I just picked up a vig triple disk convertor that came with the car I bought, im sending it in to be restalled, what should I go with? the car will be around 3700lbs, 4l65e trans, primarily street driven but I want to be able to cut some sweet 60s 3.50 gears thru a 9in with a spool also. I should be putting down around 750-800 rwhp

 

3600-4000

 

4000 def.

 

I am concerned that the 4k unit would blow through on the big end when you go to forced induction. I would stay on the tighter end of the scale so to speak.... I like 'em tight. But if you are chasing a 60' with that 3.50 gear and not concerned so much about blowing through it then keep it loose.

I presume that because it is a multi disc unit that you'll have it locked up during WOT maneuvers, if so then keep it loose. What is it stalled at currently and what did the manufacturer say when you spoke to them?

g

 

I run a 3400 made for F.I. (Yank PY3400). And it pulls hard...

 

its at 3000 right now so I know its got to be restalled, not to mention its used so I dont mind it being sent in and freshened up even though its only got 3000 miles on it, what do you mean by blowing thru it? i ultimately want the best chance of running a good time

 

Blowing through a converter refers to the condition whereby the engine rpm's are way beyond the power curve long before there is any realistic mph.

Think of it this way.... Your are at the line waiting on the green light... your are either foot braking it to the max rpm you can or you are at idle waiting to hit the throttle, the light turns green, you hit it... the converter allows the engine to go to 4k rpm's immediately, the car moves out and the boost is building quickly, you shift to 2nd gear and the rpm's are climbing rapidly, but because of the boost the engine goes right to the rpm limiter and you do not have near enough mph but you have to shift... the same thing happens in 3rd.

That may not be the best example, but it might help to get a better understanding... if you had a converter that was tighter, say 3,400 - 3,600 it would react to the boost a bit different allowing the engine to spend more time in the power band, thereby extending the pull.

Blowing through the converter can be likened to a slipping clutch... the engine rpm's go high but the car does not move out... it will feel real good on the hit but it just does not run a good number and you are hanging around the rev limiter way too long.

I am not advocating not running a 4k stall... I am advocating making the right decision for the current combination vs. the future combination... just beware that the stall speed will change when you add significant power to the converter.

g

 

thanks for the explination, can I counteract this by locking the convertor or will this slow me down and put more stress on the trans?

 

My fresh 3200 multidisk Vig flashes to over 4k (probably more, but I'm not looking down at the tach). I actually laid fins down in my 3200 single... NO WAY would I go with a 4k Vig with a SC'ed 408... That converter WILL turn into a 5k+ stall in your application. Most people say to go one higher stall than you think you need... In my opinion, when it comes to big cube SC cars, the opposite holds true for Vig converters. You need to watch out for people with NA cars/experience giving converter advice on FI cars... We start laying a lot more torque into the converter a lot earlier.

 

well now im just about clueless on what stall to choose

 

call up yank or give one of the vig sponsors a call and see what they suggest.

 

Honestly, I'd suggest 3200 for the Vig... I had the same dilema when I upgraded to multi disc. I was very inclined to go with a higher stall and I'm glad I didn't. If you search short times on FI cars, you'll see quite a few cars running 1.5x with the 3200 and little to no difference going up to 3600. If you end up blowing through the converter (which I can almost guarantee you will with a 4000 Vig in a big cube, blown and heavy car) you're throwing the $ you spent on your HP away.

 

if I go to low is the motor going to fall on its face? what about str rating, what should I be looking for?

 

If you've got a SC'ed 408 that's falling on it's face at a 4,000rpm, you've got BIG problems... My car is uncapable of anything close to a full throttle launch on the street with 315 drag radials... The higher STR is just going to hit the tires harder. Most Vig converters are in the 2.5 range according the PI.

 

i just talked to vig, there telling me between 3200-3600

 

Yank Py3200

 

my vote is for a 3600-4000

 

i already own this converter, Im not asking what brand to buy, im looking for ideas on where to tell them to stall the converter