What to fix on my Fuel System?
11-27-2015, 04:36 PM
#121
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Replaced the intercooler pipe, gained some power....
Makes 36% more power at 5,800 RPMs than it did before. Based on the fact that the torque line was still going up at 5,800 RPMs, I SUSPECT it's making more power at higher RPMs.
But no proof of that. Percent improvements over old setup:
2,800 RPMs = 119whp/221 ft*lbs (+4%)
4,200 RPMs = 220whp/272 ft*lbs (+3%)
5,800 RPMs = 326whp/301 ft*lbs (+36%)
6,900 RPMs = ?????????
Makes 36% more power at 5,800 RPMs than it did before. Based on the fact that the torque line was still going up at 5,800 RPMs, I SUSPECT it's making more power at higher RPMs.
But no proof of that. Percent improvements over old setup:2,800 RPMs = 119whp/221 ft*lbs (+4%)
4,200 RPMs = 220whp/272 ft*lbs (+3%)
5,800 RPMs = 326whp/301 ft*lbs (+36%)
6,900 RPMs = ?????????
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11-28-2015, 08:35 AM
#122
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I honestly have no idea on the pressure. I was actually still using the stock NA Fuel pressure regulator. So what ever that worked out to.
I'll need to search through my email but I should have the data log from the dyno pull I posted earlier.
Yea, I am on C16 but David made similar power to my setup on E85 with basically the same fuel system I have.
It is important to note that the dyno graph I posted was from DIYAutoTune's dyno which has shown to read @ 11% - 13% more conservative than a "EgoJet" with the same car on the same day.
I'll need to search through my email but I should have the data log from the dyno pull I posted earlier.
Yea, I am on C16 but David made similar power to my setup on E85 with basically the same fuel system I have.
It is important to note that the dyno graph I posted was from DIYAutoTune's dyno which has shown to read @ 11% - 13% more conservative than a "EgoJet" with the same car on the same day.
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11-28-2015, 11:30 AM
#123
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Looks like at 8,135 RPM I hit the highest duty cycle which is 72.8% and a pulse-width of 10.734ms. I wish I knew what the fuel pressure was but unfortunately I don't(It's whatever the "overpowered" stock FPR makes with a Walbro 255lph HP pump). The specific gravity of the fuel I run is .735 at 60 degrees F. if that help
--Ian
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01-10-2016, 01:05 AM
#124
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As an update, I made some changes to my cold air intake that significantly increased the airflow going into the motor. Enough that I maxed out my injectors at 60 PSI base pressure and hit 100% duty cycle @ 13.5 AFRs.... This was with the twin 255 Walbros.
My guess is fuel pressure dropping out. So I hooked up a sensor and confirmed. Then did math based on AFR and fuel burned, calculated required cc's/min to hit target AFR with 90% duty cycle, and then spec'd pumps that would flow the required amount at the pressure I needed to keep my ID 1000's.
Numbers are: 75 PSI base pressure gives me 1,330 cc/min on my ID 1000's. Based on my calcs, that should put me around 90% duty cycle if the fuel pumps could deliver 75 PSI + 30 PSI for boost = 105 PSI.
A Walbro 450 and a Walbro 255HP together meet the requirements with about 20% headroom. Ordered/installed. Retuned fuel.
Now at 90% duty cycle at target AFR with rock solid fuel pressure all the way to redline. Math was spot-on. I have calculations, logs, and data if anyone wants to see it. Car is bananas. 
Que 3 people to tell me to dyno it.
My guess is fuel pressure dropping out. So I hooked up a sensor and confirmed. Then did math based on AFR and fuel burned, calculated required cc's/min to hit target AFR with 90% duty cycle, and then spec'd pumps that would flow the required amount at the pressure I needed to keep my ID 1000's.
Numbers are: 75 PSI base pressure gives me 1,330 cc/min on my ID 1000's. Based on my calcs, that should put me around 90% duty cycle if the fuel pumps could deliver 75 PSI + 30 PSI for boost = 105 PSI.
A Walbro 450 and a Walbro 255HP together meet the requirements with about 20% headroom. Ordered/installed. Retuned fuel.
Now at 90% duty cycle at target AFR with rock solid fuel pressure all the way to redline.
Math was spot-on. I have calculations, logs, and data if anyone wants to see it. Car is bananas. Que 3 people to tell me to dyno it.
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01-10-2016, 01:17 AM
#126
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As an update, I made some changes to my cold air intake that significantly increased the airflow going into the motor. Enough that I maxed out my injectors at 60 PSI base pressure and hit 100% duty cycle @ 13.5 AFRs.... This was with the twin 255 Walbros.
My guess is fuel pressure dropping out. So I hooked up a sensor and confirmed. Then did math based on AFR and fuel burned, calculated required cc's/min to hit target AFR with 90% duty cycle, and then spec'd pumps that would flow the required amount at the pressure I needed to keep my ID 1000's.
Numbers are: 75 PSI base pressure gives me 1,330 cc/min on my ID 1000's. Based on my calcs, that should put me around 90% duty cycle if the fuel pumps could deliver 75 PSI + 30 PSI for boost = 105 PSI.
A Walbro 450 and a Walbro 255HP together meet the requirements with about 20% headroom. Ordered/installed. Retuned fuel.
Now at 90% duty cycle at target AFR with rock solid fuel pressure all the way to redline. Math was spot-on. I have calculations, logs, and data if anyone wants to see it. Car is bananas. Que 3 people to tell me to dyno it.
My guess is fuel pressure dropping out. So I hooked up a sensor and confirmed. Then did math based on AFR and fuel burned, calculated required cc's/min to hit target AFR with 90% duty cycle, and then spec'd pumps that would flow the required amount at the pressure I needed to keep my ID 1000's.
Numbers are: 75 PSI base pressure gives me 1,330 cc/min on my ID 1000's. Based on my calcs, that should put me around 90% duty cycle if the fuel pumps could deliver 75 PSI + 30 PSI for boost = 105 PSI.
A Walbro 450 and a Walbro 255HP together meet the requirements with about 20% headroom. Ordered/installed. Retuned fuel.
Now at 90% duty cycle at target AFR with rock solid fuel pressure all the way to redline.
Math was spot-on. I have calculations, logs, and data if anyone wants to see it. Car is bananas. Que 3 people to tell me to dyno it.Surprised the 255 was necessary next to the 450. Soviet made 450hp on one with id1000s.
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01-10-2016, 01:20 AM
#128
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I originally thought twin 255's would be enough. They were border line ok if you go buy the charts posted AND you give both pumps 13.5V under full load. But throw in a few PSI pressure drop in the lines/filter at really high flow rate, and a bit of voltage sag, and after 6,500 the pressure was falling out from under me limiting my fuel.
This setup has about 20% headroom in the pumps on paper.
This setup has about 20% headroom in the pumps on paper.
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01-10-2016, 01:22 AM
#129
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I originally thought twin 255's would be enough. They were border line ok if you go buy the charts posted AND you give both pumps 13.5V under full load. But throw in a few PSI pressure drop in the lines/filter at really high flow rate, and a bit of voltage sag, and after 6,500 the pressure was falling out from under me limiting my fuel.
This setup has about 20% headroom in the pumps on paper.
This setup has about 20% headroom in the pumps on paper.
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