lifegrddude Posted March 28, 2005 Share Posted March 28, 2005 Hi, I recently bought a fuel pressure regulator from Aeromotive that's on its way. I figured I'd ask a few questions to make sure I'm doing this correctly. I have 370cc injectors and a Walbro fuel pump currently. When I install the fuel pressure regulator, what pressure level should I run? I was thinking of setting it to 43psi at idle since that is what they are tested at, but won't that make the car run way rich? I am sort of concerned that if I lower the psi from 43 that it might affect the spray pattern of the injectors. Is this even a valid thought? Also, when setting the idle fuel pressure, do you all set it with the vacuum line disconnected or connected? (sorry for the noobie questions, I just want to make sure I'm doing this right) I plan to run about 12psi on a t3/t04B turbo with a Spearco i/c. I still have the stock afm and ecu too if that helps to clariy things a bit. A big thanks in advance too! John Quote Link to comment Share on other sites More sharing options...
Thumper Posted March 29, 2005 Share Posted March 29, 2005 With vacuum disconnected I ran 40psi and got a 12:1 a/f ratio. You also need to adjust your afm 18 teeth. If you do not know what I mean please do a search it has been discussed many times. Enjoy the boost. Quote Link to comment Share on other sites More sharing options...
BleachZee Posted March 29, 2005 Share Posted March 29, 2005 What one did you buy? AEI-13109? Quote Link to comment Share on other sites More sharing options...
Clifton Posted March 30, 2005 Share Posted March 30, 2005 The stock regulator is 40 psi. Running +/- 3 psi isn't going to do much. Quote Link to comment Share on other sites More sharing options...
lifegrddude Posted March 30, 2005 Author Share Posted March 30, 2005 Thanks for the help, I guess I'll set the pressure at 40psi and go from there. Bleach, I'll give you the part# as soon as it arrives, I can't remember it right now. John Quote Link to comment Share on other sites More sharing options...
BleachZee Posted March 30, 2005 Share Posted March 30, 2005 Is the stock 280ZX FPR a rising rate or linear or what? What does it compare to the aftermarket ones that always rise 1:1 with boost? MSA sells a RRFPR for the turbo 280ZX, so is that a hoax or is it better than the factory Nissan unit? The MSA is over $200 Quote Link to comment Share on other sites More sharing options...
Clifton Posted March 30, 2005 Share Posted March 30, 2005 All EFI fuel pressure regulators have a port for vac/boost. It will increases fuel pressure 1 psi per 1 psi of boost, 1:1. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted March 31, 2005 Share Posted March 31, 2005 the RRFPR MSA sells is from Corkey Bell.. the guy who wrote that amazing Turbocharger and Forced Induction book... look it up under Bell Enterprises.. or Bell Engineering or something.. you can find the SAME unit for much cheaper than MSA.. Quote Link to comment Share on other sites More sharing options...
BleachZee Posted March 31, 2005 Share Posted March 31, 2005 Alright. I don't see the point of putting larger injectors and then setting the fuel pressure lower especially when the ECU isn't going to take advantage of the larger injector flow. What we really need is a Rising Rate regulator that can be manually set a little lower than stock pressure at idle (for larger injectors) Then when the boost comes in it should increase higher than a factory RRFPR so that you get more fuel at the top end like you need because the stupid ECU isn't going to increase the length of time the injectors are open. I'll run stock turbo injectors, stock ECU, but with a good RRFPR. I'll slowly turn the boost up 1psi to about 12 max and see how that goes for the stock turbo and fuel ratio. seems that to take advantage of larger injectors I need a programable ECU or at the very least an 87-89 300ZX turbo ECU. THEN I can use a hybrid turbo and 15+ psi. - - - - Thanks for the info on Bell Engineering. I did a search and found they have what 'they' call the best FMU or RRFPR. You can actually adjust not just the fuel pressure but the onset of the rising rate! THAT sounds like what I'm looking for. http://www.lightningmotorsports.com/begi.htm Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted April 1, 2005 Share Posted April 1, 2005 Looks like it's cheaper than MSA too... that website has it for $199 compared to $229.95 !! ------------------------------------ Rising Rate Fuel Pressure Regulator, Non Turbo Z/ZX Rising Rate Fuel Pressure Regulator, Non Turbo Z/ZX Code: 11-3073 Price: $229.95 Quantity in Basket: None The newest technology to unlock hidden power for your fuel-injected Non Turbo Z & ZX! This rising rate regulator works along with the stock regulator, and responds to your car's need for more fuel only when conditions call for it. When you want more power, the regulator increases fuel pressure. Under normal driving conditions, lower pressure is maintained for best mileage. We have received reports of 15-20 horsepower gains! --------------------------------- Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 2, 2005 Share Posted April 2, 2005 I use that Bell Engineering RRFPR on my setup with stock 280zxt injectors. The RRFPR does NOT affect fuel pressure at idle/vacuum conditions and you can't use it to change your fuel pressure at idle/cruise. If you're going with bigger injectors, the best way to compensate for the enriched fuel curve during 'normal' driving is to adjust the tension of the AFM flapper door as Thumper specified. What the Bell RRFPR does is add additional fuel pressure as boost comes on, at a rate of greater than 1:1 (which on this unit is adjustable). The stock 280zxt does already up the pressure at a rate of 1:1, and the Bell RRFPR isntalls inline after the stock unit to raise it further ONLY under boost. About the onset adjustment, it is useless on an already-factory-turbocharged EFI setup. This adjustment allows you to have the RRFPR start affecting fuel pressure even before boost kicks in, and is to help cover transient lean spots that turbocharged hondas usually get, which is a side effect of turboing a non turbo MAP sensor EFI setup which is what Hondas use. I actually bought the unit that has this adjustment, but was told by Trey Hermann over at Bell Engineering that for my application to just adjust the thing all the way out so that it has no effect. I THOUGHT you could use this adjustment to set it up so that the thing didn't start functioning until some given level of boost had been reached, say, 7psi (so that it didn't add any extra fuel until boost levels higher than stock had been reached) but unfortunately, it doesn't work that way. The highest it can be set is to not affect fuel until about 3psi, and that's with the adjusting screw backed all the way out. If you're buying one of these for your Z just get the one that doesn't have the adjustment at all you will get the same effect. Anyways they are the same unit and can be freely converted from one way to the other. As far as that Aeromotive is concerned, honestly, there was no need to even buy an aftermarket FPR... you could have easily ran the 370's with the stock FPR, and now if you install the aftermarket unit, it would be best just to set it at the stock pressure setting that the stock FPR would have provided you anyways. I would NOT turn fuel pressure down as a means of leaning out the mixture at idle/cruise... lower fuel pressure can hurt performance as the fuel will come out of the injectors less atomized. Perfect example, take any spray bottle like Windex. Squeez the trigger slowly... the windex literally just dribbles out, then pull the trigger hard as you can, notice you get a nice finely atomized spray... same thing applies to your fuel injectors, more pressure, better more even atomization. Running higher than stock fuel pressures like I am will actually help performance in this respect, up to a point Of course, you can use the adjustable FPR to turn fuel pressure UP if you want more fuel, and this would function very similiar to adding larger injectors, i.e.: you richen up the whole fuel curve, and will probably have to compensate by tweaking the AFM spring tension a bit to get your idle/cruise mixtures back in line, but should still see richer mixtures on boost/WOT. Quote Link to comment Share on other sites More sharing options...
BleachZee Posted April 4, 2005 Share Posted April 4, 2005 thanks for your reply. That was good info. The $199 regulator I listed a link to is part #2025 http://www.lightningmotorsports.com/begi.htm ...that part number is listed on the BEGi website as being for aftermarket turbo applications just as you suggested! Also, the manufacture's suggested retail price is $259 for those regulators. http://www.bellengineering.net/Pages/products_FPR.html I'm also seeing on Bell's webpage they have a standalone type that should do the job and replace the factory Nissan FPR. That might not be a bad idea as well. Maybe Lightning Motorsports can get the other regulators at a good price if you give them the correct part number you want. Check those out at Bellengineering.net as linked to above. I've got my eye on part MR2032 Quote Link to comment Share on other sites More sharing options...
Daphur280 Posted December 14, 2010 Share Posted December 14, 2010 I use that Bell Engineering RRFPR on my setup with stock 280zxt injectors. The RRFPR does NOT affect fuel pressure at idle/vacuum conditions and you can't use it to change your fuel pressure at idle/cruise. If you're going with bigger injectors, the best way to compensate for the enriched fuel curve during 'normal' driving is to adjust the tension of the AFM flapper door as Thumper specified. What the Bell RRFPR does is add additional fuel pressure as boost comes on, at a rate of greater than 1:1 (which on this unit is adjustable). The stock 280zxt does already up the pressure at a rate of 1:1, and the Bell RRFPR isntalls inline after the stock unit to raise it further ONLY under boost. About the onset adjustment, it is useless on an already-factory-turbocharged EFI setup. This adjustment allows you to have the RRFPR start affecting fuel pressure even before boost kicks in, and is to help cover transient lean spots that turbocharged hondas usually get, which is a side effect of turboing a non turbo MAP sensor EFI setup which is what Hondas use. I actually bought the unit that has this adjustment, but was told by Trey Hermann over at Bell Engineering that for my application to just adjust the thing all the way out so that it has no effect. I THOUGHT you could use this adjustment to set it up so that the thing didn't start functioning until some given level of boost had been reached, say, 7psi (so that it didn't add any extra fuel until boost levels higher than stock had been reached) but unfortunately, it doesn't work that way. The highest it can be set is to not affect fuel until about 3psi, and that's with the adjusting screw backed all the way out. If you're buying one of these for your Z just get the one that doesn't have the adjustment at all you will get the same effect. Anyways they are the same unit and can be freely converted from one way to the other. As far as that Aeromotive is concerned, honestly, there was no need to even buy an aftermarket FPR... you could have easily ran the 370's with the stock FPR, and now if you install the aftermarket unit, it would be best just to set it at the stock pressure setting that the stock FPR would have provided you anyways. I would NOT turn fuel pressure down as a means of leaning out the mixture at idle/cruise... lower fuel pressure can hurt performance as the fuel will come out of the injectors less atomized. Perfect example, take any spray bottle like Windex. Squeez the trigger slowly... the windex literally just dribbles out, then pull the trigger hard as you can, notice you get a nice finely atomized spray... same thing applies to your fuel injectors, more pressure, better more even atomization. Running higher than stock fuel pressures like I am will actually help performance in this respect, up to a point Of course, you can use the adjustable FPR to turn fuel pressure UP if you want more fuel, and this would function very similiar to adding larger injectors, i.e.: you richen up the whole fuel curve, and will probably have to compensate by tweaking the AFM spring tension a bit to get your idle/cruise mixtures back in line, but should still see richer mixtures on boost/WOT. I'm using a FPR adjusted at 37-40psi and my mixture remains lean and furthermore leans out at higher RPM's, could this be an affect from the FPR or from the AFM? I've adjusted the AFM in all sorts of adjustments both where the mixture leaned out and (in theory) where it should have richen the mixture but my mixture remains lean. Quote Link to comment Share on other sites More sharing options...
l28stockecukingofdyno340p Posted January 21, 2015 Share Posted January 21, 2015 I set the 370svo injectors lowering with a regulator to 22 to 24 at idle with the vacuum hose connected and at idle with the engine on adjust turning the plastic gear spring to the right direction lean side until make the idle smooth at 1000 rpm or a little bit more and that it with this set up I went to the dyno and l28turbo stock put 340 hp to the wheels 370 pound feet of torque you need good Intercooler walbro 255 pump 3 inch exhaust and 18p.s.i. of boost. Quote Link to comment Share on other sites More sharing options...
l28stockecukingofdyno340p Posted January 21, 2015 Share Posted January 21, 2015 the key is at the afm spring tension. Quote Link to comment Share on other sites More sharing options...
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