Question about torque converters...

Old 10-07-2007, 10:37 AM
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kwillymac
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Default Question about torque converters...

We had a 1970 Camaro with a 540 BBC in it. We went to the track and the car went 10.70 @126mph. It has a TH400 4.11 spool with 30x12.5 ET Streets. The converter was a TCI Super Street fighter.

The car was shifted at 7,000 in second and third gear. It crossed the line at 6,800 rpm. The car was a lot slower then we were hoping.




My question is does this sound like a converter issue...maybe not locking up?
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Old 10-07-2007, 12:39 PM
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Tod74
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Default Re: Question about torque converters...

Originally Posted by kwillymac
We had a 1970 Camaro with a 540 BBC in it. We went to the track and the car went 10.70 @126mph. It has a TH400 4.11 spool with 30x12.5 ET Streets. The converter was a TCI Super Street fighter.

The car was shifted at 7,000 in second and third gear. It crossed the line at 6,800 rpm. The car was a lot slower then we were hoping.




My question is does this sound like a converter issue...maybe not locking up?
I think they will need a lot more info than you have given them.
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Old 10-07-2007, 01:01 PM
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woodsman
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kwillymac not knowing all the specs just going by the numbers of 10.70 @126 you are getting all the converter is going to give. Now if you have a HP number that you feel does not match your ET than I would say it may be your trans but the converter is locked up. Thats JMO.
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Old 10-07-2007, 01:24 PM
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kwillymac
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If I use the torque converter slippage calculator it says 14%. Crossing the finish line with 30" tall tires at 6,800 RPM with 4.11 gears doesn't add up with that MPH.

Engine Specs

Block GM 502
Crank Scat Crank 4.25 stroke
Rods Scat Rods
Pistons J&E 10:1 Compression
Heads Dart Pro 1 335 CNC Ported
Cam Comp Cams Roller 260/268 @.050 .714/.714 Lift
Intake Dart 4150
Carb 1000 CFM Race Demon
Distributor MSD Billet Distributor with 6AL Box
Exhaust 2 1/8 Hooker Super Comps with 3" Flowmasters
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Old 10-07-2007, 02:05 PM
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SST4530
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Sounds like they are driving through the converter to me. I would order a converter from Hughes, Chance or ATI.

What are the 60' times?
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Old 10-07-2007, 02:08 PM
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kwillymac
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The 60' was 1.58. Pretty bad for this combo. That was launching off the foot brake at around 2,500. Just taking it easy.
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Old 10-07-2007, 02:09 PM
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woodsman
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kwillymac on converter slippage numbers I would not know what I was looking at. I am just going by your MPH and it is right on the money for your ET so I would say what ever slippage that you have has to be right for your ET & MPH. May be one of the guy's that knows more than I do will pipe in on there opinion if they feel my info may be wrong. From your 10.70 @ 126 your car is efficient.
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Old 10-07-2007, 02:09 PM
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I PERSONALLY would like to know how much the cars weigh's ?
and how much HP is your motor making ?
Brian
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Old 10-07-2007, 02:13 PM
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kwillymac
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Originally Posted by bjuice
I PERSONALLY would like to know how much the cars weigh's ?
and how much HP is your motor making ?
Brian
The car weighed 3610 with driver at the time it was run. Unfortunately, besides the Engine Analyzer program I have it was never dynoed.
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Old 10-07-2007, 02:15 PM
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kwillymac
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Originally Posted by woodsman
kwillymac on converter slippage numbers I would not know what I was looking at. I am just going by your MPH and it is right on the money for your ET so I would say what ever slippage that you have has to be right for your ET & MPH. May be one of the guy's that knows more than I do will pipe in on there opinion if they feel my info may be wrong. From your 10.70 @ 126 your car is efficient.
I understand the MPH matches the ET. I don't understand how a 30" tall tire with 4.11 gears crossed the line at 6,800 RPM with only 126 mph.
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