Allmost all of the dyno numbers from 3rd Gens seem to have low tourqe numbers compared to the old 24v and 12Vs I see alot of 3rd Gens over 500 hp but only mid 900s on the tourqe I had 2 12valves pryor to my 03s and they dynoed 415hp and 970 tq and 350hp and 850tq. It just seems like the tourqe does not match the HP numbers for the 3rd Gens.

 

Higher redline on the new truck might have something to do with this. So your 3rd gen isn't developing as much torque as your old 12v but it provides that power over a wider rpm band so the higher hp and lower torque.

Hp = (RPM x torque)/5252

If you can run to 5252 rpms: hp = torque, diesel or not. When you look at the dyno graphs of higher reving motors the hp and torque lines intersect at this point. Here's a heavily bombed viper graph as an example: Viper Dyno

 

Multiple injection events, lower cylinder pressures, fueling limited by boost, lack of fueling at low rpm's. All designed and engineered to meet emissions.

 

I've seen 12 valves w/ 300hp and 900tq!

 

Adding a little timing and a performance box solves that problem.

MikeyB

 

Jesse,
Maybe one of these hot rod pumps will fix the issue.

 

Because the 24 valve engines carry their torque higher into the RPM band than the 12 valve engines. As posted earlier, it all goes back to HP = (Torque x RPM) / 5252. The question could just as easily be asked, "Why do 12 valve engines make so little HP relative to their peak torque?" It's just a difference in the characteristics of the two engines, their injector pump programming, etc.

Rusty

 

I always assumed it was because the 3rd Gens are computer controlled, giving us certain programming parameters that are very hard to get around for high low end torque. On the 12 valves you manually adjust timing and fuel to change the HP and Torque curve however you want. Easy right?….and one action has a direct reaction from the other so you can put it right where you want it. More timing and fuel earlier = more torque. On the 3rd Gens your adjusting 1s and 0s…binary, with parameters that restrict reaction to your actions. Them darn computers.

On the 12 valves, turn up the power and you get every bit of that power right off idle, as soon as you hit the go pedal, resulting in insane low end torque. The 3rd Gens fuel according to boost thanks to computers. It just doesn't fuel until it sees boost, then the fuel is regulated according to the amount of boost it sees and you don’t get 100% fueling until full boost is attained. Even the performance boxes for the 3rd Gens fuel according to boost. They can report to the ECM that there is more boost available right off idle, which will wake up the low end torque a good bit, but even they are limited.

It can be done quite easily but does not give you a very streetable truck. The best way to get around it on a 3rd Gen, at least with currently available parts, is to use a performance module that maximizes low end torque, the king of torque, the TST Twins module. Then install a set of smoky 100hp honed injectors for an extra 250ft lbs of torque across just about all RPMs. Together, that combo has produced over 1300 ft lbs of torque at 600hp many times when all other supporting mods are there. That is just not a combo you see being used much as it is very smoky, and very hot, resulting in not a lot of that 1300 ft lbs being usable on the street.

 

Well if it has to do with fuel on the low end then I guess Im on the right path with the EZ,BDDL stack becuase they produce tons of smoke at low boost.

 

I'm 512 / 934 and open for suggestions!

 

Saw a 12 valve today that was 425 / 960.

 

depends on the truck. I was going over our last years fall brawl dyno numbers last night. There were two 24 V trucks that made more HP than me on #2, but on #2 only, my truck had the highest torque. Mt HP was 613, there trucks were 624 and 65?. Both of them didn't break 1100 on the TQ. In fact, for #2 only, I had the highest TQ of the event.

 

What about modding the TST so it sees full boost right off idle? I've read you can put a switch in the MAP harness so the wires are able to be switched "on" fooling the TST into thinking it has boost right off idle.

Perhaps that stacked with a BDDL will bring the torque up. I'm sure it will be SUPER smoky, though. Not very streetable, IMO.

 

I think it just has to do with the number of valves. the more valves you ad per cylinder increases your air volume and you HP levels but the ratio of torque to hp is just different.

I am no expert but I can see trends and I have just noticed multiple valve engines tent to be higher HP, higher rpm. so I am not sure if it is really less or just a different ratio of power. I think it just how the air flow to the engine. more velocity vs higher volume of air.

It is like this on most platforms though that have a 2v and a 4v version though.

 

Well, maybe it's not so much that the torque numbers are low but that the 3rd gens just make more hp than the older trucks with the same amount of torque.