Competition @ what speed to lock converter up in 1/4 mile

[EHarvey]

Hey guys , planning on making a couple 1/4 mile passes this summer , im not sure when to lock up converter . I have a bd switch in the truck that locks at 18mph if i switch it from a stand still. Just curious if you guys wait until a certain mph and switch it on manually?. And just one more question do you guys run with overdrive switch on or off? Sorry one more question do you start in drive or in second and then hit drive at high rpms.

 

[WUnderwood]

I wouldnt mess with the overdrive switch, just leave it in regular 'D'

I would hit the lockup switch right after the 1-2 shift

hope this helps

 

[JVolpe]

I usually locked mine as soon as possible(manual switch) after 1-2 shift. The last few times at the track, I locked it as soon as rolling good in 1st gear. If you think the transmission will hold it, 18mph sounds good to me. I assume that is still in 1st gear.

 

[EHarvey]

I wouldnt mess with the overdrive switch, just leave it in regular 'D'

I would hit the lockup switch right after the 1-2 shift

hope this helps

that first shift is pretty quick just wasnt sure when you lock it up , how the truck gets that little bit of lug on it because the rpm arn't up, if your losing time/ guess its gonna be trial and error. How about spooling on the line, with an auto , how much boost should i see. Thanks for the help.

 

[EHarvey]

I usually locked mine as soon as possible(manual switch) after 1-2 shift. The last few times at the track, I locked it as soon as rolling good in 1st gear. If you think the transmission will hold it, 18mph sounds good to me. I assume that is still in 1st gear.

not sure about your transmission but i believe my first to secont shift is around 12 to 15mph and it seems when i lock it that early it feels like its lugs a bit . Im wondering if its just because the turbos not fully spooled at that point.

 

[JVolpe]

I try to get to about 20psi 4wd boost launch. For me that is overfueling a lot and trying to keep it there for the tree. The video in my signature was between 25-30psi. Not necessarily what I try to do, but that was just what happened.

 

[JVolpe]

Well I have well over 200 times slips from the track on my built transmission and mods. As dumb as it sounds, I am not sure what mph my 1-2 shift is, I am always monitoring other things and since my lockup switch is manual, I never look at mph, at least not in the launch and early part of run. With a 20psi launch I don't really feel any lug locking in first as my SPS66 is fully lit after that and holds boost pretty well with my fueling.

 

[AMassaro]

JVolpe your truck rocks... I'm shooting for mid 12's also. Have you ever dynoed that beast and do you care to share any numbers?

 

[paulb]

A lot depends on your torque converter and transmission setup. I have mine setup to do the 1-2 shift at 2700rpm, and the 2-3 at 3100rpm. I throw the lockup switch (manual switch), at the top end of 2nd gear, so that it does the 2-3 shift and then locks. I have a 4th gear switch, that forces the transmission to shift to 4th (OD), at 75mph.



I have over 1100 1/4 mile passes on my truck now. I leave with a 15psi launch. That is where my truck is most consistent. With a badly prepped track I will leave as low as 12psi. I would not recommend doing a 1-2 locked shift.



Hope this helps...

Paul

 

[Highfinance97]

Hey guys , planning on making a couple 1/4 mile passes this summer , im not sure when to lock up converter .

At a bout half track put it in reverse and then lock the converter,thats what i do on my pulling truck. LOL



Michael



JK

Earl I hope you get the truck back soon

and by the way I going to switch the wheels this weekend, just so you know

 

[Partyat33]

I would be worried about breaking a shaft if you don't have billet shafts.

 

[JVolpe]

JVolpe your truck rocks... I'm shooting for mid 12's also. Have you ever dynoed that beast and do you care to share any numbers?

Well the last time I dyno'd around 583rwhp, not the stack I normally run on the track, just ran out of time to do more. I had spikes of 620 or so, but not really sustained.



I do have all billet shafts in my transmission along with many other heavy duty parts, clutch packs, everything machined to exact specs, etc. Along with Dunrite 3 disc custom stall TC and Suncoast Laminated Flexplate.

 

[AMassaro]

I have fully built transmission also EXCEPT for the output shaft... So I always have that impending doom hanging over my head when I leave the line... :-laf

I try to leave at around 10lbs of boost just because of that...

 

[BlitzkriegSSII]

I have a transmission from suncoast, I leave in 4X4 at about 12# and lock the converter in first at about 2000 rpms. My last run was a 13. 007 at 104.