Engine/Transmission (1998.5 - 2002) why is my hp so low??????????

[Sick Boy]

well from what i have been told my hp should be at 500 rwhp with no problem for the mods i have (see mods below). dynoed a couple weeks ago an only put down 438/875. any ideas where the rest of the power is? thought maybe my comp was bad but edge says it is ok. the only thing i can think of is i n need a bigger turbo then the bell (pius)turbo i am running now. any turbo sug?

 

[Fishin Guide]

What gears you have in that thing? What kind of dyno was it?



I would guess that the tire height killed you on the dyno. Try running some smaller rubber.



Dave

 

[KLockliear]

Tire height isn't gonna kill 60hp. Maybe 10.



What turbo are you running? I assume you were locked in OD for the runs?

 

[PC12Driver]

You wouldn't happen to be using the scotch lock that came with the Comp to tap the pump wire, are ya? I just spent way to long and a couple of dyno runs to find out that the @#*$! thing didn't tap properly. It worked part of the time though. A Swenco Posi-Tap fixed the problem and my hp was found.

 

[Fishin Guide]

Tire height isn't gonna kill 60hp. Maybe 10.

true, but that's also under the notion that he had 500HP to start with. Maybe he never has had that kinda power.



I agree that it sounds low, but with really big rubber, a tall gear ratio, and maybe a slower spooling charger, is it not possible for the power to not show on the rollers?



Dave

 

[Graphic man]

i would look at gear and tire size, it takes a lot of power to turn big tires

put on a set of 265 on it and re run it just to see the difference

i bet you see 40hp+

 

[mcoleman]

Some of it is probably in the tire size. I would try making a pull with the drag comp on setting 4 for the blinking sub level. And as mentioned are you locking it in overdrive and locking the tc clutch up? You should be in the 530hp range.

 

[RJPotts]

I can only assume the larger tires made the difference, or some bad air, was that corrected or actual, and if it was corrected (lets hope its not since you should be around 500-550) what was the correction factor?

bad air can play h*ll on a dyno run.

Just this weekend I saw DavidTD (12 valver making 550 and 1200 or so) lay down an uncorrected 500, completely due to bad air.

-R. J.

 

[Jetpilot]

We dynoed the same truck back to back (about 15 mins to change out rear tires), one run with 35" tires the next with 265. What we saw was an increase of 5HP and a decrease of 5 TQ with the smaller tires... ... This was on a 500 HP truck setup a lot like DieselFreak2's. Tire size just doesn't make that much difference.



Doug

 

[KYLE4]

How are your EGT's and fuel pressure ???

 

[0013]

maybe valves need to be adjusted????

 

[Sick Boy]

i am running the factory gearing 3. 55 an yes the overdrive was on. the turbo is a bell made by pius. i think he said the housing on it is app. 12-1/2 cm. turbo has got to be to small. egt are at 1600 +fuel pressure is good 15 psi. valves have never been adjusted truck has 62,000 on it. i know i am fueled enough guess i need to move more air. keep the sug. coming! thanks

 

[ob1kobi]

I have done the same test that Doug mentioned on my own truck, tires don't make that big of a difference on the dyno. My truck made the same numbers that he mentioned, and was similiar in setup. In fact, is that my truck that your talking about Doug, cause I think you were even there the day I tried that.



Which Pius turbo do you have the USB or ASB. If I remember correctly (its been a while) you have the USB, and that turbo will flow plenty of air for you. What kind of boost did you make on the dyno, have you pressure checked the system (maybe the intercooler is leaking), and if you can find another Comp to use, try that, just cause Edge checked it out doesn't mean that they did anything other than making sure it turned on.



Ted

 

[ob1kobi]

It won't make that much of a difference on the dyno, I have personally tested it with a set of 265's and a set of 315's on my truck with 4. 10 gears. On the street you are definately correct, it will make a HUGE difference, but his tires aren't causing his loss.



If I remember from when I delivered the truck, you have always had those tires on it haven't you? Is this the first time you have dynoed it or do you have anything to compare it to?

 

[Morse]

Even at the drag strip, my diesels haven't seen much loss with larger tires. . I know my gas trucks were greatly effected, just not the same for my diesels. . MPH was actually a little better with 39's than with 35's or 245's on my duramax. . It actually ran a 14. 1 in 2wd on 39's, which was as fast as the truck ever did in 2wd. . I was always a little leary of launching with the large tires in 4wd. . I haven't heard anyone else with a duramax mention it, though I tore everything out of the front end at a truck pull and ran over my own front tires. . Sucked bad. . I wanted a straight axle bad after that. . Just one more reason I switched to the the dodge. .

 

[ob1kobi]

RD, I agree with you that the tires will affect his power somewhat, but they aren't going to cost him 60 HP, especially if he has already dynoed with the same tires before, and made more power. The truck has something else wrong with it, its not the tires.

 

[ob1kobi]

What makes you think the times aren't correct?

 

[ob1kobi]

I have played with it some, part of the reason it sat so high was cause of the tires I was running. It has a smaller tire on it now, that I ran last year, dropped the rear another 2" with some lowering shackles and put some drag shocks on the front. Its not running as well as it did last year, but considering that I am running injector only, no box, its not bad. I want to get into the 11's on the single, then I will play with the nitrous. As far as I know, nobody else has run a motor only 11 second pass with a single, at least in a Dodge.

 

[ob1kobi]

ahh RD, don't know where you get your info, but whoever it is doesn't know there facts. I don't have the turbo that you think I have, and my truck doesn't weigh enough to be allowed to run the nitrous... . yet. All the times it has ran this year, are Injector only, no box.

 

[ob1kobi]

I am running a Pius USB turbo, its the same turbo I ran the times in my signature with last year. It was also used on the "work" truck when I was racing it.



Sickly is resting for later... .