BAIN

iTrader: (5)

I have been told in the past that you want to match up the converter size with the peak TQ of your car to get the best results ex.. my cam only car makes peak TQ @ 4800 rpm so I bought a Yank PT 4800 stall.
The question I have is all the top cam only cars are running a 5300 + converter so am I missing something or misinformed? I want to get the most out of my setup, but I also have a 4l60e so that may be harder to do.

Anyone have any ideas or suggestions as to why using that high of a stall is better?

Here is a dyno graph of where my car makes peak TQ & HP:

JL ws-6

iTrader: (50)

With a converter, it's hard to really see where the tq peak is. I'm sure my 402 doesn't hae a tq peak that's anywhere near where my stall is ( stall is very loose ) but I am sure the converter being like it is will be faster then if I had it tightened up.

Most of the cam only guys are probably running the loosest converter then can and still get thru the traps at xxxx rpm, that would be my guess.

BAIN

iTrader: (5)

The blue graph is locked so you can see the "real curves". The red is unlocked.

BAIN

iTrader: (5)

Come on guys any more help?

JL ws-6

iTrader: (50)

I talked to Eastside abotu this very tpoic, and the bottom line is taht theory si great and all, but every time they loosen a converter on any one of their customers cars, or their personal cars, it goes faster.

That being said, the guys are running the loosest converter tehn can get away with and still make it thru the traps with their limiter and gear/tire size.

gator's 99TA

iTrader: (2)

i have noticed this too. look at jugy running that ATI 5500 with h/c or cam only! same thing for magnus. it might stall slightly lower than 5500 though behind their cars. esp with light weights. ofcourse that converter is nothing but a stock eliminator converter and those guys are only running mid to low 10s most of the time.

but on the flip side, a local car is running a stroker ls1 rnning 9.40s on the bottle at 3500 lbs and his converter is flashing on the nitrous at 5300 rpms.

i think its the combination of small rear gear, tall tire and loose converter. i am trying that out this year. i am running a converter that iwill probably flash at over 5K on the nitrous but am running a 3.73 gear and 28" tire. hopefully i can get through the traps at 7Krpms.

6secNaLs1

iTrader: (5)

i went from a 8 inch 4600 to a 8 inch 4800 and went slower...juans verter is a 4600 if you order it from turbo action..it goes 5100 or 5300 on the brake

gator's 99TA

iTrader: (2)

ah, that brings up another point. some converters stall up higher on a TB than flash stall too.

BAIN

iTrader: (5)

I'm confused on what you're trying to say here. Are you saying the looser the converter is the harder it is to stay under the rev limiter ie..the rpms slip more?

If so that brings us to another thought. You also have to match up the loosness of the stall to the shift extension so you are in the car's powerband all the way down the track right? Ex..my shiftpoint on my 4800 converter is 7000-7100 and the shift extension is 5900-6050 which is a little low for my powerband. Should I be looking for a converter with a shift extension more around 6400-6500 to stay higher in the powerband according to my dyno graph?

gator's 99TA

iTrader: (2)

you want the converter to not drop belowe 6400 rpms???

daniel6718

iTrader: (36)

your supposed to get a stall 500-1000 before th torque peak,this allows the body to flex and the front to raise and back to sink which will take another 300-500 rpm id guess in an initial hit from a stop

gator's 99TA

iTrader: (2)

fast cars dont squat the rear end. body flex? blah. get out of here. teh fastest stock internal ls1 cars run the pt4400 converter. not even close.

BAIN

iTrader: (5)

The shift extension on those 5500 stalls can't be much less than that right?

ty_ty13

iTrader: (42)

i know alot of times when you have to go to a huge stall it tells me that they are not getting a good bite with the smaller stall...

some people use a high stall to act like feathering a clutch.... this isnt always the case but you'd be suprised at how many people think they are hooking and arent at all...

daniel6718

iTrader: (36)

well idk...i know ls1 guys need a bigger stall...but my car on stock suspension stock heads stock bottom end, no motor mods besides a cam...LT stall and gears i cut 1.60-1.62 on motor making 320hp with a 3200 stall and 3.73...so i guess i could be wrong...if i was going for a cam only record id get a 4000 and have a manual lockup switch for the big end!
i think anything over 4600 or so is over kill, unless you have a very small cube motor and no power adders

gator's 99TA

iTrader: (2)

lets hear from the fellas with big stalls.

Pro Stock John

iTrader: (34)

Magnus ran an 8" ATI, it was pretty loose.

1QuickT-A

iTrader: (12)

Thats the exact same thing that I am about to try... TCI "Ultimate" Street Fighter stalled around 4500 and will probably flash 800-1000 rpms on the nitrous.. Hopefully its not too loose...

I'm running 3.50 gears with a TH400 & 28x10.5's at the moment..

BAIN

iTrader: (5)

What was the shift extension like on that stall?

gator's 99TA

iTrader: (2)

didnt magnus and juggy run the same converter? the ATI 5500.