Re: Effect on converter stall speed
[Re: BDW]
#3217228
03/01/24 10:57 AM
03/01/24 10:57 AM
|
Joined: May 2019
Posts: 163 W. Pa
usp4u
member
|
member
Joined: May 2019
Posts: 163
W. Pa
|
The lower torque you are making than the other guy will help lower the stall.
BUT
You are considerably heavier than the other guy with a considerably higher gear. This will raise the stall, likely more than your lack of torque will offset.
Pass on that used convertor.
Something like a TurboAction 17805M would probably be a better bet.
Last edited by usp4u; 03/01/24 11:00 AM.
|
|
|
Re: Effect on converter stall speed
[Re: mshred]
#3217260
03/01/24 12:59 PM
03/01/24 12:59 PM
|
Joined: Jan 2003
Posts: 2,916 A shed in England
Tig
master
|
master
Joined: Jan 2003
Posts: 2,916
A shed in England
|
Don't know if this is any help but changing from a 4.10 to a 3.73 rear gear increased stall by 1000rpm on our combo.
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials. 9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge. RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
|
|
|
Re: Effect on converter stall speed
[Re: FurryStump]
#3221628
03/20/24 10:45 AM
03/20/24 10:45 AM
|
Joined: Aug 2003
Posts: 4,676 On the parachute mount
n20mstr
master
|
master
Joined: Aug 2003
Posts: 4,676
On the parachute mount
|
fluid can tighten or loosen the converter, Straight tractor fluid to straight dexron or a mix of them can move the stall a few hundred rpm. IF this is a "street" race or no prep type deal, looser is usually better....just saying
....BAD A$$ STREET CAR.....
|
|
|
Re: Effect on converter stall speed
[Re: n20mstr]
#3221631
03/20/24 11:02 AM
03/20/24 11:02 AM
|
Joined: Oct 2004
Posts: 2,820 Connecticut
FurryStump
master
|
master
Joined: Oct 2004
Posts: 2,820
Connecticut
|
Depends, I flash to 3500 rpm because that is all my 6” tire can hold. The rest of the combo wants 5000+ flash. Some in the FAST use a programmable box to pull timing. Not there yet. My SLR is pretty low with 4:10 and a low 1st gear 904. Lets me tolerate a small bit of wheel speed before I need to pedal.
Last edited by FurryStump; 03/20/24 11:05 AM.
|
|
|
Re: Effect on converter stall speed
[Re: FurryStump]
#3221699
03/20/24 04:20 PM
03/20/24 04:20 PM
|
Joined: Mar 2006
Posts: 9,835 MI, usa
dvw
master
|
master
Joined: Mar 2006
Posts: 9,835
MI, usa
|
A 230@.050 cam is a lot of duration for a heavy car with a 8.5-1 360 and a 3.08 axle. Been there, you will not like it. Not a happy combo on the street Doug
Last edited by dvw; 03/21/24 07:41 AM.
|
|
|
Re: Effect on converter stall speed
[Re: FurryStump]
#3221756
03/20/24 07:54 PM
03/20/24 07:54 PM
|
Joined: Jan 2003
Posts: 2,916 A shed in England
Tig
master
|
master
Joined: Jan 2003
Posts: 2,916
A shed in England
|
Don't know if this is any help but changing from a 4.10 to a 3.73 rear gear increased stall by 1000rpm on our combo. But that is somewhat artificial. The definition of flash is the highest rpm seen before the car moves. The car moves sooner/easier with the 4:10 than with the 3.73. That earlier movement might be more beneficial that then increase in flash rpm. Did the car improve in the 60’? Always trying to understand more about the converter No, 60ft dropped a 10th. Slower by 2 10ths, Mph dropped 4 - 6 mph while rpm remained roughly the same through the traps. Slip increased from 10 to 17 %. I have since fitted another converter but no track time as yet.
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials. 9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge. RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
|
|
|
Re: Effect on converter stall speed
[Re: n20mstr]
#3221865
03/21/24 10:40 AM
03/21/24 10:40 AM
|
Joined: Apr 2009
Posts: 3,415 Toronto
mshred
OP
master
|
OP
master
Joined: Apr 2009
Posts: 3,415
Toronto
|
fluid can tighten or loosen the converter, Straight tractor fluid to straight dexron or a mix of them can move the stall a few hundred rpm. IF this is a "street" race or no prep type deal, looser is usually better....just saying Its just a street car that I am trying to NOT turn into a full blown race car lol. It may get nitrous or a blower in the future though... I can't remember, but what I recall the tractor fluid, like hygard, tightens by a couple hundred rpm, right?
|
|
|
Re: Effect on converter stall speed
[Re: dvw]
#3221866
03/21/24 10:42 AM
03/21/24 10:42 AM
|
Joined: Apr 2009
Posts: 3,415 Toronto
mshred
OP
master
|
OP
master
Joined: Apr 2009
Posts: 3,415
Toronto
|
A 230@.050 cam is a lot of duration for a heavy car with a 8.5-1 360 and a 3.08 axle. Been there, you will not like it. Not a happy combo on the street Doug Honestly, I thought that too, but this is what was recommended by the cam grinder, even giving all of the information on the combo. They also recommended an even larger grind, but I chose the smaller of the 2. That said, something like this, would you say would like more or less converter? I am back and forth between this converter I mentioned in my original post, or a factory high stall 340 converter. Other then what I have already noted, the car MAY get a set of 3.55 gears in the future, but I know it will hurt the driveability on the highway, so that is slightly up in the air.
Last edited by mshred; 03/21/24 11:12 AM.
|
|
|
Re: Effect on converter stall speed
[Re: mshred]
#3222032
03/22/24 01:46 AM
03/22/24 01:46 AM
|
Joined: Oct 2004
Posts: 16,479 Canada
CrAzYMoPaRGuY
I Live Here
|
I Live Here
Joined: Oct 2004
Posts: 16,479
Canada
|
I'm wondering the same. I just picked up a 360/380hp crate engine. 3400 pound car, 3.23 gears, 27" tall tires and a 904 based lockup. 230 ish duration at .050 I think 1 3/4" Super Comps, 650 AVS2, and an irresponsible driver.
I drive mostly highway, I like to drive at a brisk pace, but should I change the converter? It's a lockup trans and probably not a lot of options...? Factory 318 4 barrel engine in it now. 155hp? I could swap cams in the 360/380 if necessary but I would rather not!!!
CrAzYMoPaRGuY
|
|
|
Re: Effect on converter stall speed
[Re: Tig]
#3222068
03/22/24 09:54 AM
03/22/24 09:54 AM
|
Joined: Oct 2004
Posts: 2,820 Connecticut
FurryStump
master
|
master
Joined: Oct 2004
Posts: 2,820
Connecticut
|
Don't know if this is any help but changing from a 4.10 to a 3.73 rear gear increased stall by 1000rpm on our combo. But that is somewhat artificial. The definition of flash is the highest rpm seen before the car moves. The car moves sooner/easier with the 4:10 than with the 3.73. That earlier movement might be more beneficial that then increase in flash rpm. Did the car improve in the 60’? Always trying to understand more about the converter No, 60ft dropped a 10th. Slower by 2 10ths, Mph dropped 4 - 6 mph while rpm remained roughly the same through the traps. Slip increased from 10 to 17 %. I have since fitted another converter but no track time as yet. Sounds like the converter definitely not happy. I know people who have tried increasing slip % at the top to try and increase torque multiplication down track, but no real results yet. 10% seems a bit high. I’m at 4-5 % at the stripe. Which car?
|
|
|
Re: Effect on converter stall speed
[Re: mshred]
#3222072
03/22/24 10:16 AM
03/22/24 10:16 AM
|
Joined: Apr 2004
Posts: 324 Northport, al.
tvt59
enthusiast
|
enthusiast
Joined: Apr 2004
Posts: 324
Northport, al.
|
ATI makes 20w and 30w type f transmission fluid. Going from the 20w to the 30w affected mine about 200 rpm
Nothing worth anything comes easy. It is always harder to do the right thing.
My Grandfather
|
|
|
Re: Effect on converter stall speed
[Re: FurryStump]
#3222087
03/22/24 11:21 AM
03/22/24 11:21 AM
|
Joined: Jan 2003
Posts: 2,916 A shed in England
Tig
master
|
master
Joined: Jan 2003
Posts: 2,916
A shed in England
|
Don't know if this is any help but changing from a 4.10 to a 3.73 rear gear increased stall by 1000rpm on our combo. But that is somewhat artificial. The definition of flash is the highest rpm seen before the car moves. The car moves sooner/easier with the 4:10 than with the 3.73. That earlier movement might be more beneficial that then increase in flash rpm. Did the car improve in the 60’? Always trying to understand more about the converter No, 60ft dropped a 10th. Slower by 2 10ths, Mph dropped 4 - 6 mph while rpm remained roughly the same through the traps. Slip increased from 10 to 17 %. I have since fitted another converter but no track time as yet. Sounds like the converter definitely not happy. I know people who have tried increasing slip % at the top to try and increase torque multiplication down track, but no real results yet. 10% seems a bit high. I’m at 4-5 % at the stripe. Which car? 8" ATi converter, it was originally specified for a 750 ish HP 528motor. It worked ok with the 572/580 motor and and 4:10 rear, showed over 900hp on a good day at the track going off the numbers and the weight (4023lb). Stall was originally 5200 (4:10) and it would go to 6000+ with the 3.73 gear. Data showed around 9 - 10% slip (4:10) which I was OK with as the car worked ok. I guess the change in rear ratio pushed the converter too far We have fitted an ATi converter (9 1/2") that was built for our 655ci motor with 1000+ hp and a 4:10 rear, hopefully that will improve things.
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials. 9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge. RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
|
|
|
Re: Effect on converter stall speed
[Re: dvw]
#3222090
03/22/24 11:34 AM
03/22/24 11:34 AM
|
Joined: Jan 2003
Posts: 9,996 Frostbitefalls MN (Rocky&Bullw...
gregsdart
master
|
master
Joined: Jan 2003
Posts: 9,996
Frostbitefalls MN (Rocky&Bullw...
|
A 230@.050 cam is a lot of duration for a heavy car with a 8.5-1 360 and a 3.08 axle. Been there, you will not like it. Not a happy combo on the street Doug i agree.it will really hurt torque. A cam like a Comp 268h would be ideal,,,,,
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
|
|
|
Re: Effect on converter stall speed
[Re: tvt59]
#3222093
03/22/24 11:46 AM
03/22/24 11:46 AM
|
Joined: Apr 2009
Posts: 3,415 Toronto
mshred
OP
master
|
OP
master
Joined: Apr 2009
Posts: 3,415
Toronto
|
ATI makes 20w and 30w type f transmission fluid. Going from the 20w to the 30w affected mine about 200 rpm Stalled higher or lower with the switch?
|
|
|
Re: Effect on converter stall speed
[Re: dvw]
#3222094
03/22/24 11:47 AM
03/22/24 11:47 AM
|
Joined: Apr 2009
Posts: 3,415 Toronto
mshred
OP
master
|
OP
master
Joined: Apr 2009
Posts: 3,415
Toronto
|
Runing a low gear like the 3.08 doesnt allow the rpm to get high enough to couple. We ran Dizusters turbo car with a 2.76 gear. It ran 10.50's but the slip was as I recall was over 25%. Why? The car wasn't done accelerating. My street car ran a 5300 with a 3.55. Slipped like mad. Felt like it had a V V T trans. Same converter with a 4.30 it drives great on the street. Cam, converter, gear all have to be in sync to drive nice. Doug So in this case, would the 2500 stall or the 4000 stall be ideal? Cam company said 2500+ stall for converter giving them all the combo details. Maybe the lower stall would work better as to couple sooner?
|
|
|
|
|