thunderstruck507

iTrader: (18)

We were just dicking around doing laps. But when the local guys do a track day at Hallet in OK they do 20min sessions.

20 mins straight of very hard driving might be enough to tax the trans temps...but I'm not certain either, never done it nor do I know anyone who has tracked a stalled 4l60e.

kingtal0n

iTrader: (1)

it depends on myriad factors. weight of the vehicle vs stall speed vs rear gear, I think is the most important. If you have a deep rear like a 2.83, and a very high stall like 3000 or 3800rpm, with a very heavy vehicle 3800lbs, the trans is going to sit at max stall, slipping, generating ALOT of temperature rise.

On the other hand, something that gets out of its stall range quickly and tightens up like a 3.73 gear with 2800stall in a 2800lbs vehicle will probably never get hot. \

Once you are moving good, if you have the converter clutch for it, you lock it up. They make a triple plate lockup clutch for even nitrous users trying to lock it 1:1. This takes all the slip out of the equation, and this is mostly how you will want to track it, it will behave as if you had a manual trans. The ONLY reason it cannot completely mimic the manual is because the auto's internal parts are slightly heavier, giving you a few % less economy and a few % less power at the wheel. Th gear different (engine speed vs road speed) is negligible with a converter since you can unlock at will (simulating a "downshift" without downshifting). Such a minor price to pay for such consistency/ease of use.

redtan

iTrader: (5)

I was pushing the car as hard as it could handle. Now I'm no pro and the course wasn't exactly high speed, so the WOT bursts were relatively short save for the long straightaway... but nonetheless, I was on the accelerator pedal with an unlocked stall for much of that 20 minute session.

And don't forget, this is a big *** cooler I'm talking about, something in the range of 45,000 BTUs...not some wimpy little thing. So not all coolers are created equal or have the same capacity to cool. And if they are placed in a poor position where they don't get much airflow and rely only on a fan to move air it might not be as efficient as one in the exposed nose of the car where it had 0 obstructions and was fed direct air at high speed.

bjdouglasz28

I realize this is an old post but if youre going with an auto you better build it strong before I did the t56 swap in my fbody I took it to my local road course with an auto 4160e just to see how long it would last I knew it wouldnt last long because i was ***** 450 rwhp. Sadly the transmission didnt do well it lasted 2 laps and was destroyed after going around the last corner. If you dont like the idea of a manual trans with better gas mileage and that will perform better on the track Id get whatever auto trans you get it take it to a reputable shop to have it heavily beefed up. Let me know what you choose if you havent chosen yet, even so an update would b cool.

.boB

iTrader: (1)

I can't think of any good reason to use an automatic on a road course. Too big, too heavy, too difficult to keep cool, and not enough control.

IMO, about the best thing out there is a Levy Racing T5, with a 5" dual disc clutch. Still has an OD for the highway. And saves about 60 pounds over the stock T56. Also available with dog rings and straight cut gears.

Some day...

ZOBETZ

Since this post I actually picked up a T56 for 500$ from someone local. Needed rebuilt so at the moment I'm saving up to send it to tick for a full rebuild. Thanks for all the input fellas.

GarrettM

iTrader: (6)

I loved being able to cruise down the highway and mash on the gas with my auto. It was relaxing. But once I got serious about AutoX I traded my car for a 6 spd. If you want to be competitve, its hard to do so when you and the car arent working in unison. The 6 spd allows you more control of the car for upshifts, downshifts, engine braking, weight transfer etc. You can get it done with an auto no doubt, but it would be more difficult.

At the end of the day whats important to you. When I was drag racing we all knew tit for tat, autos when every time. Throw corners into the mix and that all goes out the window though.

redtan

iTrader: (5)

After driving both a 4 speed auto and 6 speed manual on a roadcourse, I would tend to agree to that statement.

However, I will ask this, since you mentioned being competitive in AutoX...what is the benefit of having a 6 speed manual and staying in 2nd gear the ENTIRE run (which is the case for 99% of AutoX runs) vs. a 4 speed automatic and also staying in the same gear the whole time? In that case, why wouldn't you be as competitive with an auto as with the manual?

DietCoke

iTrader: (18)

Direct coupling to the driveline vs no coupling at all.

Though to be fair, I know of a couple fast powerglide cars that have autoX stalls in them (900-1200 stall speed) that work pretty well