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Discussion Starter · #1 ·
I finally got the T56 in and the 4.10 rear gear installed and I am beyond thrilled. I have however noticed an odd thing and I am wondering if its just me or if this is common. When I am , for example, just cruzing on the freeway. If I have the ac on I can actully feel a subtle jerk in the car when the AC clutch kicks on. Is this just something normal for this setup or is it a sign that parhaps my ac unit is providing a higher than normal load when it is engaged?

On a side note... Everyone should have a T56 and 4.10s in their cars. It is awesome!
 

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I have a T-56 and 4:10s also. Mine doe'snt do what your describing. What clutch and flywheel do you have? I have a stock LT1 camaro flywheel and a centerforce stage 3 clutch and plate.
And your right its awesome.Once you get its like getting a new car!
 

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Discussion Starter · #3 ·
Stock camaro clutch and flywheel. It is real odd. I have owned several manual cars and never noticed this before. I wonder if maybe its my ac compressor, but there are no odd noises from it and it still works just fine so I'm a little perplexed
 

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Have had T56/4:10 since 05 with several types of clutchs and now a McLeod "non sprung hub" twin. No feeling of AC clutch kicking in as OP describes

The only problem I continue to have is my rear tires wear faster than the fronts...

yeah, GM should have offered the SS with a T56 :)
 

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Never had that issue either. I do have issues with the PS pump nearly stalling it although that's getting better the more I tune.

You're running the 5 spring hub right? Not the one with 4. I went through the ones with 4 a few times before I found a 5 at my local Autozone.

-Brian
 

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Yess!

Just purchased my T56 lookin to start the install in a month or so. Also gonna be installingy new built 9c1 rear end with 410s I'm excited!
 

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I've had my T56 and 4.56's in since 2004 and haven't noticed the compressor switching on/off. I used to run a Spec 4 unsprung but now run a spec 4+ unsprung if that helps at all.
 

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Discussion Starter · #9 ·
I guess it's just my car being a moody pain. According to the gf I gave the car a sex change because now it has a stick to play with but I am guessing it still has the hormones it had before the surgery. At least at the moment it isn't a huge thing, just a little annoying as I always want everything to work just right. Not always an option with 210,000 miles on the clock.
 

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Discussion Starter · #11 ·
What did you do with the Park Neutral wiring?
What flash is in the PCM ?
At the moment it is connected to the park switch from the colum shifter. The car will start any time I turn the key no matter what I do. I plan to wire it to the clutch next time I dig in to the wiring. I have the computer flashed by Brian H at PCM For Less for the manual. I did get the z28 cluster installed last night though so at least I have a tach. I should have wired the reverse lockout and the nutral switch then but it was getting late. Maybe next weekend.
 

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I was referring to the P-N signal wire to the PCM, not the start wiring.


I ask because I was wondering if you have a modified Automatic flash and the PCM thinks the car is in park making the IAC compensation of the AC clutch act differently
 

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When an auto is in park or neutral PCM terminal C 15 gets grounded

If you have that grounded ( many do under the dash because they found their trunk release would not work without ) decell fuel cut does not work, IAC follower does not work and I am wondering if the AC vs IAC is different.
 

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Discussion Starter · #14 ·
Ah I see what you are getting at. As far as I know the computer thinks the car is in park all the time. What would be the better way to wire it? Do you know where i can track down some instructions? As far as I recall I just followed the instructions on the swap manual but I may have just taken it the easy way out as I was rushing to get it back together. I know I didn't wire anything to the PCM at that time. It was all under the dash.
 

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Discussion Starter · #16 ·
http://ww2.justanswer.com/uploads/therock500/2011-02-24_052020_94_camaro_pcm_c_connector.gif


Open up the connector , remove the #15 wire and tape it back.

Now try driving the car.

If you by chance find the car doesn't drop revs the same , that probably means it is working correctly but the IAC follower tables were not adjusted as well as they could have.
Thanks for the info. I will try to get it pulled in the next few days and I will report back. What changes should I expect to see from doing this?
 

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It has been a long time since I studied this and I don't have an LT1 any more.

Pretty sure, if the car thinks it is in park ,
The EGR will not work,
The decel fuel cut will not work,
The IAC follower table will be ignored,
Canister purge might not work

The A/C clutch vs the IAC is a total guess


Sent you a PM
 

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Welcome to the club. Swap aside, I have owned cars that would do this. I think it's somewhat normal for older cars to slightly "jerk" or drop in revs(very minute)when the compressor kicks on. I want to say it's just the compressor dragging things ever so slightly. Just a thought.
 

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Discussion Starter · #19 ·
It has been a long time since I studied this and I don't have an LT1 any more.

Pretty sure, if the car thinks it is in park ,
The EGR will not work,
The decel fuel cut will not work,
The IAC follower table will be ignored,
Canister purge might not work

The A/C clutch vs the IAC is a total guess


Sent you a PM
Saturday I got that wire pulled out of the pcm plug. It's didn't make a difference on the behavior on the ac clutch but it did put it in the mode to look for a clutch switch (that is not wired at the moment) so I now know what to pull when I finally do wire up that switch but for now it will have to go back in.
 

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Sorry not getting what your are saying

One clutch switch is to prevent cranking unless the clutch is depressed ( not connected to PCM )

Other clutch switch is in series with brake signal switch to cruise module to disengage the cruise if you push in the clutch ( again not connected to the PCM )

While my LS7 "knows" clutch, I don't believe the 94-97 LT1 F bodies did

If the car runs "goofy" with the park wire disconnected, My bet is the conversion on your programming to "be a manual" might be lacking.

Gerry
 
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