Could converter be bad?

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555RAT
Posts: 47
Joined: Sun Feb 24, 2008 8:59 am
Location: Central Oregon

Could converter be bad?

#1 Post by 555RAT » Sun May 15, 2011 8:07 pm

I thought it might be the carb at first but am leaning toward converter. Leaving at 4200 the car acts like the converter is tight, gets out a ways then accelerates real quick. On the shift at 6700 it drops to around 5,200 and stays there for a bit and then starts accelerating, almost like it's too loose. Not to mention it very inconsistent. On the burnout it doesn't seem turn the tires over until the secondaries open and rpm gets pretty high. The converter is an 8" borrowed from a car that it stalled around 5600 with same size engine but more comp, cam, and head.
Thanks, Keith
8.90@149 and 3,000lb, no Juice, no boost!

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Marty Chance
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Location: Cheney, KS

Re: Could converter be bad?

#2 Post by Marty Chance » Mon May 16, 2011 7:17 am

possible that the sprag in the converter is broke or it may simply be too tight for your motor. where does your motor make peak HP and peak TQ?
Neal Chance Racing Converters
Home of the World's Fastest Automatic Doorslammers!
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555RAT
Posts: 47
Joined: Sun Feb 24, 2008 8:59 am
Location: Central Oregon

Re: Could converter be bad?

#3 Post by 555RAT » Mon May 16, 2011 9:20 am

Thanks Marty, I haven't had the engine dynoed but am guessing peak tq at around 5000 and hp around 6500. 406, 11.5:1, 260/264@.050", ported vi Jr heads, 1.80 glide, 4.56 w/32 tall tire, around 2850lbs.
Thanks, Keith
8.90@149 and 3,000lb, no Juice, no boost!

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Marty Chance
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Joined: Fri Sep 19, 2008 6:34 am
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Re: Could converter be bad?

#4 Post by Marty Chance » Tue May 17, 2011 1:24 pm

Actually sounds like the converter may be just a little too tight. (as your description of the shift recovery) what rpm do you cross the finish line with this converter?
Neal Chance Racing Converters
Home of the World's Fastest Automatic Doorslammers!
www.racingconverters.com

555RAT
Posts: 47
Joined: Sun Feb 24, 2008 8:59 am
Location: Central Oregon

Re: Could converter be bad?

#5 Post by 555RAT » Fri May 20, 2011 5:05 am

To tell the truth, it's hard to say because the et is all over the place and the finish line rpm varies. I've only run 1/8 mile and it varies how long it stays at the shift rpm until it starts climbing again. It did mph between 96-104! :scratch:
Thanks
8.90@149 and 3,000lb, no Juice, no boost!

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Marty Chance
Posts: 193
Joined: Fri Sep 19, 2008 6:34 am
Location: Cheney, KS

Re: Could converter be bad?

#6 Post by Marty Chance » Fri May 20, 2011 9:13 am

OK if the mph varies 96-104 something is way wrong.
? converter fins pulled ,blocking fluid flow worse on some passes than others? (check for debris in fluid)
? tire spin you dont know is happening?
? weak ignition system?
just a few of the gremlins that mey be haunting you. You may have to do process of elimination. change one thing at a time until you find the problem.
Neal Chance Racing Converters
Home of the World's Fastest Automatic Doorslammers!
www.racingconverters.com

555RAT
Posts: 47
Joined: Sun Feb 24, 2008 8:59 am
Location: Central Oregon

Re: Could converter be bad?

#7 Post by 555RAT » Fri May 20, 2011 2:12 pm

Thanks Marty, I'm putting my converter from my 555in and see what happens. It stalled at 6200 in that motor I'm hoping for around 5000 in the 406.
Thanks, Keith
8.90@149 and 3,000lb, no Juice, no boost!

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