If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #15 – May 26, 2007, 10:11:33 AM Quote from: Sick88Tbird;149816IThe pump made no discernable difference for me.It made no difference because for some reason you did not experience the problems we are having.Trust me, if you were here I would take you for a rip and show you first hand the problem with a stock pump on an HO swap with slight mods. Hell maybe I will go to Welland and Take baXo for a rip this weekend and he can tell you what it feels like.:hick: Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #16 – May 26, 2007, 10:13:49 AM Quote from: Sick88Tbird;149816The pump made no discernable difference for me.I'm going to have to reinforce that statement. My 3700lb 20th went 13.7 @ 102 MPH (~ 270 RWHP) when it was N/A using the stock SO pump. That was a 9.7:1 compression P-headed combo that had excellent accleration too (as the track times verify). OTOH, since technically a 70 lph pump is only good for about 225 flywheel HP, I would advise upgrading the pump to at least a 110 lph pump (~350 FWHP) on N/A HO conversions. :hick: Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #17 – May 26, 2007, 04:32:49 PM If you're talking about the top end buck, that's not due to your fuel pump. Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #18 – May 27, 2007, 09:47:20 PM It could also have to do with the age of the pump. The pump in his Mark VII was 21 years old so I doubt it was still working at full capacity;) Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #19 – May 27, 2007, 10:35:38 PM no, I am talking mid rpm and up, say around 3000-6000rpm, sometimes it starts sooner, depending on how hard it hooks. or if I spin it bad you can feel it just die. Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #20 – May 28, 2007, 01:41:38 AM Quote from: slicksport88;146658The fuel pumps in the 96-97 DOHC cobras were standard 150lph pumps. Should be able to get em at most auto parts chains.oh really? sure about that?if so, do you know if the aftermarket matches oem? as far as LPH? Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #21 – May 29, 2007, 04:29:48 PM Quote from: 1WLD BRD;150274no, I am talking mid rpm and up, say around 3000-6000rpm, sometimes it starts sooner, depending on how hard it hooks. or if I spin it bad you can feel it just die.Hmm I'm not sure. His Mark VII just felt low on power till about 3,000 rpms then it would wake up till about 4,500 rpms. If you floored it at 60 mph it would lag off as rpms climbed due to lack of fuel. New fuel pump solved it all though. Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #22 – May 29, 2007, 04:34:35 PM I got a 255HP pump I gotta install one of these days...just not particularly looking forward to dropping the tank. Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #23 – May 29, 2007, 04:40:22 PM Quote from: Red_LX;150616I got a 255HP pump I gotta install one of these days...just not particularly looking forward to dropping the tank.It's fun:hick: . Just make sure you have a helper as you'll need it taking the tank down and putting it back up. Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #24 – May 29, 2007, 05:31:13 PM QuoteI'm going to have to reinforce that statement. My 3700lb 20th went 13.7 @ 102 MPH (~ 270 RWHP) when it was N/A using the stock SO pump. That was a 9.7:1 compression P-headed combo that had excellent accleration too (as the track times verify). OTOH, since technically a 70 lph pump is only good for about 225 flywheel HP, I would advise upgrading the pump to at least a 110 lph pump (~350 FWHP) on N/A HO conversions. OK, it's math time again!1 gallon = 3.8 liters. = approximately 6.5-6.8 pounds for one gallon/liter of gasoline. I like to use 6.8 so here goes........SO injectors = 14 lbs/hr = 2.06 Gal/hr = 7.824 liters/hr8 SO injectors = 62.592 liters/hrHO injectors = 19 lbs/hr = 2.79 gal/hr = 10.62 liters/hr8 HO injectors = 84.96 liters/hrusing 6.5 pounds to the gallon we get:SO injectors = 14 lbs/hr = 2.15 Gal/hr = 8.185 liters/hr8 SO injectors = 65.486 liters/hrHO injectors = 19 lbs/hr = 2.92 gal/hr = 11.108 liters/hr8 HO injectors = 88.862 liters/hrNow, gasoline does expand and contract a decent amount with temperature (colder gas is denser gas -- a gallon will weigh more when cold) Believe me on this one. You can ask anyone who has worked on aircraft and had them filled up overnight only to watch them vent gas an hour or so after sunrise.14 pound injectors have been proven to sufficiently feed a stock HO motor at stock fuel pressure on a dyno. There is almost no safety margin though. I'm gonna guess with a 270 RWHP combo, that at part throttle and idle conditions the car ran fine with an SO pump. At full tilt I bet she started runnin real lean after 4500 RPM.Also, let me add that changing fuel pressure changes flow rates for both injectors AND pumps. As you raise pressure, injectors will actually flow more, however a fuel pump will flow less. More pressure on the pump means more restriction upstream. More pressure to an injector means more force behind the gas coming out of it, simply put anyway........A chart for reference Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #25 – May 29, 2007, 07:21:12 PM Paul sometimes you amaze me. Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #26 – May 29, 2007, 07:38:51 PM So for a TC;1 gallon = 3.8 liters. = approximately 6.5-6.8 pounds for one gallon/liter of gasoline. I like to use 6.8 so here goes........"Green Top" injectors = 30 lbs/hr = 4.41 Gal/hr = 16.758 liters/hr4 x injectors = 67.032 liters/hr"Brown Top" injectors = 36 lbs/hr = 5.29 gal/hr = 20.118 liters/hr4 x injectors = 80.472 liters/hrThat's a LOT less then I would have figured! WOW! I have a 255 pump in my car, and I have a set of 56# injectors..."56"s = 56 lbs/hr = 8.235 gal/hr = 31.3 liters/hr 4 x injectors = 125.2 liters/hrI have 100 extra lph for nothing! In fact, by these calculations, 255 / 4 = 63.75 / 3.8 = 16.77 gal/hr x 6.8 = 114# injectors!!??! Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #27 – May 29, 2007, 08:16:19 PM You have to account for your fuel pressure at boost in a turbo or blower application. Again higher pressure = more injector flow, but less pump flow. TC injectors are still rated at 40 or so PSI when in fact at full boost they see more. Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #28 – May 29, 2007, 08:27:19 PM Quote from: thunderjet302;150618It's fun:hick: . Just make sure you have a helper as you'll need it taking the tank down and putting it back up.It's especially fun when you DON'T have a helper and a little more than 1/2 tank...it's amazing what you can do when you're doing it out of necessity. Quote Selected
If you have done a 5.0 HO conversion/swap you NEED a HO fuel pump Reply #29 – May 29, 2007, 08:49:16 PM Quote from: Sick88Tbird;150651It's especially fun when you DON'T have a helper and a little more than 1/2 tank...it's amazing what you can do when you're doing it out of necessity.yeah, try doing exactly that 3 times in one week like I had to. NOT FUN.:flame: Quote Selected
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