Excellent! 3" always sounds better IMO!!
CK5
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94 Z28 coupe
- Thread starter Bent77
- Start date
It’s a bit throatier, less rasp. So that’s a win
And me cutting it apart didn’t ruin it either. Also a win!
So I’ll explain how the science part of this works, and how they assemble these new, just for fun:
This is a series 10 model. Quite literally, one half and another half is how it works
This is the section with the V break in it, and a cone shape with a hole opposite
I cut all this out/off and upgraded it to 3” from 2.5, and the same with the port in the cone, and the outlet
This is the main flow chamber, it is the driver side
I tried to take a pressure reading in this side of the case with a manometer, but it was pulsing like a draft tube in a header
This is a series 10 model. Quite literally, one half and another half is how it works
This is the section with the V break in it, and a cone shape with a hole opposite
I cut all this out/off and upgraded it to 3” from 2.5, and the same with the port in the cone, and the outlet
This is the main flow chamber, it is the driver side
I tried to take a pressure reading in this side of the case with a manometer, but it was pulsing like a draft tube in a header
When they build these, they take the outer case assembly and stack the pieces on the outlet and then each plate inside
What makes this different than a straight through is the outlet on each side. With the driver side done, we need to reverse the flow back to the pass side
From L-R
1. Crossover port. 1.75” inside. I did not alter this. Part of the reasoning, this side acts like a balancer, taking what is essentially the excess pressure and running it into an empty chamber (the port 2 is sealed off from)
2 Port through, sealed in the second (middle) chamber. Opened this up from 2.5 to 3”, sealed on both chamber plate ends
3 passenger outlet. This tube is pressed in from the outside into that plate, then welded to the case end plate. Any pressure that does go through port 2 circles through port 1 back to here and out. Opened this up to 3” to make sure the 2nd chamber isn’t creating back pressure
This the first small 4” wide chamber where the inlet is dumped into, the press sealed around port 3 to not leak
What makes this different than a straight through is the outlet on each side. With the driver side done, we need to reverse the flow back to the pass side
From L-R
1. Crossover port. 1.75” inside. I did not alter this. Part of the reasoning, this side acts like a balancer, taking what is essentially the excess pressure and running it into an empty chamber (the port 2 is sealed off from)
2 Port through, sealed in the second (middle) chamber. Opened this up from 2.5 to 3”, sealed on both chamber plate ends
3 passenger outlet. This tube is pressed in from the outside into that plate, then welded to the case end plate. Any pressure that does go through port 2 circles through port 1 back to here and out. Opened this up to 3” to make sure the 2nd chamber isn’t creating back pressure
This the first small 4” wide chamber where the inlet is dumped into, the press sealed around port 3 to not leak
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A new hat and a pipe! sweet!
Stock valve body, right?
My son was able to see that my 4L80E went to 6350 rpm with the shift point at 6200. Remember that we did a shift kit in it and he had to work on the shift parameters after that because the PCM was trying to slow down the shifts.
Are you considering a shift kit?
My son was able to see that my 4L80E went to 6350 rpm with the shift point at 6200. Remember that we did a shift kit in it and he had to work on the shift parameters after that because the PCM was trying to slow down the shifts.
Are you considering a shift kit?
It is stock, and honestly I don't see a benefit adding one being as it is still set to stock line pressure, which is 90/255
Suggested is 120
I did modify the elapsed shift time in this before
Shifts are clean and smooth, but not harsh
Waiting to see how it shifts after the gear change before i do anything to the line pressure
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@ktmoutfront
In addition to what @6872xtc and John already messed with on that one, I had an observation.
Not sure if is the same on those ECM units or not, but:
Because of the multiple shift tables, it will prioritize based off one table or another if at full TPS
In the case of the 8051 ECM, it will do MPH shifts at part throttle, and RPM shifts at full
In the tables, that MPH call for shift is set about 7-800 RPM lower than what the RPM table is set to, so it only runs to that full RPM at full TPS
So at full TPS, it goes past the MPH number, therefore being met as a requirement for the shift
Thus, the scalar, divisor, and scan tool numbers have to be changed to cover for any gear change calculation, or it won't exceed the MPH, and then it won't shift at WOT TPS values
In addition to what @6872xtc and John already messed with on that one, I had an observation.
Not sure if is the same on those ECM units or not, but:
Because of the multiple shift tables, it will prioritize based off one table or another if at full TPS
In the case of the 8051 ECM, it will do MPH shifts at part throttle, and RPM shifts at full
In the tables, that MPH call for shift is set about 7-800 RPM lower than what the RPM table is set to, so it only runs to that full RPM at full TPS
So at full TPS, it goes past the MPH number, therefore being met as a requirement for the shift
Thus, the scalar, divisor, and scan tool numbers have to be changed to cover for any gear change calculation, or it won't exceed the MPH, and then it won't shift at WOT TPS values
Now my head hurts. Tells me to put a throttle stop on the pedal so I never hit WOT.
That will make it shift off TPS vs MPH
text me when you start
I'm thinking some of the tables may be different. The theory should be the same
Have you guys looked into the blue cat transmission table builder? I used it on my Holley and I actually liked it and I prefer the GM method to the madness.
While I believe that you are thinking properly about waiting until after the gear swap, line pressure isn't necessarily what I would go to first or primarily. The orifice sizing in the separator plate can be as big of a factor in my knowledge. Yes, line pressure comes into play with those, but being able to pass the oil into the clutch pack or band apply faster.
And after discussing things with John about the Corvette servo for the band, I would recommend that anytime. He can tell you what he found from several sources.
I don't have any idea if the Camaro got one any different.
Ask John about the suburban that he did for his FIL.
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Link?
Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com - View Single Post - Bluecat Transmission Table Software 1.37
Chevy Camaro Forum / Camaro ZL1, 1LE, SS and V6 Forums - Camaro5 & Camaro6.com
www.camaro5.com
I did ask John. He knows more about this than you. You’re afraid of the governor in yours
I do need to research what the stock servo is
Yes he does!I did ask John. He knows more about this than you. You’re afraid of the governor in yours
I do need to research what the stock servo is
And I haven't made my governor a priority, because a certain buddy helped me dive into a big block!
(like that's the only reason..)
So full manual valve body!
