7AT Valvebody upgrades?
 

As far as I know, no one is making valvebodies or doing upgrades to the OEM valvebody...

Are there any that are planning to?

There are some of us who got the 7AT, and now with the numbers being tossed around with the TT kits and SC kits...I imagine there may be a market...as for me...maybe...lol...it's only money, right?

There's a Valvebody upgrade kit by Transgo. I believe GTM has it on their website. No idea if it's a solid piece or not though.

what would a valve body upgrade do for us 7AT ers?

Actually our Auto already has very quick 'Locked-up',so upgrading the valvebody is useless,i think it is already a good autobox.

People over at my350z have felt neck snapping shifts with the GTM kit lol... Im waiting to do this myself with a set of 4.08 gears

I spoke to Sam at GTM last week and they will have the VB soon with upgrades torque converter.. Its a transgo kit, for the VB. My stock 7 AT shift well at 7900 rpm.
A tranny cooler is my next investment.
Now add my GTM SC, with the 4.08 diff I have and its going to fly.
11's coming soon at the 1/4 mile track.

Auto' trannies from Nissan are flawless. It's money you could put to better use---such as savings for an emergency, dude! Cheers.

were the 4.08s worth it, grant it I will be adding them to the 5at

From what I've read (and with little understanding!), most people with automatics do a valve-body upgrade and add a trans cooler when they run with any form of forced-induction.

Just seeing how far off those upgrades are...just in case I decide to make my car insanely good...


So, that begs the next question, is that all that is needed in regards to the transmission for forced induction?

Given his drag slip times...lol-yes!

so its just stronger to keep the extra TQ from breaking them?

Higher fluid pressure can help keep the clutch plates engaged when more torque from power modifications is introduced. Transmission kits usually open up the fluid path for faster engagement and faster clutch release. Accumulator pistons and springs are sometimes replaced with solid bars resulting in very firm shifting.

That's what I'm guessing. I'm at my limit of knowledge on this subject ;)

Not that this is the source of what I know of how they operate, but it gives a good basic principal.

HowStuffWorks "Planetary Gearset Ratios"

The above link shows how locking different parts of the transmission for one gear-pack will give a few ratios to play with.

With that, I'm not sure how the clutchpacks and "bands" play into it, in relation to the valvebody - I imagine the valvebody would increase the pressues to each of these, and allow for more torque to go through the transmission without slippage.

Ok, so does this mean that every shift will be super firm? I'm wondering how this would affect everyday driving. Hard shifts in the rain probably wouldn't be desirable.

It will shift normally if the RPMs are low (driving around normally). Absolutely no problems driving in the rain, even with forced induction (unless the driver is being stupid).

However when you get on it and the RPMs are up, the line pressures in the transmission go up and the time in between shifts go down. It will feel like you are popping the clutch in an MT and you'll be easily chirping gears.

Additional clutch packs are only needed if the stock ones can't hold the power.

Clutchpacks are generally what go bad and cause for rebuild, aren't they?

I mean, they're the weakest link...valvebody helps keep the pressure up to the solenoids, but other than that, the weakest mechanical link to it all is the clutches AFAIK. :)

no it's usually the friction bands that go first. once you increase the fluid pressure there is more force on the bands and clutches so they are less likely to wear out from slipping.

terrycs how is your 5AT holding up with the forced induction installed? Do you have any transmission upgrades?

BUMP- Any idea if this is available for the 7ATS yet?

GTM is still currently working on 7AT upgrades, with the recent finish of the stage II supercharger development we might see some news soon on the 7AT.

Very true

One of the best mod's i ever did.Driving normal you can still feel it but its not bothersome but whe you get on it...whoa the shifts are instant...esp with FI as you will need it.I would also def install a trans cooler to all the 5 or 7 at's as it will prolong the life of our tran's.

Thanks for insight now we play the waiting game

Any idea how much it would run if you have GTM remove your valve body and reinstall?

i feel stupid now. I thought the ATs already had a trans cooler mounted in front of the radiator. I have an '11 with the 7AT and there is a little silver radiator of somesort just in front and to the left of the large radiator, what is that there to cool? is it the A/C condenser? I've never seen one that small.

okay, i just went out and took a quick look. There is a small cooler mounted in front of the a/c condensor. It has rubber hoses connected to it, what is it for? Thanks.

Are you taling about the 1-2 inch tall on the left side of the radiator when you are standing infront of the car? I think thats for power steering.

yea, thats it. Thanks.