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convertor disappointment long post #1081382
09/24/11 10:18 AM
09/24/11 10:18 AM
Joined: Apr 2005
Posts: 399
metro detroit
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turner Offline OP
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metro detroit
I was running a Coan 3500 convertor, turning 7.14 1/8 mile times. I took my car, had it dynoed and determined my peak torque was at 5200 rpms and was 430ft/lbs, upon discussion with fellow racers and the dyno shop i was told that I should get a convertor around the same rpm stall as what my peak torque was approx. I BORROWED a friends TA convertor that supposedly flashed at about 5400, This convertor was in his ride when he blew his motor, and i think it got hurt. The convertor has tons of slippage on its 2-3 shift, so much Im worried about my trans., my 3500 Coan never slipped on the 2-3 shift.

I ran the car 2 passes at a track with no bite of the line first pass, I footbrake the car holding my foot on the brake and take the motor to 3700 rpms and launch, the tires went up in smoke hit my revlimiter and I shifted and the tires go up in smoke again....no traction

on my second pass i picked the other lane and launched ok with a 1.62 60' time wich is what my 3500 convertor does, everything felt good until I shifted from 2-3 wich slipped horribly.....ended up runnning a 11.32 at 122mph.....it seemed once 3rd gesr caught it started charging hard on the top end, but probably slipped for a whole second.

I believe this convertor is too much for my combo, and I believe that this convertor is hurt, the service desk at Turbo Action warned me the convertor could be hurt if it was in when the old owner hurt his race motor and then let me borrow it.

Is the slipping 2-3 shift an indication of a bad convertor, My trans was shifting fine last week with my other convertor.I was looking for my first 10 second run and it looks like I have the MPH but the slipping killed it, I have never ran my 3500 convertor in the 1/4 mile, but I may just get my 10.99 with that convertor

Does anybody have a similar isssue with a hurt convertor and what times should have been had at the 122MPH mark?

Re: convertor disappointment long post [Re: turner] #1081383
09/24/11 10:41 AM
09/24/11 10:41 AM
Joined: Jul 2008
Posts: 30,248
Florida STAYcation
dIc dOc Deity ! Offline
The village idiot's idiot
dIc dOc Deity !  Offline
The village idiot's idiot

Joined: Jul 2008
Posts: 30,248
Florida STAYcation
I have never heard of a converter slipping only in a 2/3 shift. IF the converter is bad ..... it is going to slip and slide in all ranges.

Re: convertor disappointment long post [Re: dIc dOc Deity !] #1081384
09/24/11 10:46 AM
09/24/11 10:46 AM
Joined: Feb 2004
Posts: 2,495
Richmond , Virginia
BEEQUIK Offline
top fuel
BEEQUIK  Offline
top fuel

Joined: Feb 2004
Posts: 2,495
Richmond , Virginia
If its slipping on the 2-3 shift that's not the converter, thats your trans.

Re: convertor disappointment long post [Re: BEEQUIK] #1081385
09/24/11 11:00 AM
09/24/11 11:00 AM
Joined: Nov 2006
Posts: 637
Kokomo,IN
StripeHOG Offline
mopar
StripeHOG  Offline
mopar

Joined: Nov 2006
Posts: 637
Kokomo,IN
check cable adjustment


Andrew Brough D372 1969 Dodge Dart GTS 1.43 60'best 6.82 1/8 98mph "the light came on and I ran out of talent"
Re: convertor disappointment long post [Re: StripeHOG] #1081386
09/24/11 12:35 PM
09/24/11 12:35 PM
Joined: May 2007
Posts: 174
Oklahoma
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hemiiroc Offline
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Posts: 174
Oklahoma
Converters don't slip on the shift,they slip after the shift

Re: convertor disappointment long post [Re: hemiiroc] #1081387
09/24/11 01:16 PM
09/24/11 01:16 PM
Joined: Apr 2005
Posts: 399
metro detroit
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turner Offline OP
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metro detroit
I suppose that the cable could be off location, but i dont think so its a quarter stick style shifter with the morse style cable. I had no problems b4 this in my shifting, and all i did was pop the cotter pin and pull it out from linkage arm.I kinda think this convertor is a little big for my application..its an 8" 5400rpm stall. I have a440 w/cnc ported performer heads, 4:10 gear, and a 28x10 slick.

I have the car on jack stands and will try to simulate the 2-3 shift on my shifter and then check and make sure the arm on the trans. has fully hit its detent like its fully engaged.The car only starts in park and nuetral so the shifter must be close, but i know it doesnt take much adjustment to make a difference. I do have about 400 runs on this shifter cable set-up, so this is no new build.

Re: convertor disappointment long post [Re: turner] #1081388
09/24/11 01:25 PM
09/24/11 01:25 PM
Joined: Jun 2003
Posts: 9,225
Charleston
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sixpackgut Offline
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Charleston
i'm thinking your low on fluid. unless your motor is very similar to your buddies race motor i would think the converter would stall a little lower. give it a second chance


Gen 3 power 6.22@110, 9.85@135
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Re: convertor disappointment long post [Re: turner] #1081389
09/24/11 02:27 PM
09/24/11 02:27 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
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Bend,OR USA
Two things come to mind, one is fluid level and the other is cable adjustment Make sure that the cable is adjusted so the pin will slide right into the shift lever in all three forward gears if it won't adjust it so it will when trans slip on the 1 2 shift(EDITED or any gear change) it is the trans, not the converter as already said Now, get to work

Last edited by Cab_Burge; 09/24/11 02:44 PM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: convertor disappointment long post [Re: Cab_Burge] #1081390
09/24/11 02:41 PM
09/24/11 02:41 PM
Joined: Apr 2005
Posts: 399
metro detroit
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turner Offline OP
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metro detroit
I have just checked my cable adjustment and it does go into all gears as stated without issues, but I cannot pull the cable pin in any of them, let me adjust the cable slightly and see if i can make the pin "center" better in the arm hole. I will re-check my fluid level as well once I readjust my cable. I thought that my 1-2 shift was acceptable it was my 2-3 shift that was slipping heavily....like it wasnt fully into gear. Seeing as how I cannot pull the pin on the shifter arm in any forward gears makes me believe that cable adjustment may be in order.

Re: convertor disappointment long post [Re: turner] #1081391
09/24/11 04:49 PM
09/24/11 04:49 PM
Joined: May 2004
Posts: 3,210
robin hood country
deaks Offline
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Posts: 3,210
robin hood country
What cam, comp, weight, tyre size and gear do you have.
Mick


69 Dart GTS 440 mopar .590 cam, Edelbrock heads, 3200#
best et 6.45, 106.78, 10.14, 132.88 mph, 1.47 60ft
best 60ft 1.36
Re: convertor disappointment long post [Re: turner] #1081392
09/24/11 05:58 PM
09/24/11 05:58 PM
Joined: Oct 2005
Posts: 164
Savannah, GA
mopar400 Offline
member
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Joined: Oct 2005
Posts: 164
Savannah, GA
Make sure you're checking the fluid in Neutral I know this should be obvious on this forum but is commonly overlooked. Kevin


1965 Fury II 1970 Challenger 440, 509 cam, 11:1 w/ 452 iron heads, 6.99 1/8, 11.29@ 120mph 1/4 (1999 Magnolia Drag strip track champion) 1992 Jeep XJ Crawler
Re: convertor disappointment long post [Re: turner] #1081393
09/24/11 06:29 PM
09/24/11 06:29 PM
Joined: Oct 2010
Posts: 2,393
Ambridge, Pa.
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rickraw Offline
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Ambridge, Pa.
i think u have too much converter for ur application. i agree with what to other members stated. does ur fluid smell like burnt clutch?? i'd also check line pressure. 160 to 180 works great. detent is very critical. u can burn a clutch quickly if it's off. stay safe, seeya.

Re: convertor disappointment long post [Re: rickraw] #1081394
09/25/11 12:06 AM
09/25/11 12:06 AM
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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joedust451 Offline
super gas
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Branson, Mo.
Why would you change out converters? When you got the Coan did they set it up for your current combo? You can "never" trust a used cnverter, Plus it'll flash differently from 1 combo too another, Its not just the engines torque that dictates that, its also the weight its pulling & so forth, I'd do like the others suggest, but IMO it could be the converter, not thats its "bad", just its reaction too "your" combo. You say that converter flashes 5400 from what you were told, Your peak torque is 5200, thats the 1st. problem, it needs to be at or a bit lower then peak torque. & did you "test" flash this converter in 3rd. gear at around 15-20 mph to see where it went in "your" car? I say the engine has more load in 2nd. 3rd. gear so if the converter is flashing too high for the peak torque, Its going to feel spongy in the higher gear shifts & slip more, Its not that the engine is making "less" HP/Torque in the higher gears, its just under more load so its affected & the converter will react to those changes.


75 Duster, 451 10.87 @ 123.58 NA 97 Z28 6sp., 12.01 @ 115 on a 100 shot 71 Swinger. 360 magnum. 12.58 @ 105 78 cutlass, 469 BBC. 12.70 @ 108 on street tires. http://www.youtube.com/watch?v=Z2kqNmMfheU
Re: convertor disappointment long post [Re: joedust451] #1081395
09/25/11 09:24 AM
09/25/11 09:24 AM
Joined: Apr 2005
Posts: 399
metro detroit
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turner Offline OP
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metro detroit
I bought the Coan so I could stay somewhat streetable, but after bracket racing this car for 2 years I thought I would throw in a higher stall convertor and pick-up the performance that my Coan had left on the table, seeing as how at 3500pms i have over 200ftlbs less torque than at 5200rpms. I have run at least 50, 7.15's in the 1/8th and figured I am so close to the 10.99 Ive been chasing that the convertor swap would be a shoe-in for my 10.99 run.....wrong

spongy is a good description of how this convertor felt during my 2-3 shift

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