How do high stall converters work?

[gozza]

How do they work and what is the purpose

[4.9 EF Futura]

Amazing thigs, torque converters.

A "high stall" converter is simply a torque converter which has been designed/modified to increase the RPM at which the converter is said to stall.

http://auto.howstuffworks.com/torque-converter.htm

[LTDHO]

The 'work' part can be difficult and technical to explain.

Their purpose is to alter the RPM that they are efficiant at and their torque muliplying factor. Simply, the cam works from 2500 the car would 'bog down' under this so it would suit the drivability to have the converter to slip up to this RPM.
A high stall is pointless and a money waste until the engine is built, it is not a case of walking into a shop and asking for a 2500 to suit EF for example. Also the diff gears will also need to be changed for optimum performance gains.

[gozza]

so it doesn't idle at the revs its named(2500 stall converter)...wats happens when u put your foot down...does it rev untill the stall and then engage...i'll read up on that link too
thnx guys

[Aaron_EF8]

It doesn't rev then engage at 2500 (eg: for a 2500 stall). If you put your foot on the brake and pull the handbrake, a stock Falcon torque convertor will rev to 1800-2100 (depending on engine) whereas a 2500 will rev to 2500, thats about the easiest way I can think of explaining it.

[old_mate]

You can also flash a converter whereby you stand on the gas from idle and the converter will have a different stall speed again (usually higher) depending on the engine

they seem to me to be complicated things but im learning

[gozza]

i get it now
so basically it stalls higher lol
i think i was trying to be too complicated with my thoughts
i didn't put it into a practical scenario...ive stalled up my auto for burnouts or to get off the line quicker..when i thought of it that way it makes more sense

[stockstandard]

Just think of them as the equivalent of the clutch on a manual box. Normally you want to rev to about 1500 or so then start letting the clutch out. On a performance engine when you want to drive hard, you would rev to about 2500-3500 or more before you let the clutch out. Same idea with the stall convertor. You decide when you want the power to be locked to the back wheels and get the matching convertor.

the difference is that with an auto/stall convertor, you will still have some power being put to the wheels at lower rpm - just not all of it. Kind of like slipping a clutch I guess.

[gozza]

sweet sounds like a mod i need to do
thnx for the info i understand it now
so just say i got ya normal stock slushbox with a shiftkit...wat stall converter would be applicable for my eb and how much do they cost

[4.9 EF Futura]

Originally Posted by gozza

sweet sounds like a mod i need to do
thnx for the info i understand it now
so just say i got ya normal stock slushbox with a shiftkit...wat stall converter would be applicable for my eb and how much do they cost

The stock converter will be fine. The problem we have with the standard btr transmissions is the ratio of the 1st gear.

A hi stall converter is used when you need to get the revs up due to cam/head/whatever pushing the power band further up the rev range. Refer to LTDHO's post above.

[Supa R00]

Ive been in an EF XR6 with a 2500 stally, was pretty cool, much like dumping the clutch and flooring it in a manual. stomp on this thing and it would go straight to 2500 and start spinning

[gozza]

Originally Posted by Supa R00

Ive been in an EF XR6 with a 2500 stally, was pretty cool, much like dumping the clutch and flooring it in a manual. stomp on this thing and it would go straight to 2500 and start spinning

thats sounds mad

[gozza]

ok well i don't have cams
just headers hi flo cat exhuast and pod
so i'm guessin a high stall wouldn't be needed.. but as per using it just to stall up to the revs and drop...is that stupid?
i want like a 2500-3000 one cos my eb off the line is a tank

[old_mate]

thought about diff gears?

[gozza]

yeah i thought about that
my mates got an eb and just got given some diff gears...i wanna see how that gos on his

[Aaron_EF8]

2500 is the safe limit for a torque convertor on a BTR, the TCM/ECU weill go into limp home mode (LHM) if it stalls to over 3000 rpm.

I have a 2500 TCE convertor in my car and it made a decent improvement, and i'm using stock heads/cam/manifold.

Cost for a high stall convertor is around $900 fitted, ring around for prices.

[gozza]

thanx man
wats BTR?

[Aaron_EF8]

The company that builds the 4-speed auto's for EAII-BA Falcons

[eb six on boost]

imo dont run a stall higher than what your cruise rpm is, as you know it wont be locked and will loose power and fuel eco.

[Aaron_EF8]

I have no problems at cruising speed on mine, the stall speed doesn't have anything to do with the torque convertor lockup. It still locks-up at 1500rpm in 4th if I want it to.

[Stav]

Reasonable torque converter is rated at a certain rpm .However if you put out more engine torque the stall goes higher. 2500 stall converter is definately a streetable combo on a standard car . I have done my homework well.Also another factor is that torque converters have torque multiplication which manuals do not have. If your car puts out 300ftlbs of torque at 3000 rpm torque converter can deliver 600ftlbs of torque with a multiplier of 2.The au ford has a multiplier of 2:1. Just changing the multiplier to 3:1 should make the car chirp in gears and of course take advantage of a greater amount of engine torque at the higher engine speed.
A 2500 stall converter can stall up to 3000 rpm flash with a bigger cam and tricks.

[Stav]

Here yas go...

http://www.tciauto.com/tech_info/tor..._explained.htm

[eb six on boost]

Originally Posted by Aaron_EF8

I have no problems at cruising speed on mine, the stall speed doesn't have anything to do with the torque convertor lockup. It still locks-up at 1500rpm in 4th if I want it to.

yes thats true unless like me you have had the lockup removed at manufacture.