5EAT & Stage I ... how safe?

Ok,

 

I have an 05 LGT, 5EAT.

 

I was considering flashing it to Stage I using open source.

 

One of the tuners from OSECUROMS mentioned that because of the relatively high stall speed on this transmission, it could be dangerous to introduce much more torque in the lower RPM ranges.

 

Given the way people describe the Accessport... is this also true? Is there a lot more boost/torque introduced under 3000-3500rpm?

 

Here are some quotes describing Stage I maps (Open-source)

 

Keep in mind that this STAGE 1 map increases boost a LOT below 3500 rpm over stock. This will put an increased strain on the transmission since it is below your torque converter stall speed.

 

Question about the torque converter stall issues... are all Stage I maps unsafe?

 

I believe the Cobb Accessport also introduces more torque down low from the descriptions others have given.

 

Is it possible to make a Stage I map that is safer for the transmission/engine? (5EAT obv)

 

It is super easy to make a more conservative tune for a 5EAT. The difficult part is making an aggressive tune that doesn't mess up under a variety of conditions.

 

I don't own a 5EAT and have only tuned a couple so I don't know if it is "unsafe" but I do know that 5EAT are VERY expensive. It's a lot more expensive than a shortblock. I also know that a lot of torque below the stall speed of the torque converter can put a lot of strain on an auto tranny because the torque converter is slipping a lot. That's why I think anyone who mods a 5EAT should at the very minimum get a transmission cooler.

 

I can easily dial down your boost for you below 3500 rpm. I'm going to start posting on romraider's base map forum. You can find me there.

Whether OS or otherwise, if you mod your 5EAT equipped LGT you need, at the VERY LEAST, a transmission cooler. If you go beyond "stage 1" an IPT VB mod will not only ensure your 5EAT will live longer, it will work better as well.

 

After that it gets much more complicated, and expensive.

im running stage 2 with a large cooler. if i was to go any higher than stage 2 the VB mod would be my next step. my last car had a vb mod and was somewhat awkward for daily driving but the shift speed was amazing

What will a transmission cooler really do though? The torque will come on instantaneously applying more pressure... I don't see why the cooler would help much here.

 

Also, does anyone know if installing a trans. cooler will void a warranty? I am only at 30k miles and would like to maintain my powertrain warranty up to 60k.

i think the tranny can handle some sort of the power increase but its the heat that destroys it. no it doesnt void the warranty according to my dealer

im having my dealer install the tru-cool trans cooler so i imagine that it shouldnt.

I've done alot of research about what kind of power levels should i not go over to preserve the tranny. And honestly it depends on what you intend to use the car for. If you track, then hell yes get the works. If you just want a spirited street cruiser and have little or no intention of any motorsporting then simple tranny mods should be fine. But, and this is a big but, any modding to the car, in terms of gaining more power, will put the tranny under more strain. Some people have their trannys go @ stage 2 some are running completely stock 5eats @350+ hp and comparable tq figures. Just assess how you drive, how much power your trying to achieve, and strengthen your transmission accordingly, and dont launch the car if you dont know how.

What will a transmission cooler really do though? The torque will come on instantaneously applying more pressure... I don't see why the cooler would help much here.

 

Also, does anyone know if installing a trans. cooler will void a warranty? I am only at 30k miles and would like to maintain my powertrain warranty up to 60k.

a trans cooler does just that: cools your tranny. YES, it's the heat that will kill your tranny faster than anything else, especially if you live in a warmer climate. Throw on a turbo to that mess and WOT under load, and boom! there goes your tranny. A tranny cooler will not void your warranty, and unless installed incorrectly, I don't really see how it can have a negative impact. Also, they are very easy to install, there is a how to in the tech section, step by step with pictures. maybe 30 mins if you know what you're doing and no more than an hour if you don't. I believe it took me 45 mins to do mine?

 

Stage 1 is pretty safe provided you have a good tune to go along with it. ECM is only as good as the mods you install and the tuning that goes on the car. We've seen a few members on this site blow up their tranny or engine completely stock with less than 10K miles, stg 1 or stg 2 and beyond. There isn't always a fine line, but some of us who've been down the road can tell you from our own experiences the things to look for and what you can do to help prevent premature wear and tear.

 

I HIGHLY recommend upgrading your valve body. Sure it's a little spendy, but a lot cheaper than a new transmission if you plan to do a heavy Stg 2 and really launch or track your car. You should definitely do it if you go Stg 3, but I would do it right before that or at the same time. I know that my poor 5EAT limped along until I figured out the VB needed upgrading when I first went Stg 3 over a year ago, mostly from my tracking and launching the car at stg 2. If I had done the VB mod sooner, I'm sure the car would have been even better to drive.

 

And remember, no matter what you do to your tranny or engine to help beef it up, will not ensure invincibility. Things happen and anytime you modify or add more power, you run the risk of detonation or something breaking. Then again, you can do that in a completely stock car.

According to my research the same JATCO 5EAT that we have on the LGT is equipped on the G35 and 350z. As you already know, those engines put out 300hp/tq from the factory and there still is wiggle room. There are tuned Gs and Zs over those figures and the JATCO tranny is holding up fine.

Stage 1 is completely safe, I've been on Stage 1 for a year now with no tranny cooler and the tranny is crisp as always, knock on wood. I never launched her, aka torque braking. Nebraska sees some hot summers, tripple digit sometimes and the coolant temps have sometimes been as high as 220*F at stoplights ...

Stage II, get a tranny cooler.

 

I don't understand the high stall speed comment. High stall means that you can rev the tranny up before it actually starts moving your car, correct? That's funny, because I've tried to see what the stall speed is a few times at a stop light and it seems to engage almost right away. Thus, the stall speed is low, not high. Or is it the other way around?

According to my research the same JATCO 5EAT that we have on the LGT is equipped on the G35 and 350z. As you already know, those engines put out 300hp/tq from the factory and there still is wiggle room. There are tuned Gs and Zs over those figures and the JATCO tranny is holding up fine.

Stage 1 is completely safe, I've been on Stage 1 for a year now with no tranny cooler and the tranny is crisp as always, knock on wood. I never launched her, aka torque braking. Nebraska sees some hot summers, tripple digit sometimes and the coolant temps have sometimes been as high as 220*F at stoplights ...

Stage II, get a tranny cooler.

 

I don't understand the high stall speed comment. High stall means that you can rev the tranny up before it actually starts moving your car, correct? That's funny, because I've tried to see what the stall speed is a few times at a stop light and it seems to engage almost right away. Thus, the stall speed is low, not high. Or is it the other way around?

 

I was under the impression that our 5eats were made by prodrive, read it in wikipedia.

If you hold the brake and put your foot on the gas (torque brake), you will find that the stall speed is actually high. Granted, with the VB mod, I could TB about 4500 RPMS before the car couldn't hold anymore (this also with Brembo brakes). On the stock brakes and stg 2 gutted pipe set up, I could TB to about 3500 rpm. I wouldn't recommend this. We don't get 100+ F temps here and I ended up HAVING to do the VB mod when the tranny showed signs of premature wear (most likely from the TB).

I was under the impression that our 5eats were made by prodrive, read it in wikipedia.

prodrive? No. They are Jatco trannys. Also found in teh Nissan Titan I believe, however, like most things, they aren't exactly the same and therefore cannot necessarily HOLD all that power and torque like people seem to think. Those of us who added more power and torque can tell you this from experience.

I was under the impression that our 5eats were made by prodrive, read it in wikipedia.

http://en.wikipedia.org/wiki/List_of_Jatco_transmissions

Search for Legacy, you'll come across the JATCO JR507E

Then again, the article may be outdated. Can anyone else shed some light with a technical paper confirming the use of the JR507E in the 05+ LGT?

If you hold the brake and put your foot on the gas (torque brake), you will find that the stall speed is actually high.

Then that means I am a bigger pussy than I know and freak out when I feel the car starting to coil at just 1500rpm

well, it's not really very good for your car. generally speaking, with a tranny cooler and cooler temps (70 F or less), if you do go to the strip, you are fairly safe to torque brake the car til about 2500-2800 RPM. This is just to build up a little boost and you don't want to HOLD the RPMs there, just foot on brake, and add a little gas, then go.

 

This vid is from last year. My second 12 sec run in the LGT. DON'T DO THIS UNLESS YOU ARE SET UP FOR IT!!!! Watch the RPMs and boost when I launch.

Test N Tune Jul 18 07 :: 12.93 run vs Phil 7.18.07 video by trdvibe - Photobucket@@AMEPARAM@@http://vidmg.photobucket.com/player.swf?file=http://vidmg.photobucket.com/albums/v384/trdvibe/Test%20N%20Tune%20Jul%2018%2007/e7c90ec9.flv@@AMEPARAM@@vidmg@@AMEPARAM@@mg@@AMEPARAM@@v384/trdvibe/Test%20N%20Tune%20Jul%2018%2007/e7c90ec9

Holy freakin' crap that was a nice launch, so tempting to try it but I won't. You took off like a bat outta hell. By my count about a 3 second torque brake all in all?

Tranny cooler and VB, correct?

Well, the news that G35's are using the same trans makes me feel a bit safer about going Stage I (if I decide to).

 

I might add a transmission cooler anyway though since it's so inexpensive.

aklgt i forget did you have a full tranny build from ipt or just the vb with tranny cooler?

VB with tranny cooler. But remember, my temps and weather here is much cooler than down South. 80's is a big time heat wave. In the summer, we are usually 60-70's.

Again, don't ever do that if you aren't set up for it. I had a Brembo BBK, IPT VB and tranny cooler plus an SOA tech at my side (not in the car with me) who could help me put the car back together again should something go terribly wrong.

 

AK Wagon gives me crap because I practically have a personal Subie Tech who has built my LGT and will most likely do the same to the STI. Though I'm a huge advocate of the IPT VB mod, in no way will it prevent detonation or make your tranny invincible. If your tranny is on the way out, nothing will help it at that point. I did a lot of torque braking and beating on the LGT when I was just stg 2 and before the VB and cooler. I can tell you that I probably did a bit of damage to the car. So even if you only plan to go stg 2 on the car but you launch it or drive it overly agressive/track, then please do yourself a favor and upgrade that VB as a precautionary. Besides, your shifts will be quicker and cleaner, more power to the ground and really.... it's awesome! Just as much of a performance mod as helping the tranny last a bit longer.

Ahh i want the vb mod. I have the tranny cooler(the largest one you can fit i thinkg 4454 or something like that), but the vb mod sounds soooo tempting.

^^ +1, cant wait to feel the difference.

How hard is it to install the tranny cooler yourself?

How hard is it to install the tranny cooler yourself?

easy!

 

http://legacygt.com/forums/showthread.php?t=17293&highlight=transmission+cooler

There's a walk-through posted on it. You can do a search