Thread: meet Bertha

Cause a T42 will run the 4t80 out the box with full functionality.

so when does one of these trans go in my car

Sub'd... : )

Originally Posted by 91parkave

Cause a T42 will run the 4t80 out the box with full functionality.

close but no cigar, there's no point in spending ~150+$ for a tcm and tunercat work when i can run the 4t80e with a 10$ relay if i wanted.

then there's the general issue with traction control/tq management at the shifts as the 65e/7440 pcm's dont have the same desired tq functions as our PCM is setup for an integral trans control system

so that would not be full functionality...it would potentially just be a working trans....would also probably be fun trying to keep the TCM vin in yer head/written down somewhere so you can hookup a scanner to try and diagnose any issues.

i just dont see how an external TCM is any help or of any worth when the OEM TCM controls it just fine minus one or two diagnostic functions

Has anyone asked themselves how it was done in the Bonneville? I never looked to see if the pcm is the same, but Bonnevilles could come with either the 65 or 80 depending on motor.

the PCM/file for the N*/80e bonnies is different. ran into the issue with the riv/aurora platform

in jeff's bonnie he's running it with an old diesel 4l80e TCM and tunercat work on it

Dave got his 97 going using a custom bin. ive often wondered if the trans type parameter could be changed to allow for the inverted 80e solenoid but i wonder if there would be any issues from the two fdiffernt files

Has me wondering.. since you can swap transmissions around using TT, wonder if someone with the skill would be able to toss an 80 into the mix and have the invert happen or if the hardware of the pcm is not able. That's what I was getting to on the pcm in the Bonne. But TCM explains it.

thats what mr Norris has done...he's using the 80e trans file with the 65e pcm.

sort of a hybrid i guess.

without doing that the only other option is to invert solB logic using an inverter and possibly losing tcc function.

the ideal combo would probably be the 03+ pcm with the 00-04 IMS 80e...and you even keep TCC diagnostic function

i swear i just want to get one of our powerplants wired so i can test the shift solenoid activation with the dhp "trans type" changed. i know the nnumbers for the 4t45/60/65/etc so id figure the 80e may be a higher digit....ill know when the shift solenoids activate in the 80e pattern....at least im hoping.

Yeah, the box is crazy expensive. You can send Dave Norris your PCM along with $150, and he will make all the changes necessary to run the 80e.

yeah daves modified (i believe he and tunercat worked together on that) bin is using 80e solenoid logic so you dont need to use the signal inverter on the shift solenoid b.

for your trans diagnostics and the future use of an IMS equipped trans you may want to consider the 03 pcm as the more i tear into it its the best solution for the drive by cable guys (96-02) as they can use the more plentiful 00+ tranaxles with the internal mode switch to remove the headache of the external range switch.

yeah i know you can use the 65e sensor onthe 80e range bracket, but that wont clear off the shelf PS headers for someone doing a sc3800/80e build.

conceivably it would let you use off the shelf turbo crossovers, except the primary issue with those is that the 80e has the large dry sump cover and the oil fill tower where most 65e trans turbo setups would have the turbo.

so its probably a wash but it is a compromise for some builds that should be figured on.

my one question with daves file is iff all the tq/load calcs function or integrate the same and whether they switched the PCS pwm frequency.

if your looking to get it driving without the coin for the file you can use a regular 5 pin relay and pigtail to do the solenoid inversion using the relay in a NC config and easily reverse it once your ready for a custom file...at the least it would help you confirm the trans works.

btw folks find a nice one and buy it without the warranty. read the fine details and they wont warranty it anyways...not till you tow them the car within the 30/60/90 day warranty period, and they confirm its not functioning correctly and that the car is unmodified. (oh **** yer cars modified? what were you thinking!)
you can usually get 100$ kncked off AFTER you ask for the price/trans info and their inventory number (make sure they dont slip you a questionable trans)....then tell em you want the price without the warranty, you can sometimes haggle this down more if its not a big yard.

well its a minor part but its pretty much finalized...gonna add in a gusset across the top. slight difference from one case to another but the bugger works

It's likely wrong that I know there's two holes in the block there. H bodies use one the bottom as a ground location.

I was finally able to put a 4t80e converter and flexplates from a Northstar on the CMM.
Bolt circle centerline is 9.815" so id say the 9 13/16" bolt circle is correct.
At least with that info its easy to measure and scribe a flexplate with the 4 bolt pattern with just a 6" dial caliper and some maths.

Im having my two Meziere flexplates and a few 3 window stockers machined with the 4 bolt pattern....so I figured you'd want to know

Originally Posted by Turbocharged400sbc

well its a minor part but its pretty much finalized...gonna add in a gusset across the top. slight difference from one case to another but the bugger works

im gonna need that bracket and whatever other "off the james shelf" tricks you have to make a 4t80/3800 as bolt in as possible! those look great too!!

that piece is nearly finalized....ive been looking at an additional bolt tab to tie it to the block at the m8x1.25 bolt hole above the bracket but to the right of the m10x1.5 hole which i drill and tap to 1/4" npt for the rear knock sensor. its not fun since i want it to be removable without removing the knock sensor. though i will admit it's craploads easier to leave this bracket on and remove the engine than the oem 65e stuff since the 80e bolts on the new ***** bolt at the trans side....no more needing that 42" extension.

yesterday i finished welding up the new engine mounts so today Al and I are going to be checking everything out with some plumb bobs to make sure everything's square since i cant put the whole damn engine and trans onto a giant CMM....a work around is in order lol
plus i made some caster wheel plates that bolt to the adjustable engine and trans mount brackets so the whole drivetrain can be wheeled around easily without a cart. (same plan we have for the 442's rear powerplant unit)

i honestly doubt anyone wants to buy our style mounts but i have eyeballed some abbreviated mounting plates that could go to the OEm subframes but ive got bigger fish to fry. ive been trying to get alot of stuff done for when Al and I go to Wally's in NC to work on the chassis fitment

im making the rear powertrain as compact and self contained as i can...we hope to use it as a engine/trans dyno with it out of the car...for easy testing of JY tranny's/etc since the axles/brakes and suspension will be attached so we can load it while testing.

i need to clone myself