Boosted Auto Trans Owners.
 

Hi Guys,

Just seeing what limits people have pushed the auto to?.

Just looking to know at what power/torque will I need to build the box etc etc.

Thanks!

How much power are you wanting to run? The transmission copes decently well with less than 300 whp and 225 lbs ft of wheel torque. It gets a little sketchy when increasing power beyond that.

My car was supercharged for a bit and with the built engine was putting down 350 whp and nearly 300 lbs ft of wheel torque. It ended up being too much power, transmission was freaking out when doing high throttle pulls, lots of slipping until I let off the throttle for a couple seconds. I had to run a slightly larger pulley (less torque and around 325 whp) for it to not freak out, but the transmission still couldn't keep up too well with the extra power.

Damn thats not what I wanted to hear lol. Power will be in the 400whp catagory. With alot of Torque. Guess ill push and see what happens and build the spare if needed.

subbed....any 6AT like to share their goodies for the twins? I plan to shoot for eldebrock with 300hp near future.

Im at about 300hp right now. And it seems fine. Im just worried cause im hoping to push round 400+ depending on how the transmission holds! Ill be pushing mine more in the next week or so maybe 2 depending on parts arriving. So ill come back and update how its going either way.

I am at 323 with edelbrock and e-85. Automatic tranny, lots of track days, and no problems at all. I always heard the automatic was actually stronger then the manual. I also run a tranny cooler and normally see 230 to 240 tranny temp on track.

Nice! thats great to hear. Yeah I added a cooler its a must being boosted and if you do any sort of spirited driving really.

Youll need a clutch pack and valve body upgrade for 400whp.

Yeah I have the Valve Body stage 2 from SSP been considering the clutch pack to but not sure they sell it any more cant find it on there site sadly.

@Lunatic...what kind of cooler u add on? Any pros/cons bout it?

I don't think the clutch pack was ever pictured but last time I talked to them they still make it.

I was told the clutch pack and valve body would be good for 400 lbs of torque, not HP. HP would be higher.

Don't know the brand. I went to the local auto parts store and bought the biggest cooler I could fit. Made my own custom mount. And had a Toyota mechanic friend help me install the lines in-line with the stock cooler.

I went with an out board installation behind the removed fog light.

look good when finished....thanks for the post man.:thumbup:

Thank you. I put the engine oil cooler on the opposite side.

Torque is what breaks things. Not horsepower. HP is a product of torque.

From the nature of this engine, if you have 400 lb ft of tq, you'll have more hp.

Yes, correct, that is my understanding.

Thats good to know will shoot them an email and see what the deal is thanks!

@liquidsky44 should be able to chime in ;)

Well mine seems to be slipping now :( had to dial it back a bit. Contacting a few places about clutch kits for the next stage.

Nicely done mate!

What size is the cooler? Thinking of doing a similar set up

11" wide, 7" high. Seatab 6 series if I remember correctly.

ATF oil cooler does help with the slippage, but the oem clutch pack would not hold the high torque for long. Either way all the parts mentioned above should be replaced for it to hold 300torque.

Even at the power im doing now as long as I didnt try to push over the 400whp anything under it seems to be holding fine with it. Oil cooler helping for sure.

Decided against building the trans further. Cars nuts as it is and im just enjoying it. I also got a spare trans sitting round for if shit does go bad.

270whp and 220tq holding well over here. Gonna try to install a tranny cooler in the summer. I think 250tq is close to the limit of the stock trans.

You bet.

Looking good.

Good to hear it's holding up, I'm really leaning towards the edelbrock s/c. eventually id probably chase 400whp & I know that the boost would be too high for a stock box and tranny
Could you tell me what is the boost psi on the base tune and torque & HP numbers? I don't want a rebuild right away I like to take it step by step for the experience and financial reasons too

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9 psi boost

Oh that sounds to be very safe. Thanks for the quick response bro😉

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Im sitting at 400hp on quite a low reading dyno. And its having no issues.

And at 400hp it is just quite absurd to be quite honest! anything above half throttle in auto mode to get on it a bit from a roll and your spinning wheels.

In manual mode getting on it decently it just spins 1/2/3 if your really into it. Fun but a bit scary!.

Driving in auto mode is actually realllllly sketchy if you are rolling along and decide do lay into it. You will just go sideways. SC might be a bit diff to turbo in that respect though as its not a rush of boost all at one time.

How much torque are you putting down?

250 @ 5800 rpm.

Wow😂 what tyres are you running

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255/35/18 on 9.5.

Will try and go 265+ on rear next time I think.

I was thinking of that tire size next time around. Do you currently rub? I heard 265s will rub a little in the rear unless you shave back the tab on the bumper.

No rubbing yet. Have a few ppl over here running 265+ in the rear depends on offset I guess and how low you actually are?

I'm close to you, at 323 and 255/40/17's 1st and 2nd are worthless. But boy is it fun once you hook up. I can't imagian what 400 would be like.

How are you guys all handling the rev limiter with the increased power?

I'm asking because at least on my JRSC + HBP+ E85 car, I will hit the limiter before the trans is able to shift from 1st to 2nd in automatic mode.

Normally I'm in manual mode when I want to have fun and I shift it when needed to account for that.

Just wondering.

I also notice that there is a slight delay in the shift from 1st to 2nd and 2nd to 3rd when I'm full out. As in I click the paddle but I stay in gear still accelerating for a split second longer. The shift itself seems pretty quick once it starts.

I have the same hanging issue.




When I'm shifting above 4k and on the throttle, the RPM dips like it's suppose to, but you're able to see a little waver at exactly 4k before it starts climbing in the RPMs again.