ajcool2

iTrader: (11)

I asked this question in another thread in the FI Forum but didnt get a responce. Basically I have a 1998 maxima that I modified to run the transmission at full line pressure with a flick of a switch. The result is the transmission shifting into gear very fast just like the VB mod. Its done by wiring an on/off switch to the line pressure solnoid and turning it on only when you go WOT. I've been using this mod when racing my maxima for 2.5 years now and 172000 miles on the tranny and it still shifts fine. My question is if this is possible on my 5AT Z and if so how can I access the line pressure solnoid to try it? If you want to know more about this mod you can read here. http://forums.maxima.org/showthread.php?t=208756

rcdash

iTrader: (18)

I thought about doing this myself. Theoretically, yes you can - particularly the way you mention with a temporary on/off switch. I've heard that the TCU "learns" and adapts though so a single electric modification may loose effectiveness over time. I don't think that will happen with what you describe. However, the other issue is the vb is embedded within the tranny itself. I don't know if you can access the wiring harness that goes between the ecu and tcu to trigger the desired effect... I think it IS possible because when you put in a full standalone and disconnect to stock ECU, the TCU shifts VERY (unacceptably) hard (by report). So it's just a matter of finding the right wire. Good luck!

superchargedg

iTrader: (4)

Just get the sgp/forged performance vb,it is awesome how fast and hard this thing shifts now.And i would think you might have a hard time with this tranny doing what you want to do.I think it could be done but as mentioned above it might be tricky.

Jeff92se

iTrader: (4)

I don't think it's as easy as the maxima. The maxima AT featured a resister that was accessible from the engine bay. If you disconnected it, it sent full line pressure though tranny all the time. At WOT it gave great shifts. At part throttle, the shifting was herky jerky.

The 5at for the G/Zs don't have this resister, thus you can't accomplish this (not like this anyway). I think like pressure is done though the TCM program.

I've seen a maker now offer TCM program mods but it's like $700. Or go though the mechaical route w/ a VB modification.

But I've never understood why these VB mods are so expensive. $700-$1,000. Hot rodders have been modding their VBs with shift kits for years at a fraction of the costs.

ajcool2

iTrader: (11)

This is one reason why I think it is possible. From what I read in the thread about our AT tranny's in the FI forum if the transmission detects an error in one of its systems it will go into a failsafe mode which will cause the tranny to run at full line pressure. I'm by no means an expert on this stuff but I believe with enough research and mechanical skills it can be done. Hopefully someone with more knowledge about our transmissions will take this on as a little project.

rcdash

iTrader: (18)

Ideally all you need is a firmware reflash... if anyone comes up for one for our TCM. I've not heard of one being available. The $700 product mentioned by Jeff may be Osiris, which does NOT alter the TCM in any way (only the ECM).

helldorado

iTrader: (4)

Maybe the UpRev guys will be the first to crack the TCM. Who knows if its a real priority for them or not. I wonder if a TCM reflash be able to up the pressure the same as a physical modification anyway.

I know Powertrain Control Solutions had a TCM controller that worked with some variations of the RE5R05A, but not the G/Z because of the TCM placement.

ajcool2

iTrader: (11)

I just found a product that should do exactly what we are looking for. A guy on the maxima forums actually found it and contacted the owner and they told him that they would be able to modify it for our (maxima) transmission. Its called the Suprastick V4. Individual shift points for each gear, torque converter control for each gear, 2 maps (one for race one for normal), manual shift mode using paddles or switches, shift light, automatic protection from downshifting. It is a complete standalone TCU programmable via a PC. It was orginally made for supras but I'm sure if we contact the company they can modify it for our Z's like they are doing for my max. You can download the manual here. Here is the webpage for the product. Let me know what you guys think. http://www.latentsolutions.com/suprastickuv.html

rcdash

iTrader: (18)

Hmmm, again I doubt it will work because of the TCM placement. There are only CAN wires going into the TCM from the ECU (I believe).

helldorado

iTrader: (4)

https://my350z.com/forum/engine-and-drivetrain/316633-suprastick.html