Landracing Forum
Tech Information => Technical Discussion => Topic started by: slepe67 on June 02, 2009, 09:43:47 PM
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This is a wierd one, and I figured I'd ask in here, as well as the HAMB. I am building a 32 Roadster to Land Speed Race out on the flats. I plan to run a Windsor block (289, 302, or 351W).
I was at my local hot rod shop, having a cold one, and this older dude, who had been racing vintage stock cars for YEARS, said I should run a converter-less, 2 speed Powerglide, mated to said Windsor.
This is where it gets gray. He said that off of the two holes on the case, I hook up two lines, which go to my clutch reservoir/assembly. I push in the clutch, it disengages the trans, so I can shift gears while at a stop (or from D to R, etc). While driving, I just shift normally as I would any auto trans, no clutch pedal required.
He also said the clutch is a TINY roundy round style clutch, and it wasn't meant for hard shifting, such as you would need for drag racing, but for stock cars, and LSR, he said it would be PERFECT. Apparently guys HAVE used this type for drag racing, but they only last for a pass or two, then they crap out.
I've read a lot of the high power guys run autos without torque converters. I assume these are the guys who need a push off the line ???
This would also help out in the horsepower loss associated with a normal auto trans, correct? I'm shooting for around 350 RWHP, but that may or may not be the case. Depends on how much money my wife will let me have! haha, but seriously....
Anyone know if this would work on a SEMI streetable hot rod/LSR car? I don't plan on driving all over town, just down the highway once in a while.
What do you think? Would you do it? Oh yeah, it's final drive is 1:1, and the rear end gears I have currently are 4.10:1, posi. That is changeable.
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I would plan on running a TQ converter normally and just replace it with a pump drive unit and push off---there have been lots discussions on this set up in the past have you tried the search..
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and get rid of the posi.
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Try www.mikestransmission.com pg. 3 of the catalog. Looks like you leave out the clutch as well. :cheers:
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I would plan on running a TQ converter normally and just replace it with a pump drive unit and push off---there have been lots discussions on this set up in the past have you tried the search..
thanks guys. Having never heard of this before actually, I didn't even know what to type in...what is this setup called? I had heard of guys not using torque converters, but, not this...
as far as the posi goes...haha, well, I guess I'll see what it does. As they say," if you have posi and it spins, go peg leg. And vise versa..." But yeah, I know what you mean. Thanks JL
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you can run a direct drive hub that replaces the converter. It drives the pump and input shaft of the transmission.
The oil also circulates through it so the trans is lubed correctly.
You need a push off , then pop the trans into low gear.... run the car to what ever RPM you desire and lift on the throttle when you clik the shifter for high gear.
ATI has a super case and bell housing that will bolt the glide to a Ford engine.
This setup is not streetable.
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Anyone know if this would work on a SEMI streetable hot rod/LSR car? I don't plan on driving all over town, just down the highway once in a while.
I have run a John Kilgore turbo 350 automatic without a torque converter in my roadster at El Mirage. It has a reverse shifting pattern. I would just push the car up to about 20 mph and the driver would pull the shift lever into first gear. Then the driver would bring up the rpm until 1st gear matched the speed and drive off the push vehicle. It has performed flawlessly.
This particular unit would not work on the street, without a torque converter. If you really want to drive the car on the street I would suggest going to a manual transmission.
Tom G.
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When i bought my roadster it had a clutch-flite in it. A torque flite with a clutch instead of a converter. And clutch hydros were used years ago. And now some seem to do very well with just a coupler. Guess there is more than one way to skin this cat.
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Here's what the circle jerkers use. They take off under there own power with 4.10s and the such.
(http://www.tciauto.com/Products/CircleTrack/component/744400.gif)(http://www.tciauto.com/Products/CircleTrack/pump/745000-745050.gif)
TCI makes it. Jegs sells it. You must use the right valvebody for the 'clutch pedal' type. You can also use a ball valve.
TCI Circle-Matic
Componets http://www.tciauto.com/Products/CircleTrack/circle_track_components.asp
Front Pump Drives http://www.tciauto.com/Products/CircleTrack/circle_track_pump_drives.asp
Built Trannys http://www.tciauto.com/Products/CircleTrack/circle_track_transmissions.asp
TCI also makes a servo cover for the push start setup
(http://www.tciauto.com/Products/CircleTrack/744409.JPG)
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I would rethink and consider a 350 you are not going to like your initial accleration or the drop between gears
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What's the advantage over a 4-speed with a close 3rd and 4th?
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yeah, I'm on to what Stan's saying. I HAD a TH400, but read a lot about power loss via the auto trans...I'm going to go the 4 speed route. Thanks for all the help, hopefully somebody can use this post in the future!
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I ran a powerglide the first 2 years on the salt because that's what I had. When I changed to the 4 speed Jerico I could tell a big difference in the way the car ran.
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We're just real old school.
Plus I think it's just one big drag race to the quarter. If we couldn't go 200 in the quarter, we might as we'll go get back in line. Careful use of 1st and 2nd gear gets you to about 5000 in third, not 1500.
Don't even have a hydraulic throw-out bearing -- just something else that may go wrong. If the mechanical linkage breaks, you might be able to fix it.
Mechanical water pump -- don't have to remember to turn it on.
Batteries only for starting -- if they don't work, push it (never have had to).
God, the Stone Age was wonderful!
Stan Back
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Stan, I agree with you, I tryed the electric water pumps and had problems, tryed hydraulic clutch and had problems, built my own clutch linkage with lots of holes for adjustment, works great as long as I keep it greased good after each salt flat event. Also learned to have a check list that my wife takes care of which frees up me to think about the run instead of all the little details. This sure is a lot of fun, sitting on the return road at the 7 mile mark waiting for the tow vehicle and looking at the mountains and listening and watching the next cars run on the course.
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Some real world experience. E/MS with TH350 no converter............Best run 205 mph
Same car and motor with small clutch and Liberty air shift 5 speed...Best run 205 mph
I think this is why Flowbench says " Without data, your just someone with an opinion "
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I prefer mechanical to electric or hydraulic because the ancient coal-burning brain cells suss levers better than electrons, and (as said) you might be able to fix it.
Trying to find an air bubble in 30 feet of hydraulic system with 5 components and 17 joints does not yield to profanity, or even self-mutilation (proof on request).
Detecting a bad ground that "always worked before", but has now decided to visit another galaxy is another example of "how to make bloody holes in your palm with your fingernails".
The non-converter PG I've seen has a simple valve that bypasses part of the valve body line pressure that engages low gear. Valve closed: must be pushed, but no loss/no slip. Valve cracked will allow the engine to idle in gear (brake on!!) to check for leaks, linkage, etc. Valve open 25% allows the car to be "walked" slowly by blipping the throttle softly. The valve could be a motorcycle type clutch lever, pedal, or large twist knob - driver's preference and interior space factors.
Since this was developed to allow trailering and pit movement only, I have no faith that it could be used to actually launch the car, but it might reduce driveline stress when used with a push-start.
As to terminal speed for different boxes: it's only a general rule that as speeds go up, and RPM at peak power goes up, that a tight (small % drop) shift into high gear has more value. Cars that are traction limited or have very broad power ranges (diesel, turbo) won't follow this path. No original auto trans that I know of has a useful 2-3 or 3-4 shift (although the 4L80 is pretty good at 75%), but it's not necessarily going to hurt every time. IMHO super-close ratios (less than 10% loss into high gear) are not useful unless the torque curve has a big spike in it, and dead on either side.
Some common ratios: http://victorylibrary.com/mopar/aod.htm
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Doug --
Here's some data that may be missing from your equation . . .
The TH350 is a 3-speed, the glide is a 2-speed.
(And just maybe 205 was as fast as it would go in direct no matter how many speeds it took to get there.)
Stan
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Doug --
Here's some data that may be missing from your equation . . .
The TH350 is a 3-speed, the glide is a 2-speed.
(And just maybe 205 was as fast as it would go in direct no matter how many speeds it took to get there.)
Stan
Bob Joenck used hi gear only in his roadster because one of his drivers used to miss shifts :-P
JL222
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You guys stay out of this -- we're talking about cars where the tires are going the same speed as the ground.
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With t he ball valve on the power glide... in years past usually it is used to blow off pressure from the pump. You hook the valve into the pump at front of trans.... other end is hooked to the pan so the oil is circulating
As you close the ball valve the pressure builds... the band is applied ( low gear) if the shifter is in low gear. the vehicle will roll away like leting a clutch pedal out if the gearing allows it.
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Tony, refresh the collective memory, please: what do you do for a living? :-D
Mike
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Tony, refresh the collective memory, please: what do you do for a living? :-D
Mike
I build performance automatic transmissions for a company in Phx AZ
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If it's Hughes, ain't nobody better.
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If it's Hughes, ain't nobody better.
I've been at Hughes for 10 yrs... We work hard at getting stuff correct
i've worked on automatics for a couple of decades. when the clutch pressure plate came through the floor and hood of my 68 Chevelle SS 396 , I got interested in automatics. That was 1974 or so.
:-D