Regarding UNA breaking his 604, one of the things that needs to happen in any serious 604 build is a 4th gear 'lockout' based on torque as any real torque will blow right through 4th gear in a 604 and there's no cost effective way to fix that that i know of. I dont see it as much of an issue because even the shortest gearing possible in a 604 (~4.28:1 final drive with factory parts) still has 3rd gear redlining at a fast enough speed for a fast car to make a full 1/4 mile pass. An adjustable pressure switch reading boost is the simple part. The rest needs to be figured out.
Dont push the red button.You hear me?
either MS or the factory controller could be programmed to lockout 4th if in boost.
if not, some trickery could be done to lock in 3rd once 3rd has been shifted into, and disable other connections to the shift solenoids if in boost. once boost has gone away, allow normal operation. it would probably put the controller into limp mode though.
but if this is a MS and factory controller discussion, then trickery shouldnt be needed.
Brian
Originally Posted by turbovanman
If i'm correct in assuming that D and 3 shifter positions are the exact same as far as the manual valve is concerned, then the TCM will see the shifter change solely based on the range sensor reading. If that is true, then you could wire a pressure switch to a relay and a resistor that would modify the range sensor 4th gear signal to look like the 3rd gear signal whenever above your boost target. That would kick you out of 4th without codes, but you would still have to get rid of the forced 3-4 upshift in the software to make it dumbproof. It shouldn't have any effect on 1-3 operation other than sticking you into the slightly modified '3' position shift schedule, which won't have any effect if you're in boost anyway (you'll already have late shifts due to throttle position).if not, some trickery could be done to lock in 3rd once 3rd has been shifted into, and disable other connections to the shift solenoids if in boost. once boost has gone away, allow normal operation. it would probably put the controller into limp mode though.
If it can be done totally in the software, all the better!
Dont push the red button.You hear me?
It already locks out OD if you are in the 3 position, or at least mine does. Maybe if it hits rev limiter it might shift, but I haven't been able to stretch it out that far in 3rd yet. I did hit 5500 in 3rd and it didn't force a shift.
Some do force an upshift and some don't. But, there needs to be a 'dumbproof' solution because most people will use the regular OD shifter position most of the time, and if something isn't changed to downshift out of 4th with boost, people will break them and then half of those people will either ditch the trans or the whole project because most people won't attempt their own auto trans repairs.
Dont push the red button.You hear me?
I wonder what kind of strategy the PTGT's used?
My PT GT with a Stage 1 PCM will not autoshift. It will bounce off the rev limiter in every gear. You can even start the car from a dead stop in 3rd.
So it turned it into a manual shift like if you put a manual valve body in?
If you have it in manual shift mode yes, otherwise it shifts just like any other automatic. It's really cool.
I'm confused as to what the community is calling Manual Shift mode.
The only item deleted to accomplish this is a shift schedule with still leaves the most complex portion of clutch to clutch timing, torque hand-off and learned adaptation as components wear.
Additionally, a manual valve body is not feasible on a 41TE... the torque hand-off is not hydraulically handled, still requires solenoid apply and release control and accurate timing to accomplish the shifts.
Last edited by 5DIGITS; 11-11-2017 at 09:50 PM.
There are ways to improve 4th gear an TCC durability and they go hand in hand.
The 41TE uses 100psi LP in 1st and 2nd but it drops to 80psi in 3rd and 4th, due to TC pressure limitations ( TC lock up is hydraulically limited to 3rd and 4th).
This is due to TC ballooning during elevated pressure which causes the TC to expand, preload the thrust bearing in the engine and destroy the trans front pump.
BUT...
If the TC is built to minimum spec clearance (you'll know this is accomplished when the stator is tight after the front cover is welder to the impeller) the TC will have the clearance to expand and take a set that does not violate the available space between the trans front pump and crank.
This then allows LP to be increased throughout and with machining of the reaction plates for added clutch discs along with the 5-pinion carrier and reinforcement welding to the diff housing the trans will have a chance.
FYI -
The 604 (41TE) was intended to go behind the 16V Lotus in the Phantom R/T and with a slippery converter, due to the poor low end of the Lotus, it did quite well in development at sea level.
Although, when it was taken on altitude trips for prep for Mexican production, the vehicles couldn't get out of there own way during a vehicle launch ... so scrapped was that concept.
auto stick or just putting the lever in L or 3 or D probably.
i think what WarlockSyno is saying is that when he is selecting a gear via the shifter in whatever way his PT has, it doesnt automatically shift like all the 41te cars ive been in at redline. it holds the commanded gear.
so if one wanted to use a 41te with all the tweaks above done to it, and possibly a trans cal (prowler? or custom prowler? as mentioned) what would be the appropriate year range and donor vehicle trans controller to get that would play nice with something like a SMEC where its reading TPS and RPM? then what year gearbox do you use?
it gets tricky when you want to bolt a 2.4 with an adapted distributor off the cam to a 2.4 bellhousing 41te (cloud car) what controller is going to play nice with something like a 89 smec. or even a megasquirt where the only option to control the Trans controller is going to be RPM and TPS signals.
Brian
Originally Posted by turbovanman
I was wondering about that too. The early 604s just have the regular speed sensor in the extension housing but the newer ones have input and output speed sensors with nothing in the extension housing. I can't remember if the early trans has an input speed sensor. The early controllers are wired directly to the sensors/tach ouput instead of getting the TPS and RPM data from the CCD bus like the newer ones do. So it seems only the early controller would work with MS or an SMEC. AFAIK all the extension housings are interchangeable(even the a413 ones). You just need to make sure you get the extension housing that matches the bearing on the diff(later transmissions have a larger bearing) so any trans should be able to work with the early controller. The main problem I see is being able to easily flash it. I'm pretty sure the early controllers are not flashable. I remember Shelgame saying that they are essentially an SBEC with missing parts.
Remember, this was a production package for Mexico... see if service controllers are available.
The best approach is a costly one - have the bell housing cut off and weld a 555 or 568 mounting flange in it's place.
See above but also realize mexican trans cases exist for the 2.2 and 2.5.
is there anything US production that is the same that can be used? hardware wise....that can be flashed or socketed and burn a chip to run said code....?
i doubt anyone is going to do that.... especially without having a tuneable controller to make the trans live.
yes they do. but a working controller is key to all the hardware. there are a large percentage of folks on here that can do hardware and mechanicals.... the electronics are the hard part for many.
im a facilitator by nature. i desire to find a working combination of parts that most can obtain and put together to make their combo work..... even if mine doesnt run.
hence why whenever i got info on how to tune these things, i taught as many people to do it themselves as possible.
its also why i hassle you from time to time.... cause you have the info and i want to spread it around.
Brian
Originally Posted by turbovanman
i alway wanted to do a dual or triple Tc clutch discs with billet cover like they do in the diesel world .
i cant not remember when i modded my 41te if i put thinner /extra discs for 4 gear but i do remember throwing the wave spring out and thicker snap ring put into the case .
I also remember throwing out the 4 gear thermostat in VB so i could get in to 4 th when cold
The extension housings with the speed sensor can be swapped onto transmissions without. I had to do that for my test 41TE because I needed that sense for Megasquirt and my speedo. You have to redo the the preload on the diff if you swap the housings.
Megasquirt uses the Bosch CAN network which is different than the SCI or CCD bus that Chrysler uses. Two different languages. I believe Chrysler went to the Bosch type later on but that's when the TCM and PCM were merged together.