Does anyone know of a company who does custom programming on our transmissions? I called Technosquare, and they only address the engine side of things. I am going in the direction of the modded t/c (~2700 rpm) and valve body, and would like to tweak the shift points and lockup characteristics. I am sure there are several forum members out there (gurgenpb---MeanGene esp.) that could benefit from this as well.

Lockup at highway speeds (or even 1/4 mile speeds) is dependant on load in all computer-controlled trannys that I'm aware of.

I'm not exactly a novice to this, as I owned a custom chip company a couple of years back that modified LT1 and LS1 cars. In my heavily modded LT1 car I had a monster stall, but mileage was not greatly penalized due to the lockup programming. Having the converter lock up after the 1/8th mile mark helped keep up the MPH at the end of the run, mitigating a lot of the loss generally associated with a "loose" stall speed. This and other tweaks to line pressure vs. load tables allowed for a very docile car at moderate throttle and a screamer barking third at full throttle.
That being said, this is my first Japanese car. I have no first-hand experience modding these cars, so I am relying on the enthusiast community to assist me (and hopefully other folks) with this quest.
MUST GO FASTER!!!!! AAARGH!!
Thanks in advance.

'04 G35X Graphite/graphite, NAV, wood, premium

 

I believe 'Gurgenpb' has modded his tranny programming as well as changed out his T/C. P/M him for details and G/L. [img]/w3timages/icons/smile.gif[/img]

<font color=red>GSM</font color=red>
<font color=red>GSM</font color=red>
<font color=black>Silverstone Coupe</font color=black>

 

Stillen's currently testing their "shift kit" on a AT G35 Sedan. To the best of my understanding it will work on all the G35s and 350Zs with auto transmissions. I hope to be one of the first to test it. It should complement my Street Edge Torque Converter nicely.

Here's the latest information from Stillen.

"We will shorten the shift time that the 5AT takes and make the shifts much more pronounced. Since we haven't gone to final design yet or looked at what the exact production version will be, costing of the product hasn't been done. We hope to release the kit in the next 6-weeks. This doesn't necessarily answer your questions directly, but I'd rather be general at this stage than specific. Because we haven't truly finalized the product, trying to get specific might end up unintentionally misleading you and the other board members should the Bill of Materials change.

I hope that you will accept this for now. MY350Z will be among the first sites to know when the kit is ready for completion. I have driven the prototype version and can tell you that the shifting is incredible. This will work very well with both NA and FI cars!

Stay 'Tuned',

Alex Cates
STILLEN"



DaveO - 2003 G35 Sedan / DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TS ECU / E-Fans
Street Edge TC / B&M Cooler / Stillen Exhaust

 

Hey Guys

I do NOT have the tranny programming modified, just the T/C (Gene has both the TC and the VB mod), but I would the FIRST to be tester car for such a thing. TechnoSquare will not be addressing the TCM programming, they are sticking to what they know best.

But I can only imagine how useful such an update is; you could lock the T/C earlier (or at higher loads), turn up the line pressure (doing away with the need for an invasive/crude VB mod), adjust the shifter poitns, make the manumatic mode behave PRECISELY like an MT (no downshifting), etc. That would truly be great!

I wonder if ANY company out there has ever done such mods for the tranny on Nissan cars. It would be relatively easy for them to do the programming for our G's.

Gurgen

 

Gurgenpb wrote: "But I can only imagine how useful such an update is; you could lock the T/C earlier (or at higher loads), turn up the line pressure (doing away with the need for an invasive/crude VB mod), adjust the shifter poitns, make the manumatic mode behave PRECISELY like an MT (no downshifting), etc. That would truly be great! "

That is EXACTLY what I am referring to. You could keep the converter unlocked under certain conditions to provide maximum torque multiplication, but still keep highway mileage stock by locking under light load/TPS voltage The line pressure adjustment by the computer is limited to the physical restrictions of the valve body. On most domestics you can crank up the line pressure tremendously through the computer, but an inexpensive (for domestics) "shift kit" that changes orifice size and check ball/springs makes a MUCH MORE DRAMATIC DIFFERENCE imho. In my LT1 car it was the difference between chirping the tires in second and having the whole car kick sideways on the 1-2.
The greatest advantage for me was the ability to 'pull' line pressure. This allowed the valve body mod to operate at full strength under full throttle, but would reduce pressure under light loads allowing for a much more streetable vehicle. It was truly the best of both worlds.
BTW, for those who are concerned about tranny life after these mods, remember that is SLIPPAGE that causes damage along with those cushy shifts.

'04 G35X Graphite/graphite, NAV, wood, premium

 

"...make the manumatic mode behave PRECISELY like an MT (no downshifting)..."

I thought the manual mode did this already. I've only had my coupe for a couple of weeks, but the few times that I did put it into manual and left it in 5 and stomped on it, it wouldn't down shift no matter what speed I was at. It just slowly picked up speed as revs climbed.

 

Wow....this is pretty exciting news for us 5AT drivers, me thinks....In addition to this "shift kit", anyone know what other mods will we potentially have to purchase?

Ivory Pearl Coupe/5AT/Aeros/Premium/Nav/Type-N Front Bumper/Z-Tube+Popcharger/V1

 

" I thought the manual mode did this already. I've only had my coupe for a couple of weeks, but the few times that I did put it into manual and left it in 5 and stomped on it, it wouldn't down shift no matter what speed I was at. It just slowly picked up speed as revs climbed. "

Ys, but my sedan (and I think that it maybe limited to the 03.0 sedans) DOES downshift in manual mode. It sucks!!! You guys (coupes) and the 03.5+ sedans do NOT downshift - I'd love my car not to do that. I am actually considering swapping in the later sedan's TCM into mine.

EDIT: Yes, the shift kit (the valve body upgrade) is my next mod too - next to the TTs).

--G

<P ID="edit"><FONT class="small"><EM>Edited by gurgenpb on 03/31/04 12:56 PM.</EM></FONT></P>

 

you may want to try powertraincontrolsolutions.com I know they are the one I turned to for the auto in the IS300 they may ahve something for the G35. if you need some more info or a contact just send me a pm and I will dig it up for you

Henry

 

yes i would like the contact info and I'll se what they offer

Thanks
Gurgen

 

I sent you a PM

 

In manual mode in my coupe.It will down sift if you go WOT.It did it on the dyno. When I was dynoing it in 4th and stomped on the gas ..it down shifted and we had to start over. I had to slowly add gas untill I got above 3,500 rpm and then add gas a little faster till I had it floored

Couldnt afford it when young...gonna play when Im old

 

What year is your coupe? Mine didn't have any problems on the dyno. Just get it into 4th, then floor it. Never downshifted at WOT.

 

Booger--what year is your coupe??

"Couldn't afford it when young...gonna play when I'm old "

NICE!

'04 G35X Graphite/graphite, NAV, wood, premium

 

Guys we maybe onto something.

If my theory is correct, i.e. the 03.0's downshift and the later models don't (both coupes and sedans), the booger has an 03.0 5AT Coupe.

Gurgen