Competition Ran 12:3 But We Ouched The transmission

[HVAC]

Lock Up?

Christian,



>Or is it better to let the converter spool a >little to get the truck off the line then

lock it up?



I think that's where it's at for most folks including me. Especially those that tow huge loads. I think most folks know that using a converter with especially high fluid coupling effeciency will sacrifice torque multiplication down low. My truck doesn't need the torque multiplication but a higher stall would be cool.

 

[banshee]

I overheard a certain Vendor in Muncie claim they could get into the 120 percentile in torque multiplicaton with their milled Stator.

Well in that case they better hurry up and get a patent on that sucker... it seems they've invented the first perpetual motion machine ever. Sorry, but the 120% violates the 2nd law of thermodynamics .



John

 

[Diesel Freak]

Originally posted by banshee





Well in that case they better hurry up and get a patent on that sucker... it seems they've invented the first perpetual motion machine ever. Sorry, but the 120% violates the 2nd law of thermodynamics .



John

gotta love the old "Conservation of Energy principle"





wow it looks like I have found my long lost twin brother! Oo. Oo.

 

[Strick-9]

I just did some testing at the strip this weekend.



Hitting lockup in second gear is actually slower than pulling in fluid coupling into 3rd and hitting lockup. With the proper converter of course. The 60' to 330' is quicker out of lockup. Looks like Christian has noticed this as well.



The gear changes are too much for our engines. You want to keep the engine at peak HP going down the track. A locked to locked shift pulls the engine down too low and it bogs.



93% of peak HP (fluid coupling) is higher than 100% of the HP available at 1800 rpm (locked shift). People keep forgetting that.



HVAC,

If you have traction problems at 8 psi of boost now, what leads you to believe the truck will hook with 20 psi of boost + drugs?



-Chris

 

[Todd G]

If you have traction problems, why not use a wider slick? I'm a little slow when it comes to the strip. I understand that a one ton axle is a little narrower without the spacers. Why couldn't we use one of these and put some really wide slicks under there. Of course wheel-well mods may be neccessary.

 

[StakeMan]

Originally posted by Strick-9

I just did some testing at the strip this weekend.



Hitting lockup in second gear is actually slower than pulling in fluid coupling into 3rd and hitting lockup. With the proper converter of course. The 60' to 330' is quicker out of lockup. Looks like Christian has noticed this as well.



The gear changes are too much for our engines. You want to keep the engine at peak HP going down the track. A locked to locked shift pulls the engine down too low and it bogs.



93% of peak HP (fluid coupling) is higher than 100% of the HP available at 1800 rpm (locked shift). People keep forgetting that.



HVAC,

If you have traction problems at 8 psi of boost now, what leads you to believe the truck will hook with 20 psi of boost + drugs?



-Chris

If it bogs the engine then maybe it should be shifted later, thus keeping the rpm's closer to peak while still using lockup. At what RPM did you shift at?

 

[HVAC]

How To Hook It Up???

#ad

 

[HVAC]

Drugs? =O

BTW. We don't use drugs! My truck lives on #2 only



Member: Joe Donnelly "Just Say NO!" organization for the prevention of drug use. Clean and sober for a year and a half now

 

[CUMINNTSTRKN]

guys



i like the low stall of my converter. i can make 20psi at 1600rpm with my latest converter. i feel that is the perfect rpm because our trq peak has got to be close to that rpm. i will most likely test a looser converter to see if we get closer to the hp peak, and see if we go faster. i have never been able to slip lockup in any of my bd converter's, so this is not a concern for me. my only concern is shifting lock to lock. and if you don't shift lock to lock you will be busy locking and un-locking the converter for every shift. i don't care what anyone says about lock-lock shifting. if something doesn't slip something will break at this hp level, it may not break the 1st time but it will break if nothing is slipping. so i believe the best method right now is to lock it up in 3rd, then unlock it and lock it back up in 4th. the only problem is you will need a very effeicient converter to not need lockup.

this is just my opinion.





chris



so what did you end up running? i heard that lag pig is really running now.

jim

 

[StakeMan]

Lets not let this turn into another transmission :-{} .

 

[CUMINNTSTRKN]

stake



we are talking about racing with our trucks, i was just telling you guys how i do it. and i wanted to let the guys see what i thought about launching off the line and locking the transmission up, at this hp level. i know eric hasn't broke anything yet, but i would like him to add another 200hp and see what happens.





jim

 

[DHRA]

Originally posted by CUMINNTSTRKN

stake



i know eric hasn't broke anything yet, but i would like him to add another 200hp and see what happens.

jim

Then I will have like 400hp!!!!!

I don't need 200 more hp 12. 0 is only a flick away. I need cooler air right now, which may equate to more hp, not 200. Until I can get that part ironed out, I don't need more heat. I could make it easy and buy some Nitrous, but that's no fun.

I lock up just past the 60'. By the time I launch and flip the switch, I'm past the 60'. But I have run with not locking it up until 3rd and I was . 15-. 23 seconds slower. I think alot of it has to do with the individual transmission. Mine spools real slow, but that may not be a bad thing for the transmission parts.

 

[CRoth - BD-Power]

Eric also shifts at higher RPM (>3500?) then the 24 valve guys, so while in lockup he may not lug the engine down. Also the extra RPM helps maintain boost as well as stator efficiency. So realistically he still as an advantage against us.

I think alot of it has to do with the individual transmission. Mine spools real slow, but that may not be a bad thing for the transmission parts.

I think it is pretty truthful that the stator that Eric has may not be as efficient as some of the others out there, but this is not a bad thing in this case. Eric uses RPM more the we do, so he needs to get there faster.



The slow spool could be a result of a over fueling issue at low RPM. Less fuel while spooling is actually better, remember you can actually snuff the flame out with fuel at low RPM and even high RPM.

 

[CUMINNTSTRKN]

Originally posted by Stack'd-n-Jack'd





Then I will have like 400hp!!!!!

eric

maybe 425

rpm is a big factor for us over valved. we need more of it. i know you said at 20 psi you were at 2700?rpm. christian is right that is probably perfect for your motor. 12. 0's are right here but i want to see how fast we can get a 7k# boat anchor down the track.



jim

 

[DHRA]

I agree about the RPM's. I shift at 4000 (the gauge is pegged) and I am launching with 20 lbs at ~2100 RPM's. 2700 was my near 30 psi launch.

I am just pleased to see all of these trucks in the 12's! This drag racing thing is really getting popular, maybe we need a sanctioning body for us

 

[Strick-9]

Eric,

The few times that you have dyno'd how much HP did you make at 4000 rpm versus 2600 rpm? I don't know much about your twin setup, but even the mitchell setups that I have spoken to lose 100 HP by 4000 rpm.



Have you tried shifting at a lower rpm?



It looks like a tighter converter would really help your ET.



Are you having any traction problems launching at 20 psi of boost?



-Chris

 

[DHRA]

Yea, I have tried shifting at lower RPM's and there wasn't much difference, definately not slower or I wouldn't do it I used to determine shift points by the heat index. Now that I have cooler air I can stay in the R's longer.

You're right the peak hp wasn't at 4000.

I have had some traction issues, but very rare. I can adjust air pressure to correct it usually. Sometimes it's just a slick track.

 

[StakeMan]

I would seem to me that since Stacked went from a manual to an auto he probably knows his shift points better than most would.

 

[Mopar-muscle]

Originally posted by CRoth - BD-Power

Everybody go to your closest dyno and do two runs, one in lockup and one out of lockup. Post the results and we can discuss those.

i haven't read past this but mr. roth , you ain't running a dyno down the quater mile , you are moving a mass that is over 6000 lbs. torque makes it move ...



edit , i see that christian knows that it does take torque to get you moving .



i'm not trying to turn this into a transmission war . HVAC has the only 94 TC that was put into public hands and it seems that its to tight for his setup .



as far as locked vs. unlocked you can't compare the auto trans to a stick , the stick uses gearing for torque mulitplican . yes there is gearing in an auto trans but not like a manual trans . test have proven that the same drag car with a purpose built auto trans vs a purpose built stick , the stick was faster , the auto was more consistent . the problem we face is losing boost between shifts , if there was a race stck built that could handle the cummins the sticks would be spanking the autos .



last thing i'll throw out , lockup is nothing new , drag racing trans builders tryed it years ago , it didn't work , no one running a serious car with an auto in racing uses anything other than a fluid coupling torque convertor .



stake , i think part of your problem is your convertor isn't tight enough which explains why you go a tad faster locked , with the stock TC in my truck once i got to the 400 hp level my WOT shift drops were 100 rpm , i was just driving right thru the stator , reason i couldn't wait till lockup ...



HVAC , i wonder how yours would fare with an 89race TC ????? higher stall to build more boost . and i also agree , if you are spinning at 8 psi , 20psi is going to be a whole lot worse ...

 

[CRoth - BD-Power]

Horsepower is the end product of torque and RPM. HP gets you places, diesels have so much bottom end torque = High bottom end HP. All the conversions for quester mile times negate any torque value at all. All this bottom end defiantly helps the truck get of the line.



This theory can be debated forever... ... ... ... ... ... ... .



The best example of this (I know its an import car) but the Acura Integra and the Integra GSR. Same base engine with a different head that allows more revs and HP above 6500 RPM. Both these engines have the identical torque value but the GSR engine has an additional 30 HP@>7500RPM. Yet the GSR is faster than the integra by at least 0. 2 of a second. Same torque more HP.



I will agree that if we put a F1 engine in a Dodge, you would not be able to get off the line at all. But once you spin that engine up 850HP@18,000 RPM watch out.





.

Everybody go to your closest dyno and do two runs, one in lockup and one out of lockup. Post the results and we can discuss those

The reason for the comment is that you will experience greater torque and HP in lockup then out of lockup. No matter if you have a 120% greater fluid coupling.