Dyno thermometer showed 107F ambient with 6% Humidity yesterday... so it was warm... and very dry. I posted my Maggie graph up to show what appears to be a tire balance issue I'm having... as both graphs (2 seperate dyno's) are pretty choppy. NO KR was logged during both runs so I am confident that its not that. The tires I'm running are Goodyear LS... 275 55 20's. I'll be buying tires soon so looking for recommendations.

Anyway, I am running a relatively fat tune with 14 degrees of timing. I plan on leaving it that way until this Fall when temps fall below 80F or so. I am also out of fuel big time. For reference I do have a Magnuson intake pump that came with the Maggie I had... no other fuel upgrades other than 42lb injectors. By about 5000 RPM my fuel pressure starts to drop quickly and is at 46psi by 5500RPM. I am not seeing any KR but I don't have a whole lot of timing in it either. So, next project is a fuel upgrade. I'm thinking an inline Bosch 420 and provide a boost referenced return. I have a question for some to ponder. In Will Handzel's book the W2W guys crank up fuel pressure to 80psi on the 42lb injectors. Is anybody cranking their fuel pressure up that high?
At any rate I am very happy with the performance of this 60-1 turbo. It has a divided (but ported) .68 housing. I'm not sure what the back pressure is. I do have a port to check that and its on my to-do list. However, the performance is definitely there even though I start to drasticly lose fuel above 5000RPM. I'm lovin the 400lb of torque at 2500RPM. It doesn't hit as hard as the Magnuson off the line but boost is immediate from a dig. I'm hoping that after I get my fuel fixed that I can carry the horsepower to 6000RPM. Also note that A/F seems to be lean for the first half of the pull. My tuner used my AEM Wideband to tune the truck and it shows around 11.7-8 initially and drops to 11 by lift. The dyno wideband also seemed to be slower in the signal feedback...
Next up is the 4L80E install... and then an 03 LS6 cam. Not sure after that if I'll hit the wall on the 60-1... as I'll probably keep it around 9psi... and allow the Winter time cold air boost increase.

Bill


Here is my Maggie Dyno run for reference... completely stock 5.3L at 7psi.


Here is my dyno run with the turbo at 9psi... stock 5.3L with 918 springs and Magnum pushrods... Airaid CAI and Corsa Sport catback... no cats.

 

Looks like quirte an improvement over 2500rpm, good deal. This is on stock cam too!

 

Yes... stock cam for now. The LS6 cam should certainly help me carry the horsepower to 6000+ RPM along with more fuel...

Bill

 

I was considering that Bosch 420 myself but opted to go 60lb mototrons and a magnavolt bap.

 

Nice number Bill. When do the 42lbs. fall off hp wise at 55psi.?

Rick

 

Despite the fuel pressure dropping it appears to be getting plenty. It looks a little too rich past 4000, down in the high 10's at 5000. If their wideband was lazy though, don't trust any of this.

 

Hmm... Magnavolt. I'll have to consider that. Fundage is low too. Any thoughts on higher fuel pressure? Or just go with the 60's? My 42's are at 90% at 5500RPM but the pressure is only 46psi. A BAP sure would be a quick and effective solution.

Bill

 

Rick,
At 5000RPM my fuel pressure is about 52psi... down from about 55-56psi at start of dyno. By 5500RPM fuel pressure is at 46psi... and if we kept going then I'm sure the pressure would have continued to drop. Like James said though it appears we're still supplying enough fuel.

James,
Ya the dyno wideband is lazy and reads a higher A/F than my AEM. The first dyno pull we went dipped into the 10's on the AEM. My tuner tooks some fuel out up top and kept it at about 11. He is a very conservative tuner... and really wants me to run at 11.0 at least until the summer heat subsides. I know there is power still on the table but I just cannot afford to pop this motor right now.

BILL

 

I put a Magnavolt on mine, and I couldn't tell if it was working. Check your PM's

 

Bill try moving the smoothing to a higher nubmer when dynoing, that might clean the bouncing up. Its been a while since I have been on a dyno. But hope to be there this month.

Rick