Anybody ever look into doing something like this for a transmission controller? MegaShift/GPIO Transmission Controller
The more I drive the more I'm thinking a lower first gear or a higher stall converter, more sensetive downshifting, higher revs before shift(my engine wants to rev to 6000rpm or better), and tighter shifts would be very nice. The above DIY option could be a more affordable option to the compushift.

Obviously the higher stall and lower first can't be helped with a controller, but taking off better with downshifts and upshifts to match the engine would be helped/fixed by the controller.

A custom converter with higher stall, higher t case gears for reduced cruising rpm, and a custom converter might be close to the apex for the factory zf trans with a gm engine.

 

Something doesn't seem right with you shifting. I have 35's and 4.43 gearing my RPM at 70mph is 2750. Also my shift points are much lower around 3,000rpm or lower.

 

Its eerily quiet in here.

Just took my Rover out on a shakedown run with the 5.3 swap and 35" tires. Had a blast. I had some minor rubbing after some trimming. I think a little more will do the trick.

 

Awesome, very nice... I had 12.5" 35's for awhile and was disappointed with the performance.... moved to a skinnier 35 and its night and day! Way better: Went from a 315/75/16 to a 285/75/18.

 

Still having issues with flashing M&S on startup. Only about one out of ten starts is a successful one with either no M&S light or S lit on dash and that is being generous. When using one of the recommended scan tools from iCarsoft that is for Land Rover/Jaguar I get strange response when scanning A/T ecu. N__MOT invalid (flag F__N__MOT) and I can go ahead and erase whatever code the transmission is bitching about and go on about my daily drive without issue except for an ongoing Knock Sensor circuit 1 input voltage low message on the GM ecu which doesn't come back once cleared. I am pleased one start up out of the day if I have no cel or flashing M&S light. Whatever the issue is it's intermittent. Setup is : New Interstate battery and 150 amp Rover alternator, 2nd new ckps that is bosch, Relay on the two computers that used the switch wire from the swap and a direct positive wire from the battery terminal inside the uderhood fuse box. New MAF on the way for a 4th gear ration incorrect code. Enjoy the power and am getting between 14 and 16mpg just average all around driving so nothing there to complain about but I can't put my wife in it even for a minute by herself and expect her to be able to clear a code which I'm pretty sure is going to happen. I've read all the common issues with the flashing M&S lights and opted for the ACE wire harness support for the underhood portion. .016 gap on the ckps and tach is fine. I know i'm beating a dead horse here and there is likely a ground or power issue somewhere. I am using the stock mesh ground strap to the driver side LS head to firewall and have a ground wire from ecu to firewall plus engine to chassis cable to ground. Speartech LS harness is grounded to the stock LS ground bolt on the back of the engine behind the cam sensor. This is my one and only issue that is keeping me from loving this swap. It has been on an 1800 mile trip out to Taylor Park Co and back and did everything asked of it so it is a proven swap as far as i'm concerned. Just running out of ideas. Trans ECU flaky? XYZ switch flaky? Just continuing to trouble shoot this problem. What other code reader are folks using to read the transmission codes and has anyone else gotten the weird message MOT?

 

I got the MS flashing light with 2 amigos at one point. I cleaned the terminals on the battery and also sprayed the xyz unit/connector on the transmission with WD40 (read it on the forums somewhere) and the issue went away. Give it a shot.
​​​​​​
Also, are the wires going to the conversion box soldered together or did you use butt connectors?

 

All conversion wires soldered and I did clean terminals when I installed the new large Interstate. I did drill out the rivets on the XYZ switch and look inside it but didn't see the usual wiper assembly in there. I instead found a series of bumps or cams on the rotor that open or close point sets that are hard to access. Thought these switches were all the same. Since I didn't see a practical method of cleaning the contact points inside the switch I just sprayed inside it with contact cleaner and dried it out then used 6-32 screws to put it back together. I suppose this could be an issue but will need to resolve my scanner issue before I can go further I suppose. Just venting because I really like the swap but this one thing is a pita!! Any experience you all can share will be used accordingly. Thank you all.

 

Double and triple check the wiring on the ECB conversion box. I did find that the instructions were slightly confusing. Is it maybe possible the ECB box is bad? Might be worth getting another one to cross that off the list. I really think it comes down to a grounding issue from what I've read.

 

Since I run a repair facility in my "spare" time it's hard to secure some time to commit to fine tuning this swap but I know the devil is in the details. I already found an issue right away which came from me assuming that the wire harness colors on the speartech harness were the same as a gm harness and that had to do with a vss signal to the box. Corrected that but will go through the box connection step by step again when I get time and then contact ACE about a replacement box. Thanks

 

I triple checked mine bc in the instructions some wires are required to be cut with one end disregarded and some connections are splices.