not. Plus with the gearing that you have I am not sure if the hypertech unit will change the shift tables correctly for that gearing and can cause other problems in it self. When you change the gears there is more than just speedo corrections that have to be accounted for with an Auto trans.
i did notice that the car shifts harder after the gear change and after the hypertech was used to fix the speedo . i didn't get the computer tuned by anyone because i didn't think i had enough mods to justiy programing yet ( i'm not done getting all the stuff i want to do to it ) i just wanted the speedo to read right and its my daily driver so sending the computer out to be reprogramed was not an option yet .but why is the 9c1 faster stock with mufflers than mine theres got to be something his has that mine does not also his has way more mileage (mine has 94000km his has 250000km) and worn out feeling and does not ride or drive as nice as mine but his feels more powerful. maybe its the sound of the flowmasters and it all in our heads. :)
Two things come to mind.

The mufflers (even crappy flowmasters) are probably letting it breathe better than the restrictive stockers.

The cam is different in the '94.

I've raced, and beat, a lot of later year B bodies with 3.73 gears when I had 3.08's.
So there is a difference its the cam ok now i know thank you very much. by the way what are specs on the 94 vs 95 cam not that i going to put in a 94 stockcam ? i will go after market later.
So there is a difference its the cam ok now i know thank you very much. by the way what are specs on the 94 vs 95 cam not that i going to put in a 94 stockcam ? i will go after market later.
Not sure, but they were pretty small differences, but I can't help but think they did get the car moving better. They had different part #s too. The info used to be on here before the great crash of '09.
Factory Camshaft Specifications:
1992 Y-body: 205/207 0.451/0.450 lift 117 LSA
1993-1995 Y-body, F-body: 202/207 0.450/0.460 lift 116 LSA
1994-1996 B-bodies (including L99 4.3L): 191/196 0.418/0.430 lift 111 LSA
1996 Y-body, 1996-1997 F-body: 200/207 0.447/0.459 lift 117 LSA
1996 Y-body, F-body LT4: 203/210 0.476/0.479 lift 115 LSA

According to all information I've been able to find, all 94-96 Gen II B-body engines--both LT1 & L99--used the same cam, PN 10243779.

The differences could be cylinder heads, which have different PN between years, but mostly it's OBDI vs OBDII, from all I've seen or heard.
In 250k someone could have mildly warmed the engine over? dont forget the 9c1 without all the lights and equip is lighter. perhaps by a few hunderd pounds? A previous owner could have had programming done too. until you guys actually race we wont really know which is really faster. SOTP is VERY subject to other senses,especially sound! His car have carpet or rubber floor?
Supprised no-ones mentioned this yet, but 9C1's come with factory electric fans and B4U's come with factory mechanical fan for towing. While not a whole lot of power loss when coupled with the fact that as stated above he probably has ther lighter car and has aftermarket mufflers and you don't, thats probably enough to make the SOTP difference you guy think your feeling.

Race and let us know who wins. That as stated above is really the only way to know fo sure.
well he has mats and i have carpet and his engine has not been moded and the computer has the stock tune cause i flashed a new pcm at work when he was chasing a stalling problem. so i came see the engine driven fan but i would have thought the gears would have woke the car up a bit more than it did but my next change is the exhaust and torque converter. i have use the s10 conveter on a 94 c1500 and it was a different truck after way more fun to drive. :)
It's the mirrors.

Bigger surface area causing more drag, almost twice the glass, etc. is a lot more weight. It's killing your SOTP calculations.

Leave your truck mirrors at home, and you'll be faster, and get better mileage too.
It's weird, i've raced a couple Impala SS's and ive beat them rather easily. But they probably weren't fair races since i'm guessing my 9C1 had more mods than them.

But the last time my 9C1 was in the shop, my mechanic told me when he test drove it that it felt way faster than a nice '95 Impala SS he had in his shop at the same time, and both cars had 3.73s, Hypertech, etc, very similar mods. I've heard 9C1s are slightly faster than the Impalas, but i'm sure Impala SS owners would disagree too. Might just depend on which car you get and the mods.
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