How much hp will it take?

[White Duramax]

How much power does it take to run 4th low with 33" BFG A/T 3.73 gears? We have very tight clay tracks, but nice transfer sleds that let us get good speed and hit harder on the big end. Pulling in a 2.6 class but I can run a stepped cover charger. Any thoughts?

 

[bullfrogjohnson]

How much power does it take to run 4th low with 33" BFG A/T 3.73 gears? We have very tight clay tracks, but nice transfer sleds that let us get good speed and hit harder on the big end. Pulling in a 2.6 class but I can run a stepped cover charger. Any thoughts?

My truck dynoed 741 and it doesnt like 4th gear with 3.73's. The key is having a converter unlock switch which I dont have. I am running a 3.0 charger though.

 

[TrentNell]

My truck dynoed 741 and it doesnt like 4th gear with 3.73's. The key is having a converter unlock switch which I dont have. I am running a 3.0 charger though.

I have never seen anyone run the unlock except for the last little bit of the pull ? I can imagine it would help hold 4th gear much because it couldnt be used the whole pull unless you wanted to fry the TC . I would guess 750 - 800 hp for the hero gear but i am no sled puller .

 

[McRat]

To exert the same effort, 50% more than running in 3rd. Pretty tall order unless the track is pretty loose, IMO.

3rd is going 27mph at 4000rpm, which is a pretty good amount of wheel speed, and when the sled starts trying to pull you off the charger, you actually climb up the torque curve and boost curve. In other words, as you buzz along with 27 mph wheel speed, and the sled comes up, you'll go down to 26mph and pick up power, 25 more power, 24 more, 23 more, 22 more,21 same power ,20 same, 19 then finally the power will start to fall.

 

[redws6rocket]

or a set of gears since they are easly overlooked. that is a cheap and easy upgrade!

 

[White Duramax]

I think that most that are running 4th low are running 4.10 or 4.56 gears. I may be better off running 35's and staying in 3rd gear. I ran 3rd low this year running 285's with most pulls around 4k sometimes up to 4200. Plan on adding some hp over the winter and a new set of tires.

 

[othrgrl]

Winston and I both pulled in 4th with 3.73s on 33s and 285s with no problems. Making 750+ in both trucks.

 

[McRat]

Here is 3rd on 32's (3.42's) :

http://mcratracing.com/k/caspersleddog.wmv

Don't know the HP, we had to run a restrictor. It beat D'amico's TTS truck, and the Big Power Diesel Dodge and won the Superstreet class.

 

[redws6rocket]

I think that most that are running 4th low are running 4.10 or 4.56 gears. I may be better off running 35's and staying in 3rd gear. I ran 3rd low this year running 285's with most pulls around 4k sometimes up to 4200. Plan on adding some hp over the winter and a new set of tires.

well if your like me and don't have alot of money to spend on hp then gears have the same effect. i was able to run with alot of trucks this year with far more power than me!

 

[White Duramax]

I don't really want to change gears out. I am going to get a set of tires and planning on a bigger charger than what I am running and a few other little things.

 

[RolltheCoal]

crap i gots around 510 horse.. i clicked fourth at a pull... def. had to bring it back down to 3rd... not enough hp lol...

 

[ecc_33]

Ray, I have already tried 3rd gear and 35's. It wont make a difference. Still wont be enough....I have tried it all. 3.73 gears with worn out 33 sts mudd's and 4th gear tc unlock switch. 285 toyo open country ats on 8 inch wide wheels, 4th gear and tc unlock. Ive also tried the same with 35inch DC fun country II's. and staying in 3rd gear. two inches of tire doesn't change anything IMHO Gears is the only way you will be able to pull it off TRUST ME!!!! I have 4.56 gears and now have 33's and sometimes I still have to unlock the TC. That is with a s400 with a 2.6 cover

 

[redws6rocket]

Ray, I have already tried 3rd gear and 35's. It wont make a difference. Still wont be enough....I have tried it all. 3.73 gears with worn out 33 sts mudd's and 4th gear tc unlock switch. 285 toyo open country ats on 8 inch wide wheels, 4th gear and tc unlock. Ive also tried the same with 35inch DC fun country II's. and staying in 3rd gear. two inches of tire doesn't change anything IMHO Gears is the only way you will be able to pull it off TRUST ME!!!! I have 4.56 gears and now have 33's and sometimes I still have to unlock the TC. That is with a s400 with a 2.6 cover

exactly i am glad you got on here. i just wish people would understand and get that through there head. a set of gears will really wake your truck up, you leave it alone at the same hp level and a set of 4.56 gears or even more and you will be suprised!!

 

[Mike L.]

Converter choice is always critical no matter what setup you run.

 

[White Duramax]

Well thats why I asked, I didn't know if it could be done with stock gearing or not. Will 4.10's do it or have to go 4.56's. I still drive the truck some.

 

[redws6rocket]

Well thats why I asked, I didn't know if it could be done with stock gearing or not. Will 4.10's do it or have to go 4.56's. I still drive the truck some.

i still drive mine as well, with a 4.56 i was able to pull 4th gear with a stock charger, i just downshifted to third when i felt the load really hit.

 

[KEVINL]

What is the advantage of running in 4th?

 

[bullfrogjohnson]

What is the advantage of running in 4th?

Drivetrain is in 1:1 with the engine

 

[duramaximizer]

Why is 4th better than 3rd though? It's just a gear change. It's like the ford guys claiming 4.88's pull awesome in OD....isn't that the same as 3.73's in 4th?

 

[KEVINL]

x2 The transmission might be 1 to 1 but you still have the transfer case reduction and the rear end gearing. I guess the lower axle gears might make it easier to get the sled moving but thats not what the original question was.