You guys seem to really know how to read these graphs,when then the peak power comes in and when it dies out.Could someone tell me some about my dyno sheet.I'm happy with my dyno being the only thing that changed was a set of LC,plate moved back and AFC housing in the middle.I did crank the star forward a bit but not loose.The last AFI dyno in Mar 08 the truck had 131 DV,plate,AFC and star all forward.

Dyno Mar 08: HP 353 torque 735

Dyno May 09: HP 359 torque 740

Should of moved the plate,AFC and star all forward to see if the same results would of came in different as the Vex dyno.

 

If you look at the profile of the HP curve, it looks exactly like the #10 plate profile. I would expect the curve to just move up with any adjustments to the plate/AFC position.

 

I bet that its your governor spring that starting to defuel the truck at 2700 rpm. The torque curve drops off fast at 2700 rpm.

Put in a 4kGSK and heavier valves springs and run it up to 4000rpm's. Next issue is you have to burn all that fuel.

 

I don't know about that.. with my 3K springs I can hold full boost well into the mid 3K range (done it by accident). I need valve springs for that all the time.. LOL...

 

Jason, do you have any of old dyno sheets from your truck. Dave's truck just nose dives in torque at 2700 rpm's. The pump has to be cutting fuel. If its a lack of air, the torque curve would be more flat. The turbo has a limit of cfm. We can try a bigger turbo, but my guess is the pump is de-fueling. If you have fuel you should be still gaining in power. The valve springs usually floats that stops the engine for reving further.

Dave, do you want to try a few different combo's. A little trial and error would fix her up. If we had a fuel test bench to just to play with.

its only beer and time right...

 

I thought that I share this, I found a cool post on tuning these P7100 pumps.

http://www.competitiondiesel.com/for...ad.php?t=56197

Lots of cool diagrams and cut aways.

 

I have notice that it has been defueling lately...Didn't have that problem with the 3K when I first put them in...Unless my govenor adjustment I did screwed it up...

 

I think you guys are right with defuel.. The profile just looks like fuel curve of the #10 plate as it tapers off..

I have a dyno sheet from the VEX show.. But the RPM was set to cut off near 3K on the load.

The Green and red lines were warm ups with not enough load. Especially the green, I was pedaling it. The pink was a better load but still only about 42 psi boost. The blue line was a solid 45 psi boost and 1300°F pull. Oh and the load is kW, not HP.

Dave, I would just start checking fuel filters etc. You replaced the lift pump when the whole pump thing went south right?

 

Just replaced the fuel filter about a month ago...LP replaced,overflow valve replaced 3 years ago...My truck is cranked back right now..AfC in the middle,fuel plate pulled back a bit...star screw in thightened up also...Those things shouldn't defuel the truck at 2700 RPM....or could it?

 

I'm not familiar with 12valves at all, but wouldn't one start with what boost & the EGT levels are during a dyno run or a WOT pull on the street?

Plus how much smoke is being produced on run?

If the boost is well up there, smoke is light, & the EGT's are low, then more fuel is needed.
If the boost is low, EGT's high, smoke is heavy, then more turbo/air is needed?

This is likely a gross simplification... Any ideas what your boost & EGT's are during a dyno run or hard street pull, Dave?


I think my data logging plan is 4 guys in my truck monitoring & taking notes of all my gauges during a dyno run!

...Joe

 

Thats why I like running my own rig.. The Vex guys would never had known that the load was too low.

Your simplification is really fact.

 

I was trying to figure this stuff out last night. Does the governor controls where the pump is on the fuel plate? A higher speed governor should raise the rpm where the pump is fueling. How hard does the pump start to defuel once it hits or approaches the limit on the governor? The defueling is very consistant, so I have a hard time thinking that its from the lack of fuel from the lift pump. I bet its something inside the injection pump. I would change the plate and/or governor spring and see what happens. Just do simple little things first before doing any major changes.

Dave, I bet you can feel the truck starting to lay down pretty good after 2700 rpm, so you don't need a dyno pull to do some tweaking.

 

It's hard thing to tell with Dave's truck running on the Bio. It produces less heat than #2 and less smoke, so you can't really use the regualar indicators like us on #2.

 

Chris, you're truck injection pump is set-up fairly similar to Dave's. Does your truck nose nose in torque at the higher rpm's? Looking at Jason dyno sheets, the torque curve drops slightly but not like Dave's truck. I wished that I listen to the truck run the day of the dyno. Mine dropped abit in power/torque similar to Dave's truck but thats the way Edge set-up the comp box. I'm ok with that, as I hardly rev her up. Mines a RV tow pig for now.

I have a 215 pump, we could put in as is and see. Then put in the other performance stuff and see what happens. That way Dave's 160 pump is in left as is. Valve springs and a new turbo are an easy afternoon workout. I have to figure out that pump anyways for my 24V P pump engine that I'm planning.

 

I could tell I have a RPM drop..With the 4:10 gears my RPM at 75 MPH is around 2500...When I push it from there a slight defuel happens...

Here is my dno sheet from Vex dyno from June 2008.I had LC at the time and the plate,afc and star screw where all forward.

Got to find my dyno sheet from AFI on March 2008 with the 131 DV.