Manual VB W/Ratchet Shifter vs Auto VB

Krazeeun said:
If it matters to any of you, most of us here at the shop lock our trucks in 1st gear between 12-18mph.... we all use PCS's though.
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I lock mine in first, currently at 12mph, using a pressure switch off of govenor pressure.

Jason,

It's not just the speed difference but how hard it is for the TC clutch to lock up. In first gear the TC has a large mechanical advantage over the rear tires (large gear reduction). When the TC locks up it has an easier time matching the crankshaft speed to the input shaft speed. In OD for example it is much harder for the clutch to match those two speeds.

Paul
 
paulb said:
I lock mine in first, currently at 12mph, using a pressure switch off of govenor pressure.

Jason,

It's not just the speed difference but how hard it is for the TC clutch to lock up. In first gear the TC has a large mechanical advantage over the rear tires (large gear reduction). When the TC locks up it has an easier time matching the crankshaft speed to the input shaft speed. In OD for example it is much harder for the clutch to match those two speeds.

Paul
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Ok, so 1st is best, but top of 2nd is well, 2nd best? :)

Maybe I might see about swaping VB's when I add that extra turbo.
 
question about locking up in first,,,, how well will this stand up on a very high hp truck, say in the 1200+ range?

Also, how about a transbrake at this HP range? How will the rest of the drive train handle that too,,, lol (I think I know the answer to that one,, )
 
While it's apples and oranges, in DirtyMax we found the earlier we locked the quicker we ran. Of course we broke a few parts in the process!
 
If you think about it, gear reduction is on your side when locking in first gear.. our pro street trucks both well over 1000hp and weighing in approximately 6,000lbs each, one 2x4 and one 4x4 both lock in first gear. Both of our full bodied quad cab 4x4 (one of them being mine) lock in first gear as well.

To date we've never had any tranny failures that can be related to locking in first gear out of any of our race trucks. I broke a sonnax input after twisting it to nearly a 45* angle first but that was purely my fault for not letting off the throttle in a severe 4x4 spin and it hooked, shock loaded and popped it.
 
Well then,, locking in 1st it will be... can this be setup with the manual VB? I dont like the idea of having additional gizmos trying to do the work for me if possible

Thnx
 
We can make it lock in first but WHEN in first would be the tricky part. It would almost have to be on a timer or boost reference with a manual on/off switch unless you wanted to manually control it at all times.
 
I like paulb's idea and run it off a pressure port on the trans!

And I just did some conversions. I lock at about 40-45mph! geez, I bet that's good for 0.2 improvement!
 
Traction can be an issue on some tracks IMO depending on weight/HP, I use mid 2nd gear lock-up because most tracks won't hold sooner lock-up on my truck. Just something to think about.
 
morkable said:
question about locking up in first,,,, how well will this stand up on a very high hp truck, say in the 1200+ range?

Also, how about a transbrake at this HP range? How will the rest of the drive train handle that too,,, lol (I think I know the answer to that one,, )
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Cole Dow (Smokin93) locks at the top of 1st, and he's had the least transmission troubles of any 9 second diesel I know of. Course he's "light" too...
 
I am shooting for somewheres in the mid 5000# mark before I come out to race... it is in the process of a major weight loss (driver too,, lol).. should be around 1200 hp ish,, (depending on how liberal I decide to be on the little red button)

So far I have been running a full race tranny, it has all billit shafts, servo, clutch drums, extra clutch packs, sc tc. Once moving the tranny has worked well,, but I have never been able to launch at over 17 psi,, every single time I tried I have to replace all the forward clutches.....

I am the first to admit I am not a tranny expert,, I dont even try. I just want something that is going to work, allow me to get some boost at the lights and not melt down every time I look at it. I am not afraid of having the clutch packs replaced if needed, but not every race if you know what I mean
 
Krazeeun said:
We can make it lock in first but WHEN in first would be the tricky part. It would almost have to be on a timer or boost reference with a manual on/off switch unless you wanted to manually control it at all times.
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Hmm, manually controlling it would be tough, as there is alot to do for that first 100 feet or so,,, not sure it would be something that would always be remembered to be honest.

Rob, you bring up a valid point also,, as my truck gets lighter and lighter, and that my suspension (for at least this season) is fairly old school, this could be an issue. Man, it is a tough call isnt it,,, I will be running full on slicks this year so that will be one thing to consider.
 
Blacksdieselhp said:
Yes, Dave G can do lock up in first. He is working on trans brake, but until it is perfect, he will never let it out of his door. So we are still waiting on that.
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That's what I thought, was surprised when I read that transbrakes were no problem. They've been nothing but a problem so far at least with the high HP high torque trucks. Will be great when it really happens though.
 
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JQmile said:
Cole Dow (Smokin93) locks at the top of 1st, and he's had the least transmission troubles of any 9 second diesel I know of. Course he's "light" too...
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Rich Buckley went over 100 9 second passes on 1 transmission!
(in his old 2wd truck)
 
morkable said:
Hmm, manually controlling it would be tough, as there is alot to do for that first 100 feet or so,,, not sure it would be something that would always be remembered to be honest.

Rob, you bring up a valid point also,, as my truck gets lighter and lighter, and that my suspension (for at least this season) is fairly old school, this could be an issue. Man, it is a tough call isnt it,,, I will be running full on slicks this year so that will be one thing to consider.
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I think you would have good luck going with the goerend that locks in second, all you have to do is flip the switch in staging lanes and shut it off at end of track. I am not sure, but since you are in first for such a short time how much would you gain locking in first?
 
devon lock said:
I think you would have good luck going with the goerend that locks in second, all you have to do is flip the switch in staging lanes and shut it off at end of track. I am not sure, but since you are in first for such a short time how much would you gain locking in first?
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This is true,, I guess I was thinking more about the life of the tranny,, giving it every chance to live a little longer... probably more of a case of being to gun shy...

I should remember that I have ran in the 10's with no lockup,, found out after that my co-pilot was not working properly and wasnt actually doing anything....
 
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9 LIVES said:
Rich Buckley went over 100 9 second passes on 1 transmission!
(in his old 2wd truck)
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Thats so weird. I had lunch with him today and thats what we were talking about for some of the time. He def enlightened me a lot to the point im going to try to get him to build another race trans. Gotta see if a 4wd can hold the whole time. Im aiming for 5k lbs in mine. But his truck ran very very well and his mustang is going to be very interesting this season.
 
Most "tranny" failures we see from very high HP trucks come from torque converter failures... way too much power and weight just melts them, the earlier you can lock it the less heat is generated and the longer the converter/fluid/clutches live.
 
Krazeeun said:
Most "tranny" failures we see from very high HP trucks come from torque converter failures... way too much power and weight just melts them, the earlier you can lock it the less heat is generated and the longer the converter/fluid/clutches live.
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Don't forget the amount of heat that the converter creates when trying to spool on the line. Being able to stage and spool quickly will help tremendously.
 
This is true,, pretty much my main reason for using nitrous, to help spool the big chargers faster,, faster spool = less heat
 
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