is there anything to mod our 5AT transmission!? I NEED TO KNOW! i would LOVE it if there was anything to make it shift faster or help it in anyway...PLEASE REPLY ASAP! THANKS!

 

Stillen offers a valve body upgrade.I think that level 10 makes a torque converter, but I can't find a decent link for it. There are also racing transmissions out there, but I've never heard of anyone actually using one. Changing you're final drive gearing has some affect too.

 

Took the words right out of my mouth. Stillen does offer a transmission valve body upgrade for the 5AT. Only problem is that its a little pricey and requires a core change, so you'll be immobile for a few days. A less pricey option is Gordgee's Grounding Gear. I personally haven't tried it yet (my kit is on order as we speak) but a lot of people with the 5AT Performance kit say they have noticed much better response and smoother shifts. Do a search, you'll find plenty of responses. Also Gordgee has a FAQ thread in the DIY Forum.

 

Edge racing Converters sells a torque converter for our cars. Level 10 has a combo converter service and valve body upgrade. Stillen has a valve body. I don't know of anyone else right now that is modding the 5AT.
Good luck.

 

well the groundinggear is only going to do so much... but a valve body upgrade and torque converter upgrade would definitely help... however, the cost isn't worth it unless you track your car often or if you have a turbo/supercharger setup. I think a few people on the forum have upgraded auto trannys... there are a few long threads out there that discuss the results...

 

hmmm.......maybe there's a SC in my future

 

just thought i would share what i have learned so far thru my own searches for information. i think i will be doing the differential swap to stock 6MT gearing of 3.5 during the summer.

Valve Body Upgrade:
your stock valve body is reworked... this is supposed to quicken the shift and increase tranny line pressure(?) resulting in crisper shifts, less of a delay when shifting in MM mode, and the ability to handle more power. down side is that you will be without the car for a while as they work on it, and you will have to pay labor to remove the VB and again to re-install it in the car.

Final Drive Gear Swap:
will help the car accelerate through the gears quicker... you will reach a given speed faster, but at the expense of cruising MPG on the highway (i.e. instead of 80mph at 3000rpm it may be like 3300-3500rpm). comes in 2 flavors: 3.5 ratio (from a stock 6MT) or 3.9 (sold by 350EVO). stock ratio on a 5AT is around 3.3... the higher the ratio the quicker you'll be, but the worse MPG on the highway. this mod also lowers the effective top speed by several mph (not that that would matter much on US roads). if you go with 3.5, it's easier to get the entire differential ("pumpkin") off a 6MT car and just swap the diffs instead of dissecting it to get to the gears.

Torque Converters:
sorry, i don't have much info on this one... from what i understand raising the stall speed of your T/C puts you closer to the meaty part of the powerband when you launch... so instead of launching at say 2000 you might raise it to 2500 or something. transmission experts, feel free to jump in and add some insight on the T/C mod

 

also i believe SGP Racing in Houston is doing valve body work... do a search on here (and check out My350z.com, their members are much more hardcore with mods and there will definitely be some threads about it somewhere on there)