High Stall Torque Converters
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Joined: Mar 2006
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From: Tampa Florida
High Stall Torque Converters
How many horsepower would you expect to lose with a high stall torque converter on the dyno? The car is a 98 w/ a4 has Dynatech Supermaxx LT's w/ no cats, BPP Vortex Intake, Borla XR-1 Exhaust, 3.42's, High Stall Torque Converter. I have seen similar cars with this setup make 320-330 rwhp. On the dyno mine made 305 rwhp. I was told by the tuner that the car will not make as much horsepower because of the High Stall Converter. The car feels much faster now, I am just curious about the horsepower numbers because they seem low. Can someone please explain to me what I dont know???
Instructor
Joined: Dec 2006
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From: Phoenix AZ
Dry, warm day on the dyno?
(higher density altitude, sucks horsepower)
Engine runnin about 180 or up around 220 degrees?
(hotter running also sucks horsepower, have seen a motor drop 40hp as the day got warmer, on the dyno)
Hi-stall converter is all about torque multiplication, they dont kill horsepower.
If a motor makes 330hp with a 10" converter, it will make that much with an 8" converter.
-Frank *my 2 copper*
(higher density altitude, sucks horsepower)
Engine runnin about 180 or up around 220 degrees?
(hotter running also sucks horsepower, have seen a motor drop 40hp as the day got warmer, on the dyno)
Hi-stall converter is all about torque multiplication, they dont kill horsepower.
If a motor makes 330hp with a 10" converter, it will make that much with an 8" converter.
-Frank *my 2 copper*
Safety Car
Joined: Jun 2007
Posts: 4,050
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From: Los Angeles CA
Generally the high stall converter will make the car faster but doesn't do anything for power, as the same with gear upgrades. They aren't power adders. They get the car to launch quicker but the true horsepower output will be less. If you don't race the car and just want to show off it's numbers then a converter is not needed. If you are more concerned with racing then do the converter.
I don't know how much HP you can expect to loose though.
I don't know how much HP you can expect to loose though.
Race Director
Joined: Jan 2003
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From: San Antonio Texas
St. Jude Donor '05-'06-'08
Generally the high stall converter will make the car faster but doesn't do anything for power, as the same with gear upgrades. They aren't power adders. They get the car to launch quicker but the true horsepower output will be less. If you don't race the car and just want to show off it's numbers then a converter is not needed. If you are more concerned with racing then do the converter.
I don't know how much HP you can expect to loose though.
I don't know how much HP you can expect to loose though.
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Joined: Mar 2006
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From: Tampa Florida
Car was dynoed at RexExtreme in Bradenton Florida in the summer time so it was a hot day. I thought that with the LongTube's I would see higher horsepower than the 305 rwhp. The car feels MUCH faster, I have just seen other cars with similar mods dyno higher. Thanks for the Input!
Safety Car
Joined: Jun 2007
Posts: 4,050
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From: Los Angeles CA
Car was dynoed at RexExtreme in Bradenton Florida in the summer time so it was a hot day. I thought that with the LongTube's I would see higher horsepower than the 305 rwhp. The car feels MUCH faster, I have just seen other cars with similar mods dyno higher. Thanks for the Input!
I'm not an expert or anything, but I did stay at a Holiday Inn Express..... just kidding. I'm not an expert but I would think if someone without the high stall TC and similar other mods got 320-330 then with a high stall and gears you would probably get 310-320ish. Maybe you can check with your tuner to give it a good once over and make sure it's still in tune and tuned correctly for your mods.
best of luck.
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Joined: Mar 2006
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From: Tampa Florida
Thanks for the respsonses fellows! I thought the horsepower numbers seemed low. Can a hot day rob that many horsepower? I have since ran it in the quarter mile and ran 13.00 flat, however I forget what the trap speed was so I would think the tune is still good. Am i still missing something???
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Safety Car
Joined: Jun 2004
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From: Stoney Creek Ontario
A hot/humid day can rob you of horsepower big time..... I've run 13.336 @ 107 in 90F @ 90% humidity and run 12.973 @ 108 at 58F and 20% humidity... with a stock '02 vert A4 and 2.73 gear.....
Advanced
Joined: Jul 2006
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From: Lyndon, KS
Temperature certainly can make a big difference...I'm curious what the climate was for your 13 flat run.... seems even with the minor mods you have you should run faster than that.
Something does seem fishy with the statement that the TC will rob horsepower... before it's flash point, yes, but typically you ignore any dyno figures lower than that because they're meaningless (as the torque multiplication will be a bigger factor, hence the "faster" feeling). Once it flashes, it's effectively a solid unit and will have minimal loss. Certainly not an additional 25hp worth of loss. I'd be curious to see your tune (I dabble).
Jon
Something does seem fishy with the statement that the TC will rob horsepower... before it's flash point, yes, but typically you ignore any dyno figures lower than that because they're meaningless (as the torque multiplication will be a bigger factor, hence the "faster" feeling). Once it flashes, it's effectively a solid unit and will have minimal loss. Certainly not an additional 25hp worth of loss. I'd be curious to see your tune (I dabble).
Jon
Burning Brakes
Joined: Apr 2004
Posts: 1,236
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From: Glendora CA
If the convertor was NOT locked you will see lower numbers. Some convertors are NOT ment to be locked at WOT. If the convertor was locked then it sounds like your are down a power a little bit. Also do NOT try and compair dyno numbers from a m6/m12 to even a locked A4 the auto will always show lower numbers.
