With all else being equal how much gain would you see from a 9.5" converter over a 12"?
Thanks

 

Too vague. For what size motor?? mods??? stall????

 

I can help with this one. I just put a 2800 Vigilante with rebuilt tranny in my car. I can not tell you how much horsepower it gives, but what i can tell you it is the best mod i have done with all my other mods combined.

I run a 2.73. Before the 2800, It had great hook-up(no wheelspin) and it also had a big dead spot (usually from 2100 to 3100).

Those are both gone. I get sideways and there is no dead spot. I pull like crazy now, my car really pushes me back in the seat now. My girl turned and smiled, the deer stopped and stared, a NY driver let me go in front of him.

I know the 9.5 Vigilante is 10 lbs lighter than stock.

 

Sound nice man...How much $$ did the transmission rebuild cost u dude?????

 

If all else is truly equal, nothing. The size of the converter per se is not meaningful. However, in general, smaller converters are lighter, which is a good thing. In general larger converters are more efficient, but this isn't due to the size as such. It's that a larger converter usually stalls lower. And all else being equal, lower stall = greater efficiency. OTOH, a large converter with a high stall is often quite inefficient.

Sorry if the above seems confusing. What I am trying to get across is that there would be an optimum size to achieve a given stall for a particular combo. Aftermarket converters are usually smaller diameter and higher stall. They are therefore lighter but may be less efficient than the stocker. The loss of efficency is (hopefully) more than compensated by allow the motor to stay in the powerband.

One other thing, for lockup converters a smaller case may mean that the area of the lockup clutch fricition surface is less. This may mean increased wear and decreased ability to handle big hp.

Rich Krause

 

This is kind of what I was looking for. 10 lbs off of the rotating assembly would seem like it would make a big differance.

Right now I'm pretty much stock except for obdi conversion, Flowmaster muffler only, g2 induction, tb bypass but I have been collecting parts for a full exhaust, 218-224 xe cam, 3.23 gears.

I'm thinking around 2800 but was just wondering the differances of getting a large or small converter.

 

The P. I. Industries 9.5" is about 15 lbs lighter. The increased clutch area on this TC (37 square inches vs. 20-21 square inches for the stock 12" TC). I don't like or use 12" TC's on anything that you want to be quick, or has over 425 horsepower. They are way to heavy, hard on parts, and their torque multiplication ratio is low. The 2,800 rpm stall is good if you drive moderately agressive for the 3.23's. If you drive somewhat conservative, then this is to much stall. I hope this helps.

 

Sounds like the P. I. Industries 9.5" is the way to go. I do drive conservatively MOST of the time and I have 50 miles a day to drive to work (mostly interstate). Would a 2400 stall be a better choice?

 

I got the Stage II Transmission.
http://www.ls1speed.com/catagory.cfm?catagory=trans

rskrause, is of course correct in his statements. If you want the best combo your car should be matched to the stall.

I told the guy at LS1Speed my combo and he suggested the 2800, I dont goto the track, only street.

Today was my 1st full day with it (yesterday we had snow) and this thing is truely an act of god. When I was debating the $650 for the Vigilante I really wasnt sure, I could get just as good for $450. I had heard other good things about the other convertors, but I also kept hearing GREAT things about the Vigilante. And so for another $200 I figured why gamble with something that may not be as great.

After 65 MPH at full throttle it takes some time to get around 90 or so. Today I was thrown back in my seat and It just kept pulling. I wish I did this years ago.

Daily driving, because I put 60 miles a day on the car, is just like stock, RPM's are right where they were before, it feels no different. They say with a Vigilante you get .4 off the quarter mile, I think on the street where everything isnt from a dead stop, is worth a bit more.

If I could do it all over again, I wouldnt.