Author Topic: MS3X/MS2 Trans Control on 4L60E  (Read 2088 times)

Offline quagmire

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MS3X/MS2 Trans Control on 4L60E
« on: December 22, 2015 - 01:11:21 PM »
For anybody who has seen my previous threads, I just finished switching over to a 4L60E trans and using an MS2 as a TCM.  I also am running a true crank trigger and LS2 truck coils (no more distributor).  I'll be yanking my intake due to a vac leak and for some port work and dropping in my CMP sensor to go full sequential in a week or two.

Overall, the swap really was not terribly difficult.  The 4L60E is a tight fit, but almost fits like it came that way from the factory after flattening out the pinch welds right above the bellhousing.  Most parts are readily available and off the shelf; my original 1350 driveshaft that was a hair too short for my 904 was actually PERFECT for this, so I swapped the yoke and ran with it.

My biggest headache was dealing with the Quicktime bellhousing.  They have no clue what it takes to make this work, nor what exact 4L60E trans they used for development.  According to them, no spacers or anything are required - which is based off of nothing when you cannot say what was used for mockup and design.  I'd strongly recommend running Silver Sport Transmissions sweet cast aluminum bell, if they still have them.

I had to cut a small access hole in the scattershield to install and torque the TC bolts, and had to order up an ATI GM to Mopar crank spacer and Quicktime shims to get the correct spacing to space the TC engagement and avoid having the TC bolts hit the scattershield.  Mine required 17mm of spacing, but you should always check your particular bell since who knows if they are the same from unit to unit with those guys.  The ATI spacer clearly wasn't validated either, since I had to have the flexplate pilot turned down to fit a Mopar flexplate.  Only cost $35, but unexpected headache nonetheless....  SST's requires none of this crap.  If I knew they were buying out Keisler before I made the purchases I did, I wouldn't have gone with Quicktime at all.

I got my crossmember and shifter conversion kit from SST, and had to modify the crossmember trans mount due to the Quicktime spacing issue above.  At least I have a welder to use for other projects now....  Again, use the SST bell and this is a non-issue.  I built the trans harness and used Metripack 150 connectors for jumpers until they go into my Ampseal bulkheads.  For the cooler lines, you'll need 6 AN 90 degree fittings at the case and 6 AN flex lines of your choice to adapt to the frame rail.  I use 3/8 steel line after that since I'm not a fan of that much hose.  5/16" is too small for this trans!

I built the trans myself to handle a lot of power, and it seems to be performing perfectly.  I had a gauge installed initially to dial in my line pressure curve (absolutely critical!!!!).  I'm now tweaking lockup and shift point settings.  I can monitor VSS, trans temp, and Tunerstudio/Megalog Viewer can now calculate MPG as well with the vehicle speed input.  The MS3X and MS2 work perfectly together and share signals via the two CAN wires.  I don't need duplicated wiring for ECT, TPS, RPM, etc...  It's all shared.  My fan control, A/C control, closed loop idle control, and a number of other "engine" side controls can utilize VSS to work even better.

On my first run out, I was able to hit a sustained 20+MPG at 70+ MPH, and this is with a still largely untuned engine and a vacuum leak on one bank bad enough to see a large difference in fuel trim!  At 50MPH in 4th lockup, it'll sustain 26MPG at 1500RPM on flat roads.  I'm confident I can get low to mid 20's at highway speeds out of this one I get everything dialed in and fixed.

For a converter, I'm running a Street Edge 9.5" 3500 stall lockup converter.  The unit as a whole drives much better than the old 904.  The shifts are crisp and off the line it doesn't feel like a boat anymore.  It's eerie going into lockup at 45MPH and only turning 1600 RPM or so.

If anybody needs specific details or questions, feel free to ask away...  Overall, not too bad and I'm pleased with the results.
« Last Edit: December 22, 2015 - 01:16:36 PM by quagmire »




Offline GreenFish

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Re: MS3X/MS2 Trans Control on 4L60E
« Reply #1 on: December 23, 2015 - 07:55:35 AM »
great info, i'm using a manual on mine, but interesting choice going with the auto and using the MS to control it. I was wondering how their TCM was going to work.
70 cuda, 440, KB pistons, 10.5:1 compression, edlebrock heads,RacerBrown cam, 5-Speed Tremec, Megasquirt EFI

Offline quagmire

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Re: MS3X/MS2 Trans Control on 4L60E
« Reply #2 on: December 23, 2015 - 11:53:53 AM »
So far, it works pretty darn good.  There are other standalone TCM modules out there, but the integration is the biggest bonus doing it this way.  That, and it was less than half the price of the others.

By having the two modules talk to each other over CAN, I can tune and datalog signals from both at the same time.  It makes it a lot easier to look at the big picture when everything is in the same recording graph.  It also cuts down on wiring substantially which obviously reduces potential issues with it.

Only minor hiccup so far is that the VSS signal does get erratic at really high speeds (80+), so I'll be using a GM DRAC module to filter and clean the VSS signal and send it to the TCM.  It'll send out a 5v square wave and can pulse at much slower frequencies (as low as 2000PPM vs. whatever a 40 tooth wheel pulses in a mile) than what the VSS puts out directly, which eliminates signal noise/high voltage/ saturation issues. Mine was less than $40 on eBay and GM used them for decades; they are proven and made to perform this function with this sensor.  I could fiddle around with resistors, caps, and diodes, but for less than $40 I don't think I can go wrong here.