Time to refuel for more boost?
02-28-2008, 10:03 PM
#41
thats exactly what I have on the suburban, actually thats ALL I have on the sub. a MSD boost a pump hits the pump with something liek 16v when it sees boost normal voltage otherwise. Of course stock pump with 60 lbers I'm out of fuel around 550 at teh wheels. Next step for me is a bigger intank.
03-01-2008, 11:17 AM
#44
I don't have specs but I did take a pic of the two. I was running 43# injectors at 83% DC + a 200hp shot. When I installed the turbo I had twin Walbro 255 pumps. I bought a new bucket to install the Walbro's. All they had was for the 6.0l trucks. I figured the bucket where same and sense I was cut it anyway it didn't mater.
https://www.performancetrucks.net/fo...89#post3862089
Okay, this is getting interesting for me TieRod. The pump on the left is the 8.1L pump and the pump on the right is what? A walbro 255L/ph or a stock 6.0L pump? If this is in fact true, this will make things a bit easier for me. I would really like to know the flow rating for this pump. Do you know if its an AC Delco pump? Theres got to be some GM guys who know the differences in these two pumps. You were running the Raylar stuff right? No F.I. stuff right? I am running 44#'ers at 6psi and injectors are pegging at about 110%. Based on previous Dyno's I figure at the rear wheels I am right about 410/510.
03-01-2008, 01:16 PM
#45
Another way to get more flow from an existing pump is to drop fuel pressure. The 62# Mototron injectors are big enough to go from 4-bar to 3-bar on the fuel system. With a 4-bar stock fuel pressure regulator the fuel pressure won't exceed just over 60psi with no manifold pressure (WOT). With boost the stock regulator will continue restricting return flow raising fuel pressure higher than the pump and the rest of the fuel system is rated for. If you drop the base fuel pressure to 3-bar, the fuel pressure will be about 44psi with no manifold pressure (WOT). As boost comes in you'll still be under the limits of what the pump can supply. The 62# injectors are rated at 3-bar, they will work. The only hard part is finding another regulator rated at only 3-bar that will fit in place of the stock one.
03-01-2008, 01:22 PM
#46
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This info started at post #19 in a different thread if anyone wants look back at the last few posts...
https://www.performancetrucks.net/fo...89#post3862089
Okay, this is getting interesting for me TieRod. The pump on the left is the 8.1L pump and the pump on the right is what? A walbro 255L/ph or a stock 6.0L pump? If this is in fact true, this will make things a bit easier for me. I would really like to know the flow rating for this pump. Do you know if its an AC Delco pump? Theres got to be some GM guys who know the differences in these two pumps. You were running the Raylar stuff right? No F.I. stuff right? I am running 44#'ers at 6psi and injectors are pegging at about 110%. Based on previous Dyno's I figure at the rear wheels I am right about 410/510.
https://www.performancetrucks.net/fo...89#post3862089
Okay, this is getting interesting for me TieRod. The pump on the left is the 8.1L pump and the pump on the right is what? A walbro 255L/ph or a stock 6.0L pump? If this is in fact true, this will make things a bit easier for me. I would really like to know the flow rating for this pump. Do you know if its an AC Delco pump? Theres got to be some GM guys who know the differences in these two pumps. You were running the Raylar stuff right? No F.I. stuff right? I am running 44#'ers at 6psi and injectors are pegging at about 110%. Based on previous Dyno's I figure at the rear wheels I am right about 410/510.
Yes the one on the right is a 6.0l pump. I purchased it from GM dealership so I'm sure it a AC Delco. I had Raylar's HIC with 43# injectors made 400whp 440wtq N/A then with a 200 shot 550whp 640wtq on the stock pump.
03-01-2008, 01:39 PM
#47
Thanks James and TieRod. I picked up a set of flowmatched (within 2%) 60lb Seimen DEKA injectors the other day. Maybe I will throw them in and see how the stock pump does with them. If TieRod was NOS'ing to over 500rwhp with a stock 8.1L pump, hell it might be worth a shot. If this is indeed the case, I can see a few people installing a complete 8.1L basket assembly into thier non 8.1L truck tank if nothing else than to keep everything stock. I am trying like hell to find some part #'s and flow data, but everything i find says call to order with VIN when talking about fuel pumps.
03-01-2008, 02:53 PM
#48
Okay here is what i have found so far......
Using "ALLDATA" the part numbers for 02-03 all engine sizes is #15205623
This is a an AC DELCO MU1005 pump
When i cross reference the 8.1L at AC DELCO's web page, they give me a pump # of MU1517...but only for the 2500HD's
The small block truck gives an AC DELCO part number of MU1516.
I cant find flow specs on any of these pump numbers yet.....but I am still trying.
Using "ALLDATA" the part numbers for 02-03 all engine sizes is #15205623
This is a an AC DELCO MU1005 pump
When i cross reference the 8.1L at AC DELCO's web page, they give me a pump # of MU1517...but only for the 2500HD's
The small block truck gives an AC DELCO part number of MU1516.
I cant find flow specs on any of these pump numbers yet.....but I am still trying.
03-01-2008, 05:19 PM
#49
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I have been thinking about this subject too. Ideally I would love to have a custom aluminum fuel tank built just like the factory one with a sump, then run a -10 line to an aeromotive A1000 pump to a boost referenced regulator with a -8 return line. I figuire that would take care of any fueling issue you could have
03-01-2008, 05:25 PM
#50
I have been thinking about this subject too. Ideally I would love to have a custom aluminum fuel tank built just like the factory one with a sump, then run a -10 line to an aeromotive A1000 pump to a boost referenced regulator with a -8 return line. I figuire that would take care of any fueling issue you could have
WHY DOESNT ACDELCO HAVE A SIMPLE FLOW CHART FOR ITS OEM PUMPS??? I have been looking for ever now and have come up with nothing.