Input about 2nd gear lock up at WOT

RascalMafia said:
IMO if you're not going to lock the converter as soon as 2nd gear hits, there's no reason to even subject the trans to a locked 2-3 shift at that RPM.

As someone who has broken a shitload of billet intermediates and input shafts on a locked 2-3 shift, would recommend ditching that VB ASAP if you have even the slightest concern.
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See, this is what I thought. Are most 48re racing truck locking the TC almost immediately when 2nd gear engages?

I knew a guy local to me who had lockup on a WOT switch in his race truck, and another switch in arms reach to activate the WOT switch. Burn out, stage, turn on switch one, green light, petal to the metal, TC lockup. I recall he was relying on the delay of lockup to activate which allowed him to stay on top of the charger. But this was 12+ years ago.
 
3rdgenmike said:
When it locks, it's a pretty decent drop, almost 1k drop in rpm. I have the shifts decently spaced apart so it doesn't shift too quickly. 3rd gear is about 68mph and 4th is 86mph
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Please provide more specs about the engine and truck setup. Why are you dropping 1,000 rpm when activating lockup?

Are you running 1/4 mile with the truck? If so, why are you shifting to 4th gear?
 
I flip the lockup switch before I stage, and as soon as I shift to 2nd, lockup comes in right after.
 
I always locked mine right at the 1-2 shift with zero issues for 11 years. Running roughly the same set-up as you, billit wheel s468/87/1.0, Exergy 100% overs, dual stock cp3's through a Firepunk comp2 with their efi live tuning. Truck was an early '07 5.9 making 850/1400

[ame="http://www.youtube.com/watch?v=S198Wh-o3Zs"]0-60 2007 5.9 Cummins - YouTube[/ame]
 
Red Sleeper said:
See, this is what I thought. Are most 48re racing truck locking the TC almost immediately when 2nd gear engages?
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That's how my Garmon trans was set up. Flip the switch while staging, lockup right after 1-2 shift.

When I had a different brand before Jeff did my trans (breaking shafts left and right) I could lock the converter in first gear...Never tried a locked 1-2 shift as I'm sure more carnage would have followed.

When Jeff tore it apart he scrapped the VB, started with a new OEM VB, changed the 2nd gear apply lever, did whatever else Jeff does...Never broke or twisted another shaft after that with about 400 or so passes and incredibly hard street driving.
 
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So a correctly modified valve body will allow 2nd gear converter lockup when 2nd gear engages?

I’m running stock valve body with shift kit mods, and able to lockup in 1st if I so desire.
 
Red Sleeper said:
So a correctly modified valve body will allow 2nd gear converter lockup when 2nd gear engages?

I’m running stock valve body with shift kit mods, and able to lockup in 1st if I so desire.
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Not correctly, it's just a preferance thing on how you want it
 
fatty said:
Wouldn't a high stall converter do that? Doesn't necessarily mean it's bad.
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I run a high stall converter in my racetruck, starts to flash around 2300 and I am full staged by 3400. Shift at 4600 and when I make the 1-2 shift with lockup after the shift the logger shows only 1 dip in RPM. Converter is fully fluid coupled by 4000rpm.
 
Vincejax said:
I run a high stall converter in my racetruck, starts to flash around 2300 and I am full staged by 3400. Shift at 4600 and when I make the 1-2 shift with lockup after the shift the logger shows only 1 dip in RPM. Converter is fully fluid coupled by 4000rpm.
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A truck id like to know more about! How much Busch light I gotta buy you and jasonc to post threads on the race units? Ha
 
I've locked my converter up in 1st gear before but usually lock right after the 1-2 shift. Suncoast reverse manual v-body with Cheetah scs shifter and manual lockup/OD switches. Trucks been 9.76 @ 140 in the 1/4 at 7300lbs.
 
I recently learned if you launch in drive, 1st gear is applying through the sprag only. Where as if you manually launch in 1st and shift to 2nd, 3rd, OD, 1st gear is applied through the sprag and band. Something like that.
So not launching in 1st puts all your torque through that tiny low reverse roller sprag.
Now when someone hosses the gas next to me at a light, I grab 1st, shift to 4hi, build some boost, roll forward a few feet, launch, flip lockup switch, grab 2nd and boogie.
 
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