Low Dyno #'s!!!!!!!!!!!!!!!!!!!!!!

[CCoxVa]

I own a 92' d-250 130,000 miles. I have installed a Super B1, pulse man, Ol smokey fuel pin,fass fuel system, and fuel screw back out a 1/8 turn from runaway, star wheel all the way, timing at 16*, Sheid 300 plus inj,4" down with 5" stacks. I dynoed at Rockingham in march of somewere around there. All that wasnt done then that is wrote above was the timing and the fass system and fuel pin. I may be wrong but I think my numbers were off according to others i've seen on here. 230 hp?798 ft/lbs??? I would like advice and have gottn a lil discouraged.

Thanks Chris Cox

 

[Niki]

What RPM's were the peaks at, do you have a governor spring, and is your truck 5 sp or auto?

 

[OKish]

nice tq #'s.

 

[Old Smoky]

By looking at your hp to tq ratio it looks like you have an auto. Without lockup you are loosing a bunch of power through fluid coupling only.



Mike

 

[pepecat]

I had 213 HP with stock auto and 3200 gov spring 1. 5 turns in on fuel screw from stock, stock baby H1C stock intake and 3" exhaust, stock fuel pin, stock injectors. Sounds like something is wrong. .

 

[Old Smoky]

It looks like the only mods he had at the time he dynod was a fass-0hp, power pin-40hp, timing-roughly 10hp. A good stock running '92 with and auto is about 128-138hp. So, adding 50hp from the timing and fuel pin would net approx. 178-188hp. This is of course dependent on the condition of the injection pump, how far the timing was advanced, if the fuel pin was installed properly, and the type of dyno.



FWIW, when I set on of these up on the dyno with a power pin, gov. spring, slight timing adjustment, and very slight fuel adjustment, they make right at 200hp.



Mike

 

[ZedMikey]

Looks like you have that backwards, Mike. The fass, power pin and timing were the mods he DIDN'T have at the time of the dyno.

 

[Old Smoky]

Wow, a senior moment at the age of 24 :-laf . Thanks for the correction - makes more sense now.



If you had lockup, and the injection pump is in good shape and tuned well, I would guess about 285hp given the variables. It is possible that your stock lift pump could have been a bit weak, and did not have enough press/volume to supply big injectors and a turned up pump. Without lockup, maybe 250hp? It's hard to tell because the more power you throw at it the more it slips. There is really no way to tell how much you are loosing. Another thing to look at is throttle travel. You can actually pick up a good amount of power by optimizing the distance the lever moves toward the high idle stop. I have seen a slightly turned up truck make low to good power with the stock high idle setting, and pick up 25hp by just allowing for more travel. Meaning that the lever actually strikes the high idle stop to begin with, but it is better if it will also move all the way back to the pump case. You do have to keep an eye on the tach though (if you have one). Installing a gov. spring helps too. It seem like the more power you have, the more you gain by doing this.



It would be nice to see you dyno again with the fass and other stuff.



Mike

 

[MRector]

I am a friend of CCox, just inlightening here... ... ... his truck is a 5-speed

 

[bgilbert]

What's up with those Scheid 300 plus injectors? I would bypass the stock lift pump. Run the FASS straight to the injection pump. I don't see you mention a governor spring either.

 

[Old Smoky]

I guess the auto theory goes out the window.



Mike

 

[cerberusiam]

I guess the auto theory goes out the window.



Mike

Hate it when that happens. :-laf :-laf





I wonder if they dynoed it in 4th instead of 5th?

 

[JLEONARD]

I thought you were supposed to dyno in 4th... I thought that got bigger numbers. ??

 

[dpuckett]

From what Bill has told me, dynoing in 5th will net higher tq numbers as it loads the engine quicker than 4th. I'd think the power peak would be close to the same. Depends on which type of dyno it was.



Daniel

 

[cerberusiam]

I thought you were supposed to dyno in 4th... I thought that got bigger numbers. ??

It is nearly impossible to load the 5. 9 enough on a DynoJet type dyno to get true numbers. Running in direct just makes it easier on the engine to spin the rollers and not get full fuel before the governor starts shutting things down. Even in OD one has to frequently drag the brakes to build enough boost and/or load to get the fueling in early enough for good readings.

 

[CCoxVa]

I appreciate all the replies first off. I do have a five speed and dynoed in 4th and 5th. Those numbers were higher in fourth. I have the govenor springs but not adding any power sitting on my dresser. I was told not to run the fass through the inj pump only. But getting ready to try that next. Thinking about the 14mm head and rotor and DDP supersoakers????ANY MORE ADVICE WOULD BE HELPFUL.

Chris

 

[CSchafer]

I'm with bill, what are those injectors? The fuel pin should of made a big difference. What kind of boost numbers are you seeing out of the b1? When I dynoed mine it made like 20 more horse in fith than it did in fourth and I still was missing 4 pounds of boost.

 

[CCoxVa]

Those inj's are the ones they call 300 plus'. I think they are about sixty horse. I am only seeing 35 lbs of boost out of the B-1. The fuel pin didnt make a real noticable diff.

I thought the needle from the front of the pump wast riding up the pin so I called DDP and they said to put antiseeze on it. That didnt help either. ????

 

[dpuckett]

Removing the nylon washer is good for 3-5psi extra boost.



Have you had any work done to the pump? It can flow the fuel, and it can be a real screamer, but still not be right. I had the pump in my 91 gone through- replaced throttle bushing and parephenalia, along with the advance piston and spring. Made a WORLD of difference. As much as you may not like it, it may be that time, esp if it is a daily driver/ non-towing, non- working vehicle. Lighter loads are actually harder on fuel system than being loaded to the max GCVW day in and day out.



Now, on to other areas- how was TDC found to set your timing? Relying on the pin for timing is a risky scheme- you have about a 1 in 5 chance of being right. On a related note, what are your injectors popping at? Higher Pop pressure will retard dynamic timing (waiting for more pressure to pop the injector needle will inject fuel a hair later, sometimes making all the difference in the world. )



How far in from stock is "1/8 turn out from runaway"? Assuming it was stock to start with... ...



-DP

 

[cerberusiam]

Define "star wheel all the way" a little bit better. Up? Down?



You can put grease on the fuel pin and get a trace mark to see if it is actually getting into the deepest part.



Have you backed the high idle screw out and veirified you have full throttle throw?



What exhaust housing do you have? How much smoke do you get when nail it from an idle? What kind of smoke do you get at WOT?



When you dynoed did you drag the brakes and make sure the boost was up when you started the run? What mph did you start the run and what was it when you quit?



What rpm is the peak HP showing at?