We'll close on the house soon, so after I pay a thing or two off I'll be getting my F-body. I'll get the LT-1 for the lower cost and the reliability of the iron block. First I'll spray it, then STS turbo. (I don't care about split second repeatability, just the grin factor.) Then heads and cam. A rearend, SFCs, a cage...... All over time, of course. At some point I'll have to rebuild the engine with good parts. I'll probably spray it to spool the turbo if I get a stick. I may also spray through the whole run.
My question is- can a well built 4L60e handle that type of abuse? I'm going with N2o and a turbo so it will retain decent street manners while also being very fast at the track.
I think a T-56 might be stronger, and would definitely be more enjoyable for me driving it day to day. On the other hand, when an auto with the proper T/C kicks down and you get that monster torque hit........ the smile may well become permanent. The hit's not quite the same with a stick.
Can a 4L60e take that sort of thing? Not all the time, but fairly often. I'm really on the fence as to which tranny to get.
Who can tell me what I need to know?
Also, I know the street twin is around a grand. What would I be looking at for the auto build-up and converter?
Thanks in advance, Don.

 

The obvious choice between the M6 and A4 is the M6. The T56 is a strong tranny. If you are planning a drag car with extremely high-po it gets murkier. You will need an upgraded T56, a TH400 or something even more exotic in that case. But that's only if you plan to run in the 9's or darn close to it.

You will need an upgraded clutch for a hi-po M6, the McLeod Street Twin is the obvious choice in that department.

Rich Krause

 

Thanks for the reply. It brings up a couple of other questions I have. I've heard of OD units for the Turbo400. Are they all they are cracked up to be? What can a T400 handle if properly built?
I just saw another post regarding upgrading the T56, and it seemed pretty interesting. 900+ HP 800 lb ft. Expensive, but maybe worth it. What can a stock one deal with, assuming it leads a fairly hard life? (That's what they're for, right? )

 

The TH400 an be built for more hp than an LT1 can realistically produce. A tranny built to this spec with a converter of equivalent quality is not cheap. The tranny and converter I am using (Rossler and Coan) cost over $4,000. However, there are a lot of people running less expensive TH400's without a problem. The Gear Vendors OD is a very nice unit. I will be buying one when I can budget the cost. In retrospect, a lesser tranny plus the GV might have been a better choice.

T56 upgrades are not an area of particular knowledge for me. If you do a search you can find a number of threads on the subject. I think that both the input and the output shafts are prone to break under drag strip type use. If you stick with street tires, I doubt you will break a stock one as the tires will spin before the tranny breaks.

Rich Krause

 

Thanks for the help. I guess it'll be the T56. I like the higher strength for the cost, the better mileage, and the higher degreee of control. I'll miss the kickdown, though.