Engine/Transmission (1998.5 - 2002) We are in big trouble now

[Big_Daddy_T]

Alright I have an excerp from a sno go magazine of mine. This is regarding the duramax. " The dynomit increased rear wheel torque from 515 ft lbs to 711 at 2300 rpm. Just with a simple add on. Impressive! With BDs new E-Z amp plus a 4 in. exhaustand a bd power extreme air box and filter, we were able to take the duramax to multiple dyno readings of 1400-plus ft lbs of torque. Horsepower increased to a whopping 313 ponies from a stock 209! Sounds unbelievable doesnt it? We wouldnt have believed it either if we hadnt seen it with our own eyes. "

Not exactly word for word but very close. They got almost 40 hp just by changing the exhaust and airbox.

A few opinions on this claim please boys. Published in a national snowmachine rag. Judging from the article its a dyno at mid michigan performance diesel.

Whats unbelievable to me is how the horsepower only went up about 100 ponies and the torque almost completly tripled and no one thought anything was wrong with that.

 

[work2muchplay2little]

The HP is believable, but the torque isn't. Maybe they measured the torque in first gear only.

 

[BigUgly]

With the torque, I have to wonder how they set-up the dyno. From past experiences with a dynojet, you have to change the RPM interpretation in the computer. With gassers and the RPM sensor attached to a Sparkplug, you've got the dyno set to read 1 signal = 2 Revolutions, but with the Diesel and the optical sensor on the Crank Pully, you get 1 signal = 1 Revolution. Maybe they thought the DMax was pulling up to 7,000 RPM. If this was the case, then the Torque should be around 600-700, about right for low 300s hp.

Then again, this was supposed to be at a Diesel shop. I wonder if they just ran the DMax up through the gears and the shifts gave a goofy peak TQ number?

Whatever the situation, I have a very hard time believing over 800 ft lbs of torque with just 313 hp.

Interesting.

Josiah

 

[Cummins4Life]

What did they do the transmission to hold 1400ftlbs

 

[Big_Daddy_T]

Their number is in there. Do you want to call and ask?

 

[truckstom]

torque

My stock 855 cubic inch(14 liter) NTC Cummins produces 1400 ft lb. @ 350 hp + or - . My new Cat (12 liter) is making 1650 ft lbs @ 450hp. These are stock ratings. This is the same 12 liter engine that Cat has in their race truck producing 1200 HP and 4200 ft lbs tq. What I'm saying in a long winded way is it could happen, with tecnology and money.

I'm with cummins4life, I don't think it would be streetable 'cause the transmission won't hold it. :-laf

 

[Big_Daddy_T]

We are talking about a 6. 6 liter v8. Not a 12 liter inline six though. Its torque will not run away from the hp like that. I looked it up and they claim a 250 ft lb improvement. 420 rwtorque plus 250 = 1402. I looked at the dyno charts and even though the chevy has 90 more hp stock only 32 hp more ,than a stock dodge, gets to the ground. That is on one specific dyno test. Not to say all will be like that. If you want more power than this 6. 6 an ez will put you well over. Just to show they couldnt do anything fancy. Here is a quote.

"It can also be modified for use with the ez Amp (piggy backed) to achieve over 400 RWHP. Caution. . Piggy Backing will destroy Allison transmissions!!"

I dont think that there is any way to build up an allison. From what I hear only allison is even allowed to open em up.

 

[78repowerwagon]

711 (torque) X 2700 rpm divide by 5252 = 311 HP



1400 X2700/5252=720hp

 

[Hohn]

See above.- pwagon is right

IN order to make 1400 lb-ft but only have 313 hp, you would have to turn this many rpm:



(313*5252)/1400= 1174 RPM!!



It's pretty obvious that the 1400Lb ft figure include some kind of gear multiplication. Making 313 HP at only 1174 RPM is pretty tough.



Remember it this way: the HP peak is the point where torque finally tapers off faster than RPMs rise.



This is how the rice motors can be rated to make 200HP, but they are gutless. They wind it up to get the HP number, because there's very little torque-- exact opposite of CTD.



There's a good explanation of this on the HOWSTUFFWORKS web site.



Hohn