What can a Auto Tranny hold??

[ProSignandDesign]

Hello, I am a newby to the LGT forums, I really would like to put a bigger turbo into my LGT but am not sure what the stock Auto trans can hold on HP or Torque. Any insights would be much appreciated. Right now my car does have a larger turbo I will need to get specs when I can. Other simple mods, Grimm Speed Boost controller, Front mount IC, BOV, Downpipe, exhaust. Again I dont have any of the brand names because I haven't gotten to writing them down as of yet.

 

Just looking for some help when make her go a bit quicker.

 

Oh and its a 09' LGT Limited

[Max Capacity]

Around 330whp. You'll want a trans cooler too. I don't think there's much of a upgrade for the valve body like what was done for the 05-06's.

 

It sounds like you just bought this car ?

 

You'll want to make sure the tune is safe, every week there is one or two stories about, I just bought the GT and it blew up on the drive home...

[ProSignandDesign]

Around 330whp. You'll want a trans cooler too. I don't think there's much of a upgrade for the valve body like what was done for the 05-06's.

 

It sounds like you just bought this car ?

 

You'll want to make sure the tune is safe, every week there is one or two stories about, I just bought the GT and it blew up on the drive home...

 

Thanks, it has a transcooler mounted in front of the aftermarket radiator. Also yes I just came about this car about a month ago, was a member of RS25.com for quite a few years when I had my GM6. I am going to see if CAMtuning is still here in NM to see if he can check the tune.

[ktm200]

Nothing really out there that's proven to upgrade the transmission to hold more power. The hex mods valve body is only available for the 05-07 cars. The only company offering anything for the 08-09 is IPT (import performance trans and the upgrades they offer have not proven to hold any more power. A very well known user here had an IPT transmission modded valve body in his 08 or 09 with a 16g turbo (comprable to a VF52,little bigger I believe) and blew the transmission.

 

So with that said, stage 2 power levels are generally considered to be reliable with regular maintenance (tranny fluid flushes). Stage 2 on the auto I've seen net around 280-290whp with supporting mods. Downpipe, fuel pump, exhaust, EBCS, Intercooler, and a custom tune. I believe their are a few 08/09 autos around the forums with a VF52 turbo (off an 09+ etc). As I understand it, a heathy tune that tapers torque at redline is pretty important with this turbo on an auto, as well as being smart about how you drive like letting off while shifting.

 

For what it's worth I've been at a basic off the shelf stage 2 tune since about 40k miles and I'm now almost at 140k. I also don't drive it like an idiot. For spirited driving I always use manual mode since the car wants to upshift so quickly otherwise. More power and a higher gear slips the transmission.

[Max Capacity]

280-290whp, wow didn't know it was that low. But I'm not a 5eat guy.

[ktm200]

280-290whp, wow didn't know it was that low. But I'm not a 5eat guy.

 

280-290 I meant as what the typical maxed stage 2 5eats put down, and also the power level most 5EAT owners (without the hex mods VB) stay. A few guys have VF52s around 300whp.

 

There are others running more power but it seems you need to be MUCH more careful as the risk for damage goes up a lot. You need to be very careful about WHERE that power is. The trouble is the torque converter doesn't really lock up until the higher rpm range and the line pressure isn't very high resulting in the transmission slipping. So a big midrange can kill it. Also on shifts the transmission hangs and very softly shifts so if you stay on the gas during shifts it's really slipping the clutch packs. Another user, bmx045, was running a 20g on his 08 for a while. I think it was dynoed at around 330whp but he had always mentioned how he'd make sure to use manual mode and let off on shifts. Think the idea of the 20g was to move the power band past the torque converter lockup. He blew up a few short locks and ended up going down to a VF52.

 

My car since it was new, rolling in 3rd or 4th gear if you'd get on it, it would accelerate smooth up to about 3500rpm then instantly jump up to 4000rpm where the torque converter would lock up. Around where the factory turbo and the VF52/16gs are hitting full boost. Also why a lot of 5EAT owners refer to maxed out stage 2 builds as 5eat killers.

 

There was another user SeeeeeYa had an AVO380 on his 5EAT and needed to go with a built IPT transmission after his stock transmission went.

 

You'd be best served going to the transmission sub forum for feedback, there is a very long "5EAT pride" thread.

 

I've been on the forums here for quite a while now and most of the feedback I've read on big power with the 08/09 autos has always been enough to deter me from going bigger. The bottom line is that the hex mods valve body for the 05-07 cars increased the line pressure in the transmission, this allows the transmission to shift faster and for the clutch packs to grab tighter during shifts and through the rpm range. This allows the tranny to hold more power. No such upgrade is available for our cars.

 

So with an 08/09 transmission your stuck with sloppy shifts and and slipping clutch packs. You can probably get a lot more feedback on what 5EAT users are running for power in that "5EAT pride" thread.

[amm203]

I am running a conservative 18psi and like ktm200 suggested, my tuner also intentionally tapered to redline to keep torque at the shift points low. According to him, this should extend the life of the tranny.

 

I am also in manual mode 95% of the time - I think this is the most important thing. That way you can really keep it in the power-band as well as keep it out of the danger areas. Can't remember if I was told or read this somewhere; WOT to overtake while in 4th or 5th (basically cruising @ 2500-3000 RPMs and punching it) is a sure-fire way to destroy those gears in your 5EAT. I PM'd a few 5EAT owners around here before going to the VF52 and got conflicting responses. One said don't do it, you'll destroy it. Another said the it's a JATCO 5EAT similar to what's in 350Zs and will hold all day long. Most others have basically said don't beat the hell out of it and it should last. I'm close to 12K miles on the custom VF52 setup and have not had any problems.

 

Besides supporting mods, adding a Rallitek insert and a set of WL (or equivalent) rear diff inserts will help take a lot of slop out of the 5EAT.

 

ktm200 - I feel your pain with the upshifts. I'll be WOT in 2nd then upshift around 5000RPMs. The needle hits 6500 and then my upshift signal gets coupled with the fail-safe in the tranny @ redline thus sending my car from 2nd into 3rd then quickly into 4th without using any of the 3rd gear powerband. It's a timing issue that requires you to upshift much earlier than you feel is correct due to the sluggish response. Letting off throttle up high seems to be the key as well. Thankfully downshifting is great, though!