SVO 42#'s good for 500 RWHP FI
11-30-2006, 09:22 PM
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SVO 42#'s good for 500 RWHP FI I had my car dyno tuned and it put down lower numbers than expected. My WOT a/r was 11.5:1 With a huge fuel pressure drop just before redline. I think I've fixed the pressure problem, and I now know that I wasn't running very much timing. I was inthe low octane timing tables. The Injectors where just about maxed out, if I add the timing I need will I also need to add more fuel. 11.5:1 is 11.5:1 isn't it. I won't be putting any more air in the cylinders, I'll just be lighting it off a little sooner? Right? 
12-01-2006, 10:35 PM
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I was running 58 psi all the way up untill 500 or so rpm before red line. Presure dropped to 40 psi and held constant untill redline. I had put a new fuel "cheap" fuel filter on when I did the racetronics 255lph pump. I thought maybe the filter couldn't flow the volume I needed so i put a new AC delco filter on. I put my pressure gauge on and it reads 61 psi now. The guage at the dyno shop and mine are the same brand but now I'm seeing 3 more psi. MAybe the filter maybe the guage? When the injectors hit 100% dc could the fuel pressure drop like this? I'm gonna go back and get re-dyno tuned with a two bar map sensor, and I don't want to run out off fuel but I also don't want to buy 60's if I dont have too 
12-01-2006, 11:25 PM
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I did the calculator and put in 575 flywheel = 500 rwhp with .65 bsfc and that puts 50 lbs hr injectors at 80% DC. SVO 42's are like 48.3's at 58 psi so I'm pushing 85% DC according to the calc. Not much room to gain but I think I should be okay, until the 402 with 317 heads goes in 
12-02-2006, 01:02 AM
#6
Originally Posted by 2002ws-6
.... When the injectors hit 100% dc could the fuel pressure drop like this? I'm gonna go back and get re-dyno tuned with a two bar map sensor, and I don't want to run out off fuel but I also don't want to buy 60's if I dont have too
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01-08-2007, 12:59 PM
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Originally Posted by 2002ws-6
I had my car dyno tuned and it put down lower numbers than expected. My WOT a/r was 11.5:1 With a huge fuel pressure drop just before redline. I think I've fixed the pressure problem, and I now know that I wasn't running very much timing. I was inthe low octane timing tables. The Injectors where just about maxed out, if I add the timing I need will I also need to add more fuel. 11.5:1 is 11.5:1 isn't it. I won't be putting any more air in the cylinders, I'll just be lighting it off a little sooner? Right?
01-08-2007, 03:32 PM
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Originally Posted by Ed Blown Vert
With FI?
01-09-2007, 10:56 AM
#11
if your fuel pressure is droping it is probably your pump. injectors shouldnt affect your FP like that.
i ran 135mph on my 42lb svo's with about 80-90psi worth of FP (the injectors were more then maxed out) at that weight it was approximatly 700rwhp. when i was at around 550rwhp those injectors worked just fine at 58psi FP
i ran 135mph on my 42lb svo's with about 80-90psi worth of FP (the injectors were more then maxed out) at that weight it was approximatly 700rwhp. when i was at around 550rwhp those injectors worked just fine at 58psi FP
01-09-2007, 09:45 PM
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Originally Posted by smokinHawk
if your fuel pressure is droping it is probably your pump. injectors shouldnt affect your FP like that.
i ran 135mph on my 42lb svo's with about 80-90psi worth of FP (the injectors were more then maxed out) at that weight it was approximatly 700rwhp. when i was at around 550rwhp those injectors worked just fine at 58psi FP
i ran 135mph on my 42lb svo's with about 80-90psi worth of FP (the injectors were more then maxed out) at that weight it was approximatly 700rwhp. when i was at around 550rwhp those injectors worked just fine at 58psi FP
01-10-2007, 07:58 AM
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Originally Posted by SSilverSSurfer
i was thiking he needs another pump, is that what you mean?
Whats happening is this....Fuel is getting to the rails, injectors are doing there job. The pump itself doesnt supply the volume of fuel needed at the rail for the injector to spray, Basically the injectors are draining the rail and the pump itself isnt large enough to supply the fuel demanded by the injectors. Upgrade the pump, and the pressure should stay steady. Id also recommend a hot wire kit with the in tank pumps if you want to make some serious power. Do not use an inline pump to fix this issue or with an intank pump setup. The boost a pumps generally have a smaller orfice then the better intank pumps and you would only be creating another bottle neck before it gets to the rails.
Hope this makes sense.
01-10-2007, 11:03 PM
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I do have the racetronics plug and play. I had my car dyno tuned again and only had a samll fuel pressure drop at WOT. This time my max Duty Cycle was 87%. Turbos love gas. To fix my last problem i put a new delco filter on , and found my ground cable to the battery was loose. I'm right at my goal now with 505 ft lbs and as soon as I get a boost controller that doesn't suck, Ill be in the 470-480 hp range. All testing was done a dynopack dyno with Hp tuners and a manual fuel pressure guage.
01-10-2007, 11:14 PM
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Originally Posted by V6 Bird
Im going to take a stab at this....
Whats happening is this....Fuel is getting to the rails, injectors are doing there job. The pump itself doesnt supply the volume of fuel needed at the rail for the injector to spray, Basically the injectors are draining the rail and the pump itself isnt large enough to supply the fuel demanded by the injectors. Upgrade the pump, and the pressure should stay steady. Id also recommend a hot wire kit with the in tank pumps if you want to make some serious power. Do not use an inline pump to fix this issue or with an intank pump setup. The boost a pumps generally have a smaller orfice then the better intank pumps and you would only be creating another bottle neck before it gets to the rails.
Hope this makes sense.
Whats happening is this....Fuel is getting to the rails, injectors are doing there job. The pump itself doesnt supply the volume of fuel needed at the rail for the injector to spray, Basically the injectors are draining the rail and the pump itself isnt large enough to supply the fuel demanded by the injectors. Upgrade the pump, and the pressure should stay steady. Id also recommend a hot wire kit with the in tank pumps if you want to make some serious power. Do not use an inline pump to fix this issue or with an intank pump setup. The boost a pumps generally have a smaller orfice then the better intank pumps and you would only be creating another bottle neck before it gets to the rails.
Hope this makes sense.