Allow me to show my ignorance.

RonA

RonA

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Feb 26, 2008
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What dictates where the hp drops off on the graph? Is it a combination of all things? Is it the cam, the head, the pump, air, or what? I see graphs that go higher before they fall off, and would like to know how to make it so. I run 31inch tires with 3.55 gears and a 47RH. Runs are in OD. Peak hp tends to be around 3150rpm or so.
 

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My opinion is it is a combination of everything. Cam, Airflow, Fueling. Or it also could have to do with a small drum on the dyno with little load.
SHughes has a common rail headed P pumped 24V that made power past 4K. Not that it hung the big number out there that far but it didnt drop like a rock like most do past 3100. That was a first for me to personally see.
 
That has me stumped, do you have one wastgate or two? I know the ramp up is more of the turbo's spooling up, but could it be hitting peak boost up around 3150 and opening the gate(s) and causing the primary or secondary's boost to fall off?

Stupid idea number 2! Maybe your truck was hot, tired, and thirsty. Does that really say 115* for air temp:rockwoot:
 
Most of my graphs look like this. This is with my 13mm pump. I asked for full fuel till 4k. But.... I had to back the springs off 2 clicks to get it so the truck wouldn't die when I put it in gear. The dyno is a dynojet without any loading. These runs were at 115deg outside temp. There was another run made with the outside tems down in the high 90's and the intercooler cooled off for a few minutes in front of a fan. The graphs form is identical but the power went up to 882.
Brett, it will be interesting to see what it looks like on your dyno with a bit of load on it.
 
This is what my problem has been from the get go, everyone says theres pulls 3500-4000.......Mine feels good after 3 but most of my graphs do the same thing as yours.
 
What does the torque curve look like? I didn't see it or overlooked it.
 
On my dyno runs the GSK has made the biggest difference in the graph's shape.
 
Brandon,I have tried to add a few clicks to mine and it did the same thing still
 
RonA said:
Most of my graphs look like this. This is with my 13mm pump. I asked for full fuel till 4k. But.... I had to back the springs off 2 clicks to get it so the truck wouldn't die when I put it in gear. The dyno is a dynojet without any loading. These runs were at 115deg outside temp. There was another run made with the outside tems down in the high 90's and the intercooler cooled off for a few minutes in front of a fan. The graphs form is identical but the power went up to 882.
Brett, it will be interesting to see what it looks like on your dyno with a bit of load on it.
Click to expand...

Ron, with a good size load on your truck...your curve will be flatter and longer. With no load or very little load your chargers arent being lit enough down low, so thats the reason for the spike at 3K and quick fall off.

If we can get you loaded correctly your graph should be more of a shelf from 2500-3K with a gradual decrease in power till 4K.
 
airflow (shouldn't be a problem with your two big huffers)
fueling (shouldn't be a problem with your pump)
timing (not sure where it's at now, have you tried back to back runs with added timing to see the difference?)
load (sounds like you may have the drum up to speed and it isn't providing enough load at the higher rpms, maybe try a load dyno?)

I say try another dyno first, then advance the timing and try it...
 
GOT-Torque said:
airflow (shouldn't be a problem with your two big huffers)
fueling (shouldn't be a problem with your pump)
timing (not sure where it's at now, have you tried back to back runs with added timing to see the difference?)
load (sounds like you may have the drum up to speed and it isn't providing enough load at the higher rpms, maybe try a load dyno?)

I say try another dyno first, then advance the timing and try it...
Click to expand...

I can't go any higher on timing with these injectors, and any other injector will loose power or be track only(and probably loose power too:hehe:).
 
RonA- What do you have for a turbo(s)?

I hate how dyno sheets show mph--- but no rpm

you have me at high hp - yet at 80 mph i'm at 400-440 (depending on settings)

You seem to be spooling real slow?
 
Most likely its governor action sensing its on top of the load. Pretty sure it would look different on a load cell.
 
There is actually 2 problems, the max hp is too high in RPM's....why, your chargers aren't that big and it is nosing over due to the governor, likely Gov springs.

Ron, I've had this issue before, actually it was on my highest HP run I ever made, it was late 3100 for T/Q and 3400 for HP due to the 13mm pump beating the pump tappets against the cam and not enough spring....Columbus fixes this issue but at 3800 I was still over 700 hp, this was with 4K's.

Jim
 
Here's a run on a load dyno from a while back before tuning( it runs stronger and lights much sooner now even though the new graph doesn't show it. I cut the run off too early.
 

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I found a graph from Ponci's event on the same dyno as my first post. Temps were about 40-50 deg's cooler and I was standing on the brakes to try and get the turbos to light earlier. I also added approx rpm numbers on top.
 

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Ron, if you can get Jeremy or Chris to email me some of your runs as a .drf file, or I can email them the runs from our Dyno. I can put the runs from there Dyno and ours on one graph. If you want you can even go on dynojets website and download winpep7, that way you would be able to put all of your Dyno info on your own computer and overlay your different setups.

If you put winpep7 on your computer and want to play with it I can email you your files later today.
 
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