I just put in a Yank SS3800,new built tranny,my questiion is how much hp im I going to lose from the unlocked stall?I dynoed about 30 less hp then before? Is this normal?

 

Yanks normally lose about 8-10 rwhp lbetween ocked and unlocked

 

That seems about right to me.

Take a look at the locked vs unlocked dynos of a YPT4400 in the link below. There is almost a 40 hp difference at 6000rpm.

https://ls1tech.com/forums/generation-iii-internal-engine/132000-finally-dyno-d-my-10-second-cam-only-setup.html

The guy runs high 10s with a cam only


John

 

Okay so me seeing the 30hp loss is common with a high stall?I was very dissapointed in my numbers with my mods.

 

What were your peak hp numbers @ RPM locked vs unlocked with the SS3800?

John

 

Assuming you are using a quality converter efficiency will depend mainly on the stall speed of the converter and gear ratio, and the RPM it is measured at.

If you dyno 400hp locked and 390 unlocked then the converter would be 97.5% efficient. It is unlikely you will see that kind of efficiency on a 4000+ stall at 6000 rpm.

John

 

Thats what I saw on my PT4200 and I know of a few others...Now when I had my vigilante converter...It was about 30 rw difference

 

I dont have a lock up switch so i couldnt compare my numbers,it gained a ton down low,but flatens out at 5400??

 

i lost 23 hp with my old TCS 3400. 314 unlocked/337 locked.

 

You got a good one!

I can tell you that with my PT4400 I only saw 90% efficiency (measured on the street) at 6200 rpm running 3.23 gears. Below 6000 efficiency was 80%-85%.


John

 

So your comparison is between the stock TC and the SS3800 both being unlocked?

Can you post your dyno?

John

 

That is 93% efficient. What RPM was that measured at?

How about with the Vig 3200?

 

My old dyno with the Vig. 3200/3.73s was 340rwhp unlocked and 356rwhp locked. Very efficient converter.

 

dont have a number id say 5200 rpm by the peak on the graph????

havent dynoed with the vig yet....