Why a Reverse Valve Body?

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tgee43 said:
I recently bought a bunch of stuff from a guy for my drag car, a '70 Dart which will have a 440 and 727. Included with the parts was a Cheetah manual reverse valve body. The instructions dont mention band apply in 1st, but do say 1st gear, no engine compression braking. Does this mean no band apply in 1st? If not, how can I modify it to apply?
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that is correct..no band apply in 1st..

CRT was modifing them a while back...dont know.

you can also call Turbo Action...

nothing wrong with a no band apply as long as you know it limitations...as Clint would say...
 
Mopastor said:
Can anyone tell me the reason for a reverse valve body, other than the fact you are shifting away from reverse? Someone said they are better for drag racing mechanically and better on the trans. Is this true and why?
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Back in the early 70s went Turbo Action was doing the R&D on 727s they found out that a manul reverse valve body ...was faster then a stock forward pattern valve body in drag racing test...

that was really important in the NHRA Stock/Super Stock Classes....

the one i currently have was built in 1983...I have one that was a couple of years older..but sold it.
 
from Turbo Action website.....

1974 the first CHEETAH Valve Body rocks the Mopar World! It removes the 2-3 overlap and picks up Mopars approximately 0.08 seconds. Until the CHEETAH E-SHIFT no other valve body has ever brought about the performance or conversation that the first #17156 did at Gainesville, Florida in 1974. Terry Earwood put it in the Super Stock black Hemi convertible of the Bowers Brothers and instantly went faster and more consistent. A couple of months later Turbo Action was at Milan, Michigan testing the valve body in the famous "White Whale" and Butch Leal's Stocker. History was made that day as Turbo Action valve bodies, transmissions and converters were better than anything they had in their test vehicles!
 
hmm,its all upto the driver i think.i have a 71 valiant 360,904 reg valve body,w the special tweeks,that mopar engineers figured out in the 60's.a 69 barracuda 452 727 rev man cheetah valve body.they both work great.the pro to a rev man valve body in my opinion,the elimination of going into n r or p while shifting,but any good shifter will do that,but w the rev man,2-3 is a much stronger shift,more consistant.now the con,is learning to drive the car,where my barracuda pulls the front wheels,there has been good drivers use to a foward shift,that lay their hand on the shifter,and many have jumped into second right of the line,so my suggestion keep ur hand on the wheel,til after the launch.just my opinion.
 
Nice article and clears up some 'old wives tales'!
I have sometimes shifted 'third again' (3/4 strip) if the engine sounds like its 'over revving' on the track.
If it wasn't a reverse pattern 727 then the motor would have gone!
When you circuit race (like me) you change gear mainly on engine sound and track position.
In Drag racing if the motor sounds 'maxxed out' then tendency is to look for another gear, dangerous at 130+mph lol.
Seen some BAD trans explosions over the years and advise NOT to go there...
Jon
 
I was at a dealership (70ish) when the first manual valve body modification came "mimeographed" into the shop.
To my knowledge it was a Mopar mod, was definitely Reverse manual,
and was scary as hell, as we had to drill the V/B to do it, - the mimeograph didn't show the best detail, so getting a new V/B for a newstyle trans could be very expensive if you drilled incorrectly !
Once across the line, We just threw the shifter from 1st (Hi) straight up to the neutral gate and coasted.
Low gear just over-ran, - coasted , - which is perfect for street racing .
 
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Guitar Jones said:
Well actually it's a matter of low band apply and shift timing. In the drive position the rear band is not applied in first. If you pull it into first this applies the rear band. While that sounds well and good these days, in the earlier days timing the release of the rear band and the application of the front band was a problem and created a momentary drag when shifting. This already happens in the 2/3 shift when releasing the front band and applying the front clutch. Eliminating the rear band apply in first gear provided a cleaner shift.
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That has nothing to do with a reverse pattern. Reverse pattern came about for only one reason........if the shifter (which in the day were not that great) was sloppy, or YOU were sloppy and missed a shift, you would not get the thing into neutral or reverse.

Worst thing with reverse is you can skip 2nd

Back in the day they did this with push buttons. You reversed 1 and 3 because the original D was close to the PRN buttons
 
The rmvb came about having crisp cleaner shifts with no overlap. The only way to do that was to eliminate the low band being applied in first. Without the low band applying it was now possible to have that neck snapping shift on the 1-2 shift. Then they modified the front servo and accumalutor circuit for no overlap on the 2-3 shift. This is why/how the whole start the burnout in 2nd gear got started. Without low band apply the sprag just freewheels so u need to start ur burnout in 2nd gear. And yes, some rmvb need the throttle pressure wired all the way back. The way u tell us if the little stub is there and gas spring pressure on it, u tie it back or run kd linkage. Kim
 
Hi inertia,

B&M VB upgrades show the drilling of the VB body for the 1st gear 'free-wheeling'.
I still don't understand what this is actually for after all my years of drag racing lol...:lol:

At the end of the strip , I just let the throttle of 'real slowly' and apply the brakes 'real gentle' as she gets all outta shape otherwise?
Should I be changing down to 1st and coasting???

I'm very confused DOH!:steering:
 
I have a couple of Cable shift 904 trans (63-65) with reverse manual VB. One is "homemade" using the old DC kit. The other is a Fairbanks. Neither have a low band apply. Been running these since 1974.
PS: Not sure, but I might have a Cheetah, also.
 
Thanx for the reply Charlie.
How do you know if your VB is 'low-band' apply in Manual first?
According to all the books I've read, that's a stock configuration.
That's why you don't BURNOUT in DRIVE.

Does the 'VB drilling' done in the B&M transkit, transco etc. render this 'inoperative'?
If so why would you do that as the low band apply protects the SPRAG in burnouts etc...:steering:

I've read 'OldK's' thread several times to understand the logic BUT, sprag protection is critical 'AT ALL TIMES...:realcrazy:

Even running 'mid TENs' at 130mph, I never had any 'NECK SNAPPING' lol:drama:

Confused and old LIMEY...:poke:
 
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I run a mrvb and have for some 25 years.
I know how to treat it, and i know how you can blow up a sprag. and i don't do it.

However, I can't control all the thing that cause a sprag to break. drive shaft, axle or rear end breakage. but i'm knowledgeable enough, to know, that if that ever happened.........the transmission would come apart for inspection, before i ran it again.
You can't beat a no rev band 1-2 shift(mrvb). You may get that 1-2 shift with a rev band timing perfect.......and then it will ONLY shift AS WELL as a mrvb.
Argue all you want! it's a true statement.............
 
Drove in a mustang with a reverse manual.VB. Guy runs it through 2nd and goes into 3rd..BANG! Something pops and he tries to get it into neutral but he has to ratchet it back through 2nd and 1st to get N. And that loaded up the motor every time. He went back to N321 the next day with N and R lock out. YMMV
 
Agree that is the drawback of a mrvb
there is a new one out with a "clean neutral" were you push a button and it goes into neutral.
That would be vary cool. If i'm ever in the market for another........i will be looking for one of them.:thumbsup:
 
pishta said:
Drove in a mustang with a reverse manual.VB. Guy runs it through 2nd and goes into 3rd..BANG! Something pops and he tries to get it into neutral but he has to ratchet it back through 2nd and 1st to get N. And that loaded up the motor every time. He went back to N321 the next day with N and R lock out. YMMV
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Get a different shifter....my B&M Pro stick lets me shift directly from 3rd into Neutral without having to downshift into 2nd or 1st....and 1st has no engine braking....
 
I found this video but it don't show how to shift from 3d to N?
 
Run through that 3-2-1 to N obstical course at 130mph with a blowout, broken rod beating your oil pan to hell or worse, a jammed/ broken throttle return spring!! Send us that Neutral "oh ****" button shifter link.
 
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Yeah, I though it would involve a transbrake solenoid of some sort. $900 eh? Ill think about it.......Nope.
 
pishta said:
dup
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Ok ok it’s not a button:D
And more cash for another shifter.

I have had a hill billy idea to hit N with a hinges stop.
Look like it still in the “someday” folder.
 
Personally, I liked the idea of a low band apply RMVB, and bought one, once. First time I used it, I shifted into 1st from 2nd at maybe 15 mph closed throttle, and like about went through the windshield. Never did that again. always made sure I was at a complete stop before shifting 1st gear. I have never had a sprag failure, with a non low band feature, but will state, I don't make the power (even with my big block) that many of you make, and I do drive it properly.
 
With a trans brake low band apply my buddy rolled the rollers on a bolt in sprag. It wasn’t a super sprag. It also broke the tail housing and bent the tail shaft more than .060 thou. 71 super bee with more than 800 hp. Kim
 
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