roughridin89 Posted March 18, 2008 Share Posted March 18, 2008 ok well i looked all over the site i didnt find much on this topic so im going to ask myself. i have a 280z 1978 and im looking for an ADJUSTABLE fuel pressure regulator and ive been looking for one that fits my car. ive seen universal ones but i know about some uneversal parts and a lot dont fit the way they should. haha soo if anyone knows and recamends one let me know please and where to look for it thanks. Quote Link to comment Share on other sites More sharing options...
Nigel Posted March 18, 2008 Share Posted March 18, 2008 If you're looking for one that bolts in place of the stock regulator and has the same hose connections, I'm pretty sure you're going to be out of luck. Just about all aftermarket adjustable regulators that I'm aware of require some modifications/fabrications. Somebody may be able to recommend one that's at least close. Just make sure that where ever you mount it, mount it where you can keep the vacuum line as short as possible. Nigel '73 240ZT Quote Link to comment Share on other sites More sharing options...
roughridin89 Posted March 18, 2008 Author Share Posted March 18, 2008 yea i know there will need to be a little modification but im just looking for the best performance and esaiest instalation Quote Link to comment Share on other sites More sharing options...
hughdogz Posted March 18, 2008 Share Posted March 18, 2008 The best performance? Not sure what you mean...either they adjust the fuel pressure according to manifold pressure or they don't. To be honest, there isn't a regulator that will give you more power or performance more than the stock one would (all else being equal). They just give easier adjustability of the static fuel pressure. You can bump up the fuel pressure of the stock regulator too, but unless you increase the amount of incoming air, and need the extra fuel, why enrich the mixture and lose power? Quote Link to comment Share on other sites More sharing options...
roughridin89 Posted March 18, 2008 Author Share Posted March 18, 2008 i did just that i increased the amount of incoming air, and need the extra fuel Quote Link to comment Share on other sites More sharing options...
Challenger Posted March 18, 2008 Share Posted March 18, 2008 I know MSA sells one, Id maybe call them up, but dont listen to there crap about ~20hp gains, Im guessing that was on a very fuel starved engine, not a normal case. Quote Link to comment Share on other sites More sharing options...
hughdogz Posted March 18, 2008 Share Posted March 18, 2008 i did just that i increased the amount of incoming air, and need the extra fuel Ahhh...I see. You could try bumping up the static pressure of the stock FPR and that might get you where you want to be. Just take off the vac hose and get a big socket and tap the housing down to increase the preload on the valve spring inside (I'm pretty sure that's the side you want to modify). But, getting more fuel by increasing the fuel pressure is not the same as going to bigger injectors or increasing the injector opening time. i.e. If you double the fuel pressure, that doesn't necessarily mean you will double the fuel injected. You can also squirt more fuel using the stock FI by putting in a resistor, or better yet a potentiometer inline with the engine temp sensor, fooling the computer into thinking the engine is cold so it will inject more fuel... Another way is to reset the teeth or adjust tension inside the airflow meter... If the MSA one is the one I'm thinking of, it is a rising rate AFPR. It is different from a normal AFPR. Instead of 1 psi increase in fuel pressure for every increase in manifold pressure, it may do 2:1 (for instance) but it is more than 1:1. As far as easy plumbing goes to tie into the stock fuel rail, you could stay with barbed (brass) fittings and still use high-pressure FI hose (5/16"). You would definitely want to install a gage as well. People usually install a billet fuel rail and use AN hoses and fittings to make the plumbing neater and bigger than 5/16". Hope this helped...to be honest these tricks are kind of a "stop gap" (at best) and are not meant to be a substitute for a properly programmed ECU. Quote Link to comment Share on other sites More sharing options...
Challenger Posted March 18, 2008 Share Posted March 18, 2008 http://www.thezstore.com/page/TZS/PROD/PFFC14/11-3073 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! I guess theirs is a rising rate regulator, and it works along with the stock regulator. Quote Link to comment Share on other sites More sharing options...
hughdogz Posted March 18, 2008 Share Posted March 18, 2008 Interesting...I never realized they work along with the stock regulator. I heard it works great for some and not for others. Unless you could control the rate at which it rises, then it may be hard to control. I hate to say it, but how to increase the fuel pressure on the stock FI has been discussed in detail many times, I found out about those tricks from searching HBZ! There is a reason why so many of us have gone to megasquirt, etc. You may actually lose HP installing say a header or bigger cam if you don't address the fuel problem properly because of the way the Bosch L-jetronic EFI is limited in it's adjustability. Either that or you'll be so pig rich at idle and low engine loads, that you could have fouling problems...not to mention emissions and gas prices these days. Quote Link to comment Share on other sites More sharing options...
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