Can Auto stock trans handle 500whp safely?
 

I have the Stillen supercharger with the 9lb pulley, headers, test pipes and cat back exhaust. With all my mods together I'm pushing 440 whp 327tq. My question is do you guys think it would be SAFE to get the vortech impeller upgrade considering all my internals and trans are OEM? Also I have both oil and trans coolers along with the csf tripple pass radiator and my oil temp never goes above 190. Even during "spirited driving"

There is a post here somewhere about the 7AT and the manufacture rates it up to 300tq so I wouldn't think it's a good idea.

How long have you had it at 440/327 for?

I've been over 400/300 for about a year and track mine. We had it on the dyno yesterday at 418/310 and were getting no tran slipping.

Put some money in that tranny.

If I were to go FI, I'd probably have my numbers around there, 400/300. Sounds like the tranny can definitely work it out. What's your daily driving pattern like? I'm assuming you take it easy on the streets and you launch on on-ramps to freeway every now and then.

I still haven't decided whether I'd go STS turbo or a stillen SC. Personally, I'd like to keep the numbers just slightly high enough that it's still 'faster', yet, not enough to kill me or the motor/7AT.

I'm not always hard on it but I wouldn't say I'm nice to it. It has over 12K with the SC on it. I bought a set of BFG G-Force comp2s about the same time and the rears are slicks now. I'm waiting on new wheels so I can get them off the car.

This reminds me of hangover 3 on the reason why Bangkok is called Bangkok. Throw too much money into a tranny and....the rest is history. :roflpuke2:

Dude brand new tranny(no homo) is like $1800 well manual at least.
And if i remember correctly it can hold up to like 600lb of torque. If it goes its cheaper to buy a new 1 anyways. But for automatics i dont know and its cheaper to buy a manual with "$-mode" and an extra pedal, when auto goes.

I drive it every day and honestly I drive it like it's my last day on earth! I didn't buy a race car for the look. I want to be able to drive it like I stole it. I know someone on here will have something to say about it but that's my style

Our 7at trans is around 8gs bro so there is the hesitation

About 3 months. I bought the car in April and put the Stillen supercharger on a month after that. Along with all other mods. Everything went on all at once. Car was bone stock when I bought it

Thanks for the link Kai. I've read most of that thread before but didn't really get a difinitive answer. Guess its just at my own risk. I wanted to get impeller upgrade before nationals and get the tranny work done over the winter so I think it will be OK for a couple thousand miles without the extra trans work but we'll see

At the very least get a trans cooler and tune to increase the line pressure, and take it easy in gears 4-7.

OK cool. I already have the cooler and custom tune by r/t tuning and they definitely know their stuff. And I only plan to run it for a short while before building everything . thanks brother

well if GTM was still a real company then they do a stage 4 tranny upgrade for 6500 i believe it was.

AAM and Fast Intentions are both currently working on 7AT upgrades for boost solutions.

a value body upgrade paired with your tranny coller should be ok for 500/350 or 500/400 numbers your looking for. but always remember every tranny is different and it could implode at anytime even with a VB upgrade and cooling.

The question is not about HP but TQ, the 7AT is very TQ limited and even worse in the 5-7 gears.
I would say, like others, pushing it much farther is a large risk. I would say that if you want more power to first focus on the transmission but on the subject of 500whp I am not sure the stillen SC can push much more out. It seems to be limited to about 450-475HP by others.

I run mine up into 5th at full throttle on the straights. Even with tuning the 7AT the shift from 4-5th isn't great but I haven't had problems with it yet.

I really appreciate all the input guys. As far as the stillen kit I'm at 440 now and that's with some belt slips. I think with all my other mods if I got the impeller upgrade and cog pulley I would be very close to 500whp but I would be very happy at 475

Anyone know about how much the impeller upgrade adds?

I wonder how much a shop will charge to do a tranny swap (no homo) and whether it will be reliable in the long run.

There is a company in new jersey that does a rebuild for 3,200$ but I can't remember their name. I had somebody tell me in a pm but I erased it when my pm box got full.

Not including the price of the transmissions?

Is there an issue with the 7AT shifting from 4-5 when its supercharged? I mean in my NA, I do find 4th gear very lacking (as far as power goes) but I never noticed the shifts being lacking.

I can't find myself full throttling from 4-5th without potentially getting myself a felony, maybe on the track but Streets of Willow only let me get to the top of 4th.

you say 4th gear lacks power?

i'll roll around in 4th sometimes and if i floor it i'm gone.

i'm NA and my only "issue" i've found is sometimes i'll get a throttle/rev blip when going from 4th to 5th when going full throttle and shifting at high revs.

Oh, that happens to me too. I always thought it was transmission slip. idk.

I might be spoiled with the power already on straightaways/highway onramps, of course on the canyon, it's got more than enough power. It just feels as if from 3rd to 4th the power is still there and then 4th to 5th, not so much. Hell, the FX35 that my old man drives has better feel from 4th to 5th.

Which I should note, it seems as if VQ37 holds back. It's as if the VQ35HR feels like it has more torque than the VQ37. Just my opinion though.

the rev blip from 4th to 5th i feel is a ECU thing not the tranny actually slipping. i've heard it from many of the 7AT owners and i doubt every 7AT in the Z's are slipping lol

I always thought it was my 7AT being the odd one out, considering that I've taken it back and forth to the dealership for various issues. weird whistle noise, driveshaft clunk, windows going down when its supposed to go up, and etc. I still love my Z, but I was dead certain it was a quirky one.

Is there a way to tune the throttle blip so it doesn't happen?

No that shift is much slower than the others even after tuning it.

Agreed.

When I got tuned I had my line pressure raised a little since I'm only NA and still get the blip.

:iagree: I'm tuned by R/T tuning and while they did an amazing job it still does the wacky upreving between 4th and 5th but only occasionally. I noticed it does it more when shifting from the shifter than with the paddles

I really dislike the wonky feeling between 4th to 5th when i'm on my nitrous. I thought my transmission was slipping when I was at the track... It's good (kind of) to hear others having the same issue.

level10?

Gears below 5th are stouter and more able to handle the extra torque -- so no flooring it in 5th.

Upping the line pressure and a beefier trans cooler to minimize heat is a good idea.

Yes that's it! Gracias amigo

heard good things about them and they are in PA so i gotta like them.....even though its near philly :shakes head:

my car has never seen actual "automode" i only drive in manual. everyday i only use the shifter and when at the track or driving hard i'll use the paddles. just in those situations where 2 hands on the wheel seems appropriate lol

yea man trust me every AT owner has had this at some point.

thats the main reason i gave up on boost a long time ago. whats the point of boosting a 7AT when i lose the top 3 gears in the trasmission. you can get them back for $6000 in a stage 4 tranny from GTM (if they actually send it back and not just take you money lol).

7at i get this also. When i run thunderbolt i shift to 5th slightly early at 115 to 120mph and it does this.

Also on street sometimes hard accel in 4th then shify into 5th. Rarely happens on syreet though. Maybe heat related... i dunno

2009 7at touring
AAM 2.5 true dual exhaust
AAM de test pipes
Z1 headers
AAM 2.75 cold air intake r-line
motodyne m370 manifold
whiteline f/r sway bars
swift lowering springs
quaife LSD
Z1 34 row oil cooler
Z1 brake rotor and pad upgrade
Tune via hills garage
best 1/4 12.841 at 108.7mph 3540lbs with me in it

Full auto shifting is based in part on load, so it may not be slipping so much as seeing transitions in load that are not jibing with TPS, road, and engine speed, resulting in some gear hunting.

full auto shifting? what is this blasphemy you speak of? :ugh2: