z28boysteve

iTrader: (9)

How many of you fellow Turbo Folks swapped from the T56 with a conventional hydraulic non-slipper clutch to an automatic like a TH400..

How much ET did you lose and how fast are you?

BlazinT/A

iTrader: (10)

most guys actually gain due to better 60' times also an auto will help spool up the turbo faster

MY99TAWS6

iTrader: (3)

Just completed my RPM 4l80 swap. I didn't run my car at track yet . I don't miss my six speed much. I love the new stall and love driving my car much more now. Heavy traffic is no big deal again. Don't have to worry about missing shifts,hitting the limiter, shortshifting or the infamous 3 to 2. No masters to change ,no drill mod to do. No slaves no t 56 noises, clutch floater noise,machine gun shifter noise. Expecting to build good boost off the line with the auto and two step. no anitlag needed but do have option for small shots of spray as well.
M6 cars can build boost only if you get things like two step and antilag or spray it .
M6 cars are a lot harder on parts too.

I am expecting to run some good times next season and hope to be running 700 to 800 rwhp daily and mabye 1000rwhp for dyno bragging rights. Car is very heavy so not sure what it will do at track. My suspension is more street than track. Car was never built for track. But autos are much more consistent if brackets are your thing.

98Z28CobraKiller

iTrader: (17)

In your sig you have a 60' of 1.49. You should be a able to drop an easy tenth there which should equal 2 tenths on the long end. The bigger benefit is the consistancy. Once you dial everything in, you can actually measure gains or losses from other mods. IMO, people that are hell bent on going fast with an M6 are masochists. They just love the pain.

Turbo LS1 SS

iTrader: (7)

10.5 to 9.1..... 15psi vs 17psi. with a th400.

will probably go 8.7's with 17psi (haven't had much time with it), and i plan on going sub 8.5's with more boost. 3800# with me street car

99Z28LS1

iTrader: (4)

That's quite a drop... amazing!

I didn't do the swap for ET's, I did it because I didn't want to mess with expensive clutches... a twin disk would have been over $1100 and my built th400 with stall was $1425. plus, my th400 has a warranty from the builder, he said if it breaks with anything less than 1k he'll fix it and pay for the tow truck

Tiago

iTrader: (27)

haven't been to the track yet but hoping to loose 2 seconds of ET LOL

HydroStream6

iTrader: (16)

I've gained .5s so far from 10.9 to 10.4 going from 6 speed to 4L80e... converter still needs some playing around and I need a two step too... I should be closer to a .8-.9s drop once those things are dialed in.

z28boysteve

iTrader: (9)

Yeah I was pretty much also along the line of .2 of ET drop. Even though I think that's wishfull thinking since I had the 6 speed running so good and 60ing high 1.4s

99Z28LS1

iTrader: (4)

Some of the things you listed will more than likely have a big effect because you won't be a N2O car anymore and boost comes in quite differently than N20 I would think

Photochop

iTrader: (74)

This is good stuff to hear, I'm hoping by next spring my M6 will be in the process of being swapped out. Its fun, but I enjoyed how the auto spooled the turbo alot better in my last car. And, at the track I'm M6-stupid. I'm trying to decide between the 'semi-zombie' approach - with a th400, 3.08 gears and 295/45/17 MT radials...or bite the bullet and go 4L80E. I want it to be completely streetable/roadtripable, but have more fun at the track with it.

MY99TAWS6

iTrader: (3)

Turbo 400 with 3.08s can be decently streetable for sure. 4l80 gives me option to run bit more gear like my 3.54s and still cruise just over 2000 rpm on the highway in OD locked up.
I personally can't stand too low gear off boost and most of my driving is around town off boost. The 3.54 help my heavy pig car get moving and my spool up is very fast maybe too fast currently.Some guys claim the lower gears give faster spool...jury is out on that one I think... Also 4l80 has only 2.48 first, 1.48 second so can still use some gear to get things going.
But 400 route is definitely much cheaper way to go.

Zombie

iTrader: (2)

$$$$$ = go 4L80 with proper gearing
$$$ = go TH400 with highway gears or proper gearing if it's a race car.

RS_SS69

iTrader: (31)

4L80 is basically the same exact trans as a th400 just with an overdrive, same gearing and all.

4L80e
1st 2.48
2nd 1.48
3rd 1.00
4th 0.70

th400

1st 2.48
2nd 1.48
3rd 1.00

so if you go and base your gearing in either that should help what your looking for rpm wise. Many people have low gears numerically and have no trouble dipping deep in the 10s and 9s. Im going with a 3.42 strange 12 bolt with a th400 cause im more track setup and I dont mind spinning 3k or more on the highway speeds.

SKINNY69

Maybe this is the place to put this question instead of starting a whole new thread. If you guys had to start from the beginning again and start with a new f body, would you guys have all gone with the auto if you knew you'd be running a turbo?

I don't even own an f body yet but I like to do my research first and have a plan before I even start a new build. I want to build my own front mount kit and push somewhere in the neighborhood of 650+ on the street.

I need a simple answer. A4 or 6spd?

airforcemanss

iTrader: (23)

are you guys manual shifting your 4l80e's?

Photochop

iTrader: (74)

I'm curious about this as well as I don't think my 98 will control a 4l80e, will it?

MY99TAWS6

iTrader: (3)

I wanted full computer control of my shifts. Modern computers do a great job of that.
If my car was more a pure race car then full manual valve body would have been ok.
After having tons of manual cars throu the years, 96,97 and 99 trans ams..and bunch of manual dsm cars just reached the point where was sick of them. For street use standards are ok..if you can find a clutch with decent pedal pressure that is ok in sometimes heavy traffic and other situations where touchy clutches are pain in the butt.

At the track they are not so good. Too many things to blow..short shift, misshift,3 to 2,
hit the limiter..and seems always messing with slaves which stupid gm put internal compared to the 5 minute slave change my talon takes being external slave.
Masters also are pain to mess with ,broke piece on my seat messing with masters so much..Finally did the drill mod which let me actually shift at higher rpm. Tried several different masters and clutch combos.
My last one the tex twin was pretty nice ,pedal pressure was good but still didn't like the floater rattle,shifter rattle, gear noise of the t56. And the clutch was still touchy in my opinion.

As for building boost with manual you can do it with two step, antilag and or spray.
With auto just a two step can do it, some spray maybe on the really big turbos.

I like its just point and shoot now. Whether track or off track a 600 rwhp plus car is a handful and nice to be able to concentrate more on the road,less distractions.
Also manuals are harder on parts expect more breakage.

So my vote is auto . And my dedicated race talon is auto for same reasons..consistency for one. And can build great boost in it with just two step.

But..am think keeping one manual car my 97 talon. That one has two step, anitlag might go small shot on it. Fun to have one stick car in the stable.

If did have stick car again likely it would be a bone stock one like a bone stock z06 . But really plan on a paddle shifted six or more speed future car. I would have maybe went for a 6l80 and paddle shift kit but just did'n't think it was necessary. So far I love my 4l80 a lot.

So mostly street use with emphasis more on highway driving where the sixth gear is good for mileage and you can choose your gears a bit better on corners and stuff..the six speed is nice.
For track especially 1/4 mile track then its auto all the way.

I think too if you want to go auto but manual shift a turbo 400 with say 3.08 gears makes more sense. Cheap and strong and with 3.08 is still fine on highway.
The 4l80 cost me a lot more and main reasons are overdrive,and nice computer control of everything..shifts, lockup....etc.

Sluggish

iTrader: (10)

I am getting very close to getting an auto, I just don't wanna fight this t56. Last time I drove it I assume I boiled the clutch fluid because now it doesn't wanna shift into 1st or 3rd. I am looking at getting a junkyard 4l80e and a trans go stage 3 manual shift to get me started. But I would really love to hit a 9.99 with the 6-speed before I send it down the road.








I would have bought a v6 since I have changed everything on this car besides the interior, also would have bought a hard top and not t-tops.

z28boysteve

iTrader: (9)

yeah tell me about it, my car is a 2002 "NHRA EDITION" Trans Am, AND it came with an LS6 Block... means about 1 of 50 NHRA edition trans ams made in 2002 with the LS6 block....

And now its a race car